The Importance of Nocturnal Foraging in Shorebirds: A Consequence of Increased Invertebrate Prey Activity

Author(s):  
P. J. Dugan
2001 ◽  
Vol 39 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Adrian Hailey ◽  
Ian M. Coulson ◽  
Tarombera Mwabvu

Ethology ◽  
2021 ◽  
Author(s):  
Jay K. Goldberg ◽  
Genevieve Pintel ◽  
Jake A. Pruett ◽  
Stacey L. Weiss

2005 ◽  
Vol 83 (9) ◽  
pp. 1240-1245 ◽  
Author(s):  
Iain J Stenhouse ◽  
H Grant Gilchrist ◽  
William A Montevecchi

The selection of breeding habitat is of prime importance for individual fitness. Among birds, natural selection should favour the ability to recognize and select habitat suitable for nesting and rearing chicks. This study compares the characteristics of Sabine's Gull, Xema sabini (Sabine, 1819), nest sites with random points across a coastal tundra environment on Southampton Island, Nunavut, Canada. The availability of terrestrial invertebrate prey was also examined among habitats. Sabine's Gull nests were nonrandomly distributed in relation to vegetation, substrate, and proximity to water. Gulls nested within approximately 1 km of the coastline and selected sites with the greatest proportions of moss and standing water (i.e., they nested close to the edge of small freshwater ponds near shore). However, there were no detectable differences in characteristics between successful and unsuccessful nests within preferred habitat. The dynamics of terrestrial invertebrate prey communities varied between years, but the volume of invertebrates in Sabine's Gull nesting habitat was intermediate between the most productive habitats and the least productive habitats in both years. However, nest-site selection in Sabine's Gulls may also be influenced by the availability of aquatic invertebrates (not examined in this study) and their proximity to the marine coastline, where chicks are taken to be reared.


1990 ◽  
Vol 47 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Molly O. Ahlgren

The ash-free dry mass (AFDM) of detritus, invertebrates, and algae in the diet of juvenile white sucker (Catostomus commersoni) was determined by quantitative microscopy. Fish were collected from a northern Michigan pond from January through October 1986 and their seasonal diet was compared with benthc invertebrate abundance. The quantity of detritus in sucker foreguts was inversely related to benthic microcrustacean densities. In July, microcrustacean densities were high and they comprised 95% of the AFDM in foregut contents. By October, microcrustacean densities had declined to 13% of their maximum density and detritus comprised over 90% of the sucker's diet AFDM. In laboratory aquaria, sucker that were fed detritus mixed with four different densities of Artemia ingested significantly more detritus from diets that provided lower Artemia densities. In the presence of high Artemia densities, sucker completely rejected detritus and ingested only Artemia, The fact that juvenile sucker can separate detritus from invertebrates that they swallow demonstrates that detritus is not ingested incidentally. Both laboratory and field data support the hypothesis that detritus is ingested intentionally when preferred invertebrate prey are scarce.


2017 ◽  
Vol 67 (3-4) ◽  
pp. 287-300 ◽  
Author(s):  
María I. Deserti ◽  
Karina S. Esquius ◽  
Alicia H. Escalante ◽  
Fabián H. Acuña

Hydra is a genus of common, sessile, solitary freshwater cnidarians, which are defined as carnivorous and efficient predators. The purpose of this study was to obtain information on the feeding habits and diet of Hydra vulgaris collected from its natural habitat in Nahuel Rucá Lake (Buenos Aires Province, Argentina). We found three categories of food items in the coelenteron: algae, fungi, and small invertebrates. Algae dominated the diet in terms of abundance and frequency of occurrence, but their volumetric contribution was almost negligible, as was their possible nutritional value. Invertebrate prey captured, using active predation, represented the major volumetric contribution, with four different taxa found. The detection of phytoplankton in the gastral cavities reveals the input of some organisms present in the surrounding waters in addition to the invertebrates. This information is novel, since studies on the natural diet of Hydra are very scarce.


1989 ◽  
Vol 67 (8) ◽  
pp. 2008-2012 ◽  
Author(s):  
Joseph M. Culp

Diel periodicity in foraging activity of the longnose dace (Rhinichthys cataractae) was determined by measuring dace activity over the stream bed, gut fullness, and the digestive state of prey items. Although most species of minnows are either diurnally or crepuscularly active, dace began foraging within 1 h after sunset with light levels near 10 lx and ceased before sunrise throughout the ice-free period. During the day few prey were taken as the dace remained under the shelter of stones. This nocturnal foraging pattern did not appear to be affected by spawning or seasonal changes in prey composition. Nocturnal foraging in dace is not likely a response to prey availability, but may be a response to avoid diel periods when salmonid competitors or visual predators are active.


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