A5046882366- Avian ecology and behavior
- Wildlife Ecology and Conservation
- Ecology and Vegetation Dynamics Studies
- Species Distribution and Climate Change
- Plant and animal studies
- Animal Ecology and Behavior Studies
- Animal Behavior and Reproduction
- Fire effects on ecosystems
- Animal Vocal Communication and Behavior
- Fish Ecology and Management Studies
- Marine animal studies overview
- Isotope Analysis in Ecology
- Genetic diversity and population structure
- Forest Ecology and Biodiversity Studies
- Coffee research and impacts
- Bird parasitology and diseases
- Forest Management and Policy
- Science and Climate Studies
- Environmental DNA in Biodiversity Studies
- Identification and Quantification in Food
- Forest Insect Ecology and Management
- Wildlife Conservation and Criminology Analyses
- Organic Food and Agriculture
- Botany, Ecology, and Taxonomy Studies
- Lepidoptera: Biology and Taxonomy
Tulane University
2014-2024
Dartmouth College
1978-2023
Cornell University
2007-2023
The Institute for Bird Populations
2023
Cornell Lab of Ornithology
2023
Yale University
2007
Louisiana Department of Natural Resources
2007
Syracuse University
2007
Kalamazoo College
2007
Identifying the factors that control population dynamics in migratory animals has been constrained by our inability to track individuals throughout annual cycle. Using stable carbon isotopes, we show reproductive success of a long‐distance bird is influenced quality habitat located thousands kilometres away on tropical wintering grounds. For male American redstarts (Setophaga ruticilla), winter arrival date breeding grounds, which turn affected key variables associated with reproduction,...
The nature and extent of population regulation remains a principal unanswered question for many types organisms, despite extensive research. In this paper, we provide new synthesis theoretical empirical evidence that elucidates extends mechanism species whose individuals preemptively use sites differ in suitability. may be territories, refuges from predation, oviposition sites, etc. mechanism, which call site dependence, is not an alternative to density dependence; rather, dependence one...
Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may needed all phases. The bulk research has focused on although several issues remain unsettled, including spatial extent habitat influences fitness importance grounds used after breeding. Although detailed investigations have shed light ecology population dynamics a few avian species, knowledge is sketchy for most species. Replication...
Our understanding of migratory birds' year‐round ecology and evolution remains patchy despite recent fundamental advances. Periodic reviews focus future research inform conservation management; here, we take advantage our combined experiences working on Western Hemisphere avian migration systems to highlight lessons critical gaps in knowledge. Among topics discussed are: (1) The pipeline from pure applied researchers leaves room for improvement. (2) Population limitation regulation includes...
Recent declines in Neotropical—Nearctic migrant songbird populations are often attributed to events during the nonbreeding season, such as tropical habitat conversion and drought. Support for this hypothesis most species, however, is largely anecdotal or conjectural. There a dearth of demographic information about migrants on their Neotropical winter grounds. Such data needed identify specific ecological factors influencing survival, dispersal, and, ultimately, population abundances...
The distribution of individuals among habitats and their relative success in those can have important consequences for population dynamics. To examine these processes a long-distance migratory bird species, we studied the structure, age-specific reproductive output, local survival black-throated blue warblers (Dendroica caerulescens, Gmelin) two breeding differing shrub density within northern hardwoods forests New Hampshire, USA. On forest plots with dense shrubs, occurred at higher...
Changes in species composition and abundance of birds breeding an unfragmented temperate deciduous forest New Hampshire, USA, were studied intensively during 16 consecutive seasons, 1969—1984. The number the 10—ha study area any one year varied from 17 to 28, averaged 24. Total numbers individuals on plot ranged 214 89, with many (70%) declining 16—yr period. Overall, there was significant positive covariation among population trends all species, suggesting a major, perhaps single, factor...
Summary Theoretical arguments suggest that distributions of migratory birds in winter should match patterns food availability, but reality the between migrants and their may be imperfect because, for various reasons, unable to ‘track’ resources. We tested hypothesis availability influences distribution canopy‐foraging insectivorous warblers wintering Jamaica. Over a wide spatial scale (24 sites on island), warbler abundance varied significantly among habitats was dependent measures arthropod...
Abundances of forest birds in an unfragmented, undisturbed, and relatively mature temperate deciduous at the Hubbard Brook Experimental Forest, New Hampshire, changed markedly between 1969 1998. Total numbers (all species combined) declined from 210–220 individuals/10 ha early 1970s to 70–90/10 1990s. Of 24 regularly occurring species, 12 decreased significantly (four local extinction), three increased significantly, nine remained constant abundance. Nine declining were Neotropical migrants....
