Comparative foraging behaviour and efficiency of adult and juvenile great blue herons

1980 ◽  
Vol 58 (6) ◽  
pp. 1168-1173 ◽  
Author(s):  
T. E. Quinney ◽  
P. C. Smith
Keyword(s):  
Nova Scotia ◽  
Foraging Behaviour ◽  
River Estuary ◽  
Handling Time ◽  
Flock Size ◽  
Foraging Success ◽  
Small Prey ◽  
Prey Items

Foraging behaviour and efficiency of adult and newly fledged juvenile great blue herons, Ardea herodius L., were studied at the Gaspereau River estuary. Nova Scotia, in July and August 1977 and 1978. Pace and strike rates of adults and juveniles were similar, whereas capture and probe rates differed markedly. Adults captured prey more successfully than juveniles but the ability of the latter improved with age. Foraging success of adults was greater in flocks of more than five individuals. In contrast, juvenile success does not seem related to flock size. Ninety-eight percent of the identified prey were flounder Liopsetta putnmi Gill. Handling time of small prey items was the same for adults and juveniles but juveniles took much longer to swallow medium-sized prey than adults did.

Selection of Prey by Size in Ningaui Yvonneae

1996 ◽  
Vol 44 (3) ◽  
pp. 319 ◽  
Author(s):  
AP Woolnough ◽  
SM Carthew
Keyword(s):  
Energy Efficient ◽  
Prey Size ◽  
Handling Time ◽  
Optimal Foraging Theory ◽  
Large Prey ◽  
Small Prey ◽  
Upper Limit ◽  
The Relationship ◽  
Prey Items ◽  
Selection Of

The small dasyurid marsupial, Ningaui yvonneae, feeds opportunistically on invertebrates dominated by the orders Hymenoptera, Coleoptera and Araneae, but is capable of, and will, consume vertebrates such as skinks. When presented with a choice of prey N. yvonneae exhibited a strong preference for prey items on the basis of size. It consistently selected small prey items over large prey items. Small prey items represented the most energy-efficient prey option as the ningaui can more efficiently capture, subdue and consume them than it can larger prey. The relationship between prey size and handling time was exponential, indicating that there is an upper limit to the ability of N. yvonneae to process prey. Moreover, smaller cockroaches provided greater energy gain than larger ones, indicating that the costs of eating larger cockroaches energetically outweighed the energy return. These results are in agreement with optimal foraging theory.

Effect of Age on the Foraging Behaviour of Grey Heron Ardea Cinerea L., 1758 at a Submontane Dam Reservoir in the Post-Breeding Season

2017 ◽  
Vol 10 (2) ◽  
pp. 76-83
Author(s):  
Robert Gwiazda ◽  
Adam Flis ◽  
Piotr Skórka ◽  
Wioleta Oleś
Keyword(s):  
Foraging Behaviour ◽  
Capture Rate ◽  
Success Probability ◽  
Handling Time ◽  
Small Fish ◽  
Foraging Success ◽  
Grey Heron ◽  
Ardea Cinerea ◽  
Probability Number ◽  
Effect Of Age

The components of foraging behaviour and success of adult and juvenile Grey Heron Ardea cinerea were studied at the Dobczyce Reservoir (southern Poland) in July and September 2015. Juvenile and adult birds moved at similar rates during both months. Fish capture attempt rate was significantly higher for juvenile birds than for adults in July but not in September. Capture rate and foraging success probability (number of captures over all attempts) was significantly lower in juveniles in July but not in September. The foraging success probability of juveniles increased from July to September. Adult and juvenile birds caught mostly small fish, with no differences in size. However, handling time in juvenile birds was much longer than in adults in July but not in September, after controlling for differences in prey size. Thus, juvenile Grey Heron increased their efficiency of catching fish from July to September by reducing the number of mistakes, probably as a result of experience.

Diving behaviour during the breeding season in the terrestrially breeding male grey seal: implications for alternative mating tactics

2003 ◽  
Vol 81 (6) ◽  
pp. 1025-1033 ◽  
Author(s):  
Damian C Lidgard ◽  
Daryl J Boness ◽  
W Don Bowen ◽  
Jim I McMillan
Keyword(s):  
Nova Scotia ◽  
Reproductive Success ◽  
Breeding Season ◽  
Foraging Behaviour ◽  
Diving Behaviour ◽  
Halichoerus Grypus ◽  
Phenotypic Traits ◽  
Alternative Mating Tactics ◽  
Grey Seal ◽  
Mating Tactics

