scholarly journals Density‐mediated indirect interactions alter host foraging behaviour of parasitoids without altering foraging efficiency

2016 ◽  
Vol 41 (5) ◽  
pp. 562-571 ◽  
Author(s):  
MARJOLEIN DE RIJK ◽  
XI ZHANG ◽  
JUULTJE A. H. VAN DER LOO ◽  
BAS ENGEL ◽  
MARCEL DICKE ◽  
...  
Keyword(s):  
Foraging Behaviour ◽  
Indirect Interactions ◽  
Foraging Efficiency ◽  
Host Foraging

scholarly journals Multiple-stage decisions in a marine central-place forager

2016 ◽  
Vol 3 (5) ◽  
pp. 160043 ◽  
Author(s):  
Ari S. Friedlaender ◽  
David W. Johnston ◽  
Reny B. Tyson ◽  
Amanda Kaltenberg ◽  
Jeremy A. Goldbogen ◽  
...  
Keyword(s):  
Foraging Behaviour ◽  
Central Place ◽  
Foraging Efficiency ◽  
Feeding Rates ◽  
Marine Animals ◽  
Air Breathing ◽  
Baleen Whales ◽  
Multi Stage ◽  
Central Place Forager ◽  
Prey Patches

Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator–prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies.

Foraging behaviour in East Asian desert rodents and its implications on coexistence

2016 ◽  
Vol 62 (3-4) ◽  
pp. 171-177 ◽  
Author(s):  
Ling-Ying Shuai ◽  
Yan-Ling Song ◽  
Burt P. Kotler ◽  
Keren Embar ◽  
Zhi-Gao Zeng
Keyword(s):  
Foraging Behaviour ◽  
Species Coexistence ◽  
Interspecific Interactions ◽  
Interference Competition ◽  
Foraging Efficiency ◽  
Gobi Desert ◽  
Patch Use ◽  
Desert Rodents ◽  
Daily Scale

We studied the foraging behaviour of two sympatric rodents (Meriones meridianus and Dipus sagitta) in the Gobi Desert, Northwestern China. The role of the foraging behaviour in promoting species coexistence was also examined. We used giving-up densities (GUDs) in artificial food patches to measure the patch use of rodents and video trapping to directly record the foraging behaviour, vigilance, and interspecific interactions. Three potential mechanisms of coexistence were evaluated (1) microhabitat partitioning; (2) spatial heterogeneity of resource abundance with a tradeoff in foraging efficiency vs. locomotion; and (3) temporal partitioning on a daily scale. Compared to M. meridianus, D. sagitta generally possessed lower GUDs, spent more time on patches, and conducted more visits per tray per capita, regardless of microhabitat. However, M. meridianus possessed advantages in average harvesting rates and direct interference against D. sagitta. Our results only partly support the third mechanism listed above. We propose another potential mechanism of coexistence: a tradeoff between interference competition and safety, with M. meridianus better at interference competition and D. sagitta better at avoiding predation risk. This mechanism is uncommon in previously studied desert rodent systems.

scholarly journals Possums in the park: efficient foraging under the risk of predation or of competition?

2000 ◽  
Vol 48 (2) ◽  
pp. 155 ◽  
Author(s):  
Eve McDonald-Madden ◽  
Lian K. Akers ◽  
Deena J. Brenner ◽  
Sarah Howell ◽  
Blair W. Patullo ◽  
...  
Keyword(s):  
Urban Population ◽  
Foraging Behaviour ◽  
Field Experiments ◽  
Foraging Efficiency ◽  
Trichosurus Vulpecula ◽  
Initial Amount ◽  
Trade Off ◽  
Food Items ◽  
Risk Of Predation

Many eutherian mammals adjust their foraging behaviour according to the presence or threat of predators. Here, we examine experimentally whether an urban population of brushtail possums, Trichosurus vulpecula, similarly adjust their foraging behaviour. Our field experiments manipulated the quantity of food items in artificial feeders placed at different distances from trees. These experiments showed that the possums remained longer at feeders placed far from the trees, but their foraging behaviour did not change with the initial amount of food. The scanning behaviour of possums did not simply increase with distance from the trees, as predicted from studies of other vertebrates. Nevertheless, the number of physical conflicts between individuals increased as the amount of available food decreased. These data suggest that the changes in the foraging behaviour of the possums in this population do not reflect a simple trade-off between foraging efficiency and the risk of predation or competition.

