Social justice praxis in education: Towards sustainable management strategies

Idilette Van Deventer firstname.lastname@example.com
Faculty of Education Sciences
Research Unit Edu-HRight
North-West University
Potchefstroom CampusSouth Africa

Philip C Van Der Westhuizen
Faculty of Education Sciences
North-West University
Potchefstroom CampusSouth Africa

Ferdinand J Potgieter
Faculty of Education Sciences
Research Unit Edu-HRight
North-West University
Potchefstroom CampusSouth Africa

Social justice praxis in education: Towards sustainable management strategies
52C2F83D8D3FC718D3342C0D651CB16E10.15700/saje.v35n2a956determinantseducationhuman rightsmanagement strategiesrestorativesocial justice praxissustainable developmenttransformativeubuntu
Social justice, defined as an impetus towards a socially just educational world, is based on the assumption that all people, irrespective of belief or societal position, are entitled to be treated according to the values of human rights, human dignity and equality.Diverging from the classical positivist approach in social science research that takes injustice as its impetus, the researchers departed from a socio-rationalist approach into exploring sustainable management strategies for effective social justice praxis.This approach has enabled the construction of a conceptual-theoretical framework and an iterative qualitative inquiry, which has as its central principal the sustainable management strategies for effective social justice praxis.Four key findings affirmed the belief that good praxis was to be found in Gemeinschaft relationships, in the influence exerted by government and education systems and structures, where government and principals were found to be co-responsible in ensuring that the best interest of the child was served.This responsibility included practices found in collaborative efforts, where communities became the guardians of their schools due to a disciplined school that followed constitutional values.Lastly, these practitioners aligned their management strategies with human rights values, as well as human dignity and equality, and their strategies found pride of place in extant ubuntu principles.

Exigency for Effective Social Justice Praxis in a Socio-Rationalist World

Social justice -as an impetus towards a socially just world -is based on the assumption that all people, irrespective of belief or societal position, are entitled to be treated according to the values of human rights, human dignity and equality.It is evident from international and national media reports on the dire situation in many schools, however, that the movement towards social justice has remained unfulfilled.The outcomes attained in the South African education system, for instance, have been labelled as "the worst of all middleincome countries in cross-national assessments of educational achievement" (Spaull, 2013:3).A lack of education leadership and management invariably contributes to this situation (Bush, Kiggundu & Moorosi, 2011).Hargreaves and Fink (2006:1) concur, and state that "sustainable improvement depends on successful leadership.But making leadership sustainable is difficult too."South Africans in particular do not yet share to the fullest degree in such a sustainable leadership and effective social justice praxis (Spaull, 2013).

A Proposition-Based Inquiry

Diverging from the classical positivist approach in social science research, which is guided by an existing problem, that is, social injustices, this study set out from the proposition that not all school principals were contributing to injustices as they are to be found in the "growing evidence of exceedingly low levels of learning in many developing countries, including India, Indonesia, Malaysia, Mexico, Pakistan, Thailand, Turkey, and South Africa" (Spaull & Taylor, 2015:137).Rather, the Appreciative Inquiry (AI) approach of Cooperrider, Whitney and Stavros (2008) provided the opportunity to perform research from a constructive and affirming vantage point, so as to generate theory on sustainable organisational development.Those who follow the AI approach are conducting their research and theoretical propositions "in the service of their dynamically constituted vision of the good" (Cooperrider, Barrett & Srivastva, 2013:170).The AI approach offered concerns the theory development of organisations (Cooperrider & Srivastva, 1987, 1998), and is creating a positive revolution in the field of organisational development (Cooperrider et al., 2013).This article proposes that inquiry into effective, valuable praxis offers an alternative understanding of sustainable management interventions, rather than one informed by a problem-based approach, especially in an education system that is as complex and beleaguered as that which is to be found in South Africa.The rest of this paper is structured as follows: we commence by outlining the determinants of social justice praxis.This is followed by a conceptualtheoretical framework that forms the backdrop against which we performed the empirical investigation, where we then present a discussion of our findings and concluding remarks.Cooperrider and Srivastva (1987:129) postulate that AI researchers view science from a "socio-rationalist" perspective, and as social-rationalists, they are intensely involved with their own reality in an environment where trust-building, knowledge-sharing and increased social justice praxis become the norm (Calabrese, 2006).

Sustainable Management Strategies for Social Justice Praxis

Le Grange (2007:90) postulates that sustainable development in education is, inter alia, to be found in "people and people relationships" that observe the social justice principles of basic human needs, inter-generational equity, human rights and participation.However, Le Grange (2007:93) cautions that although sustainable development in South African education coincides with and is integral to school reform, the concept of sustainable development are embedded in "progress stories" about successful development and improvement.Le Grange (2007) argues that progress stories are not necessarily progressive or sustainable, nor do they necessarily lead to reforms as the outcomesbased 'saga' has shown.Such progress stories on sustainable development may even limit the impact of democracy and impede efforts towards social justice.We nevertheless argue that these stories of progress are important, as they affirm the belief that sustainable management of effective social justice praxis is indeed possible, as the participants' stories in this research showed in the discussion on sustainable management strategies for social justice praxis.These strategies also offer the space in which to rebuild a sustainable education system that realises the values of human dignity.In view of Le Grange's (2007) warning, it is important to first understand that the concept of social justice has two manifestations: justice as such, and social justice.

The essential being of justice manifests in society and is a reality that holds the inherent possibility to change individuals and institutions.Accordingly, justice as a concept underpins the concept of social justice.It provides a theoretical basis for the analysis and evaluation of social justice (not as onticity, but as modality of justice) in society and in institutions towards a transformed society.Social justice praxis (as a verb) includes acts of kindness towards others, with the aim to repair and transform the school and societal environments (Baillon & Brown, 2003).Social justice is a lived concept that encompasses acts of fairness, equality and justness towards others.Social justice acts in this sense are about how 'others' experience and understand complex concerns of race, ethnicity, religion, gender, sexual orientation, disability or class.However, social justice is also relevant for those perceived to be privileged.Both the under-privileged and the privileged ought to share in the promise of fundamental human rights and the resultant praxis of justice as fair, equitable and equal.

Figure 1 Determinants for social justice praxis (Adapted from Miller, 1999:4-7) Rawls (1999bRawls ( , 1999c) ) proposes that social justice is related to a set of principles that provide a way of assigning rights and duties, both to individuals, and to organised communities (determinants) in basic institutions of society.These determinants of a well-ordered society are found in external individual cognition, recognisable in naming, conceptualising and labelling categories of social justice phenomena that are the social and historical creations of man.In Rawls ' (1971) wellordered society, there is an elucidation as to what constitutes just and unjust acts, whilst in his Theory of Justice, he proposes co-existence of state and individual public institutional spaces, such as schools (Rawls, 1999b).In these spaces, social justice is related to "a set of principles that provide a way of assigning rights and duties -both to individuals and organised communities" -through these fundamental social institutions (Van Deventer, 2013:22).

The meaning of a human society is to be found in the co-dependency and co-responsibility of its members; who all flourish -or not -in a particular society, where socially just communities, as well as the hopes and prospects of each individual and the greater society, are affected.A society ought to have an institutional structure formed by the state, education system, and individuals.Additionally, a society requires human agency to bring about deliberate and transformational reform in the name of fairness and justice for all its citizens (Miller, 1999) (Figure 1).

Determinants of Social Justice Praxis: Government, Institutions and Individuals

The realities of social justice and education management consist of government systems and school sub-systems that manifest interdependently (Potgieter, 1980).The scope of social justice praxis depends on a mutual understanding of who is responsible for determining the allocation or distribution of the good and bad, advantages and burdens, as well as rights and duties (Miller, 1999).Teachers who advocate for social justice praxis are as agents of change in schools, however this role ought to be shared between the state and social justice agents (Francis & Le Roux, 2011).

