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Individual history of movement and the dispersal of southern elephant sealsHofmeyr, G.J. Greg (Gordon John Gregory) 05 May 2013 (has links)
While studies of dispersal note significant fidelity to natal site and to the site of first
reproduction, few consider fidelity to other sites, and none have done so systematically.
This study examined fidelity to all terrestrial sites within the study area during the
course of its life, by a migratory marine predator, the southern elephant seal, Mirounga
leonina. It also attempted to assess the role played by the winter haulout in terms of site
fidelity. Finally it examined the influence of possible deterioration in spatial memory
over time on site fidelity. The data used in this study were generated by a long-term
mark-recapture programme conducted at subantarctic Marion Island.
Although immature elephant seals of both sexes return to the vicinity of their natal sites,
they appear to avoid popular breeding beaches, returning closest to the site previously
used. At the first reproductive haulout, however, females return closer to their natal site
than any other site, while males, although hauling out in the vicinity of their natal site,
haul out closest to sites used in the year prior to the first breeding haulout.
Subsequently, adults of both sexes breed closest to the breeding haulout of the previous
year and moult closest to the moult haulout of the previous year. While males show
greater site fidelity during the breeding season, there is no difference in site fidelity during the moult. Primiparous females show greater levels of site fidelity if recorded in
the study site as an immature animal during either the winter or the moult haulouts.
Also in female elephant seals, lower site fidelity is associated with an increase in the
duration of period of absence from a site, and a lower number of visits to a site.
Various factors related to site familiarity, social factors and anthropogenic disturbance
may be responsible for the lack of strict site fidelity that is evident. Dispersal patterns
may differ between the sexes due to differences in their life history. While purpose of
the winter haulout by immature seals may be to increase familiarity with haulout sites,
and thus site fidelity, the moult haulout also plays a role. / Thesis (PhD)--University of Pretoria, 2013. / Zoology and Entomology / Unrestricted
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Physiological responses of African elephant (Loxodonta africana) immobilised with a thiafentanil-azaperone combinationChelopo, Ngwako David January 2020 (has links)
Objective To determine the cardiopulmonary and blood gas status of elephants during
chemical capture (immobilisation) with a thiafentanil-azaperone drug combination kept in
lateral recumbency.
Study design Prospective descriptive study.
Animal population Ten free-ranging adult African elephant bulls (estimated weight range
3000 to 6000 kg).
Methods Elephants were immobilised using a thiafentanil (15-18 mg) and azaperone (75-90
mg) by darting from a helicopter. Once recumbent, the tidal volume, minute volume, end-tidal
carbon dioxide, arterial blood pressure and pulse rate were recorded immediately after
instrumentation and at five-minute intervals until T20. Arterial and venous blood gases were
analysed at the time of initial instrumentation and at 20 minutes. On completion of the data
collection, the thiafentanil was antagonised using naltrexone (10 mg mg-1 thiafentanil). A
stopwatch was used to record time to recumbency (dart placement to recumbency) and time
to recovery (administering antagonist to standing). Data was checked for normality and was
found to be parametric. Data were compared using a one-way analysis of variance and
reported as mean (± SD).
Results All elephants were successfully immobilised and all physiological variables remained
constant with minimal non-significant variation over time. Average time to recumbency was
12.5 minutes. The estimated expiratory tidal volume was 21 (± 6) L breath-1 or 4.8 ± 0.8 mL
kg-1, and the measured minute volume was 103 (± 31) L minute-1. The heart and respiratory rates were 49 (±6) beats and 5 (± 1) breaths minute-1, respectively. The mean arterial blood
pressure was 153 (± 31) mmHg. The elephants were acidaemic (pH 7.18 ±0.06; bicarbonate
ion 20 ±4 mmol L-1; lactate 11 ± 4 mmol L-1), mildly hypoxemic (PaO2 68 ± 15 mmHg) and
mildly hypercapnic (PaCO2 52 ± 7 mmHg). Average time to recovery was 2.2 minutes.