Foraging Behaviour and Memory Window in Sticklebacks

Behaviour ◽  
1995 ◽  
Vol 132 (15-16) ◽  
pp. 1241-1253 ◽  
Author(s):  
R.N. Hughes ◽  
P.A. Mackney
Keyword(s):  
Adaptive Response ◽  
Gasterosteus Aculeatus ◽  
Foraging Behaviour ◽  
Handling Time ◽  
Memory Window ◽  
Foraging Efficiency ◽  
Marine Population ◽  
Freshwater Population ◽  
Spinachia Spinachia ◽  
The Stability

AbstractIndividuals were collected from a residential marine population of Spinachia spinachia, an anadromous population of Gasterosteus aculeatus forma trachura and a residential freshwater population of G. aculeatus forma leiura. After maintenance for 2 months on a diet of mysid, individuals were subjected to ten, consecutive daily trials on a diet of amphipods or oligochaetes. During this period, individuals learned to handle the prey more effectively, as measured by attack efficiency, handling efficiency and handling time. Learning was similar among populations but differed between diets, being more pronounced for amphipods, which are more difficult to catch and handle than oligochaetes. Once trained to these diets, fish were tested for foraging efficiency after successively longer periods of stimulus deprivation, when they were fed a maintenance diet of mysid. All three measures of foraging efficiency with the amphipod diet, but only that based on handling time with the oligochacte diet, declined to naive levels in the residential marine and anadromous populations. No decrease in foraging efficiency with either diet occurred in the residential freshwater population. Memory window was 8 d, 10 d and > 25 d in the residential marine, anadromous and residential freshwater populations respectively. The large difference between the freshwater and two marine populations is interpreted as an adaptive response to the stability of arrays of prey, characteristic of their respective habitats.

Response to clear-cut logging by northern waterthrushes

2003 ◽  
Vol 33 (5) ◽  
pp. 755-762 ◽  
Author(s):  
Ian G Warkentin ◽  
Allison L Fisher ◽  
Stephen P Flemming ◽  
Shawn E Roberts
Keyword(s):  
Foraging Behaviour ◽  
Habitat Type ◽  
Riparian Buffer ◽  
Foraging Efficiency ◽  
Riparian Habitat ◽  
Buffer Strips ◽  
Clear Cut ◽  
Large Numbers ◽  
Riparian Buffer Strips ◽  
Treatment Interaction

We examined the distribution and foraging behaviour of northern waterthrushes (Seiurus noveboracensis) in recently harvested and intact landscapes of Newfoundland. Data were collected along six 1-km segments of stream and adjoining upland habitat resulting in four treatments (harvested or intact, upland or stream) with three replicates each. Although known as a riparian specialist, we found waterthrush territories equally distributed across intact upland and riparian habitats. However, few waterthrushes occupied harvested uplands, while large numbers packed into riparian buffer strips adjacent to these 5- to 10-year-old postharvest clearcuts. Arthropod abundance and biomass were highly variable between years and across the four treatments, generating significant year × treatment interaction effects. Riparian habitat (in both intact and harvested areas) had consistently greater numbers of arthropod prey and more biomass than either upland habitat type. Northern waterthrushes foraging in riparian habitat adjacent to harvested uplands had lower attack rates and more frequent long flights than waterthrushes foraging in the intact treatment types. Prolonged packing of individuals into riparian buffer strips, and apparent adverse affects on waterthrush foraging efficiency, raise concerns about the effectiveness of buffer strips for sustaining viable populations of terrestrial riparian habitat specialists.

Unravelling the function of dolphin leaps using the dusky dolphin (Lagenorhynchus obscurus) as a model species

Behaviour ◽  
2017 ◽  
Vol 154 (5) ◽  
pp. 563-581 ◽  
Author(s):  
Heidi C. Pearson
Keyword(s):  
Social Facilitation ◽  
Foraging Behaviour ◽  
Prey Capture ◽  
Foraging Efficiency ◽  
Lagenorhynchus Obscurus ◽  
The Social ◽  
Negative Effect ◽  
Dusky Dolphins ◽  
Dusky Dolphin ◽  
Positive Effect

The prevalence of leaping across delphinids indicates it has an adaptive benefit. I examined leaping behaviour in dusky dolphins (Lagenorhynchus obscurus) according to signalling, social facilitation, and prey capture hypotheses. I quantified the effect of leaping on group behaviour and fission-fusion and the behavioural context of leaping. I observed dolphins in Admiralty Bay, New Zealand during 171 focal follows totalling 157 h. Data were analysed using generalized estimating equations. Clean leaping had a positive effect on party fission () and foraging behaviour (). Coordinated leaping caused a short-term wane in foraging behaviour () and had a positive effect on party fusion (). Noisy leaping had a negative effect on perpetuating resting and traveling cessation (both ). The signalling hypothesis was the most strongly supported. The social facilitation and prey capture hypotheses were moderately supported. Leaping may provide adaptive benefits such as reduced scramble competition, increased foraging efficiency, and social bonding.

scholarly journals Foraging behaviour and the risk of predation in the black house spider, Badumna insignis (Desidae)