In such a collaborative engagement between the state and individuals, constitutional values and human rights provide the impetus for social justice praxis.Taking as its cue a divisive apartheid past, the preamble to the South African Constitution (Republic of South Africa, 1996a), as well as Section 1, both aim to heal the divisions of the past, and to establish a non-racist, non-sexist and democratic society based on the values of human dignity, equality and the advancement of human rights and freedoms.These values should inform all educational management endeavours, from legislation, through to policy-making and praxis.As such, the Bill of Rights (s.7(2)) imparts to educationists (all role-players) to respect, protect, promote and fulfil constitutional provisions and the values it enshrines, to create a society that is the very opposite of the apartheid order.In addition, the legal and policy frameworks have to 'will' educators to attend to these values, so as to ensure the realisation thereof for all learners.The ideal of building a transformed schooling system is supported by a series of education white papers and policy frameworks (i.e.Africa, 1998).Of particular importance is White Paper 3, which also mentions the ideal of a future where all South Africans will enjoy an improved and sustainable quality of life, participate in a growing economy, and share in a democratic culture.

However, education remains the centre of attention, due to the breakdown in the implementation of these policies at ground level.The right to human dignity is the most fundamental in any open and democratic society.This right imparts on the state the duty that the "dignity of man shall be inviolable" and should be protected by all state authority (Goolam, 2001:45).In addition, Goolam argues that inviolable and inalienable human rights form the basis of every society, system and institution of peace and justice in the world.

Scholars provide different stances to systemic and institutional determinants for the management of social justice praxis.Rawls (1999a) argues that distributive justice is a result of a cooperative venture of mutual benefit based on two principles, the principle of equal liberty for all, and the principle of difference, both of which should be to the greatest benefit of the least advantaged persons in an equal society.Rawls' (1999d) theory of justice points towards fair and equal management, found in just institutions of government and education.Such a well-ordered educational society is governed by the relational conduct of those who are able to prioritise and make judgements on that which is right over that which is good.Leaders who make judgements as to what is 'right' base their decisions on consistent value-based conduct, which is beneficial and desirable for the individual, as well as for the school community more broadly.

Fraser (2009:72-73) extends Rawls' principles of equal liberty and difference to include claims for the recognition of cultural difference found in the "politics of recognition".She asserts that social justice understood as recognition is not assimilation into a dominant culture, rather, it is constituted by a world that embraces both redistribution of power, and resources, as well as recognition of cultural difference.Fraser (2009) argues that a politics of recognition in a difference-friendly world, is part of acknowledging the existence of difference, such as those based on ethnicity, racial diversity, or gender.This perspective locates social justice praxis in both the political-governmental and the local arena, as it describes those dimensions of justice that cut across all social strata.

The discourse about distribution and recognition should enhance the virtues of social consciousness, recognition of a common humanity, and a celebration of unity in diversity.Starratt (2009) proposes three virtuous acts to realise distribution and recognition as sustainable management in their praxis of responsibility, presence and authenticity.These acts ought to promote both the academic success of all learners, as well as be visible in the way in which they affect the democratic values of human dignity, equality and freedom.The virtue of responsibility and authenticity provide the subjective grounding and moral weight to the praxis of school leaders, who must act justly and fairly towards both those who are marginalised, as well as towards those groups privileged by social constructs (Starratt, 2009).Just and fair acts create a visible mindfulness of discriminatory, marginalising and unjust practices.

The virtue of authenticity affirms the school leader's critical presence in the lives of staff and learners, and establishes the required dialogue with the other.In being authentic, the school leader takes responsibility to express a positive or negative moral response to social injustice.In being present in the lives of teachers and learners, he or she mediates actions of authenticity and responsibility towards a fair and just educational landscape (Starratt, 2009).

School leaders who practice an ethics of care are focusing on personal and professional actions of respect.Such an ethics involves acts of integrity and cultural enrichment, namely the promotion of individuality, loyalty, human potential, dignity, and empowerment.An ethics of care brings to the fore a moral imperative of improving educational praxis and student outcomes for the marginalised and economically disadvantaged majority, who have not traditionally been served well in schools (Marshall & Oliva, 2010).Principals should understand, promote and enact social justice through a heightened and critical awareness of oppression, exclusion, and marginalisation that may have been experienced by their students (Freire, 2004).However, Brooks and Miles (2008) argue that awareness of social injustices is not sufficient in itself, because principals should, furthermore, act when they identify inequity; the authors point out that they are uniquely positioned to influence equitable educational practices, and that their proactive involvement is crucial.

Such a moral, dialogical integrity is found in the principles of ubuntu, underpinning educational professional development thought.According to Nafukho (2006) ubuntu is a concept described in, amongst others, the Southern African Ngunilanguage family (Ndebele, Swati/Swazi, IsiXhosa and IsiZulu) whilst omundu/muntu/ntu are Nguni words referring to humanity, or state of kindredness.Nafukho (2006) argues that the concept of ubuntu describes an African worldview, enshrined in the maxim 'umuntu ngumuntu ngabantu' (a person is a person through other people).

Traditional African learning articulates a basic respect and compassion for others in society.Nafukho (2006) proclaims that ubuntu provides the rule of conduct (social justice) or social ethics in society.This model of interrelation promotes religiosity, spirituality, consensus and dialogue.

According to the United Nations (UN) (2006,2013) governments should be compelled to put in place measures that will enhance equal liberty and recognise diversity, such that they are able to represent and serve the best interest of their populations.The broader international context, the pre-amble to the UN Charter expresses commitment to justice in affirming human worth in the form of dignity, fundamental and equal human rights (UN, 2006).Mahlomaholo (2011) asserts that the Millennium Development Goals (MDG) on sustainable development resonate in almost all legislative and policy imperatives and emphasise equity, social justice, freedom, peace and hope.Educational transformation, however, is dependent on a socially just educational environment that place equal value on the social justice principles of distribution and recognition (Garrett, 2010).

Education delivery is determined by management strategies executed by a person or body-inauthority (Van der Westhuizen, 1991), and is regarded by Manning (2001) to manifest in managed conversations.Social justice leaders in schools are constantly in conversation with themselves in selfreflective praxis and in dialogue with others.Intrinsically, they become agents of change in the broader educational system, and in schools.As agents of change they embrace and enhance diversity in being critically conscious of difference and sameness in a multi-, inter-and transcultural world (Van Vuuren, Van der Westhuizen & Van der Walt, 2012).Guilherme and Dietz (2015) argue that these layered concepts of diversity, consciousness, and multi, inter and transcultural difference are often used ubiquitously and indiscriminantly.The idea of diversity in education should be explored from both a monocultural and essentialising multicultural perspective as individual and collective phenomena in schools.These school leaders are bridging leaders, who overtly or covertly address inequity (Merchant & Shoho, 2010) in and through their actioned management strategies.These management strategies provide strategic direction and hope to school leaders, where matters of diversity -particularity in the school system -are encountered on a daily basis (Dantley & Tillman, 2010).

Traditionally SWOT-analyses focused on the monitoring and evaluation of an organisation's strengths (S) and weaknesses (W), opportunities (O) and threats (T).However, Stavros and Hinrichs (2009) advance the SOAR strategic planning framework, i.e. building on Strengths, Opportunities, Aspirations and (measurable) Results.This framework focuses on strengths, and seeks to understand the whole system by including the voices of the relevant stakeholders on those aspects at which an organisation excels, which skills could be further developed, and that which "is compelling to those who have a 'stake' in the organization's [sic] success" (Stavros & Hinrichs, 2009:20).For Mintzberg (1989:69), strategy making is about an inner awareness found in the "mysteries of intuition", whilst Freire (2007:69) defines it as "revolutionary leadership" and "co-intentional education".

