Group size and termite consumption in the armadillo lizard, Cordylus cataphractus

2008 ◽  
Vol 29 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Johannes van Wyk ◽  
P. le Fras Mouton ◽  
Cindy Shuttleworth
Keyword(s):  
Group Size ◽  
Dry Period ◽  
Insect Abundance ◽  
Competition For Food ◽  
Large Groups ◽  
Intragroup Competition

Abstract We investigated possible differences in the consumption of termites (Microhodotermes viator) by individuals in different sized groups of Cordylus cataphractus during different times of the year. Scats, collected once a month from small (2-3 individuals), medium (4-10 individuals) and large C. cataphractus groups (more than 10 individuals), from January to December 2005, were analysed for the presence of termite head material. We found termite consumption to be generally greater in larger than smaller groups throughout the year, but only significantly so during the dry months, March and April. Individuals in all group categories utilized termites throughout the year, but consumption was low at the end of winter, a time when general insect abundance is high. We conclude that termitophagy is important to individuals living in large groups, particularly during the dry period of the year, most probably to reduce intragroup competition for food.

The number of feeding spaces required for large groups of early-weaned pigs

1994 ◽  
Vol 1994 ◽  
pp. 167-167
Author(s):  
P.H. Simmins ◽  
S. Malkin
Keyword(s):  
Group Size ◽  
Initial Period ◽  
The Novel ◽  
Weaned Pigs ◽  
Welfare Systems ◽  
Weaned Pig ◽  
Sloping Bed ◽  
Large Groups

Inadequate feeding space allowance could limit the performance of the early-weaned pig. No information is available on the amount of space required as group size increases; this is now more typical for some of the novel welfare systems. It has been suggested that the early-weaned pigs tend to feed together for an initial period. Indications exist that, if inadequate feeding space is provided post-weaning, a proportion of piglets may suffer.The objective of the experiment was to investigate the effect of restricting access to feed on the performance of the early-weaned pig housed in large groups in a novel sloping bed weaner pen.

Vigilance Patterns of Bald Eagles Feeding in Groups

The Auk ◽  
1986 ◽  
Vol 103 (2) ◽  
pp. 263-272 ◽  
Author(s):  
Susan K. Knight ◽  
Richard L. Knight
Keyword(s):  
Group Size ◽  
Human Activity ◽  
Small Groups ◽  
Haliaeetus Leucocephalus ◽  
Potential Danger ◽  
Predator Detection ◽  
Bald Eagles ◽  
Additional Function ◽  
Scanning Time ◽  
Large Groups

Abstract Patterns of vigilant behavior of wintering Bald Eagles (Haliaeetus leucocephalus) feeding on spawned salmon were examined in 1983-1984 on the Nooksack River in northwestern Washington. Vigilance in feeding birds has, in general, been attributed to predator detection; however, we proposed an additional function of vigilance in socially feeding birds that are vulnerable to food robbery and possible injury by conspecifics. We tested predictions of two nonexclusive hypotheses: (1) eagles look up while feeding to detect danger from humans, and (2) eagles look up while feeding to detect pirating attempts or avoid injury by conspecifics. Results suggest that the function of vigilance varies, depending on the size of the feeding group. Vigilance patterns of eagles feeding in small groups (1-4 eagles) and medium groups (5-7 eagles0 are consistent with hypothesis 1, whereas those of eagles feeding in large groups (8-14 eagles) are consistent with hypothesis 2. Eagles in small groups were more vigilant (measured as scanning time and rate of head raising) when feeding near potential danger (riverbank cover) than when far from danger. Adult eagles feeding in areas of intense human activity were more vigilant than immatures feeding at the same site and were more vigilant than both adults and immatures feeding at secluded sites. Vigilance declined as group size increased from 1 to 4 eagles, and increased as group size ranged from 8 to 14 eagles. Feeding eagles that were looking up at the time of a pirating attempt were more successful in keeping their food than eagles with their heads down. In feeding areas where human activity was minimal, eagles formed larger groups than at more disturbed sites.

The relationship of social vocalizations to surface behavior and aggression in the Hawaiian humpback whale (Megaptera novaeangliae)

1986 ◽  
Vol 64 (10) ◽  
pp. 2075-2080 ◽  
Author(s):  
Gregory K. Silber
Keyword(s):  
Surface Activity ◽  
Group Size ◽  
Social Dominance ◽  
Humpback Whale ◽  
Megaptera Novaeangliae ◽  
Adult Males ◽  
Surface Behavior ◽  
Relationship Of ◽  
Large Groups ◽  
The Relationship

