scholarly journals Nutrient balance affects foraging behaviour of a trap-building predator

2009 ◽  
Vol 5 (6) ◽  
pp. 735-738 ◽  
Author(s):  
David Mayntz ◽  
Søren Toft ◽  
Fritz Vollrath
Keyword(s):  
Foraging Behaviour ◽  
Prey Capture ◽  
Prey Availability ◽  
Capture Rate ◽  
Nutrient Balance ◽  
Nutrient Composition ◽  
Web Architecture ◽  
First Instar ◽  
Predator Foraging ◽  
Web Building

Predator foraging may be affected by previous prey capture, but it is unknown how nutrient balance affects foraging behaviour. Here, we use a trap-building predator to test whether nutrients from previous prey captures affect foraging behaviour. We fed orb-weaving spiders ( Zygiella x-notata ) prey flies of different nutrient composition and in different amounts during their first instar and measured the subsequent frequency of web building and aspects of web architecture. We found that both the likelihood of web building and the number of radii in the web were affected by prey nutrient composition while prey availability affected capture area and mesh height. Our results show that both the balance of nutrients in captured prey and the previous capture rate may affect future foraging behaviour of predators.

An experimental analysis of prey availability for sanderlings (Aves: Scolopacidae) feeding on sandy beach crustaceans

1980 ◽  
Vol 58 (9) ◽  
pp. 1564-1574 ◽  
Author(s):  
J. P. Myers ◽  
S. L. Williams ◽  
F. A. Pitelka
Keyword(s):  
Prey Density ◽  
Prey Capture ◽  
Prey Size ◽  
Prey Availability ◽  
Capture Rate ◽  
Search Time ◽  
Beach Sand ◽  
Sand Surface ◽  
Prey Capture Rate ◽  
Bodega Bay

We investigated the role of prey size, prey depth, prey microdistribution, and substrate penetrability in affecting prey availability to sanderlings (Calidris alba Pallas). Five experiments were performed in the laboratory manipulating these availability factors and prey density in beach sand. The effects on prey risk and sanderling prey capture rate were measured.Prey risk increased linearly with prey size. Prey within 10 mm of the surface were vulnerable to predation but their risk decreased sharply below that depth. Substrate penetrability affected prey risk by controlling how deeply a sanderling could probe beneath the sand surface while searching for prey.Prey capture rates varied between 0.01 and 0.84 captures per second of search time over a range of prey density between 60 and 1200 prey per square metre. Prey size and substrate penetrability affected capture rate through their effect on prey risk, and substrate penetrability also influenced capture rate directly. Prey density had the strongest effect on prey capture rate. Measurements in the field around Bodega Bay, California, indicate that prey density, prey size, prey depth, and substrate penetrability can have significant impact on sanderling foraging under field conditions.

scholarly journals A comparison of morphology and web geometry between hypogean and epigean species of Metellina orb spiders (family Tetragnathidae)

2019 ◽  
Vol 32 ◽  
pp. 1-13 ◽  
Author(s):  
Thomas Hesselberg ◽  
Daniel Simonsen
Keyword(s):  
Life Style ◽  
Foraging Behaviour ◽  
Behavioural Flexibility ◽  
Permanent Record ◽  
Behavioural Adaptation ◽  
Web Geometry ◽  
Web Building

Studies on the behaviour of subterranean animals are rare, mainly due to the problems with collecting data in these inaccessible habitats. Web-building cave spiders, however, leave a semi-permanent record of their foraging behaviour, which can relatively easily be recorded. In this study, we compare size, leg lengths and web characteristics between hypogean populations of Metellina merianae with its close wood-inhabiting relative M. mengei. We confirm previous observations that M. merianae does not show any obvious morphological and behavioural adaptions to a subterranean life-style, although individuals of the cave species were significantly larger and had webs with relatively fewer radii and capture spiral turns than M. mengei. We were, however, not able to determine if these findings indicate a transition towards behavioural adaptation to caves or if they are a result of behavioural flexibility in response to the different humidity and temperature between caves and woodland. Finally, we did not find any effect of cave characteristics on either the number of radii or the area of the M. merianae web.

An Experimental Analysis of Macrophyte Growth Forms as Fish Foraging Habitat

1991 ◽  
Vol 48 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Michele Dionne ◽  
Carol L. Folt
Keyword(s):  
Plant Growth ◽  
Growth Form ◽  
Plant Density ◽  
Prey Capture ◽  
Capture Rate ◽  
Habitat Associations ◽  
Growth Forms ◽  
Plant Growth Form ◽  
Macrophyte Growth ◽  
Capture Rates

In this laboratory study we measured the independent effects of macrophyte growth form, plant density, and prey abundance on the foraging rate of the pumpkinseed sunfish (Lepomis gibbosus). We demonstrate that macrophyte growth forms are not all similar in their effects on fish foraging. Prey capture rates of pumpkinseeds foraging among Scirpus validus (cylindrical stems) were 53 and 365% times greater than for Potamogeton amplifolius (leafy stems) for cladoceran (Sida crystallina) and larval damselfly (Coenagrionidae) prey, respectively. Plant growth form influenced prey capture rates more than charges in natural plant density. Plant density effects ranged from none on damselfly capture rates to a 29% decline in cladoceran capture rate over a twofold increase in plant density. Our results indicate that in plant-structured habitats, variation in plant growth form can be an important determinant of fish foraging and habitat associations.

