A5045832132- Avian ecology and behavior
- Ecology and Vegetation Dynamics Studies
- Wildlife Ecology and Conservation
- Species Distribution and Climate Change
- Plant and animal studies
- Animal Behavior and Reproduction
- Rangeland and Wildlife Management
- Animal Ecology and Behavior Studies
- Fire effects on ecosystems
- Bird parasitology and diseases
- Animal Vocal Communication and Behavior
- Fish Ecology and Management Studies
- Conservation, Biodiversity, and Resource Management
- Wildlife-Road Interactions and Conservation
- Genetic diversity and population structure
- Primate Behavior and Ecology
- Forest Management and Policy
- Animal Disease Management and Epidemiology
- Remote Sensing in Agriculture
- Livestock and Poultry Management
- Marine animal studies overview
- Hydrology and Sediment Transport Processes
- Animal and Plant Science Education
- Lepidoptera: Biology and Taxonomy
- Ecology and biodiversity studies
Florida Museum of Natural History
2016-2025
University of Florida
2016-2025
Bowie State University
2022
World Vision
2020
Third Way
2014
University of British Columbia
2012
Institute for Scientific and Technological Research
2012
Universities UK
2011
University of Illinois Urbana-Champaign
1996-2010
Weatherford (Norway)
2007
Forest fragmentation, the disruption in continuity of forest habitat, is hypothesized to be a major cause population decline for some species birds because fragmentation reduces nesting (reproductive) success. Nest predation and parasitism by cowbirds increased with nine midwestern (United States) landscapes that varied from 6 95 percent cover within 10-kilometer radius study areas. Observed reproductive rates were low enough most fragmented suggest their populations are sinks depend...
To help fill the gap in detailed knowledge of avian community structure tropical forests, we undertook a census 97—ha plot floodplain forest Amazonian Peru. The was censused over 3—mo period spanning 1982 breeding season. cooperative venture entailed ≈12 person—months effort. Conventional spot—mapping principal method used, but several additional methods were required to estimate numbers non—territorial and group—living species: direct counts members mixed flocks, saturation mist—netting...
The different searching tactics of passerine birds foraging for arthropods among the foliage a northern hardwoods forest result in capture kinds prey. Five major modes are employed by 11 foliage-foraging bird species Hubbard Brook Exper- imental Forest, New Hampshire. These distinguished primarily rates and distances moved types forms their prey-attacking maneuvers. turn reflect how large an area is scanned, thoroughly it searched, moves from perch to its search Mean flight positively...
▪ Abstract Natural ecological disturbance creates habitats that are used by diverse groups of birds. In North America, these or ecosystems include grasslands prairies, shrublands, savannas, early successional forests, and floodplains. Whereas the extent all natural has diminished significantly owing to outright loss from agriculture development, suppression agents such as fire flooding led further losses. Accordingly, abundances many bird species adapted disturbance-mediated have declined...
Tropical montane species are characterized by narrow elevational distributions. Recent perspectives on mechanisms maintaining these restricted distributions have emphasized abiotic processes, but biotic processes may also play a role in their establishment or maintenance. One historically popular hypothesis, especially for birds, is that interspecific competition constrains ranges of closely related “replace” each other along gradients. Supporting evidence, however, based patterns occurrence...
Tropical mountains contain some of the world’s richest animal communities as a result high turnover species along elevational gradients. We describe an approach to study roles biotic and abiotic factors in establishing ranges, improve our ability predict effects climate change on these communities. As framework we use Hutchinson’s concept fundamental niche (determined by match between physical environment organism’s physiological biophysical characteristics) realized (the subset determined...
We report that interspecific territoriality is a common spacing mechanism among closely related bird species distributed along primary successional gradient in the meander belt of an Amazonian whitewater river. In first phase research, we mapped territories more than 330 large census plots encompassing complete gradient. found pairs over 20 genera showed contiguous but non-overlapping territories, such early stages were occupied by one member pair, and later other. Other additional types...
We examined the reproductive success and long—term population dynamics of Neotropical migrant birds in fragmented landscapes Illinois. Our primary objective was to assess whether annual variation abundances persistence populations within woodlots related success. Nesting migrants so low where we sampled that it is unlikely these are self—sustaining. Moreover, frequently disappear from recolonize woodlots. These data suggest source—sink metaphor for spatially structured applicable migratory...
