Gastrointestinal parasites of endemic and endangered free-ranging purple-faced leaf monkey (Semnopithecus vetulus) in Sri Lanka: effect of host group size and habitat type

Primates ◽  
2021 ◽  
Author(s):  
Lakshani Weerasekara ◽  
Kumudu Wijesooriya ◽  
Kithsiri Ranawana ◽  
Thilini Anupama ◽  
Jayantha Rajapakse
2011 ◽  
Vol 57 (3) ◽  
pp. 223-246 ◽  
Author(s):  
Solomon A. Tadesse ◽  
Burt P. Kotler

Nubian ibex (Capra nubiana) prefer steep terrain in their landscape to reduce risks of predation and human nuisance disturbances. They also use vigilance and time allocation to manage risk of predation. We studied time budgets and habitat selection of Nubian ibex to: (1) identify the habitat variables to which Nubian ibex were behaviorally responsive; (2) investigate how time budget responses of Nubian ibex were related to season, slope condition, group size, and sex-age structure; and (3) develop behavioral-based models that account for the variations in the behaviors of Nubian ibex across the landscape and seasons.To quantify time budgets, we took regular field observations on focal individuals of Nubian ibex classified according to their habitat, group size, sex, and age. For each focal observation, we quantified environmental variables that were thought to influence the behavioral responses of ibex. Then, we developed behavioral models by correlating the proportion of behaviors measured in focal animal observations to the influential environmental variables. The behaviors of Nubian ibex significantly varied with sex and age structure, season, habitat type, and slope conditions. Adult females are more vigilant than adult male ibex, especially in the spring. This correlates with breeding and nursing activities. Based on the characteristics of the habitat, ibex behave to minimize risks of predation and human nuisance disturbances while maximizing their food intake.


1993 ◽  
Vol 20 (6) ◽  
pp. 785 ◽  
Author(s):  
DM Watson ◽  
TJ Dawson

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.


1980 ◽  
Vol 7 (1) ◽  
pp. 103 ◽  
Author(s):  
ST Garnett

A population of dusky moorhens was studied between October 1974 and December 1976. Moorhens were present in the study area throughout the year, existing predominantly in free-ranging flocks in May and June and tending to form territorial groups of from two to seven birds from July to April. In a group there were from one to three males per female; all males copulated with all females. Groups formed in July were predominantly of experienced adults and did not cease territoriality until April; those formed later, in September, were predominantly of immatures and tended to cease territoriality in March. The former had larger territories with more reeds, less sexual behaviour although more frequent successful coition, and a higher productivity than the latter. Productivity did not increase with group size although those with more than four birds lost twice as many eggs as smaller groups. It is unlikely that members of a group are related. The most frequent group size was four and it is postulated that groups of this size produce the most young. The skewed ratio in groups may result from the scarcity of nest sites, which limits the number of females per group.


Author(s):  
C. Matos ◽  
C. Sitoe ◽  
S. Afonso ◽  
J. Banze ◽  
J. Baptista ◽  
...  

Apilot survey was conducted in 2 districts in Mozambique to determine the most important health problems facing smallholder pig producers. While African swine fever is the most serious disease that affects pigs at all levels of production in Mozambique, it is likely that productivity is reduced by the presence of mange and gastrointestinal parasites, while in traditional systems the conditions are favourable for the development of porcine cysticercosis caused by the pork tapeworm Taenia solium, which poses a health risk to communities. Results of the pilot survey confirmed that, with the exception of African swine fever, ecto- and endoparasites are probably the most important health risks for producers. Porcine cysticercosis is more prevalent among pigs in traditional, free-ranging systems, while mange becomes a serious factor when pigs are permanently confined.


2006 ◽  
Vol 44 (3) ◽  
pp. 410-412 ◽  
Author(s):  
Sharon Okanga ◽  
Gerald Muchemi ◽  
Nicholas Maingi ◽  
Eddy Mogoa ◽  
Elphas Munene

2008 ◽  
Vol 86 (3) ◽  
pp. 170-176 ◽  
Author(s):  
I. Barja ◽  
S. Rosellini

We examined whether group size in red deer ( Cervus elaphus L., 1758) and roe deer ( Capreolus capreolus (L., 1758)) under predation risk by Iberian wolves ( Canis lupus L., 1758) is affected by the type of habitat in which the deer reside. We hypothesized that group size (i) would be larger in open than in closed habitats, since it is an antipredator response, and (ii) would vary more with habitat type in the species that had higher wolf predation rates. In the study area, wolves were the only predator of wild ungulates, with roe deer being the main target prey. We performed monthly transects along paths to observe the group size of red and roe deer. In roe deer, the mean group size was significantly higher in open than in closed habitats, serving as an antipredator response. However, in red deer, habitat type did not affect group size. The results indicate that under predation risk by wolves the habitat type influences the grouping behavior of roe deer but not red deer. Furthermore, compared with forests, heaths offer less protection from predators and species in this habitat would benefit from larger group sizes.


2016 ◽  
Vol 45 (1) ◽  
pp. 83 ◽  
Author(s):  
A.J.M. Kethmini Aviruppola ◽  
R.P.V. Jayanthe Rajapakse ◽  
Rupika S. Rajakaruna

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