Plasticity in foraging behaviour of a lotic minnow (Rhinichthys cataractae) in response to different light intensities

1990 ◽  
Vol 68 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Chris E. Beers ◽  
Joseph M. Culp
Keyword(s):  
Foraging Behaviour ◽  
Search Time ◽  
Biotic Interactions ◽  
Foraging Strategy ◽  
Net Energy ◽  
Search Volume ◽  
Rhinichthys Cataractae ◽  
Nocturnal Foraging ◽  
Foraging Ability ◽  
High Predation

Unlike most cyprinids, the longnose dace (Rhinichthys cataractae) forages primarily at night in streams in southern Alberta. This nocturnal strategy may result from intrinsic capabilities, like dark-adapted vision, or extrinsic constraints due to biotic interactions during the day. Our objectives were to determine, in the absence of biotic interactions such as predation and competition, (i) whether this foraging habit maximized the foraging ability of the dace in terms of search time, reaction distance, and attack efficiency; and (ii) if dace foraging behaviour was sufficiently plastic to adjust to changes in light intensity. All measures of foraging ability were superior under twilight conditions. Although search times in starlight were double those in twilight, this increase was much smaller than was predicted using a hemispherical search volume model. The daces' ability to offset small nocturnal search volumes was accomplished by changing their pattern of search behaviour. In particular, use of a benthic rooting behaviour increased, and we hypothesize that this behaviour is associated with location of prey by olfaction. Although the nocturnal foraging strategy of dace does not appear to maximize net energy gain, this strategy may be a response to other constraints, such as high predation risk during diel periods with increased illumination.

Spatio-temporal patterns of foraging behaviour in a wide-ranging seabird reveal the role of primary productivity in locating prey

2020 ◽  
Vol 646 ◽  
pp. 175-188
Author(s):  
A Kane ◽  
E Pirotta ◽  
S Wischnewski ◽  
EJ Critchley ◽  
A Bennison ◽  
...  
Keyword(s):  
Habitat Use ◽  
Foraging Behaviour ◽  
Food Resource ◽  
Biotic Interactions ◽  
Central Place ◽  
Ocean Dynamics ◽  
Environmental Predictors ◽  
Nocturnal Foraging ◽  
Spatio Temporal ◽  
Marine Productivity

Predicting the distribution and behaviour of animals is a fundamental objective in ecology and a cornerstone of conservation biology. Modelling the distribution of ocean-faring species like seabirds remains a significant challenge due to ocean dynamics, colony-specific effects and the vast ranges seabirds can cover. We used a spatial and behavioural approach to model the distribution of the Manx shearwater Puffinus puffinus, a pelagic, central-place forager that can cover great distances while foraging. GPS data from birds tagged in 2 colonies over 3 yr were modelled with a range of environmental predictors of marine productivity. For both colonies, transitions to foraging behaviour correlated with chlorophyll a, and the distribution of foraging behaviour was also associated with areas of high chlorophyll a concentration in coastal but not offshore areas for one colony. Furthermore, there was evidence for colony differences in habitat use, prevalence of nocturnal foraging, and for some competitive exclusion on foraging grounds, even though the colonies were 170 km apart. Despite the extensive dataset, our models had modest predictive power, which we suggest can probably only be improved by including biotic interactions, including more direct measures of food resource distribution. Our results highlight the importance of including spatial complexity and data from multiple sites when predicting the distribution of wide-ranging predators, because patterns of distribution and habitat use likely differ across the range of a population.

Nocturnally constrained foraging of a lotic minnow (Rhinichthys cataractae)

1989 ◽  
Vol 67 (8) ◽  
pp. 2008-2012 ◽  
Author(s):  
Joseph M. Culp
Keyword(s):  
Seasonal Changes ◽  
Prey Availability ◽  
Diel Periodicity ◽  
Foraging Activity ◽  
Light Levels ◽  
Prey Composition ◽  
Rhinichthys Cataractae ◽  
Nocturnal Foraging ◽  
Gut Fullness ◽  
Foraging Pattern

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.

scholarly journals Cuttlefish show flexible and future-dependent foraging cognition