The obligation to ensure that sustainable management strategies are put in place is not only a moral one; it also implies an ongoing social agenda.In this regard, the responsibility towards social justice when devising these strategies is not restricted to the level of policy-making.It should, rather, be extended to the level of both government (at macro level) and schools (at micro level).Strategy making steers essential actions in a consistent, purposeful and coordinated manner, through continuous improvement against determinates of good practice, as described above.

Empirical Investigation

Since this research employed a socio-constructive framework to understand social justice praxis, it calls attention to individual sense-making, and to the construction of principals' social and psychological worlds.These worlds are constructed and co-constructed through rational social processes of communication and interaction.

A Qualitative Social-Constructivist Research Design

The empirical study entailed a qualitative socialconstructivist research design (Merriam, 2009) to understand and interpret, albeit subjectively, the meaning that participant-principals attached to their successful management strategies, in order to enhance sustainable social justice praxis.Socialconstructivists generally view reality as relative, constantly changing, and informed by linguistic convention.

Sampling and Research Instrument

A disproportional stratified purposive sampling procedure was followed, based on principles of fairness, and theoretical constructs (Mouton, 2001).District Officials in two South African provincial departments of education performed the purposive selection task in accordance with pre-determined criteria.These officials used their own discretion in determining whether the selected principals met the predetermined criteria.The criteria these principals were obliged to meet were, firstly, that they understood the concepts of justice and social justice praxis, secondly, that they adhered to and implemented legal, systemic and institutional determinants, and thirdly, that they acknowledged the need for fair distribution and educational trans-formation.The assumption was that general best social justice praxis could be found in the management work that the chosen school principals maintained.No biographical data of the officials was solicited.Being independently and externally chosen by their superiors affirmed that, as transformative leaders, they were not only oriented towards social justice, but that they indeed practiced it.However, they did not proportionally reflect the population.

Two of the four district officials in the North-West Province selected 14 participant-principals, who took part in individual interviews.Accidental sampling (Leedy & Ormrod, 2010) resulted in two focus-group interviews in one school district in the Western Cape, with 11 participants.Interviews were conducted in Afrikaans (presented below in translated version) and in English (verbatim).

An interview schedule served as a personal impression memo to contextualise specific schools, attitudes, and the rapport between the researchers and the participant-principals.The questions focused on the participants' role to ensure effective social justice praxis and their understanding of constitutional values and management strategies to realise these values.They were asked to share positive and negative experiences, along with their staff's preparedness for social justice in education.Lastly, they were asked to identify those who were responsible for effective social justice praxis in their schools.

The findings of this study are generalisable to the sample only.As with transferability, generalisability of this research would not lie with the researchers, but with those principals, policymakers and scholars who might use these management strategies in the future (Marshall & Rossman, 2011).

Trustworthiness, Ethical Considerations and Transferability

Rigid criteria validated the trustworthiness and soundness of the research (Marshall & Rossman, 2011).Trustworthiness was established where the selection criteria (discussed above) was credible.The interaction with the participants brought about raised levels of awareness and reflexivity on the part of both the researchers and the researched, which formed the catalyst for action that would follow in the proposed management strategies (McMillan & Schumacher, 2010).Qualitative trustworthiness was evident in the ensuing relationships, which were ethical, respectful and which continued long after the interviews with the participants (Guba & Lincoln, 2005).

The following ethical aspects were accounted for (Mouton, 2001): protection from harm, informed consent, right to privacy, honesty with professional colleagues, internal review boards, and adherence to the professional code of ethics of the university under whose auspices this research was done.The rights and expectations of participants were respected and anonymity and confidentiality guaranteed.The purpose of the research was communicated in a clear and honest manner and, as far as possible, no intrusion in the professional lives of the participants was allowed.

Data Analysis and Processing

The decision to use a qualitative constructivist research design was based on the premise that the data thus collected, analysed and interpreted would yield a deeper understanding of the qualitative data (Marshall & Rossman, 2011) in accordance with the research premise that social justice praxis was to be found in schools.The researchers recognised that constant change in social justice as a phenomenon, and of qualitative data analysis, was inevitable .The findings of the qualitative data analysis were generated from the 12 semi-structured, individual, and two focus-group interviews.The process involved organising, perusal, classification and synthesis.From these actions, the data processing followed three phases and 18 steps.Phase I started with data recording, transcription and deconstruction of the first Atlas.tiTM transcripts.Phase II included the final construction of the Hermeneutic Unit: Social Justice in Atlas.tiTM from which an Atlas.tiTM code list emerged.Phase III commenced with the construction of an Excel-file, an Atlas.tiTM  Frequency Table and network heuristics (Creswell,  2012; Merriam, 2009) that resulted in seven management strategies, of which four are reported in this article (Figure 2): optimising principal's virtues as Gemeinschaft relationships, influencing the education system and its structures, fostering a disciplined school environment based on constitutional values and a sustained social justice praxis, based on compassion, love and care.

Findings and Discussion

Principals' Management Strategy as Gemeinschaft Relationships

Principals optimised the virtues of responsibility, authenticity and presence (Starratt, 2009) as Gemeinschaft (community) relationships towards effective social justice praxis.Whereas these principals upheld the constitutional values of human rights, human dignity, equality and social justice, which included non-discrimination on the basis of race, it should be noted that the endemic racial divide is very much alive and well in education.Contextualisation of race in this discussion was, therefore necessary in order to clarify participantprincipals' stance against racialism and other injustices.Fairness formed the bedrock of their personal agency and responsibility for sustainable social justice.They were actively engaged in issues of "a life of justice, truth and respect based on shared values" (Calabrese, 2006:173), and these principals were astute activists and sensitive towards a "culturally diverse learner and teacher corps."Social justice praxis was the praxis of "love, an attitude of the heart ("hartsaak"), nondiscrimination and acceptance of the wonder of diversity of humankind which enabled ownership."

The virtue of responsibility informed the socially just activities of these principals towards those who are marginalised, but also towards those privileged in society, affirming Starratt's (2009) notion that responsibility returns to authenticity for its subjective grounding and moral weight in expressing a positive or negative moral response to social injustices.

One principal believed that it was important for teachers or school staff in "monoracial and monolingual schools to attend courses to prepare them to teach" in a diverse reality, stating "we need teachers, schools, school principals and management teams who want to do the right thing for our country."The principle of redistributive justice is regarded as normative in a cooperative venture of mutual benefit (Rawls, 1999a) and mutual respect.Another, when asked what her understanding of social justice praxis was, said "basically it's [...] our daily bread, [...] we live with it, we live it, every time everywhere you are, for as long as you're living with people, you must encounter social justice."Being a Hindu, another said "[b]efore even reading the Constitution and books … we were born with these things, you know when you are brought up as a child, these things are instilled in us: you know that [you] need to respect [others]."i The social justice praxis reported by these principals illuminate the manner in which practice and values are connected, in the sense that the "dignity of man shall be inviolable" (Department of Education, Parliament of the Republic of South Africa, 1995;Goolam, 2001:45).