Conclusion and clinical relevance African elephant bulls can be successfully immobilised
using thiafentanil-azaperone. Recumbency was rapid, the cardiopulmonary variables were
stable and within acceptable ranges, and recovery was rapid and complete. Mild hypoxaemia
and hypercapnia were evident, but does not necessarily require oxygen supplementation. / Dissertation (MSc)--University of Pretoria, 2020. / Companion Animal Clinical Studies / MSc / Unrestricted
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The demography of Balanites maughamii : an elephant-dispersed treeBijl, Alison 02 February 2017 (has links)
Balanites maughamii is an ecologically and culturally valuable tree species, heavily impacted by elephants, which strip bark selectively off the largest trees, increasing their susceptibility to fire damage. Elephants also break intermediate sized trees extensively, keeping them trapped in non-reproductive stages. The trees can however survive breaking, stripping and · toppling by elephants, as well as top kill by fires, because they resprout vigorously in response to damage. They also produce root suckers. independently of disturbance. Vegetative reproduction buffers the populations from the infrequent recruitment of seedlings, and facilitates the maintenance of populations over the short term. Balanites maughamii trees are reliant on African elephants (Loxodonta africana) for seed dispersal and to provide a germination cue through mastication. In the absence of elephants, the population experiences a recruitment bottleneck, but root suckers functionally replace seedlings and fill the "recruitment gap", so over the short term, the population is resilient. In all populations, whether elephants are present or not, another hurdle affects recruitment, and it is seed limitation due to seed predation pre- and post- dispersal. Cafeteria experiments revealed that bushveld gerbils (Tatera leucogaster) were removing many seeds but do not scatter- or larder-hoard. They are simply seed predators.
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Seasonal Changes in Behavior and Exhibit Use of Captive African Elephants (Loxodonta africana) and Black Rhinoceroses (Diceros bicornis)Mueller, Jenni Elizabeth 08 July 2008 (has links)
No description available.
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Assessing Spatial and Temporal Patterns of Human-Caused Elephant Mortality in Tsavo East National Park, KenyaKyale, Daniel Muteti 30 November 2006 (has links)
No description available.
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Spatio-Temporal Effects of Land Use Changes in A Savanna Wildlife Area of KenyaEsikuri, Enos E. 21 July 1998 (has links)
Land use changes have been shown to have significant effects on wildlife species. Sixty three percent of the national Parks and Reserves in Kenya are located in the savannas. Because of the seasonality associated with savanna ecosystems, 75% of the wildlife species and numbers in Kenya occur in savanna nonpark areas. Therefore, conservation of wildlife in Kenya has to address the changes that are taking place in savanna areas outside parks. I studied land use changes and their effects on elephant habitat quality in Amboseli Basin, Kenya. I used visual interpretation to analyze land use changes from satellite images for 1975, 1988, and 1993. I determined that during the evaluation period, conversion of areas to agricultural land has been unidirectional. The hectarage under cultivation was 2,937, 10,950, and 24,476 for 1975, 1988, and 1993 respectively. Trend analysis seems to suggest that during the evaluation period, conversion of areas to agricultural land has followed an exponential function (R² = 0.99) in Amboseli Basin. The area under cultivation was 6.9% of the total area studied. This is small but significant considering that agricultural land was almost exclusively located in areas that form the dry season fall back areas. Such areas are important for the survival of elephants and other species during critical periods.
I developed a dry season habitat suitability index (HSI) model for the African elephant based on the density of acacia trees (# of trees > 5 cm dbh/ha) and distance (km) to natural sources of water in the basin. The amount of good quality habitat (i.e., HSI > 0.6) declined from 74,666 ha in 1975 to 54,890 ha in 1988, to 23,208 ha in 1993. This is a drop of 51,890 ha (65.5%) of good quality habitat in the basin. On the other hand, low quality habitat (HSI < 0.2) increased by 272% between 1975 and 1993. The weighted HSI values in the basin showed a decline, as did the habitat units for the 3 evaluation years. The weighted HSI declined by 0.13 between 1975 and 1993, while the total habitat units (ha) declined by 40,567 ha during the 18 year period. It appears that elephant habitat quality has steadily declined in the Amboseli Basin during the period considered in this study.
The use of nonpark areas by elephants leads to direct interaction and conflicts with humans. Between June 1996 and July 1997, I recorded a total of 489 elephant damage incidents while the Amboseli National Park authorities recorded 143. The damage types were crops, livestock deaths, and human deaths and injuries. The majority of the damage cases involved crop depredation. The Amboseli National Park authorities significantly under-reported the number of elephant damage incidents in the basin (P < 0.0001). / Ph. D.
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Elephant movements and human-elephant conflict in a transfrontier conservation areaVon Gerhardt-Weber, Katharina E. M. 03 1900 (has links)
Thesis (MScConEcol)--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: In this thesis I explore how elephant movements are impacted by human activity within
the context of the proposed Kavango-Zambezi Transfrontier Conservation Area (KAZA
TFCA) in southern Africa. Being a wide-ranging species, the movements of elephants
could be an excellent indicator as to the success of TFCAs in supporting species
persistence in an anthropogenic matrix. Understanding which areas beyond protected area
boundaries are of heightened conservation importance can provide managers and
governments with insights for the management of the elephant population of KAZA
TFCA, and assist managers and governments in prioritising conservation efforts.
