Topic
Elanus
About: Elanus is a research topic. Over the lifetime, 39 publications have been published within this topic receiving 544 citations.
Papers
TL;DR: Three niche dimensions seem to be important in determining the structure of the predator community: 1) hunting activity period, 2) hunting habitat (open, or both open and dense patches), and 3) mean prey size taken.
Abstract: The trophic ecology of eleven predator species (Falconiforms: Buteo polyosoma, Elanus leucurus, Falco sparverius, Geranoaetus melanoleucus, Parabuteo unicinctus; Strigiforms: Athene cunicularia, Bubo virginianus, Tyto alba; Carnivores: Dusicyon culpaeus; Snakes: Philodryas chamissonis, Tachymenis peruviana) in two nearby localities of central Chile is analyzed. The localities exhibit the typical climate (hot-dry summers, coldrainy winters), and vegetation (chaparral), of mediterranean ecosystems. Densities of the staple prey (small mammals) were estimated by seasonal trapping during two years in both open and dense patches of chaparral. The trophic parameters examined are: 1) proportion of diurnal, crepuscular, or nocturnal prey found in the predators' diet; 2) relationship between abundance of different mammalian prey in the predators' diet, and in both open and densely vegetated habitat patches; 3) mean weight and variance of weight of small mammal prey consumed; 4) average weight of the predators; 5) food-niche breadth of the predators; 6) relationship between average weight of predators and mean weight of mammalian prey taken, its variance, and food-niche breadth; 7) overlap in food-niche between all the predator species; 8) guild packing of the predators. Parameters 1) and 2) are used to assess the importance of temporal and habitat segregation of the predators, respectively; parameters 3), 4), 5), and 6) provide information on the possibilities of partitioning the prey resources among the predators; parameters 1), 2), 7) and 8) are used to investigate the organization of the community in terms of guilds. Three niche dimensions seem to be important in determining the structure of the predator community: 1) hunting activity period (diurno-crepuscular, nocturno-crepuscular), 2) hunting habitat (open, or both open and dense patches), and 3) mean prey size taken. Segregation along these three axes results in generally low food niche overlaps ( 90% in pair-wise comparisons) can be recognized: a) the carnivorous-insectivorous guild formed by the diurnal raptors A. cunicularia and F. sparverius, which tend to hunt in open habitat patches; b) the herpetophagous guild formed by the diurnal snakes P. chamissonis and T. peruviana, which presumably hunt in open habitat patches; c) the carnivorous guild (highly specialized in the capture of two rodent species) formed by the diurnal raptors B. polyosoma, G. melanoleucus, P. unicinctus, and the carnivore D. culpaeus, which hunt in open habitat patches. The diurnal raptor E. leucurus is not clearly associated with any guild, and the only two nocturnal raptors in the community (B. virginianus and T. alba) exhibit marked differences in their trophic ecology.
159 citations
36 citations
33 citations
TL;DR: The White-tailed Kite (Elanus leucurus) is a common resident of agricultural areas and coastal plains in Colombia, Venezuela, Surinam, Brazil and southern South America.
Abstract: The White-tailed Kite (Elanus leucurus) is a common resident of agricultural areas and coastal plains in Colombia, Venezuela, Surinam, Brazil and southern South America. In Chile, it is a conspicuous raptor, ranging from 300 to 400 S latitude (Johnson 1965). Although two subspecies are sometimes recognized, E. 1. leucurus and E. 1. majusculus (Eisenmann 1971), the appearance and behavior of the two forms are virtually indistinguishable. Much interest has centered on the White-tailed Kite in North America due
26 citations
TL;DR: This note compares annual changes in food habits of WhiteTailed Kites with measured changes in the density of California voles in fields over which the kites were hunting and found vole densities similar to those of the censused field.
Abstract: White-tailed Kites (Elanus leucurus) are obligate predators of diurnal small mammals (Waian and Stendell, Calif. Fish & Game 56:188, 1970). Brown and Amadon (Eagles, Hawks and Falcons of the World, vol. 1, Hamlyn House, Feltham, 414 p. 1968) indicate that movement and nesting of kites are governed to a considerable extent by concentrations of mice, usually voles. Throughout much of the kite's range in California, the vole (Microtus californicus) is the major prey species. Hawbecker (Condor 42:106, 1940) noted a correlation between the nesting of White-Tailed Kites and vole density and suggested that a high population of voles is necessary for successful nesting of kites. This note compares annual changes in food habits of WhiteTailed Kites with measured changes in the density of California voles in fields over which the kites were hunting. At Hastings Natural History Reservation in Monterey County, California, populations of small mammals have been censused during the summers of 1969, 1970, and 1971, by means of mark and recapture techniques. The Reservation is a mosaic of grassland, oak woodland, and chaparral. Microtus predominately utilize the grassland areas. Estimated vole densities are shown in table 1. Although only one field was censused accurately, search for runways and occasional trapping in all other suitable fields within a 2-mile radius of the kite roosting site indicated vole densities similar to those of the censused field. TABLE 2. Species composition (%) of prey in kite pellets, 1969-71.
22 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2020 | 1 |
| 2019 | 2 |
| 2018 | 2 |
| 2016 | 3 |
| 2014 | 2 |
| 2013 | 1 |