The effect of group size on vigilance and feeding rate in spice finches (Lonchura punctulata)

1997 ◽  
Vol 75 (9) ◽  
pp. 1526-1531 ◽  
Author(s):  
Guy Beauchamp ◽  
Barbara Livoreil
Keyword(s):  
Group Size ◽  
Feeding Rate ◽  
Confounding Factor ◽  
Handling Time ◽  
Feeding Time ◽  
Nearest Neighbour ◽  
Feeding Rates ◽  
Search Speed ◽  
Lonchura Punctulata ◽  
The Many

We investigated group-size effects on individual vigilance levels and feeding rates in captive groups of spice finches (Lonchura punctulata). The "many-eyes" hypothesis predicts a reduction in vigilance levels in larger groups that can cause higher feeding rates if the time thus saved is used for foraging. We adopted a within-subject procedure whereby in each of six replicates we observed one adult male searching for food in groups varying in size from one to five. As predicted, vigilance levels decreased with group size up to four birds but increased in groups of five. Birds also collected seeds more quickly in larger groups, reflecting (i) a decrease in vigilance levels in larger groups, (ii) a decrease in handling time, and (iii) an increase in search speed. Nearest neighbour distances were smaller in larger groups, a potential confounding factor in the analysis of vigilance time. Although the results are partly consistent with the many-eyes hypothesis, we suggest that the arrow of causation from vigilance to feeding time could be reversed: the increase in feeding rates in larger groups, with a concomitant decrease in vigilance levels, would be caused by increased competition.

Comparative Agonistic and Feeding Behavior of Hatchery-Reared and Wild Salmon in Aquaria

1968 ◽  
Vol 25 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Owen C. Fenderson ◽  
W. Harry Everhart ◽  
Kenneth M. Muth
Keyword(s):  
Social Interaction ◽  
Atlantic Salmon ◽  
Feeding Behavior ◽  
Salmo Salar ◽  
Social Dominance ◽  
Food Preference ◽  
Feeding Rate ◽  
Feeding Time ◽  
Feeding Rates ◽  
Wild Salmon

When hatchery-reared and wild landlocked Atlantic salmon (Salmo salar) parr of the same age and size were permitted to compete for social dominance and for food in aquaria, twice as many hatchery salmon attained dominance as wild salmon. Dominant hatchery salmon also showed a higher intensity of aggressiveness than dominant wild salmon, displaying a higher and more variable mean nipping rate. Socially dominant salmon ate more food per fish than subordinates, but there were no statistically significant differences in feeding rate between dominant hatchery and dominant wild salmon, or between subordinate hatchery and subordinate wild salmon.Hatchery salmon displayed lower feeding rates than wild salmon when they were held in separate compartments of an aquarium and compared at three temperatures. This difference in feeding rate probably was not a reflection of differences in adaptation to temperature or food preference, but, rather, was the result of interference with feeding caused by the more intense social interaction among hatchery fish.It is suggested that high levels of aggressiveness may contribute to mortalities of hatchery-reared salmon planted in streams because of loss of feeding time, excessive use of energy, and increased exposure to predators.

scholarly journals The Effect of Increasing Temperature and Feeding Time on Feeding Rate on Soft Coral Sarcophyton sp. and Sinularia sp.

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Agung Mahayoni Aksari ◽  
Ni Luh Watiniasih ◽  
Widiastuti Widiastuti
Keyword(s):  
Feeding Rate ◽  
Soft Coral ◽  
Temperature Tolerance ◽  
Artemia Salina ◽  
Feeding Time ◽  
Soft Corals ◽  
Feeding Rates ◽  
Increased Temperature ◽  
Significant Difference ◽  
Increasing Temperature

Soft corals (Alcyoniidae) can obtain the nutrients through the algae symbiont (zooxanthellae) and/or captures the prey with their tentacles. Increased mean sea surface temperatures cause damage to coral reef ecosystems, one of those mechanisms is reducing the feeding capacity in soft corals. Thus, this study aims to examine the feeding rates of soft corals Sinularia sp. and Sarcophyton sp. at different temperatures, to determine the effect of increasing temperature, feeding time and interaction between those factors on feeding rates of soft corals Sarcophyton sp. and Sinularia sp. samples of Soft corals were obtained from the cultured of PT. Dinar Darum Lestari in Sumberkima Bay Waters, Buleleng Regency. before the experiment, coral fragments were acclimatized for 2 weeks and fed twice a week at 26 ° C (control temperature). The Experiment started by increasing the water temperature in the aquarium 1°C every hour to reach 31°C (stress temperature). Once the temperature reached, it held for 5 days. Each aquarium (26 and 31°C) was fed by Artemia salina on the second and fourth days with density 100 animals/fragments in the morning for 3 hours. The remained prey was taken by Pasteur pipette and counted manually. The results showed that there was no significant difference of feeding rates in Sarcophyton sp. dan Sinularia sp. at both control and stress temperatures because both types of soft coral fragments have relatively the same temperature tolerance. The increased temperature significantly affected the feeding rate in both soft corals (P <0,000). However, feeding time and interaction between temperature and feeding time did not have a significant effect on the feeding rate. It is assumed that the increased temperature reduces the feeding rate in these soft corals. Moreover, these soft coral seems stress due to continuously incubate in high temperature (31°C) caused no significant difference in the feeding rates at all feeding times.  keywords: soft coral, Sarcophyton sp., Sinularia sp., increased temperature., feeding rate, feeding time

