scholarly journals Foraging strategy of the asteroid Leptasterias polaris: role of prey odors, current and feeding status

1994 ◽  
Vol 106 ◽  
pp. 93-100 ◽  
Author(s):  
R Rochette ◽  
J-F Hamel ◽  
JH Himmelman
Paleobiology ◽  
1978 ◽  
Vol 4 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Jennifer A. Kitchell ◽  
James F. Kitchell ◽  
G. Leonard Johnson ◽  
Kenneth L. Hunkins

The megafauna and associated behavioral traces of two deep-sea benthic environments, the central Arctic and Antarctic, with a surface primary productivity differential of 104 were compared to assess the role of food availability in foraging strategy and community structure. Bottom photographs, analyzed for megafauna and trace density and diversity at comparable depths in the Arctic Canada Basin and the Antarctic Bellingshausen Basin, indicated that trace frequency was inversely proportional to organism density but that trace diversity directly reflected organism diversity. Those traces identified in the fossil record to represent efficient foraging strategies, i.e., the Nereites facies, were conspicuously absent at all depths in the Arctic and present at all depths in the Antarctic, in contradiction of the paradigm of increasing behavioral complexity and sediment exploitation as food availability decreases. Presence or absence of surface-grazing organisms seems to exert a greater influence on trace diversity than depth or nutrient supply. Trace density, however, may reflect episodic sedimentation events which intermittently influence the deep-sea trophic regime.


2017 ◽  
Vol 51 (6) ◽  
pp. 509-516
Author(s):  
T. A. Kirikova

Abstract The feeding on aquatic invertebrates, intensity and efficiency of forage intake were studied at the Sivash lagoons in 1995–2002 by the example of 6 wader species (217 birds). The diet composition significantly varied from seeds of plants to different species of aquatic and soil organisms. The diet at Eastern Sivash was based on Polychaeta, at Central Sivash — on Crustacea and chironomid larvae (Insecta). Foraging intensity depended on the abundance of main prey and the size of prey items taken. We distinguished the studied wader species as “probers” and “gatherers” of forage. The highest foraging intensity among “probers” and “gatherers” were observed at the Sivash lagoons in feeding sites with a high number of chironomid larvae, and the lowest one — in feeding sites with a polychaeta worm Hediste diversicolor. The wader foraging intensity was associated with high density and availability of prey items: at Central Sivash — chironomid larvae and brine shrimps (Artemia salina), at Eastern Sivash — chironomid larvae and polychaetes. Results of the stomach analysis and obtained correlations indicate a determinative role of polychaetes, molluscs, brine shrimps and chironomids in the foraging behaviour and distribution of the studied species of waders at migratory stopovers of the Azov-Black Sea Region.


2020 ◽  
Vol 287 (1918) ◽  
pp. 20191775 ◽  
Author(s):  
Francesco Ventura ◽  
José Pedro Granadeiro ◽  
Oliver Padget ◽  
Paulo Catry

Seabirds must often travel vast distances to exploit heterogeneously distributed oceanic resources, but how routes and destinations of foraging trips are optimized remains poorly understood. Among the seabirds, gadfly petrels ( Pterodroma spp.) are supremely adapted for making efficient use of wind energy in dynamic soaring flight. We used GPS tracking data to investigate the role of wind in the flight behaviour and foraging strategy of the Desertas petrel, Pterodroma deserta . We found that rather than visiting foraging hotspots, Desertas petrels maximize prey encounter by covering some of the longest distances known in any animal in a single foraging trip (up to 12 000 km) over deep, pelagic waters. Petrels flew with consistent crosswind (relative wind angle 60°), close to that which maximizes their groundspeed. By combining state–space modelling with a series of comparisons to simulated foraging trips (reshuffled-random, rotated, time-shifted, reversed), we show that this resulted in trajectories that were close to the fastest possible, given the location and time. This wind use is thus consistent both with birds using current winds to fine-tune their routes and, impressively, with an a priori knowledge of predictable regional-scale wind regimes, facilitating efficient flight over great distances before returning to the home colony.


Author(s):  
Luis Alfaro ◽  
Federico Sanabria ◽  
Rosalva Cabrera

The distribution of foraging strategies and associated activities of Wistar rats was examined, with food outcomes presented in small vs. large units. Groups of 4 rats foraged for food in a 4 x 3 array of covered holes, some containing 4 g of food. For some groups, food consisted of shelled sunflower seeds (small units); for other groups, food consisted of 3 pellets of chow (large units). Foraging strategies were classified as either production (seeking patches with food) or scrounging (tracking conspecifics). Production strategies were more common among groups that foraged for pellets instead of seeds. Producing food was highly correlated with contacting gates covering holes, whereas scrounging for food was highly correlated with following others in the group. The prevalence of activities associated with each foraging strategy was highly correlated with the proportion of time spent consuming food obtained from each activity (i.e., produced vs. scrounged food). Taken together, these findings suggest that, similar to other species, the finder’s advantage (low with small units, high with large units) modulates social foraging strategies in rats. A simple outcome-strategy feedback mechanism appears to mediate this modulation.


JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.


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