scholarly journals Diet and Foraging Range of Slender-Billed Gulls Chroicocephalus genei Breeding in the Saloum Delta, Senegal

Ardea ◽  
2019 ◽  
Vol 107 (1) ◽  
pp. 33 ◽  
Author(s):  
Jan Veen ◽  
Hanneke Dallmeijer ◽  
Almut E. Schlaich ◽  
Thor Veen ◽  
Wim C. Mullié
Keyword(s):  
Foraging Range

scholarly journals Foraging niche partitioning in sympatric seabird populations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christina Petalas ◽  
Thomas Lazarus ◽  
Raphael A. Lavoie ◽  
Kyle H. Elliott ◽  
Mélanie F. Guigueno
Keyword(s):  
Interspecific Competition ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Sympatric Species ◽  
Foraging Strategies ◽  
Gps Tracking ◽  
Seabird Species ◽  
Foraging Range ◽  
Common Murre ◽  
Prey Items

AbstractSympatric species must sufficiently differentiate aspects of their ecological niche to alleviate complete interspecific competition and stably coexist within the same area. Seabirds provide a unique opportunity to understand patterns of niche segregation among coexisting species because they form large multi-species colonies of breeding aggregations with seemingly overlapping diets and foraging areas. Recent biologging tools have revealed that colonial seabirds can differentiate components of their foraging strategies. Specifically, small, diving birds with high wing-loading may have small foraging radii compared with larger or non-diving birds. In the Gulf of St-Lawrence in Canada, we investigated whether and how niche differentiation occurs in four incubating seabird species breeding sympatrically using GPS-tracking and direct field observations of prey items carried by adults to chicks: the Atlantic puffin (Fratercula arctica), razorbill (Alca torda), common murre (Uria aalge), and black-legged kittiwake (Rissa tridactyla). Although there was overlap at foraging hotspots, all species differentiated in either diet (prey species, size and number) or foraging range. Whereas puffins and razorbills consumed multiple smaller prey items that were readily available closer to the colony, murres selected larger more diverse prey that were accessible due to their deeper diving capability. Kittiwakes compensated for their surface foraging by having a large foraging range, including foraging largely at a specific distant hotspot. These foraging habitat specialisations may alleviate high interspecific competition allowing for their coexistence, providing insight on multispecies colonial living.

scholarly journals Relation between size and foraging range in stingless bees (Apidae, Meliponinae)

Apidologie ◽  
1996 ◽  
Vol 27 (4) ◽  
pp. 219-228 ◽  
Author(s):  
M. G.L. van Nieuwstadt ◽  
C. E. Ruano Iraheta
Keyword(s):  
Stingless Bees ◽  
Foraging Range

scholarly journals Colony Choice in Cliff Swallows: Effects of Heterogeneity in Foraging Habitat

The Auk ◽  
2002 ◽  
Vol 119 (2) ◽  
pp. 446-460 ◽  
Author(s):  
Charles R. Brown ◽  
Christine M. Sas ◽  
Mary Bomberger Brown
Keyword(s):  
Land Use ◽  
Species Diversity ◽  
Plant Species ◽  
Food Availability ◽  
Colony Size ◽  
Plant Species Diversity ◽  
Foraging Range ◽  
Nesting Site ◽  
Site Use ◽  
A Site