PSVI-20 Extent of genetic variation in feeding behavior and genetic associations with performance and feed efficiency in crossbred growing cattle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 233-234
Author(s):  
David N Kelly ◽  
Roy D Sleator ◽  
Craig P Murphy ◽  
Stephen B Conroy ◽  
Donagh P Berry
Keyword(s):  
Genetic Variation ◽  
Feeding Behavior ◽  
Energy Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Feeding Rate ◽  
Feeding Time ◽  
Genetic Associations ◽  
Event Duration ◽  
Growing Cattle

Abstract To the best of our knowledge, the genetic variability in feeding behavior, as well as relationships with performance and feed efficiency, has not been investigated in a cattle population of greater than 1,500 animals. Our objective was to quantify the genetic parameters of several feeding behavior traits, and their genetic associations with both performance and feed efficiency traits, in crossbred growing cattle. Feed intake and live-weight data were available on 6,088 bulls, steers and heifers; of these, 4,672 cattle had backfat and muscle ultrasound data, and 1,548 steers and heifers had feeding behavior data. Genetic (co)variance parameters were estimated using animal linear mixed models; fixed effects included test group, heterosis, recombination loss, dam parity, age in months at the end of test, and the two-way interaction between age in months at the end of test and sex. Heritability was estimated to be 0.51 (0.097), 0.61 (0.100), 0.44 (0.093), 0.48 (0.094), and 0.47 (0.095) for feed events per day, feeding time per day, feeding rate, feed event duration, and energy intake per feed event, respectively. Coefficients of genetic variation ranged from 0.11 (feeding time per day) to 0.22 (feed event duration). Genetically heavier cattle with a higher energy intake per day, and faster growth rate, had a faster feeding rate and a greater energy intake per feed event. Genetic correlations between feeding behavior and feed efficiency were generally not different from zero, however, there was a genetic correlation of 0.36 (0.11) between feeding time per day and residual energy intake. Significant heritable and exploitable genetic variation exists in several feeding behavior traits in crossbred growing cattle which are also correlated with several performance traits. As some feeding behavior traits may be relatively less resource intensive to measure, they could be useful as predictor traits in beef cattle genetic evaluations.

scholarly journals Association of Feed Efficiency, Feeding Rate, and Behaviour with the Milk Performance of Dairy Cows

Dairy ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 684-694
Author(s):  
Lenka Krpálková ◽  
Niall O’Mahony ◽  
Anderson Carvalho ◽  
Sean Campbell ◽  
Gerard Corkery ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Feeding Behaviour ◽  
Feeding Rate ◽  
Feeding Time ◽  
Feed Conversion ◽  
Milk Performance

Identification of the associations of cow feed efficiency with feeding behaviour and milk production is important for supporting recommendations of strategies that optimise milk yield. The objective of this study was to identify associations between measures of feed efficiency, feed intake, feeding rate, rumination time, feeding time, and milk production using data collected from 26 dairy cows during a 3 month period in 2018. Cows averaged (mean ± standard deviation) 2.2 ± 1.7 lactations, 128 ± 40 days in milk, 27.5 ± 5.5 kg/day milk, 1.95 ± 0.69 kg feed/1 kg milk—the measure used to express feed conversion ratio (FCR), 575 ± 72 min/day rumination time, and 264 ± 67 min/day feeding time during the observation period. The coefficient of variation for rumination time (min/d) was 12.5%. A mixed linear model was selected for analyses. The most feed inefficient cows with the highest FCR (≥2.6 kg feed/1 kg milk) showed the lowest milk yield (24.8 kg/day), highest feed intake (78.8 kg), highest feeding rate (0.26 kg/min) and BCS (3.35 point). However, the relative milk yield (milk yield per 100 kg of body weight) was the highest (4.01 kg/day) in the most efficient group with the lowest FCR (≤1.4 kg feed/1 kg milk). Our study showed that the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk) had the highest rumination time (597 min/day; p < 0.05), feeding time (298 min/day; p < 0.05), rumination/activity ratio (4.39; p < 0.05) and rumination/feeding ratio (2.04; p < 0.05). Less active cows (activity time 164 min/day; p < 0.05) were the most efficient cows with the lowest FCR (≤1.4 kg feed/1 kg milk). The behavioural differences observed in this study provide new insight into the association of feed behaviour and feed efficiency with milk performance. Incorporating feeding behaviour into the dry matter intake model can improve its accuracy in the future and benefit breeding programmes.

scholarly journals Inter-Population Similarities and Differences in Predation Efficiency of a Mosquito Natural Enemy