Influence Education Systems and Structures

The second management strategy that ran like a fils rouge throughout the interviews, was that government and union officials ought to be persuaded to influence political matters that would serve the best interest of the child.This became evident in relation to disabilities and special education needs, where principals referred to "learners who were not able to read, subtract ... because primary schools followed a 'pass-one-pass-all' policy", which led to a bottleneck situation in secondary schools.This situation affirms the existence of a mismatch between actual learner achievement and government policies of the state as distributing agency (Miller, 1999).Step 8 DELETE 1 st HU: SJ_1

Figure 2 Data analysis spiral

Synthesis

Language as a barrier to access, but also as mother tongue and surrounding policy came to the fore where a principal [Afrikaans, white, male] said "I had to manage two schools on one premises, an Afrikaans and Setswana school" with a "racial division of labour between teachers and learners."He changed this situation by implementing a new integrated timetable, declaring that "they would manage the school as a single unit, no you and us, but a unitary system for all of us."He believed that "the best teacher with the highest qualification would teach all the Grade 12s in a specific subject, [i.e.] the best maths teacher whose first language was Afrikaans would teach the Afrikaans group, and then immediately thereafter he would teach the English group."Another principal [Afrikaans, Coloured/person of colour, male] managed "thirteen languages of mother tongue speakers; where multimillionaires' children were sitting next to children from the squatter camps, where powerful religious groups could be found and each form of diversity existed."Principals focused on social justice may find that the management of diversity and social justice remains a challenge.Yet, in being responsible, authentic and present in the lives of learners (Starratt, 2009) they contribute to a conscious acceptance of diversity.

These principals did not regard the state as the sole agent to institute and implement government policies, nor was the state seen as the sole distributing agent of good (and bad) practices in schools.As social justice practitioners they in collaborating with the state, took responsibility, and understood that all social activities and concurrent praxis (Miller, 1999) were theirs as well.

Inculcate a Disciplined School Environment based on Constitutional Values

Basic education is primarily about learners and their cognitive and, importantly, social development, in a sustained environment.Developing people is a fundamental task of school leaders (Leithwood & Jantzi, 2009) and is essentially linked to citizenship.Management strategies do, we suggest, inculcate a disciplined school environment for learners to embrace human diversity and dignity, democracy and ubuntu principles (Nafukho, 2006).Data analysis confirmed that the broader institutional framework of education ought to be influenced by those in power so as to optimise effective social justice praxis.

School safety and the story told by one principal [person of colour] was about a school that experienced a number of burglaries, due to its location amongst squatter camps.The principal noted that "schools were virtually plundered", but he convinced the school community that a school is "this ray of light almost like a lighthouse, where people would gather, and not a place where half of the school was carried away" [sic].He believed that "the school did not need a fence, the community should be that fence, and the fence should not be there to keep children inside, the learners should be in the school because they want […] to be there."This approach ultimately spread through the community in question, where burglaries subsequently became isolated incidents.This instance confirms Nieuwenhuis's (2010) understanding of social justice from a holistic perspective, where it would be seen to continuously challenge past injustices and practices.

Sustainable Management Strategies for Social Justice Praxis because of Compassion, Love and Care

The fourth strategy was that school principals in a diverse school environment were obliged to actualise sustained management strategies for social justice praxis with compassion, love and care.One of the major themes was diversity, which became evident in relation to racial and cultural differences with regard to disciplinary matters.Traditional methods of classroom discipline no longer worked, because "black learners, although 'born free ' [sic], learnt how to use numbers in their favour, as opposed to white learners, who would not have the support of peers if they challenged unfair authoritarian behaviour."

Fairness and discipline was a sine qua non for black learners when it came to disciplinary matters.Social justice should be a process of conscience building, of becoming acutely aware of a heightened and critical awareness of oppression, exclusion, and marginalisation (Freire, 2004).This consciousness of the potential consequences of cultural difference becomes evident in teachers who "recognised and respected black learners' propensity to sing, dance and move."One believed that "white teachers succumbed to white political guilt, and were more lenient towards black learners than their black colleagues would be."These examples of push-and-pull forces lie at the heart of what Kurland (1997) refers to as relationships that brought harmony or conflict, abundance or waste, human development or degradation, a culture of life or a culture of death, equality or fairness.

Colour blindness was found in the petit récits by a principal of colour: a Korean missionary used the parable of all people being brothers and sisters, who needed to work together and take care of one another.When he was about to leave, a little white girl said "my sister is not feeling well, can you please pray for her?"He said, "yes sure, come let's pray for her.Where's your sister?She's in the class."She went to fetch her 'sister' and to the missionary's surprise, he saw that she was black and not white.The principal affirmed later that the white girl was influenced to perceive her friend as her sister, since this little girl didn't appear to notice colour in the girl, who she had adopted as if her own sister.

It is this manner of indifference to race that the South African Constitution asks for in the shared aspirations of a nation, in terms of the values and the moral and ethical direction the nation identified for its future.Principals agreed that values and ethical conduct was of paramount importance to creating a sustainable, socially just school environment, a kind of "über form of social consensus" (Begley & Stefkovich, 2007:400) [sic].Her voice and demeanour conveyed a sense of her conviction that she and the school form part of a community of parents, acknowledging a sense of collective 'ownership'.Principals in this study created a sustainable environment in which a change of heart occurred, where teaching was seen to involve "walking on holy ground… ."This leads to a closing consideration: we are walking, by the grace of the child who allows us to, on sacred ground, when it comes to their physical, emotional and spiritual wellbeing.

These four key findings affirmed the a priori supposition that management strategies for effective social justice praxis were to be found in schools.

Conclusion

Although primarily a South African-based inquiry, the recommendations have wider implications for sustainable social justice leadership.A fils rouge throughout the research is that defining social justice amounts to the inclusion of those individual acts towards the 'other' that require from each individual that which is necessary for the common good to prevail in their schools.It is proposed that leaders in education, on individual and universal levels, ought to incorporate social justice praxis in their active engagement with learners.Social justice praxis ought to become a personal conviction, a conviction that embraces government policies into praxis, albeit in a critical way.The progress stories told confirm and acknowledge the belief that sustainable management of effective social justice praxis is, indeed, possible.Moreover, their stories offer management strategies with which to rebuild a sustainable and coherent education system.This investigation and the interactions with the participant-principals left the researchers with a deeper insight into their management strategies, and how they shared their beliefs on social justice praxis without discrimination, a praxis that was fair towards the disadvantaged as well as the privileged.These principals' management practices were based on the constitutional values of democracy, human dignity and equality, and they advanced human rights fairly to establish a non-racist and non-sexist school environment.The participant-principals' management strategies celebrated a shared commitment to, and a responsibility towards increasingly sustainable efforts to further social change, as well as celebrating diversity and cultural enrichment, both in schools and in society more broadly.By so doing, their social justice praxis substantiated the speculation that inquiry into effective, valuable praxis offers an alternative understanding of sustainable management interventions.

4. Sustainable social justice praxis due tocompassion, love and care3. Foster a disciplined school environmentOffering findings andbased on constitutional valuespropositions2. Influence education system and structuresConstructingtables / diagrams /1. Optimise principal's virtues ashierarchiesgemeinschaft relationshipsFINDINGSClassificationFiling dataGrouping intocategories/themes/codesfrequencies, themesFinding meanings in dataPHASE IIIStep 14 Final MSWord + final Atlas ti CodelistPerusal Overall 'sense' of data Preliminary interpretationsStep 13 Compare 1 st + 2 nd MS Word Code lists Step 12 Reconstruct 2 nd MSWord SJ Code List IIStep 11 Deconstruct PDs (Atlas ti Code list)Step 10 Enter PD_1-12Step 9 CONSTRUCT HU: SJPHASE IIOrganisingFilingComputer data baseDeconstruction

. These principals displayed what Starratt (2012) calls mature qualities of autonomy, connectedness and transcendence.However, the problem of conflicting home and school values was noted by study participants, where one expressed, "we have to instill […] the proper values, which is difficult, because some of our values differ from the values they bring from home.A simple example: a boy may say to you, 'why may I not smoke, because my parents give me money for cigarettes?' There's a conflict of […] values [at play in such a situation], and to bring about a mind change is quite difficultyou have to sit with that child and you have to show him the pros and the cons in connection with the issue."ii Another said the learners "can't wait to hear what you're saying and it's because of discipline, tradition, and values and morals [they experience in a school environment], that they allow you to teach them!" iii In addition, principals agreed that a vision of educational reform and social transformation was the result of a person-toperson (Le Grange, 2007) cooperation, where ownership was affirmed by a white female principal of a primarily black school.She told the parents "you know what, this is not my school, it is your school, it is your school, I'm working for you!You are my boss, you must come and tell me if I do something wrong"