Abstract One potential determinant of colony size in birds is the local availability of food near a nesting site. Insectivorous Cliff Swallows (Petrochelidon pyrrhonota) in southwestern Nebraska nest in colonies ranging from 2 to over 3,000 nests, but they feed on so many kinds of insects that direct sampling of food resources is impractical. Instead, we investigated the degree to which swallow colony size was correlated with the extent of different habitat types, land use diversity, and plant species diversity in the colony's foraging range, and used those parameters as indices of potential variation among sites in food availability. Amount of flowing and standing water in the foraging range was a significant predictor of mean colony size across years at a site, with larger colonies associated with more water. The same result held for most years when analyzed separately. The extent of flowing water in the foraging range also was a significant predictor of the frequency with which a site was occupied across years. In addition, univariate tests suggested that the amount of cultivated cropland in the foraging range varied inversely with colony size. Land use diversity, as measured by Simpson's index, increased significantly with colony size, and all of the sites with perennially very large colonies (mean colony size >1,000 nests) were associated with foraging ranges of relatively high land use diversity. Repeatability of colony size across years differed significantly from zero across all sites, but repeatabilities were significantly lower (colony sizes less similar between years) for sites situated in low-diversity habitats and for sites used less often. There was no strong effect of plant species diversity within the foraging range on either colony size at a site or likelihood of site use. We conclude that land use diversity per se (and possibly the extent of water near a site) might influence insect distribution and constrain formation of the larger colonies to certain sites. These findings emphasize that colony choice in Cliff Swallows is complex, reflecting both the socially mediated costs and benefits of group size that vary among individuals and the effects of habitat heterogeneity that may influence food availability at some sites.

scholarly journals The earliest evidence for a supraorbital salt gland in dinosaurs in new Early Cretaceous ornithurines

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Xia Wang ◽  
Jiandong Huang ◽  
Yuanchao Hu ◽  
Xiaoyu Liu ◽  
Jennifer Peteya ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
High Salinity ◽  
Salt Gland ◽  
Salt Glands ◽  
Apparent Absence ◽  
Jehol Biota ◽  
Marine Birds ◽  
Gland Size ◽  
Foraging Range

AbstractSupraorbital fossae occur when salt glands are well developed, a condition most pronounced in marine and desert-dwelling taxa in which salt regulation is key. Here, we report the first specimens from lacustrine environments of the Jehol Biota that preserve a distinct fossa above the orbit, where the salt gland fossa is positioned in living birds. The Early Cretaceous ornithurine bird specimens reported here are about 40 million years older than previously reported Late Cretaceous marine birds and represent the earliest described occurrence of the fossa. We find no evidence of avian salt gland fossae in phylogenetically earlier stem birds or non-avialan dinosaurs, even in those argued to be predominantly marine or desert dwelling. The apparent absence of this feature in more basal dinosaurs may indicate that it is only after miniaturization close to the origin of flight that excretory mechanisms were favored over exclusively renal mechanisms of salt regulation resulting in an increase in gland size leaving a bony trace. The ecology of ornithurine birds is more diverse than in other stem birds and may have included seasonal shifts in foraging range, or, the environments of some of the Jehol lakes may have included more pronounced periods of high salinity.

Modeling foraging range for breeding colonies of thick-billed murres Uria lomvia in the Eastern Canadian Arctic and potential overlap with industrial development

2013 ◽  
Vol 168 ◽  
pp. 134-143 ◽  
Author(s):  
Anthony J. Gaston ◽  
Kyle H. Elliott ◽  
Yan Ropert-Coudert ◽  
Akiko Kato ◽  
Christie A. Macdonald ◽  
...  
Keyword(s):  
Industrial Development ◽  
Canadian Arctic ◽  
Uria Lomvia ◽  
Foraging Range ◽  
Eastern Canadian Arctic

Foraging range in mice and voles: the role of risk

1986 ◽  
Vol 64 (12) ◽  
pp. 2645-2653 ◽  
Author(s):  
Paul K. Anderson
Keyword(s):  
Risk Assessment ◽  
Deer Mice ◽  
Lake Surface ◽  
Supplementary Food ◽  
Foraging Range ◽  
Time Minimization ◽  
Energy Maximization ◽  
Fourth Experiment ◽  
Foraging Ranges

The significance of risk assessment in determining the boundaries of foraging ranges of deer mice and voles was examined by comparing the distances to which resident animals were willing to follow shifting feeding stations providing equal rewards beyond their previous foraging ranges in an area with abundant cover (forest), and in one where cover was lacking (frozen lake surface). Previous foraging ranges were estimated on the basis of livetrapping and the "rediscovery distances" for the moving stations. In three experiments the distance at which animals stopped visiting the stations ("giving-up distance") averaged 3.3 times farther where cover was abundant (forest) than where it was absent (lake). In a fourth experiment, reduction of supplementary food available within the original ranges extended the giving-up distance where cover was present but had relatively little effect on giving-up distance and almost no effect on rediscovery distance where cover was absent. Supplying cover more than tripled giving-up distances on the lake. The distance at which boxes were visited was affected by snowfall, ambient temperature, food supply, and availability of cover. Results emphasize the importance of risk assessment in defining foraging range, and suggest that hoarding permits choice among energy maximization and time minimization strategies.