Humpback whale (Megaptera novaeangliae) social vocalizations (nonsong sounds) were clearly related to whale group size and surface activity. Social sounds occurred almost exclusively in groups containing three or more whales and were rarely heard near single whales, pairs, or cow–calf groups. Large groups (3 to 20 individuals) vocalized at an overall mean rate of 43.1 ± 55.52 sounds per whale/h. Group size changed frequently and a dramatic increase in vocalization rate resulted when a new whale entered a group. Large groups engaged in flurries of surface activity, such as breaching, flipper- and tail-slapping, and underwater bubbling. Aggressive encounters resulted from male–male interaction. Social sounds probably acted to demonstrate aggression or agitation as adult males competed for temporary social dominance within the group and for proximity to the female. Likewise, visual displays may have been used as threats in close quarters and were apparently produced in conjunction with sounds to convey levels of aggression. Although other studies suggested that surface activity increased with group size, I found a negative correlation between activity and group size, both in the group as a whole and per individual. In contrast, social vocalizations per group increased with group size while the vocalization rate per individual did not vary significantly with increasing group size.

Coevolution of neocortical size, group size and language in humans

1993 ◽  
Vol 16 (4) ◽  
pp. 681-694 ◽  
Author(s):  
R. I. M. Dunbar
Keyword(s):  
Group Size ◽  
Nonhuman Primates ◽  
Old World Monkeys ◽  
Time Sharing ◽  
Social Grooming ◽  
Historical Societies ◽  
Behavioural Characteristics ◽  
Personal Experiences ◽  
Group Members ◽  
Large Groups

AbstractGroup size covaries with relative neocortical volume in nonhuman primates. This regression equation predicts a group size for modern humans very similar to that for hunter-gatherer and traditional horticulturalist societies. Similar group sizes are found in other contemporary and historical societies. Nonhuman primates maintain group cohesion through social grooming; among the Old World monkeys and apes, social grooming time is linearly related to group size. Maintaining stability of human-sized groups by grooming alone would make intolerable time demands. It is therefore suggested (1) that the evolution of large groups in the human lineage depended on developing a more efficient method for time-sharing the processes of social bonding and (2) that language uniquely fulfills this requirement. Data on the size of conversational and other small interacting groups of humans accord with the predicted relative efficiency of conversation compared to grooming as a bonding process. In human conversations about 60% of time is spent gossiping about relationships and personal experiences. Language may accordingly have evolved to allow individuals to learn about the behavioural characteristics of other group members more rapidly than was feasible by direct observation alone.

scholarly journals Research groups: how big should they be?

2015 ◽  
Author(s):  
Isabelle Cook ◽  
Sam Grange ◽  
Adam Eyre-Walker
Keyword(s):  
Impact Factor ◽  
Group Size ◽  
The United Kingdom ◽  
Average Group ◽  
Using Data ◽  
Number Of Publications ◽  
Number Of Citations ◽  
The Impact ◽  
Large Groups ◽  
The Relationship

We have investigated the relationship between research group size and productivity in the life sciences in the United Kingdom using data from 398 principle investigators (PIs). We show that the number of publications increases linearly with group size, but that the slope is modest relative to the intercept, and that the relationship explains little of the variance in productivity. A comparison of the slope and intercept suggests that PIs contribute on average 5-times more productivity than an average group member and using multiple regression we estimate that post-doctoral researchers are approximately 3–times more productive than PhD students. We also find that the impact factor and the number of citations are both non-linearly related to group size such that there is a maximum. However, the relationships explain little of the variance and the curvatures are shallow so the impact factor and the number of citations do not greatly depend upon group size. The intercept is large relative to curvature suggesting that the PI is largely responsible for the impact factor and the number of citations from their group. Surprisingly we find this non-linear relationship for post-docs, but for PhD students we observe a slight but significant decrease in the impact factor. The results have important implications for the funding of research. Given a set number of Pis there is no evidence of diminishing returns in terms of the number of papers published and only a very weak cost to very large groups in terms of where those papers are published and the number of citations they receive. However, the results do suggest that it might be more productive to invest in new permanent members of faculty rather than additional post-docs and PhD students.

scholarly journals Does Group Size Affect Field Metabolic Rate of Arabian Babbler (Turdoides squamiceps) Nestlings?

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 525-528
Author(s):  
Avner Anava ◽  
Michael Kam ◽  
Amiram Shkolnik ◽  
A. Allan Degen
Keyword(s):  
Metabolic Rate ◽  
Group Size ◽  
Annual Number ◽  
Field Metabolic Rate ◽  
Negative Effect ◽  
Group Feeding ◽  
Group Members ◽  
Single Nest ◽  
Large Groups ◽  
Arabian Babbler

Abstract Arabian Babblers (Turdoides squamiceps) are territorial, cooperative breeding passerines in which groups consist of parents and helpers. All members of the group feed nestlings in a single nest and all group members provision at similar rates. We hypothesized that the field metabolic rate (FMR) of Arabian Babbler nestlings is related to group feeding; that is, FMR would be greater in nestlings of larger rather than smaller sized groups. To test that hypothesis, we measured FMR of 10 day old nestlings from small (2 and 3 individuals), medium (4 and 5 individuals), and large (6 or more individuals) groups. We also determined number of hatchlings and fledglings produced per group. There was an increase in body mass and FMR from small to medium-sized groups, but there was a levelling off or decrease in those parameters in large groups. That suggests that there is an optimum group number for provisioning nestlings, above which there may be a negative effect. The relationship between group size and annual number of eggs was not significant, but there was a positive and linear relationship between group size and annual fledglings production. Thus, more eggs reached the fledgling stage with an increase in group size, suggesting that larger groups are better able to defend the nest against predators.

