Meeting Abstract
Populations of avian species (e.g. golden white-eyes (GOWE), Mariana fruit doves (MAFD), rufous fantails (RUFA), and Tinian monarchs (TIMO)) in the Mariana island chain have declined since the regional introduction of the brown tree snake to Guam. Efforts to establish security populations of these species through collection and translocation to nearby islands have occurred via the Marianas Avifauna Conservation Program since 2004. Using a previously validated enzyme immunoassay, we measured fecal immuno-reactive corticosterone (B) in daily (24h total fecal output) samples from individual birds collected from mist nets (April-May, 2015-2018) and placed in a holding facility for health evaluation for up to two weeks before release. We observed considerable variation in fecal B on day of collection (=day 0) and day 1 in holding in all species, with most birds acclimating by day 2-3. GOWEs had the least amount of variation on day 0, highest variation on day 1, and took 1-2 days longer to acclimate. Some MAFDs and TIMOs had secondary B responses (days 3-5) attributed to concurrent health exams for recently collected birds added to the holding room. Individuals that sustained injury during collection, lost body mass during holding, or expired, exhibited a pattern of elevated B on day 0, 1, or the day of injury. Our results suggest that 1) most birds acclimated quickly to holding (>97%); 2) current management and husbandry strategies did not adversely affect health or mortality; and 3) fecal B can be used as a complement to disease and health assessment to help choose the best individuals for translocation. These methods have the potential to be applied to other avian species targeted for field conservation initiatives.