2020 ◽  
Vol 57 (6) ◽  
pp. 1983-1987
Author(s):  
Ross N Cuthbert ◽  
Tatenda Dalu ◽  
Ryan J Wasserman ◽  
Olaf L F Weyl ◽  
P William Froneman ◽  
...  
Keyword(s):  
Critical Factor ◽  
Population Variation ◽  
Temporary Pond ◽  
Feeding Time ◽  
Eastern Cape ◽  
Feeding Rates ◽  
Calanoid Copepods ◽  
Disease Vector ◽  
Vector Mosquito ◽  
Predation Efficiency

Abstract Predation is a critical factor that mediates population stability, community structure, and ecosystem function. Predatory natural enemies can contribute to the regulation of disease vector groups such as mosquitoes, particularly where they naturally co-occur across landscapes. However, we must understand inter-population variation in predatory efficiency if we are to enhance vector control. The present study thus employs a functional response (FR; resource use under different densities) approach to quantify and compare predatory interaction strengths among six populations of a predatory temporary pond specialist copepod, Lovenula raynerae, from the Eastern Cape of South Africa preying on second instar Culex pipiens complex mosquito larvae. All individuals from the sampled populations were predatory and drove significant mortality through per capita predation rates of 0.75–1.10 mosquitoes/h at maximum densities over a 5-h feeding time. Individuals from all copepod populations exhibited Type II FRs with no significant differences in attack rates. On the other hand, there were significant differences in handling times, and therefore also maximum feeding rates (maximum experimental prey density: 32), suggesting possible genetic differences among populations that influenced predation. Owing to a widespread distribution in arid landscapes, we propose that predatory calanoid copepods such as L. raynerae play a key regulatory role at the landscape scale in the control of disease vector mosquito populations. We propose that these ecosystems and their specialist biota should thus be conserved and enhanced (e.g., via selective breeding) owing to the ecosystem services they provide in the context of public health.

Quantum Constraints in π Systems: The Role of the Pauli Antisymmetry Principle for π Electronic Properties

1997 ◽  
Vol 52 (10) ◽  
pp. 717-726
Author(s):  
Michael C. Böhm ◽  
Johannes Schütt
Keyword(s):  
Hard Core ◽  
Pauli Exclusion Principle ◽  
Exclusion Principle ◽  
Nearest Neighbour ◽  
Charge Fluctuations ◽  
Fermionic Systems ◽  
Ring Atom ◽  
Quantum Statistical ◽  
The Many

Abstract It is demonstrated that the Pauli antisymmetry principle (PAP) is without influence in the π electron subspace of polyenes and (4n + 2) annulenes (n = 0, 1, 2...) as long as the hoppings are restricted to nearest-neighbour centers. Here the π electrons behave like a hard core bosonic (hcb) ensemble where fermionic on-site and bosonic intersite properties are combined. In 4n and (2n + 1) annulenes (n = 1,2, 3...) π electron jumps between the first and last ring atom lead to a Pauli antisymmetry-based destabilization. The second quantum constraint in fermionic systems is the Pauli exclusion principle (PEP). In the many-electron basis adopted in the present work it is possible to treat the PAP and PEP as two decoupled constraints. The electronic destabilization due to the PEP is enhanced with increasing size of the system. The influence of the PAP and PEP on the π electrons is discussed in terms of π energies and charge fluctuations. The model Hamiltonians adopted are of the Hückel molecular orbital (HMO) and Pariser-Parr-Pople (PPP) type. We suggest quantum statistical definitions of the quantities "aromaticity" and "antiaromaticity", qualitative descriptors which are widely employed in the chemical literature.

Group Size and Feeding Rate in Bluegills

Copeia ◽  
1984 ◽  
Vol 1984 (4) ◽  
pp. 998 ◽  
Author(s):  
Gary Mittelbach
Keyword(s):  
Group Size ◽  
Feeding Rate

Comparative Field Energetics of Two Macropod Marsupials and a Ruminant.

1990 ◽  
Vol 17 (6) ◽  
pp. 591 ◽  
Author(s):  
KA Nagy ◽  
GD Sanson ◽  
NK Jacobsen
Keyword(s):  
Feeding Rate ◽  
Energy Content ◽  
Metabolizable Energy ◽  
Ecological Modelling ◽  
Feeding Rates ◽  
Doubly Labelled Water ◽  
Water Influx ◽  
Scaling Relationship ◽  
Field Metabolic Rates ◽  
Free Ranging

Field metabolic rates (FMRs) and water influx rates were measured via the doubly labelled water method in wild Tasmanian pademelons and grey kangaroos living in the Jock Marshall Reserve at Clayton, Victoria, and in wild black-tailed deer free-ranging within a nature reserve at Davis, California. Deer expended more than 3 times more energy per day than similar sized grey kangaroos. Feeding rates required to achieve energy balance were estimated from FMRs along with an estimate of metabolizable energy content of the food. The estimated feeding rates for pademelons and kangaroos were combined with similar values for 5 other species of macropods to calculate an allometric (scaling) relationship for food requirements of macropod marsupials. Feeding rate had the following relationship to body mass: g food (DM) consumed per day = 0.20 g body mass0.79 (r2 = 0.94). The findings reported herein should be useful for predicting the approximate food requirements of free-ranging macropods and deer for purposes of ecological modelling, conservation efforts and management programmes.

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