5 research outputs found
Cape fur seals (Arctocephalus pusillus pusillus) adjust traversing behaviour with lunar conditions in the high white shark (Carcharodon carcharias) density waters of Mossel Bay, South Africa
White sharks Carcharodon carcharias are highly visual predators, leading to the hypothesis that the predation risk for foraging Cape fur seals Arctocephalus pusillus pusillus might differ with ambient light conditions. This study investigated the relationship between environmental fluctuations of ambient light and the traversing behaviour of Cape fur seals in and out of their colony at Mossel Bay, South Africa, to better describe potential predator avoidance strategies. A total of 12 144 traversing events were observed over a 4-yr period and there was an overall trend for Cape fur seals to traverse less often but in relatively larger group sizes during periods when white sharks are suggested to be more active. Specifically, Cape fur seal activity was reduced during winter when white sharks are most actively hunting, and most traversing behaviour occurred at night when Cape fur seals were less likely to be detected by white sharks. However, among nocturnal observations, Cape fur seal group sizes increased significantly with moonlight. Although nocturnal predations of Cape fur seals by white sharks have been observed before in Mossel Bay, this is the first study to indicate Cape fur seals might respond to the increased risk of improved white shark visual acuity during moonlit nights by seeking safety in numbers while foraging. Further investigations are needed to assess the effect of the lunar cycle on white shark nocturnal hunting behaviour, but observations presented here suggest that white sharks may pose a bigger threat to Cape fur seals under the light of a full moon.http://www.int-res.com/journals/meps/meps-home2020-07-18hj2019Mammal Research InstituteZoology and Entomolog
Coping with heat : behavioural and physiological responses of savanna elephants in their natural habitat
Most of southern Africa’s elephants inhabit environments where environmental temperatures exceed body temperature,
but we do not know how elephants respond to such environments. We evaluated the relationships between apparent
thermoregulatory behaviour and environmental, skin and core temperatures for tame savanna elephants (Loxodonta africana)
that were free-ranging in the hot parts of the day, in their natural environment. Environmental temperature dictated
elephant behaviour within a day, with potential consequences for fine-scale habitat selection, space use and foraging. At
black globe temperatures of ~30°C, elephants adjusted their behaviour to reduce environmental heat load and increase
heat dissipation (e.g. shade use, wetting behaviour). Resting, walking and feeding were also influenced by environmental
temperature. By relying on behavioural and autonomic adjustments, the elephants maintained homeothermy, even at
environmental temperatures exceeding 40°C. Elephants clearly have the capacity to deal with extreme heat, at least in
environments with adequate resources of forage, water and shade. Future conservation actions should provide for the
thermoregulatory, resource and spatial needs of elephants.The Paul G. Allen Family
Foundation via Elephants Without Borders, the International
Fund for Animal Welfare and the University of Pretoria.https://academic.oup.com/conphysam2017Zoology and Entomolog
Behavioural thermoregulation in free-ranging savanna elephants (Loxodonta africana)
Savanna elephants currently inhabit some of the hottest environments in Africa. Because of climate change, these environments are likely to get hotter. Due to their large body size and small body surface area to volume ratio, elephants may face difficulties in dissipating heat. Despite this suggestion, we do not understand how elephants in their natural environment respond to present day climatic extremes, which limits our ability to predict how elephants may respond to climate change.
The goal of my study was to quantify behavioural responses of elephants to environmental temperature and to investigate the thermal benefits thereof. In so doing, I aimed to assess the potential consequences of environmental temperature on habitat selection and individual fitness, as well as their ability to adapt to climate change. I used continuous behavioural observations and ambulatory temperature recording devices to quantify and assess daytime behavioural responses to environmental temperature in seven tame, free-ranging savanna elephants in Botswana’s Okavango Delta. The elephants were unrestrained and free to roam in their natural environment.
I found that environmental temperature played a significant role in dictating elephant behaviour within a day. At about 30°C, elephants adjusted their behaviour aimed at reducing environmental heat loads and increasing heat dissipation (e.g. shade use, wetting behaviour). I further found that resting increased and feeding decreased with environmental temperature. Age was not a significant factor dictating elephant behaviour. However, the presence of a suckling calf influenced family group behaviour by increasing the probability of shade use and decreasing the probability of walking.
The clear flexible ability of elephants to respond behaviourally to present day environmental temperatures is a promising observation in the face of climate change. However, I suggest that environmental temperature is likely a key determinant of habitat selection and space use in elephants that may have potential consequences for calf survival, sexual segregation and individual fitness. Further investigation of these consequences is warranted.Dissertation (MSc)--University of Pretoria, 2015.tm2015Zoology and EntomologyMScUnrestricte
Nature and level of the use of resources for electronic collection development in three Nigerian universities
The study assessed the nature and level of the use of resources for electronic collection development(ECD) in three Nigerian university libraries. A population of 208, comprising professional librarians and para-professionals was used for the study. Questionnaire, observation checklist and interview schedule were used in collecting data for the study. Data generated were analyzed using frequency counts, percentages, means and standard deviations. Different types of resources required for enhancing ECD in Nigerian university libraries such as “Internet”, “Online Public AccessCatalogue”, “Desktop computers”, “CD-ROM”, etc were identified. Available resources for (ECD)in the three institution libraries were identified. The findings highlighted challenges of (ECD) inNigerian university libraries. Strategies that will help in stemming the tide of challenges ofelectronic collection development were suggested. Academic libraries in tertiary institutions inNigeria and other developing countries will leverage on this study for a robust and efficientelectronic collection development practice
Partial migration in savanna elephant populations distributed across southern Africa
Migration is an important, but threatened ecological process. Conserving migration requires the
maintenance of functional connectivity across sufficiently large areas. Therefore, we need to know
if, where and why species migrate. Elephants are highly mobile and can travel long distances but we
do not know if they migrate. Here, we analysed the movement trajectories of 139 savanna elephants
(Loxodonta africana) within eight clusters of protected areas across southern Africa to determine if
elephants migrate, and if so, where, how and why they migrate. Only 25 of these elephants migrated.
Elephants are a facultative partially migratory species, where only some individuals in a population
migrate opportunistically, and not every year. Elephants migrated between distinct seasonal ranges
corresponding to southern Africa’s dry and wet seasons. The timing of wet season migrations was
associated with the onset of rainfall and the subsequent greening up of forage. Conversely, the
duration, distance, and the timing of dry season migrations varied idiosyncratically. The drivers
of elephant migration are likely a complex interaction between individual traits, density, and the
distribution and availability of resources. Despite most migrations crossing administrative boundaries,
conservation networks provided functional space for elephants to migrate.Billiton, Conservation Foundation Zambia, Conservation International's southern Africa's Wildlife Programme, the Conservation Lower Zambezi, the International Fund for Animal Welfare, the Mozal Community Development Trust, the National Research Foundation, the National Postcode Lottery of the Netherlands, Peace Parks Foundation, the US Fish and Wildlife Services, the University of Pretoria, the World Wildlife Fund (SARPO; Mozambique; SA), the Walt Disney Grant Foundation, and the Wildlifewins Lottery. Elephants Without Borders was funded by the Paul G. Allen Family Foundation, Jody Allen, Zoological Society of San Diego, Madeleine and Jerry Delman Cohen, Harry Ferguson, Botswana Government Conservation Trust Fund and Wilderness Trust.http://www.nature.com/srepam2018Zoology and Entomolog