scholarly journals Relationship between group size and feeding success of cattle egrets (Bubulcus ibis) in the central Free State

2008 ◽  
Vol 27 (3) ◽  
pp. 216-227
Author(s):  
Hennie Butler ◽  
Ordino Kok
Keyword(s):  
Group Size ◽  
Close Association ◽  
Time Of Day ◽  
Feeding Success ◽  
Feeding Experiments ◽  
Bubulcus Ibis ◽  
Energy Inputs ◽  
Average Group ◽  
Least Energy ◽  
Average Group Size

Regardless of habitat or time of day, cattle egrets feeding independently of hosts generally occurring larger groups than those feeding in close association with ungulates. The average group size of three individuals feeding in association with hosts stays remarkably constant with regard to divergent situations. Based on the type of habitat and the grazing speed of the host concerned, cattle egrets achieve the highest feeding success (number of prey items) with the least energy inputs (number of paces) in association with cattle, and to a lesser extent with the closely related buffalo. Compared to solitary birds, cattle egrets feeding in groups experience without exceptional higher feeding success. Results of feeding experiments, as well as the exceptional occurrence of so-called feeding lines, confirm the phenomenon that the feeding success of cattle egrets correlates closely with the size of the feeding group.

scholarly journals Social and Play Behavior in a Wild Eastern Coyote, Canis latrans, Pack

2007 ◽  
Vol 121 (4) ◽  
pp. 397 ◽  
Author(s):  
Jonathan G. Way
Keyword(s):  
Group Size ◽  
Canis Latrans ◽  
Play Behavior ◽  
Maximal Group ◽  
Average Group ◽  
Specific Radio ◽  
Average Group Size

I had close and consistent observations of a wild eastern Coyote pack (Canis latrans) from January 2000 to August 2007. During this time, I obtained 3156 radio-locations on a specific radio-collared breeding male (“Sill”) and observed him and/or members of his pack on 375 occasions. The average group size = 3.0 ± 2.3 (SD) Coyotes with 1.9 ± 1.2 (SD) being adults and 1.1 ± 1.9 being pups. Maximal group size involved 12 Coyotes (9 pups, 3 adults). During these observations, Coyotes most often behaved in a friendly manner toward each other as indicated by 80 of my observations involving play between pups, and 15 involving play among adult Coyotes. On the evening of 6 July 2007 I observed the breeding male (>8 yr old), his mate (>5 yr old), one of their full-sized probable yearlings, and five pups playing intensely for 33 minutes. This paper details social and play behavior from this pack, especially from the 6 July 2007 observation.

Agonistic behavior among mountain goats foraging in winter

1988 ◽  
Vol 66 (11) ◽  
pp. 2585-2588 ◽  
Author(s):  
Mark A. Masteller ◽  
James A. Bailey
Keyword(s):  
Group Size ◽  
Agonistic Behavior ◽  
Dominance Order ◽  
Age Classes ◽  
Oreamnos Americanus ◽  
Adult Females ◽  
Average Group ◽  
Mountain Goats ◽  
Mineral Licks ◽  
Average Group Size

During two winters we studied agonistic behavior of foraging mountain goats (Oreamnos americanus) in both natural and manipulated conditions. By maintaining food pellets at bait site we tested two hypotheses: (i) dominant goats will have primary access to the food, and (ii) kids of dominant nannies will have access to the food with their mothers. At the bait site, average group size was larger and goats in each sex–age class were more aggressive compared with those away from the site. The dominance order among sex–age classes at the bait was similar to that reported at mineral licks, except that 2-year-old males dominated adult females. When goats fed at the bait site, adult females with kids were very aggressive and nanny–kid distances decreased. At the bait, an orphan kid received much aggression, while kids with their mothers received few threats. At the bait site, dominant goats had primary, but not exclusive, access to the bait and kids fed with their mothers, which supported our hypotheses.