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Accuracy of ARGOS Locations of Pinnipeds at-Sea Estimated Using Fastloc GPS

Daniel P Costa
Department of Ecology and Evolutionary Biology
University of California Santa Cruz
Santa CruzCaliforniaUnited States of America

Patrick W Robinson
Department of Ecology and Evolutionary Biology
University of California Santa Cruz
Santa CruzCaliforniaUnited States of America

John P Y Arnould
School of Life and Environmental Sciences
Deakin University
BurwoodVictoriaAustralia

Autumn-Lynn Harrison
Department of Ecology and Evolutionary Biology
University of California Santa Cruz
Santa CruzCaliforniaUnited States of America

Samantha E Simmons
Department of Ecology and Evolutionary Biology
University of California Santa Cruz
Santa CruzCaliforniaUnited States of America

Jason L Hassrick
Department of Ecology and Evolutionary Biology
University of California Santa Cruz
Santa CruzCaliforniaUnited States of America

Andrew J Hoskins
School of Life and Environmental Sciences
Deakin University
BurwoodVictoriaAustralia

Stephen P Kirkman
Department of Zoology
Animals Demography Unit
University of Cape Town
RondeboschSouth Africa

Herman Oosthuizen
Marine and Coastal Management
Department of Environmental Affairs
Rogge Bay, South Africa

Stella Villegas-Amtmann
Department of Ecology and Evolutionary Biology
University of California Santa Cruz
Santa CruzCaliforniaUnited States of America

Daniel E Crocker
Department of Biology
Sonoma State University
Rohnert ParkCaliforniaUnited States of America

Accuracy of ARGOS Locations of Pinnipeds at-Sea Estimated Using Fastloc GPS

Background: ARGOS satellite telemetry is one of the most widely used methods to track the movements of free-ranging marine and terrestrial animals and is fundamental to studies of foraging ecology, migratory behavior and habitat-use. ARGOS location estimates do not include complete error estimations, and for many marine organisms, the most commonly acquired locations (Location Class 0, A, B, or Z) are provided with no declared error estimate.Methodology/Principal Findings: We compared the accuracy of ARGOS locations to those obtained using Fastloc GPS from the same electronic tags on five species of pinnipeds: 9 California sea lions (Zalophus californianus), 4 Galapagos sea lions (Zalophus wollebaeki), 6 Cape fur seals (Arctocephalus pusillus pusillus), 3 Australian fur seals (A. p. doriferus) and 5 northern elephant seals (Mirounga angustirostris). These species encompass a range of marine habitats (highly pelagic vs coastal), diving behaviors (mean dive durations 2-21 min) and range of latitudes (equator to temperate). A total of 7,318 ARGOS positions and 27,046 GPS positions were collected. Of these, 1,105 ARGOS positions were obtained within five minutes of a GPS position and were used for comparison. The 68 th percentile ARGOS location errors as measured in this study were LC-3 0.49 km, LC-2 1.01 km, LC-1 1.20 km, LC-0 4.18 km, LC-A 6.19 km, LC-B 10.28 km.Conclusions/Significance: The ARGOS errors measured here are greater than those provided by ARGOS, but within the range of other studies. The error was non-normally distributed with each LC highly right-skewed. Locations of species that make short duration dives and spend extended periods on the surface (sea lions and fur seals) had less error than species like elephant seals that spend more time underwater and have shorter surface intervals. Supplemental data (S1) are provided allowing the creation of density distributions that can be used in a variety of filtering algorithms to improve the quality of ARGOS tracking data.

Introduction

The ability to track the movements of animals is fundamental to understanding animal foraging ecology, migratory behavior, habitat use and general life history parameters [1,2,3]. Electronic tracking technology revolutionized the study of animal ecology and is now relied upon as the predominant means of estimating animal movement [4]. A number of electronic tracking methods are available including VHF telemetry, light-level geolocation, ARGOS satellite telemetry and, most recently, GPS tracking [5,6,7,8,9,10,11]. Of these, ARGOS telemetry is one of the most widely used in marine studies [12] and has the significant advantage that the data are acquired remotely in real time via satellite anywhere on the planet (www.ARGOS-system.org). ARGOS satellite telemetry has expanded our understanding of the fine scale movements of marine birds, [13,14,15], sea turtles [16,17], sharks [18,19] and marine mammals [7,11,12,20,21].

The ARGOS system consists of modules attached to loworbiting weather satellites of the National Oceanic and Atmospheric Administration (NOAA). Modules record satellite tag transmissions and later download these data back to Earth for processing by Service ARGOS (Toulouse France, or Landover MD). Tag geoposition is calculated from the Doppler shift of the transmitted radio frequency and requires a minimum of three successive transmissions during a single satellite pass. Locations are based on 7 levels of accuracy: location class (LC) LC-3 with a stated error of less than 150 m, LC-2 with error of 150-350 m, LC-1 with error of 350-1000 m, LC-0 with error greater than 1000 m, and LC-A, LC-B and LC-Z that do not include error estimates.

Unfortunately, the least accurate positions are the most common for many marine animal tracking studies [22]. For example, 89% of ARGOS location estimates from a recent northern elephant seal track (Costa et al. unpublished data) were of LC 0, A, B, or Z and, thus, had no declared error estimate. Furthermore, the errors for the remaining location classes, as provided by ARGOS-CLS, are 68 th percentile predictions (separately for latitude and longitude) rather than full error distributions making it difficult to incorporate into animal movement models.

Spatial error is problematic for many applications, such as determination of area-restricted search, behavioral mode (i.e. foraging, searching, migrating, etc) of far-ranging species, or even simple home-range analyses for individuals exhibiting rangeresidency [23,24,25,26,27]. If unknown, spatial error can also mask accurate descriptions of true location as well as derivedbehavioral states in a scale-dependent fashion. That is, smaller scale patterns will show increased degradation with the addition of ARGOS error. The temporal resolution of tracking data can have similarly detrimental effects on its behavioral interpretation. However, ARGOS transmitters are often set to a fixed transmission rate, so that the temporal resolution of the resulting track is solely dependent on animal behavior. Fortunately, a variety of interpolation techniques are available to mitigate variations in temporal resolution [7,24,27,28]. In contrast, spatial error is propagated both as a result of animal behavior (surfacing behavior, travel speed etc.) and technical limitations [26]. To date, spatial error of ARGOS positions has not been measured in an empirically robust manner for free-ranging marine animals. The first attempts to estimate ARGOS location error in marine animals were made by comparing the known position of an ARGOS tag prior to deployment or while the animal remained at a known location [29]. However, such estimates failed to account for animal behavior at sea. Factors contributing to location errors when animals are at sea include attenuated or missed transmissions due to rapid surfacing behavior, limited total time available for transmissions, and the commonly overlooked impact of temperature-induced frequency instability [30,31,32,33]. Vincent and others [34] attached ARGOS transmitters to captive gray seals, Halichoerus grypus, housed in outdoor tanks to simulate the natural environment and diving behavior of free-ranging seals. They compared the known position of the tank to the locations provided by the ARGOS transmitters and found a lower uplink rate and a shift toward poorer location qualities (0, A, and B) and discovered that ARGOS errors were non-normally distributed. Using acoustic telemetry, White and Sjoberg (2002) followed three free-ranging gray seals on which they had deployed ARGOS transmitters, and took comparative GPS positions from their vessel. They reported location accuracies for LC-0 LC-A, LC-B those not reported by Service ARGOS. Recently Hazel (2009) using a combination of Fastloc GPS and acoustic devices with three green sea turtles, Chelonia midas, found ARGOS errors greater than those reported by ARGOS [35]. However, the tracking devices were housed in a float tethered to the turtles making comparisons to studies where the tracking devices are directly attached to the animal (on the head or back) problematic. While these studies provide useful insights into ARGOS error, they do not provide a robust assessment of ARGOS location error for free ranging marine animals under the conditions most existing data have been collected.

