The effects of rearing method on social behaviors of mentored, captive‐reared juvenile California condors

Abstract

Puppet-reared and parent-reared captive-bred California condor (Gymnogyps californianus) juveniles were studied before their release into the wild. Behavioral data were collected during social interactions within two cohorts of juveniles (N = 11) and their adult mentors (N = 5). The purposes of this study were to (1) document the social behaviors of mentored juvenile California condors, and (2) compare social behaviors for two different rearing methods (puppet-reared versus parent-reared) during two phases of the mentoring process (San Diego Wild Animal Park versus release sites). Of the 17 behaviors examined by 2 x 2 analyses of variance (ANOVAs), two significant interactions between the rearing method and mentoring phase were found: pulls feathers and feeds alone. For both behaviors, parent-reared condors engaged in these activities more often at the zoo and less often at the release pens than did the puppet-reared condors. The main effect of rearing was also significant for two behaviors: near others, and receives contact aggression from other. Parent-reared birds were more likely to be near another bird and receive contact aggression, regardless of mentoring phase, than puppet-reared birds. The effect size for 16 of the 17 behaviors was greater for the rearing method than for mentoring phase. Rearing method differences may persist long-term, as parent-reared adult mentors were significantly more aggressive than puppet-reared adult mentors. Dominance relations were examined for both cohorts, with the first cohort exhibiting a strong linear relationship (h' = 0.86, P = 0.018), whereas the second cohort exhibited a moderate but non-significant linear hierarchy (h' = 0.63, P = 0.21). The rearing method had no effect on dominance among the juveniles, but adults were probably dominant to juveniles (P = 0.052; the difference was nearly significant). Although social behaviors between the two rearing groups were similar in most respects, this study is the first to document measurable differences between puppet- and parent-reared captive-bred California condor juveniles. Zoo Biol 27:1-18, 2008. (c) 2007 Wiley-Liss, Inc.

An analysis of monthly home range size in the critically endangered California CondorGymnogyps californianus

“…Thus, it may be that increasing monthly home range size of immature condors as they age is due to learning from adults about historic foraging ranges either directly, when parents guide offspring to new areas during the course of post-fledging care, or indirectly, when independent immature birds follow older condors to foraging sites (indirect facilitation; see Houston 1974, Jackson et al 2008). If true, this highlights the importance of having experienced adults available to mentor younger birds in the wild population, a factor that has been shown to be a critically important tool for teaching appropriate social behaviour to young birds prior to their release into the wild (Utt et al 2008, Walters et al 2010). Of note, condors that are raised in captivity and then released into the wild as juveniles often appear dependent on proffered food in their first year after release (Burnett and Brandt pers.…”

You see me, but do you hear me? The science and sensibility of trans-species dialogue

“…Failure to do so creates individuals who are fated to wander between worlds: lost souls, who do not belong to any community and sadly die alone, rejected and without the solace of companionship. The scientific literature is littered with the tragic consequences of cross-fostered individuals such as the two chimpanzees, Lucy and Billy Jo, and other human-reared animals who bear the tragic consequences of inept human interference Bradshaw et al, 2008;Temerlin, 1980;Utt et al, 2008).…”

Vanishing behaviors

“…(2) Preservation of behavioral diversity allows us to seed wild populations with behaviors that may prevent Training captive marsupials to recognize nonnative predators prior to their release Griffin et al (2000) Teaching whooping cranes (Grus canadensis) to undergo annual migrations following an ultra-light plane Langenberg et al (2002) Removing of dams to allow salmon to migrate upstream Stanley & Doyle (2003) Taking down fences that prevent large mammal movements Bartlam-Brooks et al (2011) Feeding California condor chicks (Gymnogyps californianus) destined for release using puppets Utt et al (2008) Teaching black-footed ferrets (Nustela nigripes) to hunt their prey Tresz (2007) their extermination by invasive species ("behavioral rescue:" Schlaepfer et al 2005).…”