Satellite radio collar data were used to model long-range elephant movement within
KAZA TFCA. Movement was compared between land use types (protected and nonprotected
areas). Home ranges, core areas and seasonal ranges were calculated from
collar data. Core and non-core areas were tested for significant differences in distance to
settlements, rivers, protected area, AFRI and elevation as these spatial and ecological
variables are believed to play a role in elephant habitat selection. Short-range elephant
movements were examined in a heterogeneous, patchy landscape mosaic of settlements
and agricultural fields, remnant forest patches, and secondary forests which were
surrounded on three sides by protected areas. Elephant penetration of the anthropogenic
matrix through the use of pathways was explored through ground-based surveys, and the
impact of pathways use on human-elephant conflict calculated.
I found that elephant behavioural plasticity allows for their persistence in a spatially
heterogeneous landscape. Elephants, especially bulls, penetrated the landscape matrix
beyond protected area boundaries. Land use planning initiatives are needed to identify
and protect reachable core zones/stepping stones of quality habitat outside of protected
areas, particularly in riparian zones. Differing male and female ranging behaviour within
the landscape matrix may require separate land use management strategies: bulls travelled
at night in non-protected areas at speeds that were four times faster than in protected
areas, and made use of core zones necessary for species persistence in a fragmented
landscape. A habitat corridor in the Zambian West Zambezi Game Management Area
was identified.
I found that during short range movements in heterogeneous environments, elephants
made use of pathways. Pathways may facilitate penetration of the anthropogenic matrix
and optimize foraging strategies by connecting predictable resources, such as crop fields,
with landscape features such as preferred shelter/ resting areas, crossing points at roads
and preferred drinking spots. Pathways were found to be the only significant spatial
variable in crop-raiding. Elephants foraged randomly while in homogenous crop patches,
but when travelling through a heterogeneous environment (entering or leaving
agricultural locales), movement was directional and non-random.
Lastly I suggest that crop attractiveness may be enhanced by water availability. Results
indicated that at both the landscape and the regional scale, repeat elephant movements to
core zones and along elephant pathways provided landscape ecological variables that
need to be considered by conservation managers in land use planning. In addition,
research on spatial awareness and navigational capabilities with regards to pathway use by elephants should be encouraged, as this research topic has been largely unexplored in
the scientific literature. / AFRIKAANSE OPSOMMING: In hierdie tesis verken ek die moontlike impak van menslike aktiwiteite op olifant
beweging binne die beoogde Kavango-Zambezi Oorgrens Bewaringsarea (KAZA TFCA)
in suider-Afrika. Olifante is wydlopende spesies, en dus kan hul ruimtelike strekking ‘n
uitstekende indikator wees van die sukses van oorgrens bewaringsareas in terme van die
ondersteuning wat dié programme bied om spesies se volharding in ‘n antropogeniese
matriks te verseker. Besturrders en regerings kan insig verkry deur te besef watter areas
buiten die in beskermde gebiede, van verhoogde bewarings belang in KAZA TFCA is.
Hierdie insig verleen ook bystand aan bestuurders en regerings met die prioritisering van
bewarings inisiatiewe. Satelliet-radio nekband data was gebruik om olifante se
langtermyn ruimtelike beweging binne die KAZA TFCA te modelleer. Olifant beweging
was vergelyk tussen verskillende grondgebruik tipes (beskermde en onbeskermde areas).
Tuistestrekking, kern areas asook seisoenale strekking was bereken vanaf nekband data.
Kern en nie-kern areas was getoets vir betekenisvolle verskille in afstand vanaf
nedersettings, riviere, berskermde gebiede, AFRI, en hoogte bo seevlak, omdat hierdie
ruimtelike en ekologiese veranderlikes ‘n belangrike rol mag speel in olifant habitat
seleksie. Kortafstand olifant bewegings was bestudeer in ‘n heterogene, gelapte landskap
mosaïek van nedersettings en landbougrond, oorblywende woudareas, en sekondêre
woude waarvan drie sye grens aan bekermde areas. Olifant indringing binne die
antropogeniese matriks deur die gebruik van weë/toegangsweë was verken deur middel
van landgebaseerde opnames, waarvolgens die impak van olifante se gebruik van hierdie
paaie op mens-olifant konflik bereken kon word.