Group composition and cohesion in sympatric white-tailed deer and mule deer

2003 ◽  
Vol 81 (7) ◽  
pp. 1119-1130 ◽  
Author(s):  
Susan Lingle
Keyword(s):  
Group Size ◽  
Mule Deer ◽  
Size Composition ◽  
Odocoileus Hemionus ◽  
Habitat Conditions ◽  
Small Female ◽  
Habitat Variation ◽  
The Social ◽  
Southern Alberta ◽  
Large Groups

White-tailed deer (Odocoileus virginianus) have been reported to live in smaller groups than mule deer (Odocoileus hemionus). Group size, however, generally varies with habitat conditions, and no comparison has been made between the social structures of the two species living in the same ecological conditions. I compared the size, composition, and stability of groups formed by sympatric whitetails and mule deer living in a prairie habitat in southern Alberta. Seasonal trends were similar for the two species. Females and fawns usually formed small groups during summer. Larger mixed-sex groups became increasingly common during winter, well after the breeding season. Despite the similar seasonal trend, mule deer were significantly more likely than whitetails to occur in relatively large groups composed of both sexes during winter, and whitetails were more likely to occur in small female groups. Mule deer groups were more stable than whitetail groups, and marked mule deer fawns developed strong associations with other known fawns. Habitat variation was limited and was not related to group size. These results show that the composition and cohesion of whitetail and mule deer groups differ, even when the species live in similar circumstances. The differences in grouping behaviour, larger more cohesive groups formed by mule deer than by whitetails, are consistent with those expected to result from the selection pressure of predation.

Production, behaviour and welfare of growing pigs as influenced by drinker allocation and group size

1998 ◽  
Vol 1998 ◽  
pp. 114-114
Author(s):  
S. P. Turner ◽  
S. A. Edwards
Keyword(s):  
Group Size ◽  
Empirical Investigation ◽  
Growing Pigs ◽  
Production Performance ◽  
Light Weight ◽  
Large White ◽  
Commercial Grower ◽  
Heavy Medium ◽  
Large Groups ◽  
The Relationship

The requirement for water of growing pigs in large groups has been neglected. Current MAFF recommendations suggest one nipple drinker per 10 pigs, while farmers have often used a ratio of 1 per 20 animals. Neither approach is based on empirical investigation. The relationship between group size and the number of drinking points can not be assumed to be linear. The aim was to assess group size and the two conflicting ratios of drinkers for their effect on welfare, as measured by production performance, drinking and social behaviour.A total of 640 Large White x Landrace growing pigs (start weight 36kg) were housed in a fully slatted commercial grower house for five weeks. Four replicates were used and each animal was assigned to 1 of 4 treatments in a 2 x 2 factorial design of two group sizes (20 vs 60) and two ratios of nipple drinkers to pigs (1:10 vs 1:20). The groups of 20 comprised of pigs from 3 different pens, while 9 pens contributed to the groups of 60. The floor space per pig was maintained constant across treatments. Nine focal pigs (three each of heavy, medium and light weight) were selected from each pen.

Patterns of association among female Indo-Pacific bottlenose dolphins (Tursiops aduncus) in a population forming large groups

Behaviour ◽  
2017 ◽  
Vol 154 (9-10) ◽  
pp. 1013-1028 ◽  
Author(s):  
Miki Nishita ◽  
Miki Shirakihara ◽  
Masao Amano
Keyword(s):  
Group Size ◽  
Bottlenose Dolphins ◽  
Reproductive Status ◽  
Association Measure ◽  
Remarkable Feature ◽  
Tursiops Aduncus ◽  
Large Group ◽  
Photo Identification ◽  
Factors Influencing ◽  
Large Groups

Indo-Pacific bottlenose dolphins (Tursiops aduncus) around Amakusa-Shimoshima, Japan form large groups of >100 individuals, a remarkable feature of this population, which is much larger than previously studied bottlenose dolphins. Using photo-identification data collected on 33 days in 2012, associations among 70 females were investigated using two scales of association measure (photograph- and group-based association) to know whether they associate based on their reproductive status, as is typically observed in other populations with smaller group size. Significant differences in associations between females of the same reproductive status category and those in different categories were detected, and a female that lost her calf within a year decreased associations with females with calves of the same age. These suggests that even in a population with large group size, the reproductive status of females is one of the factors influencing their associations.

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