Variation in coyote social organization: the influence of prey size

1981 ◽  
Vol 59 (4) ◽  
pp. 639-652 ◽  
Author(s):  
W. Don Bowen
Keyword(s):  
Social Organization ◽  
Group Size ◽  
National Park ◽  
Foraging Ecology ◽  
Mule Deer ◽  
Group Foraging ◽  
Winter Diet ◽  
Average Group ◽  
Average Size ◽  
Average Group Size

The foraging ecology and social organization of coyotes, Canis latrans, were studied in Jasper National Park, Alberta, from 1974 to 1977. Diet was determined from analysis of 1967 feces. In summer when rodents (43%) and neonatal cervids (19%) were the major foods, average group size in the population was 1.4 (n = 339 observations), whereas in winter when large ungulates dominated the diet (67%) average group size rose to 2.0 (n = 798). This pattern was also evident for two packs where mean group size rose from 1.5 in summer to 3.1 in winter with the incorporation of pups into the pack. The percentage of mule deer in the winter diet varied directly with group size. Packs were more successful than pairs or single coyotes in catching mule deer. In contrast, the percentage of elk in the winter diet was independent of group size. Since elk were scavenged, their occurrence in the winter diet was primarily a function of the number dying within each coyote territory. Pairs and packs defended ungulate carcasses and used these clumped resources more effectively than single coyotes. I conclude that group foraging increases the feeding efficiency of coyotes in Jasper. A comparison of the present findings with the results of the other coyote studies indicates that variation in the average size of prey eaten is an important factor determining group size and structure of coyote populations.

The effects of woodland fragmentation and human activity on roe deer distribution in agricultural landscapes

2001 ◽  
Vol 79 (4) ◽  
pp. 679-689 ◽  
Author(s):  
A JM Hewison ◽  
J P Vincent ◽  
J Joachim ◽  
J M Angibault ◽  
B Cargnelutti ◽  
...  
Keyword(s):  
Group Size ◽  
Human Activity ◽  
Landscape Change ◽  
Roe Deer ◽  
Agricultural Landscapes ◽  
Behavioural Plasticity ◽  
Landscape Modification ◽  
Average Group ◽  
Average Group Size ◽  
Field Behaviour

Landscape structure and human activity influence the distribution and abundance of species. Landscape modifications have resulted in loss of habitat, increased isolation between remnant patches, and increased disturbance. We compare distributions and group sizes of roe deer across four open agricultural landscapes of differing structure. The roe deer, essentially a woodland species, exhibits behavioural plasticity, recently colonising the agricultural plain. Our results suggest that the switch between forest and field behaviour may involve a threshold of landscape geometry concerning woodland connectivity. Where woodland fragments are numerous and widely dispersed, roe deer retain strong links to woodland structures, probably for cover and social reasons. Where remaining woodland is clumped, with little edge, roe deer adopt an open field habit, remaining at a distance from woodland. Average winter group size increased with distance from woodland, resulting in large herds typical of field roe deer populations at the more open sites. In addition, roe deer avoided areas associated with human activity, probably because of associated disturbance, particularly where woodland cover was lacking. Finally, average group size was lower in areas where the level of human activity was high. The behavioural plasticity of this species means that landscape change may not be limiting. Therefore, to predict the effects of landscape modification, models need to incorporate variation in the animal–landscape relationship due to behavioural plasticity.

Relationships between group size, feeding time, and agonistic behavior of mountain goats

1985 ◽  
Vol 63 (11) ◽  
pp. 2501-2506 ◽  
Author(s):  
Kenneth L. Risenhoover ◽  
James A. Bailey
Keyword(s):  
Group Size ◽  
Agonistic Behavior ◽  
Alpine Tundra ◽  
Feeding Time ◽  
Oreamnos Americanus ◽  
Movement Rates ◽  
Average Group ◽  
Risk Of Predation ◽  
Mountain Goats ◽  
Average Group Size

Relationships between group size, intragroup spacing, movement rates, foraging behavior, and frequency of agonistic behavior of mountain goats (Oreamnos americanus) using alpine tundra were examined during summer. Feeding time of goats increased with group size to about 12 goats because of a reduction in time devoted to alert behavior. Rates of movement by foraging goats increased with group size, whereas rates of agonistic behavior between goats declined with increased group size. Intragroup spacing declined as group size increased. Nannies and 2-year-old goats were more aggressive than were other sex- or age-classes. Two-year-old goats, yearlings, and billies received more threatening displays than did other classes. In Colorado, nannies with kids form large nursery bands on alpine tundra. This behavior can reduce the risk of predation to individuals while allowing nannies with kids to exploit forage away from precipitous terrain. Average group size may be a useful index to forage abundance and continuity on summer goat range.