2020 ◽  
Vol 16 (2) ◽  
pp. 20190743 ◽  
Author(s):  
Pauline Billard ◽  
Alexandra K. Schnell ◽  
Nicola S. Clayton ◽  
Christelle Jozet-Alves
Keyword(s):  
Food Availability ◽  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Foraging Strategy ◽  
The Other ◽  
Foraging Activity ◽  
Experimental Conditions

Some animals optimize their foraging activity by learning and memorizing food availability, in terms of quantity and quality, and adapt their feeding behaviour accordingly. Here, we investigated whether cuttlefish flexibly adapt their foraging behaviour according to the availability of their preferred prey. In Experiment 1, cuttlefish switched from a selective to an opportunistic foraging strategy (or vice versa ) when the availability of their preferred prey at night was predictable versus unpredictable. In Experiment 2, cuttlefish exhibited day-to-day foraging flexibility, in response to experiencing changes in the proximate future (i.e. preferred prey available on alternate nights). In Experiment 1, the number of crabs eaten during the day decreased when shrimp (i.e. preferred food) were predictably available at night, while the consumption of crabs during the day was maintained when shrimp availability was unpredictable. Cuttlefish quickly shifted from one strategy to the other, when experimental conditions were reversed. In Experiment 2, cuttlefish only reduced their consumption of crabs during the daytime when shrimps were predictably available the following night. Their daytime foraging behaviour appeared dependent on shrimps' future availability. Overall, cuttlefish can adopt dynamic and flexible foraging behaviours including selective, opportunistic and future-dependent strategies, in response to changing foraging conditions.

Intertidal foraging by gentoo penguins in a macroalgal raft

2020 ◽  
Vol 32 (1) ◽  
pp. 43-44
Author(s):  
James B. McClintock ◽  
Charles D. Amsler ◽  
Margaret O. Amsler ◽  
William R. Fraser
Keyword(s):  
Environmental Change ◽  
Foraging Behaviour ◽  
Foraging Strategy ◽  
Foraging Strategies ◽  
Marion Island ◽  
Pygoscelis Papua ◽  
General Consensus ◽  
Foraging Tactics ◽  
Pygoscelid Penguins ◽  
Foraging Tactic

Foraging strategies in gentoo penguins (Pygoscelis papua) have been well studied (e.g. Croxall et al. 1988, Robinson & Hindell 1996, Lescroël et al. 2004, Takahashi et al. 2008, Xavier et al. 2017). The general consensus is this largest member of the three pygoscelid penguins displays both nearshore benthic and pelagic foraging tactics to consume combinations of crustaceans and fish. In a recent study, Carpenter-Kling et al. (2017) reported that gentoos at sub-Antarctic Marion Island displayed a novel foraging strategy that consisted of alternating typical lengthy foraging trips with much shorter nearshore afternoon trips. They suggest the latter foraging behaviour may be a response to suboptimal feeding conditions caused by local environmental change. This novel discovery reinforces the fact that, despite considerable study, not all foraging tactics in penguins have been documented. In this paper, we describe what we believe to be, yet another undocumented foraging tactic employed by gentoos.

Differential effects of predation risk and competition over vigilance variables and feeding success in Eurasian siskins (Carduelis spinus)

Behaviour ◽  
2013 ◽  
Vol 150 (14) ◽  
pp. 1665-1687 ◽  
Author(s):  
Jordi Pascual ◽  
Juan Carlos Senar
Keyword(s):  
Food Intake ◽  
Predation Risk ◽  
Foraging Behaviour ◽  
Interference Competition ◽  
Ecological Factors ◽  
Intake Rate ◽  
Similar Length ◽  
Feeding Success ◽  
High Predation ◽  
Food Intake Rate

Many investigations have studied the effects of predation risk and competition over vigilance and feeding success, but they have proven to be difficult to discriminate. Moreover, none of the studies that have avoided the confusion has considered all the vigilance variables, food intake rate and time spent in the foraging patch. In this study, we designed an experiment with Eurasian siskinsCarduelis spinusforaging on three bird table feeders: one with low predation risk and competition, one with low predation risk and high competition and one with high predation risk and intermediate competition. Birds responded to increasing interference competition by increasing mean scan durations (probably due to the birds having to be vigilant for both other flock members and predators) and maintaining the length of mean inter-scan durations, while they responded to increasing predation risk by reducing mean inter-scan durations (probably in order to detect the predator sooner) while maintaining similar length of mean scan durations. Birds were often ejected from the feeder or departed because of disturbances, so time spent on feeders was reduced both because of competition and predation risk. Pecking rates were affected by competition but not by predation risk. Our results clearly show that birds vigilance strategy while foraging might be very different when they are mainly concerned with scanning for predators or when they primarily monitor competing flock companions. In addition, they stress the importance of recording all the vigilance and feeding variables when studying the effect of ecological factors over the foraging behaviour of birds.

