Patterns of Foraging on Dead Birds in a Coastal Mangrove Environment
Abstract
South Florida falls along the Atlantic Flyway, the migratory route for numerous North American bird species. In particular, the coastal ecosystem of South Florida provides habitat, protection and a food resource. However, the migration is energetically taxing and the mortality rate of these birds is unknown. One way to evaluate mortality is to monitor the number of carcasses, but bird carcasses are rarely observed in South Florida coastal habitats, presumably due to a high rate of carcass scavenging. To address this knowledge gap, infrared automatic game cameras at stations baited with frozen feeder chicks (to simulate dead migratory birds) were used to assess the scavenging communities in three common South Florida coastal sub-habitats: (1) wet mud areas around the roots of mid-/high tideline red mangrove Rhizophora mangle and black mangrove Avicennia germinans, (2) permanently dry grounds above the high tideline around invasive Australian pine trees Casuarina equisetifolia, and (3) highground coastal scrub habitat. Other than one chick buried overnight by an ant colony, all carcasses were removed within 24 hours of initial deployment. The game cameras have shown three vertebrate species scavenging the carcasses placed in all three habitats: opossum Didelphis virginiana, northern raccoon Procyon lotor, and marsh rat Oryzomys palustris. Only one feral housecat Felis catus was seen in the camera deployments, although individuals are known to reside locally. Data for carcass scavenging in mangrove habitats in South Florida will provide a better understanding of migratory bird populations and their local mortality rates.
Faculty Sponsors
Dr. David Kerstetter
Project Type
Event
Location
Alvin Shermany Library
Start Date
4-5-2019 1:00 PM
End Date
4-5-2019 5:00 PM
Patterns of Foraging on Dead Birds in a Coastal Mangrove Environment
Alvin Shermany Library
South Florida falls along the Atlantic Flyway, the migratory route for numerous North American bird species. In particular, the coastal ecosystem of South Florida provides habitat, protection and a food resource. However, the migration is energetically taxing and the mortality rate of these birds is unknown. One way to evaluate mortality is to monitor the number of carcasses, but bird carcasses are rarely observed in South Florida coastal habitats, presumably due to a high rate of carcass scavenging. To address this knowledge gap, infrared automatic game cameras at stations baited with frozen feeder chicks (to simulate dead migratory birds) were used to assess the scavenging communities in three common South Florida coastal sub-habitats: (1) wet mud areas around the roots of mid-/high tideline red mangrove Rhizophora mangle and black mangrove Avicennia germinans, (2) permanently dry grounds above the high tideline around invasive Australian pine trees Casuarina equisetifolia, and (3) highground coastal scrub habitat. Other than one chick buried overnight by an ant colony, all carcasses were removed within 24 hours of initial deployment. The game cameras have shown three vertebrate species scavenging the carcasses placed in all three habitats: opossum Didelphis virginiana, northern raccoon Procyon lotor, and marsh rat Oryzomys palustris. Only one feral housecat Felis catus was seen in the camera deployments, although individuals are known to reside locally. Data for carcass scavenging in mangrove habitats in South Florida will provide a better understanding of migratory bird populations and their local mortality rates.
