away. Within their nesting territory, hobbies have been recorded using several different perches for activities including, the transfer of food between male and female, for feeding independently and for guarding the nest. Research has shown that brooding is shared by both male and female hobbies. However, feeding of the nestlings after hatching becomes the responsibility of the female. Early on in the nestling period the male hunting rate increases to supplement the female with observations indicating food is brought to the nest every three hours, with a longer break in the middle of the day. Vocalisations Research undertaken comparing the vocalisations of Australian falcons, found that two structurally distinct calls were emitted when a male hobby was restrained. This included a wide band harmonic vocalisation and a trill-type vocalisation. The trill-type vocalisation was given sporadically upon initial handling and harmonic vocalisation was assessed as the most common call of the species being used in situations of territorial defence and mobbing. Observations of hobbies during breeding identified that two main calls were used by adults. One was a rapid peevish chatter Kee-Kee-Kee-Kee-Kee which was given by the male as he brought prey to the nest area and was given by both sexes in alarm, when mobbing other predatory birds and when selecting and defending the nest. The second call resembled a squeaky chittering and ticking which appears to be used in a social dominance and food possession or food begging context. Juveniles were observed calling in an unslurred chittering whine when begging for food and in a chattering kee-kee-kee... when alarmed, or excited, from the feathering stage. Calls by the Australian hobby are similar, but higher pitched, to the male peregrine falcon (Falco peregrinus) when arriving at the nest with food. The hobby is also described as having similar alarm and contact calls to the Nankeen kestrel (Falco cenchroides). Conservation and threats The International Union for Conservation of Nature (IUCN) lists the Australian hobby as a species of least concern. It is not listed as a threatened species within Australia. It is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES). Appendix II lists species that are not necessarily now threatened with extinction but that may become so unless trade is closely controlled. After dichlorodiphenyltrichloroethane (DDT) was introduced to agriculture in 1946, egg shell thickness of some species of falcon, including the Australian hobby, was significantly