scholarly journals Diurnal feeding strategies of the Ferruginous Duck (Aythya nyroca) in Lake Tonga (Northeastern Algeria)

2019 ◽  
Vol 27 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Khalil Draidi ◽  
Badis Bakhouche ◽  
Naouel Lahlah ◽  
Imed Djemadi ◽  
Mourad Bensouilah
Keyword(s):  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Time Budget ◽  
Search Time ◽  
Environmental Parameters ◽  
Feeding Strategies ◽  
A Minor ◽  
Northeastern Algeria ◽  
Foraging Time ◽  
Minor Activity

Abstract Although the Ferruginous Duck (Aythya nyroca) has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present paper we studied the diurnal feeding behaviour of ducks. We monitored the annual cycle of birds through two fieldtrips per month. The instantaneous behaviour of birds was recorded in regular 30-minute intervals from 7 a.m. to 4:30 p.m., amounting a total of 456 observation hours. Food searching activity corresponds to a quarter of the total diurnal time budget of the Ferruginous Duck. Foraging behaviour was classified into five categories dominated by the “diving”, which is almost 45.61% of the total search time. Foraging activities at the water surface considered to be secondary activities, including feeding by “bill”, “neck and head”, and “beak and head” in a rate of 19.86%, 14.53%, and 13.98%, respectively. The “toggle” remains a minor activity and represents only 5.99% of foraging time. The feeding behaviour of this species correlated to several environmental parameters (rainfall, temperature and wind velocity), and linked to the group size of ducks visiting the lake. Regarding the food intensity, our results show the highest values for “bill and head” behaviour. “Diving” has the longest feeding interval (16.16±14.1 minutes), while foraging by “bill” has the shortest (0.69 ± 0.48 minutes).

Behavioural control of daily fattening in great tits (Parus major)

1996 ◽  
Vol 74 (9) ◽  
pp. 1612-1616 ◽  
Author(s):  
Kristjan Lilliendahl ◽  
Allan Carlson ◽  
Jonas Welander ◽  
Jan B. Ekman
Keyword(s):  
Foraging Behaviour ◽  
Parus Major ◽  
Mass Gain ◽  
Foraging Strategy ◽  
Time Of Day ◽  
Energy Reserves ◽  
Normal Pattern ◽  
Daily Cycle ◽  
State Dependent ◽  
The Cost

Many species of temperate-zone passerines show a pronounced daily cycle in body mass. Energy reserves are built up during the day and consumed the following night. The size of reserves is often viewed as a compromise between the risk of starvation and the cost of carrying an excessive fat load. This trade-off calls for state-dependent foraging behaviour, where current reserves and time of day are two crucial factors. The foraging strategy of the birds may then be reflected by the pattern of daily mass gain rate. We temporarily increased energy expenditure in captive great tits (Parus major) by experimentally lowering the overnight temperature. The birds' response to the treatment was to rapidly compensate for reduced morning reserves. Such an increased rate of mass gain suggests state-dependent foraging, and that some feeding opportunities are normally rejected. The rate of return to the normal pattern of fat accumulation suggests that in these birds, foraging is not constrained by physiological limitations.

