Mechanisms driving postfire abundance of a generalist mammal

Changes in vertebrate abundance following disturbance are commonly attributed to shifts in food resources or predation pressure, but underlying mechanisms have rarely been tested. We examined four hypotheses for the commonly reported increase in abundance of deer mouse ( Peromyscus maniculatus (Wagner, 1845)) following forest fires: source–sink dynamics, decreased predation, increased food resources, and increased foraging efficiency. We found that reproduction of deer mouse was considerably higher in burned versus unburned forests and survival did not differ between habitats, indicating that burned forests were not sink habitats. Comparable survival also suggested that predation rates were similar between habitats. Increased reproduction in burned versus unburned forest suggested better resource conditions, but abundance of seeds and arthropods (the primary food resources for mice) either did not differ between habitats or were higher overall in unburned forest. Foraging experiments indicated that seed removal from depots was substantially higher in burned versus unburned forests after controlling for mouse density. Additionally, in both habitats, mice were captured more often in open microhabitats and the odds of individual insect removal increased with decreasing cover during certain sampling periods. Of the four hypotheses tested, greater foraging efficiency provided the best explanation for elevated populations of deer mouse. However, predation risk may have influenced foraging success.

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Feeding in murky waters: acclimatization and landmarks improve foraging efficiency of zebrafish ( Danio rerio ) in turbid waters

Biology Letters ◽

10.1098/rsbl.2019.0289 ◽

2019 ◽

Vol 15 (7) ◽

pp. 20190289

Author(s):

M. A. Sekhar ◽

Richa Singh ◽

Anuradha Bhat ◽

Manjari Jain

Keyword(s):

Foraging Efficiency ◽

Visual Environment ◽

Behavioural Plasticity ◽

Foraging Success ◽

Visual Landmarks ◽

Water Turbidity ◽

Turbid Waters ◽

And Function ◽

Extended Exposure

Fish inhabiting human-dominated ecosystems are prone to altered sensory environments in which they must live and function. Increased turbidity is one such change that they must deal with. We tested whether an increase in water turbidity and the presence of visual landmarks (coloured stones) affect the foraging efficiency of wild zebrafish. We also tested the influence of extended exposure to differing turbidity levels on the subsequent foraging efficiency of acclimatized individuals. Feeding latency (time taken to find food) increased significantly with increase in turbidity levels from a minimum of 4 s to ca 300 s. However, extended exposure of fish to varying levels of turbidity decreased feeding latencies in acclimatized conditions, indicating that acclimatization to the immediate visual environment plays an important role in determining foraging success. Most significantly, we found that feeding latencies in turbid conditions decreased significantly if visual landmarks were present. This demonstrates that zebrafish use visual landmark cues to navigate to foraging sites when visibility is impaired. This study has important implications on the role of behavioural plasticity and spatial learning in animals that allow them to cope with altered sensory environments such as episodes of enhanced turbidity that could be natural or anthropogenic.

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Foraging efficiency of a predator flock for randomly moving prey: A simulation study

Modern Physics Letters B ◽

10.1142/s0217984916501359 ◽

2016 ◽

Vol 30 (09) ◽

pp. 1650135

Author(s):

Sang-Hee Lee ◽

Ohsung Kwon

Keyword(s):

Foraging Behavior ◽

Simulation Study ◽

Food Resources ◽

Foraging Efficiency ◽

Prey Detection ◽

Time Step ◽

Detection Ability ◽

Simulation Results ◽

Flocking Behavior ◽

Iteration Time

Flocking behavior of animals is highly advantageous for taking food resources. The degree of the advantage is related to the ability of flock members to detect their prey and the mobility of prey individuals. In this study, to explore the relation, we constructed a model to simulate a predator flock and its randomly moving prey. The predator members have the prey detection ability, which was characterized as sensing distance, [Formula: see text], and a sensing angle, [Formula: see text]. The mobility of the prey individuals was characterized as the maximum traveling distance of an iteration time step, [Formula: see text]. The relative flock foraging efficiency, [Formula: see text], was defined as [Formula: see text]. [Formula: see text] and [Formula: see text] represent the spent time for the flock to eat all prey individuals and to uptake the last remaining 10% prey, respectively. Simulation results showed that [Formula: see text] increased, maximized, and decreased with the increase of [Formula: see text], regardless of [Formula: see text]. As the number of prey, [Formula: see text], increased, the tendency of the increasing and decreasing was diluted. The result was briefly discussed in relation to the flock foraging behavior and the development of the model toward applications for real ecosystems.