scholarly journals Long-distance pollen flow assessment through evaluation of pollinator foraging range suggests transgene escape distances

2008 ◽  
Vol 105 (36) ◽  
pp. 13456-13461 ◽  
Author(s):  
R. S. Pasquet ◽  
A. Peltier ◽  
M. B. Hufford ◽  
E. Oudin ◽  
J. Saulnier ◽  
...  
Keyword(s):  
Pollen Flow ◽  
Long Distance ◽  
Foraging Range ◽  
Transgene Escape

scholarly journals How slow breeding can be selected in seabirds: testing Lack's hypothesis

2006 ◽  
Vol 274 (1607) ◽  
pp. 275-279 ◽  
Author(s):  
F. Stephen Dobson ◽  
Pierre Jouventin
Keyword(s):  
Body Size ◽  
Strongly Correlated ◽  
Individual Selection ◽  
Ecological Constraints ◽  
Foraging Range ◽  
Reproductive Rates ◽  
The 1960S ◽  
David Lack

The historical debate of the 1960s between group and individual selection hinged on how the slow breeding of seabirds could be explained. While this debate was settled by the ascendance of individual selection, championed by David Lack, explanations for slow breeding in seabirds remain to be tested. We examined the slowest breeding of these birds, the albatrosses and petrels (order Procellariiformes), using analyses that statistically controlled for variations in body size and phylogeny. Incubation and fledging periods appeared strongly correlated, but this turned out to be largely explained by phylogeny. Nonetheless, developmental and reproductive rates were associated with the distance to the foraging range, as predicted under the hypothesis of ecological constraints on breeding pairs, and these results were independent of body size and phylogeny. Slower breeding in these seabirds appeared associated with the rigors of farther pelagic feeding, as Lack originally hypothesized.

scholarly journals Ranging behaviour of Cape Vultures Gyps coprotheres from an endangered population in Namibia

2007 ◽  
Vol 17 (4) ◽  
pp. 331-339 ◽  
Author(s):  
Andrew J. Bamford ◽  
Maria Diekmann ◽  
Ara Monadjem ◽  
John Mendelsohn
Keyword(s):  
Breeding Population ◽  
Intensive Management ◽  
Adult Males ◽  
Wild Ungulates ◽  
Feeding Sites ◽  
Foraging Range ◽  
Ranging Behaviour ◽  
Nesting Behaviour ◽  
Endangered Population ◽  
Tracking Devices

AbstractThe Cape Vulture (Gyps coprotheres) is an obligate cliff-nesting vulture endemic to southern Africa. Its range and population size have declined markedly over the last century. Namibia has just one colony, located on the cliffs of the Waterberg Plateau, with a population estimated to be eight adult birds, including two females. The species is regarded as Critically Endangered in Namibia, and establishing a secure breeding population may require intensive management. Data on movements, foraging range and behaviour of Cape Vultures, important in any management programme, have been lacking. Five adult males and one immature were captured near the Waterberg site and fitted with satellite-tracking devices. Only two of the adult vultures still roosted on the cliffs and only one of those exclusively; the other individuals roosted in trees. Three individuals were observed building and attending to nests in trees, and, for one of these, the partner was identified as an African White-backed Vulture (Gyps africanus). The foraging range of the adult birds was large compared with other studies of this species. Most foraging took place on freehold farms. All adults avoided areas of communally owned land where wild ungulates are uncommon, thus further decreasing their potentially available food supply. Two ‘vulture restaurants’, feeding sites specifically for vultures, within the foraging range of the adult birds accounted for a large proportion of their time spent on the ground. The ranging behaviour of adult vultures varied throughout the year, and was apparently related to their nesting behaviour.

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