Foraging behaviour of the endangered Australian skink (Liopholis slateri)

2014 ◽  
Vol 62 (6) ◽  
pp. 477 ◽  
Author(s):  
Megan A. McKinney ◽  
Christine A. Schlesinger ◽  
Chris R. Pavey
Keyword(s):  
Foraging Behaviour ◽  
Foraging Strategy ◽  
Field Of View ◽  
Wide Field ◽  
Buffel Grass ◽  
Wide Field Of View ◽  
Burrow Entrance ◽  
Central Australia ◽  
Ambush Predation ◽  
Straight Ahead

The foraging behaviour of the endangered Australian skink (Liopholis slateri) was investigated through detailed observation of a subpopulation of lizards during seven months of sampling. Slater’s skinks primarily exhibited ambush predation, darting from burrow entrances to distances of up to 4 m with a success rate of ~70%. The direction of darting was often straight ahead and almost always in an 180° arc in front of the burrow entrance. Juveniles foraged more frequently and further from burrows than adults. Ants were the most common prey item taken and juveniles targeted small ants as prey more often than adults and often moved further to capture these prey. The spread of introduced buffel grass (Cenchrus ciliaris) in central Australia in recent decades is a possible contributing factor to the decline of L. slateri. A wide field of view appears to be critical for the success of the sit-and-wait foraging strategy employed by the skinks and additional research is required to determine whether further encroachment of buffel grass around burrow systems will impede visibility and directly affect foraging behaviour of these skinks.

Energetics of free-ranging large herbivores: when should costs affect foraging behaviour?

2000 ◽  
Vol 78 (9) ◽  
pp. 1604-1615 ◽  
Author(s):  
Helen M Armstrong ◽  
Antony Robertson
Keyword(s):  
Energy Balance ◽  
Foraging Behaviour ◽  
Ovis Aries ◽  
Energetic Cost ◽  
Domestic Sheep ◽  
Net Energy ◽  
Large Herbivores ◽  
Wind Speeds ◽  
Free Ranging ◽  
The Impact

Published relationships were used to build a mathematical model that predicts the daily net energy balance of free-ranging domestic sheep (Ovis aries L.) grazing in the U.K. hills. Net energy balance was predicted for a plausible range of environmental conditions. The behaviour of the model suggested the following predictions. Locomotion will be a relatively unimportant energetic cost. Ambient temperature and rainfall alone will rarely affect energy expenditure, whereas wind will greatly increase energetic costs in winter. These are further increased, but to a relatively small extent, by any concurrent rainfall. Predictions of foraging behaviour based on maximisation of energy intake alone are likely to significantly overestimate dry matter intake from climatically exposed vegetation in winter. Where shelter is available, such models will also overestimate total intake in winter by not taking account of sheltering behaviour. This effect will be most pronounced when forage is of low digestibility or availability, wind speeds are high, or the level of coat insulation is low. Foraging models based instead on maximisation of net energy balance are likely to greatly improve predictions of the impact of large herbivores on vegetation and the mechanisms driving their population dynamics.

scholarly journals Evolution of foraging behaviour in response to chronic malnutrition in Drosophila melanogaster

2012 ◽  
Vol 279 (1742) ◽  
pp. 3540-3546 ◽  
Author(s):  
Roshan K. Vijendravarma ◽  
Sunitha Narasimha ◽  
Tadeusz J. Kawecki
Keyword(s):  
Path Length ◽  
Foraging Behaviour ◽  
Foraging Strategy ◽  
Complementation Test ◽  
Energetic Efficiency ◽  
Search Behaviour ◽  
Chronic Malnutrition ◽  
Alternative Hypotheses ◽  
The One ◽  
And Control

Chronic exposure to food of low quality may exert conflicting selection pressures on foraging behaviour. On the one hand, more active search behaviour may allow the animal to find patches with slightly better, or more, food; on the other hand, such active foraging is energetically costly, and thus may be opposed by selection for energetic efficiency. Here, we test these alternative hypotheses in Drosophila larvae. We show that populations which experimentally evolved improved tolerance to larval chronic malnutrition have shorter foraging path length than unselected control populations. A behavioural polymorphism in foraging path length (the rover–sitter polymorphism) exists in nature and is attributed to the foraging locus ( for ). We show that a sitter strain ( for s2 ) survives better on the poor food than the rover strain ( for R ), confirming that the sitter foraging strategy is advantageous under malnutrition. Larvae of the selected and control populations did not differ in global for expression. However, a quantitative complementation test suggests that the for locus may have contributed to the adaptation to poor food in one of the selected populations, either through a change in for allele frequencies, or by interacting epistatically with alleles at other loci. Irrespective of its genetic basis, our results provide two independent lines of evidence that sitter-like foraging behaviour is favoured under chronic larval malnutrition.

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