My bevindinge wys dat plastisiteit in olifant gedrag dra by tot hul voortbestaan in ‘n
ruimtelik heterogene landskap. Olifante, maar meer spesifiek olifantbulle, penetreer wel
die landskap matriks buite beskermde area grense. Grondgebruik beplannings inisiatiewe
word dus benodig om bereikbare kern areas van kwaliteit habitat buite beskermde areas te
identifiseer en te beskerm – veral in rivieroewer sones. Verskille in bul en koei ruimtelike
strekking gedrag binne die landskap matriks, mag afsonderlike bestuur stratgieë vereis:
bv. bulle beweeg vier keer vinniger in die aand in onbeskermde areas teenoor in
beskermde gebiede, daarby maak hulle ook gebruik van kern areas wat kardinaal is vir
die voortbestaan van spesies in gefragmenteerde landskappe. ‘n Habitat deurgang was
geïdentifiseer in die Zambiese Wes-Zambesie Wildbestuurarea. Die studie het gevind dat
olifante gedurende kortafstand bewegings in heterogene omgewings gebruik maak
toegangsweë. Toegangsweë mag penetrasie van die antropogeniese matriks fasiliteer, en
verleen ook dat olifant weidingstrategieë die optimum bereik deur voorspelbare
hulpbronne soos gewaslanderye te konnekteer met landskap eienskappe soos voorrang
skuiling/rusareas, kruisingspunte by paaie, asook voorrang drinkplekke. Toegangsweë
was gevind om die enigste betekenisvolle ruimtelike veranderlike in gewasstrooptogte te
wees. Olifante wei lukraak in homogene gewaslanderye, maar in teenstelling, wanneer
hulle deur ‘n heterogene omgewing beweeg het (binnegang of uittog uit landbou
lokaliteite) was die beweging gerig. Laastens, die studie stelvoor dat gewas aantreklikheid verhoog kan word deur water beskikbaarheid. Resultate dui aan dat by
beide die landskap- en streekskaal verskaf herhaalde olifant beweging na kern areas en
langs olifants togangsweë, landskap ekologiese veranderlikes wat in ag geneem moet
word deur bewaringsbestuurders tydens grondgebruik beplanning. Bykomend, navorsing
op die ruimtelike bewustheid en navigasie vermoëns van savannah olifante met
betrekking tot die gebruik van toegangsweë, moet aangemoedig word aangesien hierdie
onderwerp grootliks onverken is in wetenskaplike literatuur.
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The impacts of herbivores and humans on the utilisation of woody resources in conserved versus non-conserved land in Maputoland, northern KwaZulu-Natal, South AfricaGaugris, Jerome Yves, January 2008 (has links)
Thesis (Ph. D.)--University of Pretoria, 2008. / Title from PDF title page (viewed on Nov. 11, 2008). Includes bibliographical references.
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Elephant feeding behaviour and forage offtake implications in the Addo Elephant National ParkLessing, Joan Susanna January 2007 (has links)
Elephants, as megaherbivores and keystone species have major impacts, both positive and negative, on ecosystems such as the Subtropical Thicket of the Eastern Cape. The feeding behaviour of elephants was quantified so as to firstly determine the preferred feeding heights of elephants, and secondly to determine if feeding behaviour and impact varies with size and sex. The preferred feeding height was determined with experimental feeding trials. Feeding height, pluck size, foraging rate and the proportion of plant material discarded were used to test for differences between elephants of different sizes and sexes in the Addo Elephant National Park. The influence of plant growth form on sex-specific feeding was also considered. Elephants preferred to feed at the lowest heights. The preferred feeding height was not related to body size. A wide range of feeding heights was recorded including and extending beyond, both the preferred and maximum feeding height of co-existing indigenous browsers. There was no difference in feeding height between the sizes and sexes. In free ranging conditions, all elephants fed at levels above the preferred foraging height when browsing. There was no difference in feeding behaviour between the different sized elephants, or between males and females. Adult elephants however exhibited larger ranges of feeding heights, pluck sizes, foraging rates and intake rates, including the maximum and minimum values. Growth form influenced the feeding of male and female elephants differently. Elephant feeding behaviour appears to limit opportunities for resource partitioning by way of feeding height segregation. Elephants are also capable of dominating the browse resources available to co-existing browsers by removing large amounts of forage at lower heights. The extent of elephant impact seems to be comparable between sizes and sexes, although adults and especially larger males are often able to use foraging opportunities that other elephants can not effectively utilize. Findings suggest that the feeding heights of elephants are determined by forage availability and reflect the diet in terms of browse or grass. The findings can be used, together with browse inventory methods, to determine browse resources available to elephants, and can also be used to develop monitoring tools to assess the impacts of elephants on plants.
