60 research outputs found
Notes on age determination, growth and measurements of Brown Hyaenas<i> Hyaena Brunnea</i> from the Kalahari Gemsbok National Park
Brown hyaenas were aged on the basis of tooth eruption and wear and five age-classes were recognised. Weights and seven different body measurements were recorded from 38 immobilised hyaenas. Full size is reached at the age of 30 months, but age-class 5 animals were significantly lighter than were animals from the other adult age-classes. This was probably due to the worn down premolars of old animals resulting in less efficient bone chewing. With a few puzzling exceptions the sizes of brown hyaenas from different parts of their distribution range are similar
Notes on wild dog <i>Lycaon pictus</i> and lion <i>Panthera leo </i>population trends during a drought in the Kruger National Park
Wild dog Lycaon pictus and lion Panthera leo populations in the Kruger National Park appeared to undergo an increase during a drought period in the early 1990s. Newly established packs, high adult survival and pup productivity contributed to an increase in the wild dog population and evidence for high predation success during the height of the drought is presented. An increase in the lion density between 1989 and 1993 on the northern basalt plains, as well as changes in the structure of the population, seem to be related to changes in prey populations, particularly to a decline in numbers and condition of buffalo Syncerus cafer
The scent marking behaviour of the brown hyaena Hyaena brunnea
The deposition onto grass stalks of two distinct, strongsmelling substances produced in the anal scent pouch, is the most common form of scent marking in the brown hyaena (Hyaena brunnea). It is called pasting. The behaviour associated with pasting is described, as is the related functional anatomy of the scent pouch. The dispersion pattern of pastings within a group territory and the rate of marking in different parts of the territory were ascertained by direct observations on radio collared hyaenas. The data were analysed by the computer programs SYMAP and SYMVU which graphically display the data as a three dimensional map. Brown hyaenas leave most pastings in those areas in which they spend most time. This is in the central part of the territory. When they visit the boundaries, however, the frequency of pasting increases. GLC analyses of the pastings from two known individuals show distinct differences in the relative concentrations of the many compounds in the pastings of each. Behavioural observations show that the hyaenas are able to recognize different individuals' pastings. Pasting could function to inform group members of each other's movements as well as to inform outsiders that the territory is occupied
Notes on some smaller carnivores from the Kalahari Gemsbok National Park.
Notes on relative densities, habitat choice, food and foraging, social organisation and anti-predatory behaviour of certain small and medium-sized carnivores are presented. Possible mechanisms of niche separation and the evolution of different anti-predatory behaviours are discussed. -Author
Diversity and depletions in continental carnivore guilds: implications for prioritizing global carnivore conservation
Large carnivores are important ecosystem components but are extinction prone due to small populations, slow growth rates and large area requirements. Consequently, there has been a surge of carnivore conservation efforts. Such efforts typically target local populations, with limited attention to the effects on the ecosystem function of predator guilds. Also, there is no framework for prioritizing these efforts globally. We compared taxonomic and functional diversity of continental carnivore guilds, compared them with the corresponding guilds during the Late Pleistocene and synthesized our results into suggestions for global prioritizations for carnivore conservation. Recent extinctions have caused taxonomically and functionally depleted carnivore guilds in Europe and North and South America, contrasting with guilds in Africa and Asia, which have retained a larger proportion of their carnivores. However, Asia is at higher risk of suffering further extinctions than other continents. We suggest three priorities of contrasting urgency for global carnivore conservation: (i) to promote recovery of the threatened Asian species, (ii) to prevent species in the depleted guilds in Europe and North and South America from becoming threatened, and (iii) to reconstruct functionally intact sympatric guilds of large carnivores at ecologically effective population sizes
Comparison of land-use strategies of spotted hyenas (Crocuta crocuta, Erxleben) in different ecosystems
Estimation of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park using a capture–recapture survey
A previous estimate of the lion (Panthera leo) population in the southwestern Kgalagadi Transfrontier Park (KTP) was made over 20 years ago. This together with increased fears regarding the viability of the population as a result of recent killings of roaming animals, an observed increase in non-violent mortalities during 1996, and possible reduced genetic viability due to suspected isolation, prompted another investigation. Between October 1996 and December 1996, 68 lions were captured and marked and subjected to two recapture (resighting) samples. The minimum estimate derived from direct enumeration of marked and unmarked individuals is between 100–103 individuals. Assessment of the adult and subadult population using the Lincoln-Petersen estimator and the software program NOREMARK gives a figure between 92 and 125. The current estimate is below the previous estimate of between 113 and 140 lions. Lion densities of 1.2 adult and subadult lions/100 km2 in the semi-arid southern Kalahari are considerably lower than those in more mesic regions. Furthermore, there appears to be some demographic variability with the ratio of females to males being twice as high as that recorded 20 years ago.Keywords: Lincoln-Petersen, Kalahari, semi-arid, carnivore, population estimate, demography
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