Starvation endurance in the antTemnothorax nylanderidepends on group size, body size and access to larvae

2013 ◽  
Vol 38 (1) ◽  
pp. 89-94 ◽  
Author(s):  
ANDREAS P. MODLMEIER ◽  
SUSANNE FOITZIK ◽  
INON SCHARF
Keyword(s):  
Body Size ◽  
Group Size

The effects of age, sex, reproductive status and temporal factors on the time-use of free-ranging red kangaroos

1993 ◽  
Vol 20 (6) ◽  
pp. 785 ◽  
Author(s):  
DM Watson ◽  
TJ Dawson
Keyword(s):  
Body Size ◽  
Group Size ◽  
Time Use ◽  
New South ◽  
New South Wales ◽  
Time Of Day ◽  
Adult Males ◽  
South Wales ◽  
Free Ranging ◽  
Foraging Time

The effects of temporal (time of day and season) factors and size, sex, female reproductive state and group size on the diel time-use of free-ranging red kangaroos (Macropus rufus) was examined. Particular emphasis was given to the effects on their foraging behaviour, with foraging divided into cropping, chewing and searching components. The study was conducted in semi-arid western New South Wales from July 1991 to March 1992, a time of deepening drought conditions in New South Wales. Group size had very little influence on the time-use of M. rufus. It was negatively but only weakly correlated with the proportion of foraging time spent chewing (chewing intensity). No significant differences in time-use were found between size classes of adult males (large and medium-sized males), females with or without pouch young, or females with different-sized pouch young (no visible young, small pouch young or large pouch young). Differences occurred between adult males, adult females and subadult kangaroos. These differences were mainly associated with their chewing and searching behaviour and were related to body size; as body size increased the proportion of time spent chewing and the intensity of chewing increased while the proportion of time searching and the proportion of foraging time spent searching (searching intensity) decreased. Neither the proportion of time spent cropping or foraging nor the proportion of foraging time spent cropping (cropping intensity) or the proportion of active time spent foraging (foraging intensity) differed between any size/sex/reproductive class. Temporal effects had a considerable influence on time-use. M. rufus were most active at night and in the few hours after sunrise and sunset. Seasonal changes in time-use were largely a result of changes in daytime behaviour. M. rufus foraged less and rested more during the day in winter than in spring or summer. There was no increase in the intensity or proportion of time spent foraging or cropping at night to compensate for the reduction in diurnal foraging. It is hypothesised that temporal variations in time-use were related to variations in weather and vegetation conditions.

scholarly journals Group size, temperature and body size modulate the effects of social hierarchy on basal cortisol levels in fishes

2021 ◽  
Vol 136 ◽  
pp. 105077
Author(s):  
Eduardo Bessa ◽  
Bastien Sadoul ◽  
David J. Mckenzie ◽  
Benjamin Geffroy
Keyword(s):  
Body Size ◽  
Group Size ◽  
Social Hierarchy ◽  
Basal Cortisol ◽  
Cortisol Levels

scholarly journals Unavoidable limits on group size in a body size-based linear hierarchy

2010 ◽  
Vol 21 (4) ◽  
pp. 819-825 ◽  
Author(s):  
Tzo Zen Ang ◽  
Andrea Manica
Keyword(s):  
Body Size ◽  
Group Size

scholarly journals Phenotypic Clumping Decreases With Flock Richness in Mixed-Species Bird Flocks

2021 ◽  
Vol 8 ◽  
Author(s):  
Priti Bangal ◽  
Hari Sridhar ◽  
Kartik Shanker
Keyword(s):  
Body Size ◽  
Foraging Behavior ◽  
Group Size ◽  
Positive Interactions ◽  
Flock Size ◽  
Mixed Species ◽  
Taxonomic Relatedness ◽  
Western Ghats Of India ◽  
Mixed Species Flocks ◽  
Species Flocks

Animals that live in groups may experience positive interactions such as cooperative behavior or negative interactions such as competition from group members depending on group size and similarity between individuals. The effect of group size and phenotypic and ecological similarity on group assembly has not been well-studied. Mixed-species flocks are important subsets of bird communities worldwide. We examined associations within these in relation to flock size, to understand rules of flock assembly, in the Western Ghats of India. We examined the relationship between phenotypic clumping and flock richness using four variables—body size, foraging behavior, foraging height and taxonomic relatedness. Using a null model approach, we found that small flocks were more phenotypically clumped for body size than expected by chance; however, phenotypic clumping decreased as flocks increased in size and approached expected phenotypic variation in large flocks. This pattern was not as clear for foraging height and foraging behavior. We then examined a dataset of 55 flock matrices from 24 sites across the world. We found that sites with smaller flocks had higher values of phenotypic clumping for body size and sites with larger flocks were less phenotypically clumped. This relationship was weakly negative for foraging behavior and not statistically significant for taxonomic relatedness. Unlike most single-species groups, participants in mixed-species flocks appear to be able to separate on different axes of trait similarity. They can gain benefits from similarity on one axis while mitigating competition by dissimilarity on others. Consistent with our results, we speculate that flock assembly was deterministic up to a certain point with participants being similar in body size, but larger flocks tended to approach random phenotypic assemblages of species.