We examined the diving behaviour of breeding male grey seals (Halichoerus grypus) at Sable Island, Nova Scotia, from 1997 to 2001. The proportion of time spent at sea varied between 0 and 78% (N = 30). Males engaged in deep (43.4 ± 3.3 m (mean ± SE), N = 27) diving, and these dives were clustered into bouts, which mostly occurred during long trips (62.2 ± 14.7 h). We suggest that males spent time foraging during deep dives. Shallow diving (5.9 ± 0.1 m, N = 27) accounted for 40.8% of dives, which were also clustered into bouts that mostly occurred during short trips (2.1 ± 0.37 h). We suggest that shallow diving comprised a suite of behaviours, but included little foraging behaviour. Phenotypic traits had little influence on diving behaviour. Further work is required to understand the extent to which foraging behaviour enhances reproductive success, and whether shallow diving is a component of the mating tactics of male grey seals at Sable Island.

scholarly journals The Influence of Food Density, Flock Size, and Disturbance on the Functional Response of Bewick’s Swans (Cygnus columbianus bewickii) in Wintering Habitats

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 946 ◽  
Author(s):  
Chao Yu ◽  
Lizhi Zhou ◽  
Nazia Mahtab ◽  
Shaojun Fan ◽  
Yunwei Song
Keyword(s):  
Feeding Behavior ◽  
Functional Response ◽  
Habitat Management ◽  
Feeding Rate ◽  
Handling Time ◽  
Foraging Strategies ◽  
Food Density ◽  
Flock Size ◽  
Functional Responses ◽  
Cygnus Columbianus

Perceiving how animals adjust their feeding rate under a variety of environmental conditions and understanding the tradeoffs in their foraging strategies are necessary for conservation. The Holling functional response, which describes the relationship of feeding rate and food density to searching rate and handling time, has been applied to a range of waterbirds, especially with regard to Type II functional responses that describe an increasing feeding rate with food density but at a decelerating rate as the curve approaches the asymptote. However, feeding behavior components (feeding rate, searching rate, and handling time) are influenced by factors besides prey density, such as vigilance and flock size. In this study, we aim to elucidate how Bewick’s swans (Cygnus columbianus bewickii) adopt flexible foraging strategies and vary their feeding behavior components in response to disturbance, flock size, and food density. We collected focal sampling data on the foraging behavior of swans that foraged rice grains, foxnut seeds, and tubers in paddy field, foxnut pond, and lake habitats, respectively, in Shengjin and Huangpi lakes during winter from 2016 to 2018. The observed feeding rate was not correlated with food density and displayed a positive relationship with searching rate but negative relationships with handling time, flock size, overall vigilance time, and disturbance time. Handling time was negatively correlated with food density and flock size, yet it increased with disturbance, overall vigilance time, and normal vigilance time. Searching rate was negatively correlated with food density, flock size, and disturbance time. Feeding rate was affected by the combined effects of handling time and searching rate, as well as food density and searching rate. The shape of the observed functional response could not be fitted to Holling’s disc equation. However, the disc equation of the predicted feeding rate of wintering swans was found to be driven by food density. This provides insight into how wintering waterbirds adopt appropriate foraging strategies in response to complicated environmental factors, which has implications for wildlife conservation and habitat management.

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.

Multiple feeding in wolf spiders: the effect of starvation on handling time, ingestion rate, and intercatch intervals in Lycosa lapidosa (Araneae : Lycosidae)

2000 ◽  
Vol 48 (1) ◽  
pp. 59 ◽  
Author(s):  
V. W. Framenau ◽  
L. A. Finley ◽  
K. Allan ◽  
M. Love ◽  
D. Shirley ◽  
...  
Keyword(s):  
Prey Capture ◽  
Ingestion Rate ◽  
Capture Rate ◽  
Wolf Spider ◽  
Handling Time ◽  
Wolf Spiders ◽  
Feeding Regimes ◽  
Acheta Domestica ◽  
Multiple Feeding ◽  
Prey Items

Multiple prey capture, the behaviour of a predator attacking prey whilst handling a previously caught item, occurs in a variety of spiders that do not build webs. The effects of recent feeding history on the frequency of multiple prey attacks, handling time, ingestion rate, and intercatch intervals were examined experimentally in the wolf spider Lycosa lapidosa McKay. Juvenile spiders were subjected to two different feeding regimes (starvation for 14 and 28 days) and then provided with two different prey types (blowflies, Lucilia cuprina, and crickets, Acheta domestica). These two starvation levels or prey types had little effect on the frequency (75%) of multiple prey attacks. Spiders ingested approximately half the weight of any captured prey, regardless of how many prey items they attacked. At the same time, the handling time per prey item decreased with an increasing number of prey attacked. This indicates a more efficient ingestion rate when more prey are consumed. While the attacking time for the first prey was the same for all treatments, the first intercatch interval was longer for spiders that were starved longer. Chronically starved L. lapidosa appear to secure a previously caught item rather than optimise their capture rate by attacking further available prey.