Until recently GPS technology could not be used on diving animals because of the time required for the antenna to be at the surface and clear of wave splash to obtain a satellite fix and maintain the almanac. The recent development of Fastloc GPS technology has made it possible to simultaneously collect GPS and ARGOS locations from freely-ranging marine animals (Fastloc GPS hardware developed by Wildtrack Telemetry Systems Ltd, Leeds, United Kingdom). Standard navigational GPS units require many seconds or even minutes of exposure to GPS satellites to calculate positions and the onboard calculations consume considerable power. In contrast, Fastloc GPS can obtain GPS satellite information in less than 100 ms and can transmit the location information within the narrow bandwidth confines of the ARGOS system. The Fastloc uses a novel intermediate solution that couples brief satellite reception with limited onboard processing to reduce the memory required to store or transmit the location. This system captures the GPS satellite signals, identifies the observed satellites, calculates their pseudo-ranges without the ephemeris or satellite almanac and then transmits the pseudo-ranges via ARGOS. While only a portion of the locations can be transmitted via ARGOS, all of them are archived and therefore can be retrieved as long as the tag is recovered. Final locations are post-processed from the pseudo-ranges once the data are received using archived GPS constellation orbitography archives maintained by NASA (http://cddis.gsfc.nasa.gov).

Here, we assess the accuracy of ARGOS locations via comparisons to Fastloc GPS locations obtained from the same electronic tags on five species of pinnipeds. These species cover a range of marine habitats (highly pelagic vs coastal), diving behaviors (mean dive durations 2-21 min) and range of latitudes (equator to temperate) and a wide range of locations across the globe (South Africa, Eastern North Pacific Ocean, Southern California Bight, southeast Australia and the Galapagos Islands).

Methods

Ethics Statement

The animal use protocol for this research was reviewed and approved by the University of California at Santa Cruz Institutional Animal Care and Use Committee and

Data Collection

To assess in-situ error of ARGOS  [11,36,37]; all individuals were healthy adult females exhibiting normal foraging migrations.

In addition to animal deployments, we evaluated the accuracy of GPS positions on land in a stationary test of four Fastloc GPS tags. Tags were placed within a one-meter square with an open view of the sky at Long Marine Lab in Santa Cruz, California, USA to collect positions for 24 h.

Data Handling

Each deployment yielded an ARGOS track and an archived GPS track. All tracks were truncated to remove periods on land immediately after attaching the tags and immediately prior to removing the tags. ARGOS data were downloaded daily to a local database. ARGOS occasionally updated the location class of previously downloaded locations and these changes were automatically incorporated into our database. ARGOS tracks were filtered using a 100 km?hr 21 speed filter to remove extreme outliers as we were interested in the performance of the ARGOS system and not the performance of filtering algorithms. This outlier filter removes only the most obviously erroneous locations as a simple speed filter for pinnipeds typically assumes a maximum swim velocity of less than 10 km?hr 21 . As the GPS tracks were our estimate of ''true'' position and since occasional errors are generated from the GPS tracks, we used a conservative filter for all GPS tracks: 10 km?hr 21 and 170-degree angle.

To determine the accuracy of ARGOS location estimates, we first identified all ARGOS locations obtained within five minutes of any GPS position. Next, the ''true'' position of the animal at the exact time of the ARGOS uplink was estimated via linear interpolation between the two neighboring GPS positions [38]. This procedure ensures every estimate of ARGOS error was based on a GPS position proximate in both space and time to the true position of the animal. We then calculated several error statistics from each ARGOS-GPS pair: great-circle distance, bearing, longitude component of error, and latitude component of error. The magnitudes of distance errors were fitted to a lognormal distribution for each ARGOS location class using a maximum likelihood approach.  Argos location quality proportions were compared between species using a G-test. Location errors were log transformed and modeled using a linear mixed effects model (SAS 9.1) with individual animal as a random effects subject term and species and location quality as fixed effects. Model residuals were assessed for approximate normality. The ARGOS-GPS data pairs used in this analysis are available as supplementary material to allow further analysis of these data (S1).

All analyses were performed using custom-written software in Matlab R2007a (The Mathworks Natick, MA) and Systat 12 (Chicago, IL).

Results

Matched ARGOS/GPS tracks were obtained from 28 individuals comprising five species of pinnipeds. A total of 7,318 ARGOS positions and 27,046 GPS positions were collected. Of these, 1,105 ARGOS positions were obtained within five minutes of a GPS position and were retained for further analysis. The mean time between ARGOS-GPS pairs was on average 1.16 days (median 0.58 days) with less than 1% (81) of these pairs occurring within an hour of each other. An example of the data used to compare ARGOS against GPS locations is provided for a Cape fur seal (Fig. 1 (Fig. 2).

ARGOS position errors from the animal borne tests were centered on ''true'' locations but extreme outliers were numerous and did not occur in a circular-uniform distribution (Fig. 3). Similarly, for the direction frequency of ARGOS errors, the east/ west (longitudinal) error component was large relative to the north/south component (latitudinal) (Fig. 4).

We found larger than expected errors for the three LCs (3, 2, and 1) for which error estimates are provided by ARGOS (Fig. 5). The remaining LCs exhibit a stepwise increase in error and a substantial reduction in accuracy for LC-Z locations (Fig. 5). Twodimensional visualization of the ARGOS errors show increased dispersion with lower quality locations but also a distinct directional offset in the extreme outliers (Fig. 6). This was particularly apparent in LC-A and LC-B locations. As the data were clearly skewed we chose to fit the distance errors to lognormal distributions for each LC ( Table 2).

The species' diving behavior was also an important factor in the relative location error. Species with similar behaviors had similar location errors (Fig. 7 Table 3), whereas species with dissimilar atsea behaviors had divergent location errors. For example, location error was smaller for species that spend more time on the surface and make shorter duration dives (sea lions and fur seals; 2.2-4.0 min) than species that make long dives followed by short surface intervals (elephant seals; 21.3 min) (Fig. 7). It is important to note that behavior likely impacts both the relative proportion of the LCs and the error within each LC.

Discussion

We assessed the accuracy of ARGOS locations for free-ranging pinnipeds by comparing ARGOS locations to Fastloc GPS locations (matched closely in time, but also interpolated for improved accuracy), which we treated as true locations. Although our on-land stationary test of Fastloc GPS showed greater location error than that achieved with a commercial handheld GPS unit (e.g. 3m Garmin Inc., Olathe, KS), the accuracy was still 4 times greater than the best ARGOS position estimates (Fastloc GPS 36 m; ARGOS LC-3 = 150 m). We, therefore, conclude that  Fastloc GPS provides an appropriate method to assess ARGOS error on free-ranging marine animals.