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Bioenergetic analysis of prey consumption by Bythotrephes cederstroemi in Lake Michigan

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f95-014 ◽

1995 ◽

Vol 52 (1) ◽

pp. 141-150 ◽

Cited By ~ 26

Author(s):

Peder M. Yurista ◽

Kimberly L. Schulz

Keyword(s):

Body Weight ◽

Consumption Rate ◽

Lake Michigan ◽

Food Resource ◽

Lake Huron ◽

Bioenergetic Model ◽

Bioenergetic Analysis ◽

Bythotrephes Cederstroemi ◽

Resource Conditions ◽

Predation Rates

A bioenergetic model for Bythotrephes cederstroemi was constructed using measured physiological parameters to predict predation rates. The model predicts that juvenile B. cederstroemi will consume approximately 150% of their body weight per day, while adults consume 118% of their body weight per day. These rates are consistent with those of other invertebrate crustaceans. The predicted rate was twice that of an experimental measurement reported for Lake Huron B. cederstroemi; this discrepancy is attributed to experimental artifacts and to differences between B. cederstroemi populations in Lake Michigan and those in Lakes Huron and Erie. The model was most sensitive to estimation of ingestion and assimilation efficiencies and, secondarily, respiration coefficients. This model estimates the consumption rate of B. cederstroemi in Lake Michigan under optimal food resource conditions, and may be useful in predicting the future impact of B. cederstroemi predation on the zooplankton assemblages of other lakes.

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

Australian Journal of Zoology ◽

10.1071/zo98060 ◽

1999 ◽

Vol 47 (1) ◽

pp. 29 ◽

Cited By ~ 3

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

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Foraging behavior of Brazilian cormorant, Nannopterum brasilianus (Suliformes: Phalacrocoracidae)

Zoologia (Curitiba) ◽

10.3897/zoologia.35.e14664 ◽

2018 ◽

Vol 35 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Carla Gheler-Costa ◽

Fabio Henrique Comin ◽

Letícia C. Gilli ◽

Luciano M. Verdade

Keyword(s):

Foraging Behavior ◽

Optimal Foraging ◽

Sao Paulo ◽

Southeastern Brazil ◽

Foraging Efficiency ◽

São Paulo ◽

Foraging Success ◽

Short Term ◽

Ad Libitum ◽

The University

Although the concept of optimal foraging has been extensively discussed, foraging efficiency is difficult to assess in vertebrates. In this study, we determined the foraging efficiency of the Brazilian cormorant,NannopterumbrasilianusGmelin, 1789, by the direct,ad libitumobservation of a group of four to thirteen individuals in an artificial pond at the University of São Paulo, Piracicaba, state of São Paulo, southeastern Brazil. Although this study was carried out in a highly anthropic environment, we can still conclude that the Brazilian cormorant is a relatively efficient browser and short-term diver. In anthropic environments, foraging success depends on the amount of time these birds spend diving, and stealing food is less common. Stealing occurs at relatively low rates but tends to be an efficient way to get food.

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Foraging ecology of the thermophilic Australian desert ant, Melophorus bagoti

Australian Journal of Zoology ◽

10.1071/zo05023 ◽

2005 ◽

Vol 53 (5) ◽

pp. 301 ◽

Cited By ~ 60

Author(s):

Barbara Muser ◽

Stefan Sommer ◽

Harald Wolf ◽

Rüdiger Wehner

Keyword(s):