Age, Sex and Prior Site Experience Have Independent Effects On the Foraging Success of Wintering Snow Buntings

Behaviour ◽  
1994 ◽  
Vol 129 (1-2) ◽  
pp. 99-111 ◽  
Author(s):  
Richard D. Smith ◽  
Neil B. Metcalfe
Keyword(s):  
Competitive Ability ◽  
Feeding Rate ◽  
Prior Experience ◽  
Residual Effects ◽  
Flock Size ◽  
Foraging Success ◽  
Feeding Rates ◽  
North East ◽  
Independent Effects ◽  
Feeding Bout

AbstractIntraspecific variation in foraging success amongst birds is often associated with differences between individuals in competitive ability or experience. However, it is usually difficult to separate the importance of experience per se from that of age. Here we examined the feeding rates of wintering snow buntings (Plectrophenax nivalis) at Cairn Gorm, North-east Scotland in both competitive and non-competitive situations. Although flock-size/density and stage of the feeding bout accounted for most of the explainable variation in peck-rates, there remained significant and additive residual effects of both age and prior experience of the site (older/more experienced birds achieving higher feeding rates) and these effects were very similar for birds feeding alone or in flocks. Sex differences in feeding rates were only apparent in large flocks, where males (the dominant sex) had faster peck-rates than females. Birds without previous experience (whether age or site-related) showed increases in relative feeding rate during the course of the winter, whereas experienced birds did not. This suggests that the differences between experienced and inexperienced birds were due to learning rather than the disproportionate loss of poor foragers.

THE EFFECT OF HANDLING TIME ON INTERFERENCE AMONG HOUSE SPARROWS FORAGING AT DIFFERENT SEED DENSITIES

Behaviour ◽  
2001 ◽  
Vol 138 (5) ◽  
pp. 597-614 ◽  
Author(s):  
Cheryl Johnson ◽  
James W.A. Grant ◽  
Luc-Alain Giraldeau
Keyword(s):  
Group Size ◽  
Ideal Free Distribution ◽  
Passer Domesticus ◽  
Handling Time ◽  
Foraging Success ◽  
House Sparrows ◽  
Interference Models ◽  
Foraging Time ◽  
Ideal Free ◽  
The Ideal

AbstractInterference models of the ideal free distribution (IFD) assume competition among foraging animals causes intake rates to decline with increasing competitor density and that the strength of the decline influences forager distributions among food patches. However, the resulting distributions of animals may depend on which components of foraging success contribute to interference. We examined the effect of group size (1-13 birds) on the prey encounter rates, handling times, and foraging rates of house sparrows, Passer domesticus, feeding at three seed densities in a suburban backyard. House sparrows did not experience interference during search. Interference arose primarily from foraging time lost handling seeds. Foraging rates decreased with increasing seed density as a consequence of increased handling times. Also, birds experiencing significant increases in handling time with group size suffered most from interference. Our results suggest that animals adjust handling time to avoid costly aggressive interactions, indicating that handling time may be an important component of interference in some foraging systems. Future studies estimating interference should try to identify which components of foraging contribute to interference, paying particular attention to handling times for species that monitor and avoid competitors.

scholarly journals Ocean acidification impairs crab foraging behaviour

2015 ◽  
Vol 282 (1810) ◽  
pp. 20150333 ◽  
Author(s):  
Luke F. Dodd ◽  
Jonathan H. Grabowski ◽  
Michael F. Piehler ◽  
Isaac Westfield ◽  
Justin B. Ries
Keyword(s):  
Ocean Acidification ◽  
Species Interactions ◽  
Foraging Behaviour ◽  
Marine Invertebrates ◽  
Handling Time ◽  
Global Scale ◽  
Negative Effects ◽  
Marine Food Webs ◽  
Behavioural Interactions ◽  
Panopeus Herbstii

Anthropogenic elevation of atmospheric CO 2 is driving global-scale ocean acidification, which consequently influences calcification rates of many marine invertebrates and potentially alters their susceptibility to predation. Ocean acidification may also impair an organism's ability to process environmental and biological cues. These counteracting impacts make it challenging to predict how acidification will alter species interactions and community structure. To examine effects of acidification on consumptive and behavioural interactions between mud crabs ( Panopeus herbstii ) and oysters ( Crassostrea virginica ), oysters were reared with and without caged crabs for 71 days at three p CO 2 levels. During subsequent predation trials, acidification reduced prey consumption, handling time and duration of unsuccessful predation attempt. These negative effects of ocean acidification on crab foraging behaviour more than offset any benefit to crabs resulting from a reduction in the net rate of oyster calcification. These findings reveal that efforts to evaluate how acidification will alter marine food webs should include quantifying impacts on both calcification rates and animal behaviour.

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

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