Incorporating ARGOS error in track analysis is certainly not a novel idea. Attempts to measure this error empirically have ranged in complexity from simple stationary land tests to acoustic tracking of free-ranging satellite-tagged seals and turtles (Table 4). However, these studies are problematic for four reasons: (1) The methodology used in most of these studies failed to capture several sources of ARGOS location error; (2) the studies that properly account for these additional sources of ARGOS error suffer from very small sample sizes and thus cannot adequately describe the error for some ARGOS LCs; (3) many of the studies report either mean errors or 68 th percentile errors in lieu of a full distribution (this is problematic for the implementation of results in modeling exercises and may result in the application of an inappropriate distribution); and (4) the extreme variability in estimates of ARGOS error within a particular LC between studies is problematic for proper implementation. For example, published values for LC-0 error span an entire order of magnitude ( Table 4). The lack of congruence between previous studies may also be due to a combination of low sample sizes, variability in animal behavior, and study protocol. Nevertheless, it is re-assuring that the two studies that arguable employ the most realistic validation method (Fastloc GPS) obtained the most similar error estimates (Table 4; this study and [35] ). This is somewhat unexpected as we might have expected better accuracy from ARGOS transmitters in a tethered float [35] compared to tags mounted on the head or mid back (this study). Regardless, our study is one of the first to empirically determine ARGOS location error from marine animal-borne satellite tracking units where the tag was directly attached to the animal, thereby appropriately accounting for the combined effects of factors known to influence the accuracy of position estimates.

There is no question that GPS tracks are superior to those obtained with ARGOS (Fig 1). We applied only a basic speed filter to create the tracks in Figure 1 and, with the more sophisticated filtering and smoothing algorithms now available, ARGOS tracks can be considerably improved [24,28,39]. However, our estimates of ARGOS error were significantly larger than those provided by ARGOS (approximately 300% greater for LC-3 and LC-2). Although published estimates of ARGOS error vary widely (Table 4), estimates from this study show larger than expected errors for the better location classes and smaller than expected errors for poor location classes.

Inspection of the ARGOS error distributions revealed two features of interest in the direction of the offset: 1) errors are heavily biased in the east/west axis (Fig. 3); and 2) the outliers do not occupy a circular uniform distribution around the true location but instead are preferentially found on the diagonals (Fig. 5 LC-A  & LC-B). This pattern has been previously reported (22,34) and is due to the polar orbit of the ARGOS satellite. The non-uniformity of ARGOS errors around the true location has direct impacts to existing modeling techniques [26,28,39]. Typically points are sampled in one of two ways: 1) an X-Y approach by sampling from a distribution of latitudinal error and separately from a distribution of longitudinal error; or 2) a polar approach by sampling from a distribution of straight-line distance and then from a uniform distribution for direction. Both methods do not adequately account for the observed distribution of outliers (exemplified in LC-A and LC-B). We recommend a polar approach where both distance and angle distributions are defined by empirical ARGOS error data to properly account for the unique two-dimensional shape of the error distributions. These can be created using the supplementary material provided (S1).

Species-specific differences in track quality are predominantly due to variation in surfacing intervals and dive durations shifting the frequency of LCs. Hays et al. (2001) suggest that ARGOS error, even within a particular LC, is highly variable and likely  Fig. 7B). In comparison, northern elephant seal ARGOS tracks were characterized by considerably greater location error ( Table 1, Fig 7A). This result is not unexpected considering that the dive duration of elephant seals is about as long as the time an ARGOS satellite is overhead (20 min), meaning that all of the location information will most likely be transmitted during a single 2 to 3 minute surface interval. In contrast, fur seals and sea lions are likely to surface on multiple occasions while the ARGOS satellite is overhead, providing for more uplinks. In addition, an ARGOS tag attached to an elephant seal is likely to undergo a greater range of temperatures (4-15uC), and more frequent temperature changes, than a tag attached to either a fur seal or sea lion. This is because the deep diving nature of elephant seals will take the tag through a greater range of ambient temperatures and, once at the surface, the satellite tag is likely to warm rapidly after spending 21 min at depths between 400-600m. Other Table 3. Summarizes the species, sample size, location and duration of deployment and the data obtained for that species, along with data on their diving behavior.  investigators may want to create their own error distributions using an appropriate subset of the ARGOS error data provided here as supplementary material (S1), considering species-specific diving behavior (Table 3). Basic descriptions of movements over large spatial scales do not require a detailed understanding of ARGOS location error but the implementation of quantitative analytical tools that derive behavioral states requires accurate knowledge of the error structure [28,39,40]. This is particularly true for analyses at or near the spatio-temporal resolution of the tracking data itself, as these analyses will be particularly sensitive to estimates of error and may provide spurious interpretations if inaccurate estimates are used. Several studies highlight the utility of error distributions in both track ''filtering'' and behavioral interpretation [26,40,41,42,43]. New track improvement algorithms bypass traditional filtering techniques (i.e. simple removal of points) in favor of using all positions weighted by error estimates of the corresponding location class. Several studies use this approach in either a frequentist or Bayesian framework to re-create a more accurate track [28,39]. In addition, these methods are used to extrapolate the likely behavioral state of the tagged animal [39,44].

Although Fastloc GPS drastically improves the quality of tracking data of diving marine animals and will facilitate analyses at smaller spatio-temporal scales, the abundance of historic ARGOS tracking records and relative ease of ARGOS tracking (i.e. no recapture requirement) will ensure a continued demand for analytical approaches using these data. It is essential that these analyses utilize realistic error distributions to recreate a more accurate track and ensure estimates of behavioral states are not driven by noise in the position estimates. Future work should investigate the impact of track quality parameters, such as accuracy and frequency of positions, on biological interpretation of animal movement data.

Supporting Information

Data S1 The supplemental data consists of an error estimate for each ARGOS location within five minutes of any GPS position. The supplemental file is broken into separate files for each of the five species of pinnipeds. For each species file the individual animals are identified by ''Animal ID'' and the great-circle distance, bearing, longitude component of error, and latitude component of error that was calculated for each ARGOS location are provided along with the ARGOS location class (LC) given for that location and the associated GPS residual value. A digital copy of these data are available from the corresponding author. Found at: doi:10.1371/journal.pone.0008677.s001 (0.14 MB PDF)

followed the guidelines established by the Canadian Council on Animal Care and the ethics committee of the Society of Marine Mammalogy. Research was carried out under the following research permits: northern elephant seals and California sea lions, U.S.A. National Marine Fisheries Service permits #87-1743 and 87-1851; Galapagos sea lions, Parque Nacional Galapagos #084/06PNG; Australian fur seals, Department of Natural Resources and Environment research permits 978/003, RP-97-112 amd 10000187; and Cape fur seals permit issued by the Ministry of Marine and Coastal Management to H. Oosthuizen.

Figure 1 .
1A representative track of a female Cape fur seal off the western coast of South Africa obtained using ARGOS (black) or Fastloc GPS (yellow) tags. All filtered locations are presented in this figure, while the comparison between ARGOS and GPS used only locations that were obtained within 5 min of each other. doi:10.1371/journal.pone.0008677.g001

Figure 2 .
2The cumulative frequency of GPS errors from a stationary test of fast-loc GPS tags (N = 257) are shown. doi:10.1371/journal.pone.0008677.g002

Figure 3 .
3The ARGOS error measured as offset from the ''true'' position of the animal as compared to GPS locations are given in this figure. Note the logarithmic scaling of the lower panel and linear scaling of the upper panel. doi:10.1371/journal.pone.0008677.g003

Figure 4 .
4The frequency distribution of the error in ARGOS locations are provided in this figure. East/west offsets were frequent relative to north/south offsets. doi:10.1371/journal.pone.0008677.g004 location quality, elephant seals had higher errors than all of the otariid species and Australian fur seals had higher errors than the other otariids. (Sidak adjustment, p,0.001). The GPS positions obtained from the 4 tags used in the stationary test had a mean error of 35.69 m with 95% of GPS positions falling within 86 m of the mean geographic location of all positions