Foraging Ecology ◽

Soil Surface ◽

Foraging Efficiency ◽

Foraging Activity ◽

Foraging Success ◽

Success Rates ◽

Desert Ant ◽

Foraging Site ◽

Intercolony Aggression ◽

Melophorus Bagoti

The paper describes the foraging ecology of the Australian desert ant, Melophorus bagoti, a thermophilic, diurnal scavenger with ground-nesting colonies. Overlapping foraging ranges, low foraging success rates, and intercolony aggression suggest intense competition for food between colonies. Daily foraging starts when soil surface temperatures approach 50°C. Workers search individually and collect predominantly dead insects. Occasionally, they consume plant secretions. Foraging activity peaks on mid-summer days. On cloudy days the onset of foraging is delayed, and the foraging activity is low. Ants do not forage on rainy days. Typically, workers start their above-ground activities with a few short exploration runs. On average, they perform one foraging run on the first day of their outdoor lives. With age they gradually increase foraging site fidelity and daily foraging effort. Individual foraging efficiency is low at the beginning but grows with experience. However, due to a high mortality rate and, hence, high forager turnover, average rates of foraging success for a colony remain rather low. The outdoor activity gradually decreases towards the end of summer and appears to stop completely during the winter months.

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Effects of Patch Quality and Feeding Subgroup Size On Feeding Success in Vervet Monkeys (Cercopithecus Aethiops)

Behaviour ◽

10.1163/156853988x00430 ◽

1988 ◽

Vol 105 (1-2) ◽

pp. 35-52 ◽

Cited By ~ 34

Author(s):

P.L. Whitten

Keyword(s):

Food Resource ◽

Cercopithecus Aethiops ◽

Foraging Efficiency ◽

Vervet Monkeys ◽

Patch Quality ◽

Foraging Success ◽

Group Foraging ◽

Phenological Data ◽

Subgroup Size ◽

Troop Size

AbstractAcacia tortilis flowers are an important food resource of vervet monkeys (Cercopithecus aethiops) in East Africa. This paper examines the effects of tortilis patch quality and feeding subgroup size on individual and group foraging success in vervet monkeys. Feeding variables examined included net caloric gain, foraging efficiency, pick rates, and foraging bout length. The data provide some evidence in support of the hypothesis -that patch quality significantly influences foraging success. Patches where flower pick rates were higher provided foraging for a greater proportion of the troop and provided more energy intake and higher foraging efficiency for individual troop members. Phenological data indicate that flower pick rates were a direct reflection of patch size and flower cover. On the other hand, data examined here provide no support for the hypothesis that feeding subgroup size adversely affects food intake or foraging efficiency within food patches. The lack of foraging costs appears to be due to adjustment of feeding parties to the size of food patches. Troop size, however, exceeded the average number of feeding sites per A. tortilis patch. As a consequence, low-ranking troop members suffered foraging costs due to exclusion from food patches. These analyses suggest that individual differences in benefits and costs of group foraging may play an important role in the history and evolution of groups.

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Foraging interactions between wading birds and strand-feeding bottlenose dolphins (Tursiops truncatus) in a coastal salt marsh

Canadian Journal of Zoology ◽

10.1139/z2012-043 ◽

2012 ◽

Vol 90 (6) ◽

pp. 744-752 ◽

Cited By ~ 4

Author(s):

Adam G. Fox ◽

Robert F. Young

Keyword(s):

Salt Marshes ◽

Tursiops Truncatus ◽

Bottlenose Dolphins ◽

Foraging Efficiency ◽

Foraging Success ◽

Wading Birds ◽

Coastal Salt Marsh ◽

Bow Wave ◽

Ardea Alba ◽

Creek Bank

Strand-feeding is a unique foraging technique used by Atlantic bottlenose dolphins ( Tursiops truncatus (Montagu, 1821)) in salt marshes of the southeastern USA wherein a group of dolphins rushes a creek bank, temporarily stranding themselves to capture fish that have been pushed ashore by their bow wave. Wading birds are attracted to these events to forage on stranded fish. We hypothesized that birds foraging in association with dolphins experience greater foraging efficiency than birds foraging away from dolphins and that some birds are able to meet their entire daily metabolic needs by foraging at strand-feeding events. The species composition, abundance, and foraging success of birds at 569 strand-feeding events were compared with the same parameters from marsh surveys of birds not associated with dolphins. Only Great Egrets ( Ardea alba L., 1758) were proportionately more common at strand-feeding events than in the marsh overall (p < 0.001). During peak strand-feeding hours, energy intake per hour was higher for Great Egrets foraging with strand-feeding dolphins than for birds foraging away from dolphins (p = 0.04). Bioenergetic models indicated that prey intake by Great Egrets at strand-feeding events was sufficient to meet their existence and likely their active metabolic requirements.

