By 2011, human development and illegal activities such as habitat destruction and poaching threaten to wipe out endangered species, including the white bellied heron, one of the country's rarest birds. Poaching in Bhutan is an environmental issue both within the kingdom and at its borders. Many species are poached for their alleged medicinal properties. Though protected within Bhutan, wildlife products including rhinoceros horn, tiger bones, musk, and cordyceps sinensis command high prices outside the kingdom. Although porous borders are blamed for trafficking in poached wildlife, some protected species such as cordyceps have their own markets within Bhutan. Climate change Bhutan has faced ongoing and immediate climate change since the late twentieth century. Tangible climate change has resulted in the warming and recession of many of Bhutan's glaciers, increasing the frequency and severity of glacial lake outburst floods (GLOFs). Bhutan has also seen a shift in agriculture patterns due to climate change, prompting concern over the stability of agriculture in Bhutan. Glacier retreat and GLOFs Where glacial movement temporarily blocks riverflows, downstream areas may be threatened by GLOFs. Although GLOFs are not a new phenomenon in Bhutan, their frequency has risen in the past three decades. Significant GLOFs occurred in 1957, 1960, 1968 and 1994, devastating lives and property downstream. According to the Bhutan Department of Energy however, the majority of rivers in Bhutan are more susceptible to fluctuation with changing rainfall patterns than to flooding directly attributable to glacier or snow melt. Because the state of glaciers in Bhutan involves questions of climate change, the topic is somewhat controversial. A 2008 United Nations report suggested that due to rising temperatures, glaciers in Bhutan were retreating at a rate of 30–40 meters per year, poised to make many lakes burst their banks and send millions of gallons of floodwater downstream. This among many other climate-related issues identified in the report prompted the regional association of government ministers to establish the Southeast Asia Regional Health Emergency Fund in Thimphu in September 2007. Similarly, the member nations of South Asian Association for Regional Cooperation (SAARC) adopted bilateral agreements including measures on climate change and glaciers at its summit in April 2010. The 2008 UN report also indicated Himalayan glaciers would melt within 25 years, however Prime Minister Jigme Thinley expressed a more dim outlook in a press conference in late March 2010, stating, "Our glaciers are withdrawing very fast and we have reasons