Figure 5 .
5A box and whisker plot of the ARGOS error associated with each location class is given in this figure. Red bars represent the 68% error as estimated by ARGOS. Note the logscaling of the y-axis. doi:10.1371/journal.pone.0008677.g005

Figure 6 .
6This figure provides the ARGOS error as standardized to a fixed location (N = 1105). Data are log+1 transformed (negative values were reflected before transformation). doi:10.1371/journal.pone.0008677.g006

positions, we attached ARGOS-linked Fastloc GPS tags (manufactured by Wildlife Computers, Sirtrack Ltd., or the Sea Mammal Research Unit, SMRU Ltd) to individuals representing five species of pinnipeds. Nine California sea lions (Zalophus californianus) were captured on San Nicolas Island, California, USA in November 2007 and recaptured in January 2008. Four Galapagos sea lions (Zalophus wollebaeki) were captured on Caamañ o Islet, Galapagos, Ecuador during August 2006 and recaptured two weeks later. Six Cape fur seals (Arctocephalus pusillus pusillus) were captured at Kleinsee seal colony, South Africa in June 2007 and recaptured in July 2007. Three Australian fur seals (A. p. doriferus) were captured at Kanowna Island, northern Bass Strait, Australia in June 2006 and were recaptured two weeks later. Five northern elephant seals (Mirounga angustirostris) were captured at Añ o Nuevo State Park, San Mateo County, California, USA in February 2008 and recaptured in May 2008. We used standard capture, sedation, and instrument attachment protocols

Table 1 .
1The mean ARGOS error in kilometers along with the standard deviation and sample size for each of the ARGOS location classes summarized for each of the 5 species of pinnipeds.Error in km

LC-3 LC-2
LC-1 LC-0
LC-A
LC-B
LC-Z

Cape fur seal 1.38
1.08
1.13
3.03
6.58
6.98
1.50

std dev
61.62 60.92 60.99 62.52 68.77
69.30
-

n
2
5
1 9
2 1
3 8
2 7
1

California sea
lion

0.60
0.95
1.05
3.87
4.41
7.67
89.70

std dev
60.56 61.00 61.01 65.59 66.47
610.80 628.47

n
14
71
184
102
81
85
3

Australian fur
seal

0.34
0.75
2.18
10.41 19.76
97.71
9.71

std dev
60.20 60.512 61.40 613.12 635.96 6115.81 -

n
5
9
11
13
5
10
1

Galapagos sea
lion

0.26
0.94
1.04
4.34
5.22
20.50
31.87

std dev
60.18 61.81 61.09 63.350 64.63
630.85 620.36

n
1 2
1 9
3 6
2 3
1 6
8
3

Northern eseal -
0.91
3.04
3.99
101.17
49.23
164.45

std dev
60.50 0.00
65.83 6341.94 6189.33 6236.35

n
-
3
1
8
52
206
11

doi:10.1371/journal.pone.0008677.t001

). Error estimates (great-circle distance, bearing, longitude component of error, and latitude component of error) were calculated for each ARGOS position and are available as supplementary material. Mean ARGOS error for all LC combined was 19.44 km with a standard deviation of 116.89 km (median error 1.91 km). The mean ARGOS error, standard deviation and sample size for each of the ARGOS location classes are summarized for each species in Table 1. Location quality proportions varied significantly between species (G 2 = 525.3, df = 28, p,0.001). When controlled for location quality, location error varied between species (F 4,1071 = 7.8, p,0.001). Post-hoc comparison of least square means revealed that irrespective of

Table 2 .
2Parameters describing lognormal probability distribution for the distance (km) of ARGOS error for each location class.ARGOS LC
Sample Size
m
s

3
3 3
21.198
1.02

2
107
1.026
0.693

1
251
1.199
0.712

0
167
1.381
0.521

A
192
1.622
0.506

B
336
1.623
0.612

doi:10.1371/journal.pone.0008677.t002

doi:10.1371/journal.pone.0008677.t003Species

Sample
size

Mean
latitude

Mean
longitude

Deployment
duration
(weeks)

# ARGOS
positions

# GPS
positions

# positions
used in
analysis

Mean
ARGOS LC

Mean
error (km)
light filter

Mean
error
(km) no
filter

Mean
dive
duration
(min)
reference

California
sea lion

9
33.92
2119.970
8
4746
9219
540
1-0 (3.80)
3.59
9.49
2.2
Kuhn 2006

Galapagos
sea lion

4
20.764
290.413
2
344
1705
117
1-0 (3.41)
4.29
88.56
4
Villegas et al.
2008

Cape fur
seal

6
229.802 16.267
4
917
1597
113
0-A (4.53)
4.72
18.67
2.5
Harrison et al
(unpublished)

Australian
fur seal

3
239.357 146.304
2
165
919
54
1-0 (3.70)
23.21
92.74
2.9
Arnould and
Hindell, 2000

Northern
elephant
seal

6
42.739
2135.902
12
1146
13606
281
A-B (5.74)
61.38
173.11
21.3
Leboeuf et al
2000

Stationary
test of GPS
This study

4
36.949
2122.066
-
-
257
-
-
-
-
-
-

Table 4 .
4Comparison of ARGOS error from different studies. (If two values are present in a cell, this indicates 'latitude/longitude'). Note: Percentile and mean values are presented. doi:10.1371/journal.pone.0008677.t004Source
Method
Statistic
LC-3
LC-2
LC-1
LC-0
LC-A
LC-B

ARGOS
Theoretical
68th percentile
0.15/0.15
0.35/0.35
1.00/1.00
-
-
-

This study
on animals, at sea Mean
0.487
0.939
1.110
4.342
31.512
36.077

This study
on animals, at sea 68th percentile
0.486
1.011
1.201
4.182
6.185
10.276

This study
on animals, at sea 68th percentile Lat/long 0.225/0.340 0.468/0.729 0.574/0.879 1.795/2.855 2.788/4.373 4.642/8.253

Hazel 2009
on animals, at sea
68 th percentile
0.482
0.785
1.430
5.179
8.072
11.484

Goulet et al. 1999
stationary test on land 68th percentile
-
-
1.335
43.799
-
-

Keating et al. 1991
stationary test on land 68th percentile
0.361
0.903
1.188
-
-
-

Mate et al. 1997
stationary test on land 68th percentile
0.3
0.9
2.3
7.5
-
-

McConnell et al. 1992b on animals, on land
68th percentile
-
1.022
2.238
3.792
-
-

Britten et al. 1999
on animals, on land
68th percentile
-
-
-
11.5
6.8
98.5

Vincent et al. 2002
on animals, study pool 68th percentile Lat/long
0.157/0.295 0.259/0.485 0.494/1.021 2.271/3.308 0.762/1.244 4.596/7.214

Burns and Castellini 1998 on animals, on ice
Mean Lat/long
-
-
4.1/2.5
8.8/5.5
-
-

Boyd et al. 1998
Stationary test on land Mean
1.228
1.115
1.566
3.779
18.843
22.841

Hays et al. 2001
stationary test on land Mean Lat/long
0.12/0.32
0.28/0.62
1.03/1.62
4.29/15.02
1.39/0.81
5.23/7.79

Le Boeuf et al. 2000
on animals, on land
Mean
0.8
1.4
2.7
9.3
28.3
48.4

Nicholls et al. 2007
stationary test on land Mean
0.5
0.7
1.7
16
5
38

White and Sjoberg 2002 on animals, at sea
Grand mean
-
-
4.434
5.349
6.477
45.345

January 2010 | Volume 5 | Issue 1 | e8677
PLoS ONE | www.plosone.org
AcknowledgmentsWe thank the following for help during various phases of the fieldwork: Robin Weber for the creation and maintenance of the ARGOS database; Grace Smith and many otherNavyAuthor Contributions
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