Eco-ethology of the common langur Semnopithecus entellus (Dufresne) in Bangladesh

1970 ◽  
Vol 25 ◽  
pp. 3-10 ◽  
Author(s):  
M Farid Ahsan ◽  
MA Reza Khan
Keyword(s):  
Group Size ◽  
Rural Areas ◽  
Food Plants ◽  
Police Station ◽  
Plant Parts ◽  
Vegetative Plant ◽  
Semnopithecus Entellus ◽  
Average Group ◽  
The Common ◽  
Average Group Size

Eco-ethological aspects of the common langur (Hanuman) Semnopithecus entellus (Dufresne) were studied between July and September 1981 in the rural areas of Keshabpur Police Station, Jessore, Bangladesh. Three bisexual troops were monitored for 355 hrs for determining group-size and composition, age-sex relationship, and other ecological and behavioural features. The average group-size was 13.67±0.00 in July and 14.67±1.33 in September. Of the major diurnal activities viz., rest, move, sit, social groom, self groom, play and feed, the Hanumans spent maximum time in sitting (44.32%). Dyad behaviour of the Hanumans and their relationships with other animals including man has been described. Hanumans used more than 60 species as food plants of which 43 were identified. They mostly ate vegetative plant parts (74.88%), thus indicating their folivorous nature. The welfare of the Hanumans has also been dealt with. Key words: Common langur (Hanuman), Semnopithecus entellus, ecology, ethology, Bangladesh Univ. j. zool. Rajshahi Univ. Vol.25 2006 p.3-10

scholarly journals Status of blue sheep and Himalayan tahr in Dhorpatan Hunting Reserve, Nepal

2013 ◽  
Vol 21 (1) ◽  
pp. 25-30 ◽  
Author(s):  
JB Karki ◽  
BB Thapa
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Group Size ◽  
Blue Sheep ◽  
Average Group ◽  
Hemitragus Jemlahicus ◽  
The Mean ◽  
Pseudois Nayaur ◽  
Himalayan Tahr ◽  
Average Group Size

A survey of blue sheep (Pseudois nayaur) was conducted in six blocks of Dhorpatan Hunting Reserve (DHR), Nepal. A total of 852 blue sheep were recorded in 73 different groups. The average group size was found to be 11.7 individuals. The average population density of blue sheep in the reserve was found to be 1.28 animals per km2. There were 263 rams, 307 ewes, 89 yearlings and 39 lambs. Among the rams, 126 were classified as trophy rams, 92 as medium rams and 45 as young rams. The ratio of trophy rams to other rams was found to be higher than those found in the earlier studies. The mean sex ratio was 86 males per 100 females and the yearling to ewes ratio was 29 per 100 ewes. The survey of Himalayan tahr (Hemitragus jemlahicus) in Sundaha block recorded 53 individuals with 30 males, 14 females, eight yearlings, and one lamb. The results indicated that the existing quota of blue sheep hunting can be safely continued. In case of higher demands, two more quotas can be added to Barse, Dogadi and Sundaha blocks for the next five years (2008-2012). Himalayan tahrs can be hunted in all the blocks. Sundaha block can sustain four while the rest of the blocks can sustain two Himalayan tahrs per year. DOI: http://dx.doi.org/10.3126/banko.v21i1.9060 Banko Janakari, Vol. 21, No. 1 2011; 25-30

scholarly journals A metapopulation model of social group dynamics and disease applied to Yellowstone wolves