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Net carbon sink of China was overestimated by more than 35%

10.21203/rs.3.rs-1063386/v1 ◽

2021 ◽

Author(s):

Chaochao Du ◽

Xiaoyong Bai ◽

yangbing Li ◽

Qiu Tan ◽

Cuiwei Zhao Zhao ◽

...

Keyword(s):

Forest Fires ◽

Atmospheric Carbon Dioxide ◽

Carbon Sink ◽

Terrestrial Ecosystems ◽

Carbon Neutrality ◽

Relative Contribution ◽

Reactive Carbon ◽

Source Sink ◽

Global Carbon ◽

Net Carbon Sink

Abstract As a carbon source/sink of atmospheric carbon dioxide, the net regional carbon budget (NRCB) of terrestrial ecosystems is very important to effect global warming, especially China with the largest emissions at present. However, the carbon consumption is difficult to measure accurately, which is caused by the emissions of CH4 and CO, the utilization of agriculture, forestry and grass, and the emissions from rivers and other physical processes, such as forest fires. Therefore, the spatial patterns and driving factors of NRCB are not clear. Here, we used multi-source data to estimate the NRCB of 31 provincial administrative divisions of China and to develop NRCB datasets from 2000 to 2018. We found that the average of NRCB was 669 TgC yr−1, and it significantly decreased at a rate of 2.56 TgC yr−1. The relative contribution rates of fluxes of emissions from anthropogenic (FEAD), reactive carbon and creature ingestion (FERCCI), autotrophic respiration (Ra), heterotrophic respiration (Rh) and natural disturbances (FEND) were 35.17%, 26.09%, 19.68%, 17.38% and 1.68% respectively. In addition, NRCB datasets of the different administrative regions of China were mapped. These datasets will provide support for China's carbon neutrality and the study of the global carbon cycle.

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Consequences of Joint-Territoriality in a Mixed-Species Group of Tamarin Monkeys

Behaviour ◽

10.1163/156853992x00039 ◽

1992 ◽

Vol 123 (3-4) ◽

pp. 220-246 ◽

Cited By ~ 27

Author(s):

Carlos A. Peres

Keyword(s):

Time Budget ◽

Species Group ◽

Foraging Efficiency ◽

Home Ranges ◽

Foraging Success ◽

Territorial Defence ◽

Saguinus Fuscicollis ◽

Small Fruit ◽

Tamarin Monkeys ◽

Time And Energy

AbstractGroups of saddle-back (Saguinus fuscicollis) as moustached tamarins (Saguinus mystax) in a western Amazonian forest jointly defended home ranges larger than 100 ha, which were held in common throughout the year. Resources were defended by direct exploitation in extensive areas shared with other groups, or through intensive and frequent intergroup interactions along territorial boundaries. These interactions were expressed primarily during intergroup encounters, and affected the use of space, movements, time budget, and foraging success of tamarins. During encounters, animals of both species spent more time in energetically costly activities, such as rapid travel and intergroup chases, and less time in energetically positive activities, such as feeding and foraging. In addition, foraging success per unit of foraging effort within overlapping areas of the range periphery was lower than in exclusive areas of the range centre, particularly for saddle-back tamarins. The time and energy allocated by moustached tamarins to boundary contests was considerably greater than that of saddle-backs, despite the fact that only the latter species increased its foraging efficiency by shifting from exclusive areas in the group's range to those shared by other groups. This is probably because of saddle-back's greater use of depletable food supplies, such as small fruit patches and small microhabitats containing embedded prey items. These benefits are likely to justify the substantial amount of time and energy invested in territorial defence for both saddle-backs and moustached tamarins, but appeared to be highly asymmetric between species.

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