Territorial Defense Behavior

Oneida County, Wisconsin, USA

In many bird species, a male must possess a territory to attract a mate. Males defend their territory through vocal and visual displays and sometimes by physical contests with intruders.  Fighting is time consuming and potentially injurious to both combatants.  If vocalizations by the territory owner could deter a potential intruder from entering the territory, the territory owner would benefit by avoiding direct conflict.  This study to assessed the potential of the male Common Loons’, Gavia immer, yodel to function as a deterrent to territorial intruders.

Life History Strategies

Smithsonian Tropical Research Institute, Barro Colorado Island, Panama

Changes in reproductive state or the environment may affect the sensitivity of the hypothalamicpituitary-andrenal (HPA) axis. However, little is known about the dynamics of the resulting corticosteroid stress response, in particular in tropical mammals. In this study, we addressed the modulation of corticosterone release in response to different reproductive conditions and seasonality in free-living common fruit-eating bats (Artibeus jamaicensis) on Barro Colorado Island in Panama during dry and wet seasons. We found strong evidence that stress sensitivity is primarily modulated by reproductive condition. This work was done in collaboration with Stefan Klaus, Andrea Denzel (University of Ulm, Germany) and Elizabeth Kalko (STRI, Panama).

Spread of Infectious Diseases

Kimbe, West New Britain, Papua New Guinea

Australian Bat Lyssavirus was first identified in 1996.  The virus is similar to rabies and has caused several human deaths in Australia.  Since flying fox species are known to travel between northern Australia and Papua New Guinea, a program of serosurveillance was established in both countries. As part of that effort, we mist-netted bats at flowering banana and fig trees. Biometric data and blood samples were collected from 50 animals of five different species.  The blood samples are being tested for the presence of Lyssavirus antibodies.  Full results are not yet available.  This work was done in collaboration with Dr. Stefan Klaus (University of Ulm, Germany) and Dr. Frank Bonaccorso (National Museum and Art Gallery, Boroko, Papua New Guinea)

Roosts as Information Centers

Trinidad, West Indies and Smithsonian National Zoological Park, Department of Zoological Research, Washington, DC, USA

This study focused on the potential for adult female roost mates and juvenile greater spear-nosed bats, , to gain information about ephemeral food sources from adult females returning to the roost sites after successful foraging forays.  Females often return to the mouth of the roost cave after a foraging trip and emit screech calls.  More often than should occur by chance, within five seconds of the call one or more of her roost mates will emerge from the cage and the group will fly off in the same direction  It appears that these calls recruit roost mates for foraging bouts.  Research funded by a National Science Foundation, Research Experience for Undergraduates grant and a Howard Hughes Medical Institute Pre-doctoral Fellowship.  Research was conducted at the Smithsonian National Zoological Park, Department of Zoological Research, Washington, DC, USA and in Trinidad, West Indies, in collaboration with Dr. Gerald Wilkinson (University of Maryland, USA).