scholarly journals Trait overdispersion and the role of sociality in the assembly of social spider communities across the Americas

2018 ◽  
Vol 115 (23) ◽  
pp. 6010-6015 ◽  
Author(s):  
Philippe Fernandez-Fournier ◽  
Jennifer Guevara ◽  
Catherine Hoffman ◽  
Leticia Avilés
Keyword(s):  
Body Size ◽  
Group Size ◽  
Abiotic Factors ◽  
Social Systems ◽  
Null Model ◽  
Niche Space ◽  
Social Spider ◽  
The Social ◽  
Size And Morphology

Among the factors that may lead to differences in resource use among closely related species, body size and morphology have been traditionally considered to play a role in community assembly. Here we argue that for animals that live and forage in groups, level of sociality, reflecting differences in group size and cooperative tendencies, can be an additional and powerful dimension separating species in niche space. We compare 50+ communities of the social spider genus Anelosimus across the Americas against a null model that accounts for known effects of biotic and abiotic factors on the distribution of social systems in the genus. We show that these communities are more overdispersed than expected by chance in either or both body size and level of sociality, traits we have previously shown to be associated with differences in resource utilization (prey size, microhabitat, and phenology). We further show that the contribution of sociality to differences in the size of the prey captured is two to three times greater than that of body size, suggesting that changes in group size and cooperative tendencies may be more effective than changes in body size at separating species in niche space.

Inter- and intraspecific vigilance patterns of two sympatric Tibetan ungulates

2019 ◽  
Vol 101 (2) ◽  
pp. 498-506 ◽  
Author(s):  
Yunchao Luo ◽  
Lin Wang ◽  
Le Yang ◽  
Xinxin Wang ◽  
Ming Tan ◽  
...  
Keyword(s):  
Body Size ◽  
Body Mass ◽  
Group Size ◽  
Sexually Dimorphic ◽  
Small Animals ◽  
Wild Ungulates ◽  
Small Female ◽  
Social Monitoring ◽  
Negative Effect ◽  
Large Groups

Abstract Vigilance is an important antipredation technique that can be affected by many factors, such as body size and group size. Small animals are more vulnerable than large ones, so the former are expected to behave more vigilantly than the latter. This effect of body size on vigilance may occur inter- or intraspecifically. We studied the vigilance behavior of two sympatric wild ungulates, Tibetan antelopes (Pantholops hodgsonii) and Tibetan gazelles (Procapra picticaudata). Tibetan antelopes, with a body size of 33 kg are much larger than Tibetan gazelles, with a body size of approximately 14 kg. Tibetan antelopes are sexually and body-size dimorphic; that is, males are much heavier than females. Alternately, Tibetan gazelles are sexually dimorphic but the sexes do not differ in weight. Tibetan gazelles scanned their environment more frequently than Tibetan antelopes did. Small female Tibetan antelopes scanned their environment more frequently than males did, whereas male Tibetan gazelles scanned their environment more frequently than females did. Group size did not affect the vigilance of Tibetan gazelle, but its negative effect on the vigilance of male Tibetan antelopes was marginally significant. In female Tibetan antelopes, vigilance in large groups was high probably because of scramble competition and social monitoring. Our results suggested that body mass and group size play an important role in shaping the vigilance of these two rare Tibetan ungulates.

scholarly journals Are Abrolhos no-take area sites of naïve fish? An evaluation using flight initiation distance of labrids

2016 ◽  
Vol 14 (4) ◽  
Author(s):  
José de Anchieta C. C. Nunes ◽  
◽  
Miguel Loiola ◽  
Ricardo J. Miranda ◽  
Cláudio L. S. Sampaio ◽  
...  
Keyword(s):  
Body Size ◽  
Reef Fish ◽  
Group Size ◽  
Avoidance Behavior ◽  
Flight Initiation Distance ◽  
Fishing Pressure ◽  
Multiple Use ◽  
Fish Stocks ◽  
Positive Effect ◽  
Flight Initiation

ABSTRACT Fishing pressure affects the behavior of reef fish, especially of fishery-targeted species. In this context, it is critical to understand if fish behavior is preserved in no-take areas (NTAs), which are considered the best instrument for the recovery of fish stocks. Comparing the flight initiation distances (FIDs) of fish inhabiting multiple-use areas (MUAs), where fishing is allowed (including spearfishing), and NTAs is a useful approach to test whether NTAs can be effective as fish refuges. Here, we compared whether the FIDs of two target (Sparisoma axillare and Scarus trispinosus ) and one non-target (Halichoeres poeyi ) labrids are greater in the MUAs than in the NTAs. We also investigated whether group size (GS) and body size (BS) exert any effect on the FID. We sampled four MUAs and four NTAs in the Abrolhos Bank (Brazil). We found that only for the targeted species FID was shorter inside the NTAs and that the BS had a positive effect on the FID of all species. The GS and BS of the fish are greater in the NTAs than in the multiple-use areas only for S. trispinosus . Our study shows that fish, especially those species that are fishery targets, display an avoidance behavior against spearfishermen likely as a consequence of fishing pressure. We suggest that the NTAs in Abrolhos are not only important sites for the recovery of fish stocks but also possibly act as a repository area of naïve fish (fish that allow human approach), for reefs open for fishing.

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