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Applying GPS and Accelerometers to the Study of African Savanna (Loxodonta africana) and Asian Elephant (Elephas maximus) Welfare in ZoosHoldgate, Matthew Robert 16 March 2015 (has links)
African savanna elephants (Loxodonta africana) and Asian elephants (Elephas maximus) are a focus of welfare research in zoos due to their high intelligence, complex social structure, and sheer size. Due to these challenges, some argue that zoos are inherently incapable of providing appropriate care for elephants, while others believe that zoos can fulfill the needs of these species with improved husbandry. There is a general consensus from both within and outside of zoos, however, that zoos must improve their elephant programs or cease exhibiting these animals altogether. Now more than ever, applied research on zoo elephant welfare is needed to provide context for this debate.
Researchers are interested in how far zoo elephants walk due to the potential health and welfare benefits of walking in these highly mobile species. Zoo researchers recently adopted GPS technology to study elephant walking, and preliminary evidence suggests that African elephants in large zoo exhibits walk distances that correspond with wild elephants under non-extreme conditions. However, data are limited from Asian elephants and from elephants in more typically-sized exhibits. In Chapter Two, I discuss important methodological considerations of utilizing GPS in a zoo environment, including an introduction to the technology, sources of error and mitigation, methods to improve GPS performance, and possible effects of GPS device attachment on animal behavior. This review shows GPS performance is adequate for tracking zoo elephant walking when proper methodological techniques are applied, and should serve as a useful reference for zoo researchers considering using GPS.
In Chapter Three, I used GPS anklets to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 zoos. I collected 259 days of data and found that elephants walked an average of 5.34 km/day with no significant difference between species. Multivariate regression models predicted that elephants with more dynamic feeding regimens (more diverse feeding types and frequencies; unscheduled feeding times) will walk more. Distance walked was also predicted to be higher in elephants that spend time in a greater number of different social groups. Distance walked was predicted to decline with age. Finally, I found a significant negative correlation between distance walked and nighttime space experience. The results of the analysis suggest that zoos that want to increase walking in their elephants need not rely solely on larger exhibits, but can increase walking by adding quality and complexity to exhibits. However, my results failed to establish a definitive link between walking distance and other validated measures of elephant welfare. Thus, the direct health and welfare benefits of walking in zoo elephants remain unresolved.
Resting behaviors are an essential component of animal welfare, but have received little attention in zoological research. In Chapter Four, I used accelerometers in anklets to complete the first large-scale multi-species investigation of zoo elephant recumbence. I collected 344 days of data from 72 adult female African (n = 44) and Asian (n = 28) elephants at 40 zoos. I found that African elephants are recumbent an average of 2.14 hours/day, which is significantly less than Asian elephants at 3.22 hours/day. Multivariate regression models predicted that African elephant recumbence increases when they experience more space at night, and Asian elephant recumbence increases when they spend time housed alone. Both species showed a similar response to substrate, such that African elephants spending time on all-hard substrates are predicted to be recumbent less, while Asian elephants spending time on all-soft substrates are predicted to be recumbent more. The discovery that occasional non-recumbence is a common behavior in zoo elephants also introduces a new area of research that may have important animal welfare consequences. Finally, this study established that zoos should continue their efforts to replace hard substrate with soft substrate in order to provide zoo elephants with environments that facilitate recumbence.
Overall, this work assessed walking and recumbence in zoo elephants, which will allow zoos to gauge the prevalence of these behaviors in their elephants as compared to the sub-population studied here. A variety of factors that are associated with these behaviors were also identified. With this information, zoos can prioritize modifications to their facilities and animal management programs to create an environment that encourages zoo elephants to express walking and recumbence behavior, should they choose to do so.
This work is one component of the Elephant Welfare Project, the largest zoo animal welfare project ever undertaken, and is unprecedented in both scope and scale. The project was funded by the Institute of Museum and Library Services (IMLS), an independent, U.S., federal, grant-making agency that supports libraries, museums, and zoos. At the time of this writing, the first manuscripts from this project are being submitted to academic journals. These papers will describe the prevalence and distribution of a variety of elephant behaviors and welfare indicators, serve as a benchmark for future elephant welfare studies, and aid in decision making with regard to best practices in elephant management.
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