Abstract We quantified the behavior of four species passerine birds foraging for arthropods among foliage different plant and vertical strata a northern hardwoods forest in New Hampshire (USA). Two (Vireo olivaceus Setophaga ruticilla) often changed their patterns but not tree species, except white ash. In latter, both flew more frequently between perches while searching prey, which reflects open canopy sparser distribution ash foliage. A third philadelphicus) was stereotyped its search...
Abstract: Grassland fragmentation and habitat loss are hypothesized to be contributing widespread grassland bird declines in North America due the adverse effects of on breeding abundance reproductive success. To assess success birds, we measured rates nest predation brood parasitism for four species birds ( Grasshopper Sparrow [ Ammodramus savannaru ], Henslow's Sparrow[ henslowii Eastern Meadowlark Sturnella magna Dickcissel Spiza Americana ] ) 39 prairie fragments ranging from 24...
Greater nest predation in tropical than temperate birds has been hypothesized to be a primary selective force generating latitudinal differences avian life history traits. Few extensive data sets, however, have available from forests compare with forests. To increase the amount of empirical information for addressing issues related evolution traits birds, we measured nesting success understory lowland forest central Panama. We found and monitored fates 696 nests 71 species over two breeding...
Most forest birds include arthropods in their diet, sometimes specializing on that consume plant foliage. Experimental tests of whether bird predation can reduce damage, however, are few and restricted to relatively low-diversity systems. Here, we describe an experimental test a diverse tropical indirectly defend foliage from arthropod herbivores. We also compare how the indirect effects vary with different levels productivity canopy vs. understory. For three Neotropical tree species,...
Abstract Individuals of the colonial Yellow-rumped Cacique (Cacicus cela) in Amazonian Peru can defend their nests against predators three ways. First, by nesting on islands and around wasp nests, caciques are safe from arboreal mammals such as primates, which destroy many more-accessible colonies. Caimans otters that live lakes also protect island colonies snakes, vulnerable when crossing open water. Second, clustering together mobbing a group, deter avian predators, take spatially isolated...
The population dynamics of avian brood parasitism have received little attention in spite mounting evidence that many host species are adversely affected by parasites. We develop models for the and apply these to host-parasite associations which demographic data available. For generalized parasites, use species, we assume parasite unaffected any one hosts accept eggs consequences a given can be estimated if knows probability parasitism, juvenile adult mortality rates, average number...
Why do many hosts accept costly avian brood parasitism even when parasitic eggs and nestlings differ dramatically in appearance from their own? Scientists argue that evolutionary lag or equilibrium can explain this enigma. Few, however, consider the potential of birds to enforce acceptance by destroying eject thereby reject parasitism. This retaliatory “mafia” behavior has been reported one species cuckoo but never cowbirds. Here we present experimental evidence mafia brown-headed cowbird (...
Summary Life history varies across latitudes, with the ‘pace of life’ being ‘slower’ in tropical regions. Because life is coupled to energy metabolism via allocation tradeoffs and links between performance capacity use, low metabolic intensity expected animals. Low has been reported for lowland birds, but it unclear if this due ‘slow’ or a warm, stable environment. We measured basal rates (BMR) 253 bird species 2·6 km altitude gradient Peru. predicted higher BMR at high lower temperatures...
Historical and biogeographic contexts can play important, yet sometimes overlooked, roles in determining structure of local communities. In particular, few examinations historical influences on patterns species richness relative abundances tropical communities have been conducted. part, that gap our knowledge has caused by a paucity data communities, even for relatively well-studied taxa such as birds. the Neotropics, only two sites, 97-ha plot lowland Peru 100-ha French Guiana, inventoried...
We evaluated the effects of perforation, or creation small gaps, within a mature, deciduous forest in southern Illinois (U.S.A.) on abundances breeding birds. Openings 0.02–0.4 ha were created by group and single‐tree selection logging 2000‐ha tract forest. used point counts to compare birds uncut with those similar adjacent compartments that recently cut (1–5 years previously) less (10–15 earlier). Most species not significantly common logged tracts. Only Red‐eyed Vireos ( Vireo olivaceus )...
Summary Although much attention has been paid to the impacts of tropical deforestation on populations Neotropical migrants, fragmentation breeding habitat may be an equally serious problem for many these birds. Populations migrant songbirds have declining in recent decades, especially within small woodlots. Censuses from woodlots different sizes also consistently show that are area-sensitive, i.e. they absent all but largest a region. In contrast, long-term censuses large, unfragmented...