Behavioral Energetics of Overwintering in the Rifleman, Acanthisitta-Chloris

1991 ◽  
Vol 39 (6) ◽  
pp. 643 ◽  
Author(s):  
A Lill
Keyword(s):  
Population Density ◽  
Prey Capture ◽  
Activity Rhythm ◽  
Capture Rate ◽  
Microhabitat Use ◽  
Lowland Forest ◽  
Time Activity ◽  
Ambient Temperatures ◽  
Prey Capture Rate ◽  
Autumn And Winter

The role of behavioural adjustments in meeting increased daily energy requirements in winter was investigated in rifleman, Acanthisitta chloris, inhabiting lowland forest in South I., New Zealand, by comparing their population density, time-activity budget and foraging behaviour in autumn and winter. Rifleman foraged for 83% of daytime in both seasons. The combined effects on the birds' winter energy budget of increased thermoregulation costs and the shorter daylength for foraging were at least partly offset by an estimated 23-29% decrease in the amount of energy expended daily on activity and a 78% increment in prey caught per day. The reduced energy expenditure on activity resulted from rifleman spending less time on expensive flying and more time roosting. The increase in prey capture rate may have stemmed from a 35% seasonal reduction in the birds' population density and reduced prey mobility at lower ambient temperatures. Marked sexual size dimorphism was not reflected in gender differences in activity budgeting or prey capture rate, but the sexes differed in their relative use of foraging substrates. Rifleman showed few seasonal changes in daily activity rhythm or microhabitat use. The behavioural energetic overwintering tactics of rifleman are compared with those of other Australasian and north temperate zone land-birds.

Foraging patterns of Antarctic minke whales in McMurdo Sound, Ross Sea

2020 ◽  
Vol 32 (6) ◽  
pp. 454-465
Author(s):  
David G. Ainley ◽  
Trevor W. Joyce ◽  
Ben Saenz ◽  
Robert L. Pitman ◽  
John W. Durban ◽  
...  
Keyword(s):  
Foraging Behaviour ◽  
Ross Sea ◽  
Prey Availability ◽  
Dive Depth ◽  
Remotely Operated Vehicle ◽  
Mcmurdo Sound ◽  
Minke Whales ◽  
Fast Ice ◽  
Antarctic Silverfish ◽  
Ice Edge

AbstractEvidence indicates that Antarctic minke whales (AMWs) in the Ross Sea affect the foraging behaviour, especially diet, of sympatric Adélie penguins (ADPEs) by, we hypothesize, influencing the availability of prey they have in common, mainly crystal krill. To further investigate this interaction, we undertook a study in McMurdo Sound during 2012–2013 and 2014–2015 using telemetry and biologging of whales and penguins, shore-based observations and quantification of the preyscape. The 3D distribution and density of prey were assessed using a remotely operated vehicle deployed along and to the interior of the fast-ice edge where AMWs and ADPEs focused their foraging. Acoustic surveys of prey and foraging behaviour of predators indicate that prey remained abundant under the fast ice, becoming successively available to air-breathing predators only as the fast ice retreated. Over both seasons, the ADPE diet included less krill and more Antarctic silverfish once AMWs became abundant, but the penguins' foraging behaviour (i.e. time spent foraging, dive depth, distance from colony) did not change. In addition, over time, krill abundance decreased in the upper water column near the ice edge, consistent with the hypothesis (and previously gathered information) that AMW and ADPE foraging contributed to an alteration of prey availability.

scholarly journals Large-scale climatic anomalies affect marine predator foraging behaviour and demography

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Charles A. Bost ◽  
Cedric Cotté ◽  
Pascal Terray ◽  
Christophe Barbraud ◽  
Cécile Bon ◽  
...  
Keyword(s):  
Large Scale ◽  
Foraging Behaviour ◽  
Marine Predator ◽  
Predator Foraging

scholarly journals Foraging behaviour by gray wolves on salmon streams in coastal British Columbia

2003 ◽  
Vol 81 (2) ◽  
pp. 349-353 ◽  
Author(s):  
C T Darimont ◽  
T E Reimchen ◽  
P C Paquet
Keyword(s):  
British Columbia ◽  
Foraging Behaviour ◽  
Foraging Ecology ◽  
Capture Rate ◽  
Indirect Evidence ◽  
Terrestrial Ecosystems ◽  
Gray Wolves ◽  
History Of ◽  
The Relationship ◽  
Coastal British Columbia

Spawning salmon (Oncorhynchus spp.) are important resources for terrestrial ecosystems and often shape the ecological strategies of organisms with which they co-evolve. Gray wolves (Canis lupus), primarily predators of ungulates, are sympatric with salmon over large areas, but the relationship between the two remains poorly understood. We report here observations of direct and indirect evidence of salmon predation by wolves in several watersheds of coastal British Columbia and in detail report on the foraging behaviour of four wolves at one river during September and October 2001. Wolves oriented themselves upstream during detection and pursuit of salmon. The pooled mean capture rate was 21.5 salmon/h and mean efficiency (successes/attempt) was 39.4%. In most cases, wolves consumed only heads of salmon, perhaps for nutritional reasons or parasite avoidance. Preying on salmon may be adaptive, as this nutritious and spatially constrained resource imposes lower risks of injury compared with hunting large mammals. We infer from capture rates and efficiencies, as well as stereotypical hunting and feeding behaviour, a history of salmon predation by wolves and, as a corollary, a broad distribution of this foraging ecology where wolves and salmon still co-exist.

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