Summary 1. Food availability has been considered one of the most important factors limiting bird populations, yet effects food abundance on non‐breeding insectivores rarely investigated. We studied body condition ovenbirds ( Seiurus aurocapillus L.), a sexually monomorphic, ground‐foraging, Neotropical–Nearctic migrant warbler during two winters in three habitats their wintering grounds Jamaica. 2. Prey biomass decreased from early to late winter all habitats. Concurrently, ovenbird mass,...
An importance of eastern chipmunks (Tamias striatus) and red squirrels (Tamiasciurus hudsonicus) as avian nest predators was examined by monitoring predation on quail-egg-baited artificial nests six experimental plots, from which the two were removed, paired with control plots. Nests placed 50 m apart at densities 16 per 2.25 ha. The number depredated each plot differed significantly for treatment, but did not differ between removal We attribute latter finding to combined effects...
We studied a population of Black-throated Blue Warblers (Dendroica caerules-cens) in the White Mountains central New Hampshire to determine reproductive performance this Neotropical migrant species an unfragmented north-temperate forest. Over four-year period (1986-1989), female laid average 6.6 eggs per season which 5.2 hatched and 4.3 fledged. This high annual production due combination overall nesting success (63%), low nest depredation rates (22%), no brood parasitism, and, most...
As a population, Cocos Finches exhibit broad range of feeding behaviors spanning those several families birds on the mainland, while individuals feed as specialists year-round. Although this extreme intraspecific variability occurs predicted in tropical oceanic island environment, these specializations challenge contemporary ecological theory that they are not attributable to individual differences age, sex, gross morphology, or opportunistic exploitation patchy resources. Instead, appear...
Abstract: As tropical forests are cleared, a greater proportion of migratory songbirds forced to winter in agricultural and disturbed habitats, which, if poorer quality than natural forests, could contribute population declines. We compared demographic indicators habitat for focal species, the American Redstart ( Setophaga ruticilla ), wintering Jamaican citrus orchards shade coffee plantations with those four habitats: mangrove, coastal scrub, palm, dry limestone forests. Demographic...
We studied the ecology and behavior of American Redstarts (Setophaga ruticilla) Black-throated Blue Warblers (Dendroica caerulescens) on their wintering grounds in Jamaica during 3 years, 1986-1989. Winter densities were comparable to (American Redstart) or slightly greater than (Black-throated Warbler) those recorded for these species breeding areas. Males, females, first-year older individuals each occurred within same habitats study areas, with no evidence intraspecific habitat...
Many tropical habitats experience pronounced dry seasons, during which arthropod food availability declines, potentially limiting resident and migratory animal populations. In response to declines in food, individuals may attempt alter their space use enhance access resources, but be socially constrained from doing so by con- heterospecifics. If social constraints exist, should result decreased body condition. birds, correlational evidence suggests a link between condition migration timing....
This study compares and contrasts diets, based on 2834 prey individuals from 126 stomachs, of 16 insectivorous, aerially foraging Neotropical flycatcher species (Tyrannidae) that are seasonally sympatric in the humid Caribbean lowlands Costa Rica. Dietary parameters examined type, diversity (breadth) types, heterogeneity types among a species, "patchiness" morphologically indistinguishable within individual number items per stomach. An R—type factor analysis taxa flycatchers' stomachs...
To test whether male American Redstarts (Setophaga ruticilla) excluded conspe3;2; cifics from selected habitats on their wintering grounds, we removed territorial individuals four replicate sites in two different Jamaica, West Indies, and recorded territory shifts new colonizations of the vacated areas. In total, 12 (nine after-hatch-year [AHY] or older males, yearling [HY] one female) were removed, territories re-occupied by 18 neighboring newly-ap3;2; pearing redstarts (five AHY HY males...
Abstract: Since 1960, most of the forest surrounding La Selva Biological Station, an intensively studied tropical research facility in Costa Rica, has been converted to agricultural uses. We used quantitative censuses and analysis previously published categorical abundances assess changes bird community, we evaluated potential causes species‐specific by assessing their association with habitat, diet, participation mixed‐species flocks, nest type. Approximately same percentage species...
Our understanding of when natural populations are regulated during their annual cycle is limited, particularly for migratory species. This information needed parametrizing models that can inform management and conservation. Here, we use 14 years data on colour-marked birds to investigate how conspecific density habitat quality the tropical non-breeding period interact affect body condition apparent survival a long-distance songbird, American redstart (Setophagaruticilla). Body in...
Abstract Insectivorous birds reach their highest diversity in the tropics and represent a striking variety of morphological behavioral specializations for foraging, yet explanations these patterns are inadequate because both our limited understanding drivers ecological diversification within among clades coexistence mechanisms particular. Here we synthesize recent information on Neotropical insectivorous birds, including diversity, evolutionary ages locations origin, phylogenies, competitive...