1999 ◽  
Vol 47 (1) ◽  
pp. 29 ◽  
Author(s):  
Robbie J. Henderson ◽  
Mark A. Elgar
Keyword(s):  
Foraging Behaviour ◽  
Foraging Efficiency ◽  
Foraging Success ◽  
Short Term ◽  
Risk Of Predation ◽  
House Spider ◽  
The Web ◽  
Model Predator

Many animals adjust their behaviour according to the presence or threat of predators. However, the foraging behaviour of sit-and-wait predators is typically thought to be inflexible to short-term changes in the environment. Here we investigate the foraging behaviour of the nocturnally active black house spider, Badumna insignis. Experiments in which different kinds of prey were introduced into the web during either the day or night indicated that the foraging success of Badumna is compromised by behaviours that reduce the risk of predation. During the day, spiders generally remain within the retreat and take longer to reach the prey, which may reduce their foraging success. In contrast, spiders sat exposed at the edge of the retreat at night, and from here could usually reach the prey before it escaped. The spiders were able to escape from a model predator more rapidly if they were at the edge of the retreat than if they were out on the web. These data suggest that the costs to Badumna of reduced fecundity through poor foraging efficiency may be outweighed by the benefits of reducing the risk of predation

Seasonal variation in foraging behaviour of plains zebra (Equus quagga) may alter contact with the anthrax bacterium (Bacillus anthracis)

2014 ◽  
Vol 92 (4) ◽  
pp. 331-337 ◽  
Author(s):  
Zepee Havarua ◽  
Wendy C. Turner ◽  
John K.E. Mfune
Keyword(s):  
Seasonal Variation ◽  
Bacillus Anthracis ◽  
Foraging Behaviour ◽  
Dry Season ◽  
Wet Season ◽  
Contact Rates ◽  
Bacterium Bacillus ◽  
Environmental Pathogens ◽  
Host Foraging ◽  
Plains Zebra

Pathogens transmitted via the environment are often aggregated in space, and seasonal variation in wildlife foraging behaviour may alter contact rates with environmental pathogens. The soil-borne bacterium Bacillus anthracis Cohn, 1872 causes anthrax, and herbivores acquire gastrointestinal anthrax by ingesting spores. Therefore host foraging behaviour could be a fundamental component of anthrax epidemiology. This study investigated seasonal changes in bite density and diet of plains zebras (Equus quagga Boddaert, 1785) in relation to anthrax seasonality in Etosha National Park, Namibia, where most zebra anthrax cases are observed in wet seasons. The diet of zebras shifted from more short grasses during the wet season to more tall grasses in the dry season, suggesting a greater potential for soil ingestion in wet seasons. Zebras also foraged most intensively in the wet season with the number of bites/step declining through the dry season. This higher bite density in wet seasons may lead individuals to ingest greater concentrations of the pathogen if foraging in a localized infectious area. Although sex and reproductive state affected bite density, no sex difference in anthrax occurrence was observed. This study demonstrates how considering variation in host foraging behaviour may enhance our understanding of disease seasonality for pathogens with foraging-dependent transmission.

The diving behaviour of Pigeon Guillemots (Cepphus columba) off southern Vancouver Island

1994 ◽  
Vol 72 (5) ◽  
pp. 863-872 ◽  
Author(s):  
James S. Clowater ◽  
Alan E. Burger
Keyword(s):  
Foraging Behaviour ◽  
Handling Time ◽  
Vancouver Island ◽  
Dive Duration ◽  
Diving Behaviour ◽  
Foraging Efficiency ◽  
Model Predictions ◽  
The Mean ◽  
Water Depths ◽  
Foraging Time

The foraging behaviour of Pigeon Guillemots (Cepphus columba) was observed off southern Vancouver Island, British Columbia. Diving bouts comprised 1–24 dives. Birds returned to the surface with prey in 22 of 248 (9%) dives, and mean handling time for prey was 34.7 s. Dives averaged 87 s (ranging from 37 s in water 14 m deep to 144 s at 34 m) and the mean postdive pause lasted 98 s (range 24–232 s). Birds foraged in water depths from 6 to 45 m. The duration of both dives and pauses increased with water depth. Our model of Pigeon Guillemot diving behaviour predicts foraging time at the bottom to be maximized during dives to depths of 22–24 m, while foraging efficiency, (foraging time)/(dive + recovery time), is maximized at 10 m. Calculated work to resist buoyancy and drag during descent and foraging phases of the dive cycle suggest that energetic savings from reduced buoyancy at depth may not explain how birds increase dive duration with increasing depth. Pigeon Guillemots appear to maximize time spent in the foraging patch. In 82% of transects, the most frequently chosen foraging depth was 15–20 m (mode). Model predictions were supported by observations that 43.6% of Pigeon Guillemots preferred water depths of 15–20 m, while 19% preferred water depths of 10–15 m.

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