2021 ◽  
Vol 118 (10) ◽  
pp. e2020023118
Author(s):  
Ellen E. Brandell ◽  
Andrew P. Dobson ◽  
Peter J. Hudson ◽  
Paul C. Cross ◽  
Douglas W. Smith
Keyword(s):  
Group Size ◽  
Group Dynamics ◽  
Multiple Scales ◽  
Dynamic Assessment ◽  
Population Level ◽  
Host Population ◽  
Metapopulation Model ◽  
Social Species ◽  
Average Group ◽  
Average Group Size

The population structure of social species has important consequences for both their demography and transmission of their pathogens. We develop a metapopulation model that tracks two key components of a species’ social system: average group size and number of groups within a population. While the model is general, we parameterize it to mimic the dynamics of the Yellowstone wolf population and two associated pathogens: sarcoptic mange and canine distemper. In the initial absence of disease, we show that group size is mainly determined by the birth and death rates and the rates at which groups fission to form new groups. The total number of groups is determined by rates of fission and fusion, as well as environmental resources and rates of intergroup aggression. Incorporating pathogens into the models reduces the size of the host population, predominantly by reducing the number of social groups. Average group size responds in more subtle ways: infected groups decrease in size, but uninfected groups may increase when disease reduces the number of groups and thereby reduces intraspecific aggression. Our modeling approach allows for easy calculation of prevalence at multiple scales (within group, across groups, and population level), illustrating that aggregate population-level prevalence can be misleading for group-living species. The model structure is general, can be applied to other social species, and allows for a dynamic assessment of how pathogens can affect social structure and vice versa.

scholarly journals Population status, distribution and potential threats of the Blue Bull Boselaphus tragocamelus (Mammalia: Cetartiodactyla: Bovidae) along the Tinau River of Rupandehi District, Nepal

2016 ◽  
Vol 8 (14) ◽  
pp. 9638 ◽  
Author(s):  
Mohan Aryal ◽  
Saroj Panthi ◽  
Manoj Bhatta ◽  
Thakur Prasad Magrati ◽  
Ashok Kumar Shrestha ◽  
...  
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Group Size ◽  
Habitat Destruction ◽  
Population Status ◽  
Average Population Density ◽  
Average Population ◽  
Average Group ◽  
The Status ◽  
Average Group Size

The status and conservation of the Blue Bull Boselaphus tragocamelus is becoming one of the prominent discourses of wildlife research.  The study was carried out along the Tinau River at Rupandehi District in western Nepal to ascertain the population status, distribution and potential threats to the Blue Bull.  The study was conducted along six transect lines in the forest.  A total of 40 Blue Bulls were recorded in different transects.  The average group size was five.  The average population density was 0.228 Blue Bulls per ha and the sex ratio was 1 male: 3 females.  The potential threats of the Blue Bull along the Tinau River were habitat destruction, overgrazing, conflict, flooding and accident.  

Further evidence of a context-specific agonistic signal in bottlenose dolphins: the influence of consortships and group size on the pop vocalization

Behaviour ◽  
2015 ◽  
Vol 152 (14) ◽  
pp. 1979-2000 ◽  
Author(s):  
Nicole L. Vollmer ◽  
Lee-Ann C. Hayek ◽  
Michael R. Heithaus ◽  
Richard C. Connor
Keyword(s):  
Regression Analysis ◽  
Group Size ◽  
Bottlenose Dolphin ◽  
Bottlenose Dolphins ◽  
Low Frequency ◽  
Shark Bay ◽  
Average Group ◽  
Context Specific ◽  
Male Alliances ◽  
Average Group Size

Pops are a low-frequency, pulsed vocalization produced by Indo-Pacific bottlenose dolphins (Tursiopscf.aduncus) in Shark Bay, Western Australia and are often heard when male alliances are consorting or ‘herding’ a female. Previous research indicated that pops produced in this context are an agonistic ‘come-hither’ demand produced by males and directed at female consorts. Here we examine pop occurrence during focal follows on bottlenose dolphin alliances with and without female consorts present. Regression analysis was conducted to determine if pop numbers were higher in the presence of female consorts, and if variables including group size alone and the interaction between presence/absence of a consortship and group size, influenced pop production. While the presence or absence of a consortship significantly affected the number of pops, average group size had no significant effect on pop production. Our research provides further evidence that the pop vocalization plays an important role in consortships.

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