Persistent low densities of plains ungulates in Etosha National Park, Namibia: testing the food-regulating hypothesis

1996 ◽  
Vol 74 (8) ◽  
pp. 1556-1572 ◽  
Author(s):  
William C. Gasaway ◽  
Kathleen T. Gasaway ◽  
Hu H. Berry
Keyword(s):  
National Park ◽  
Growth Management ◽  
Survival Rates ◽  
Food Resource ◽  
Mortality Data ◽  
Equus Burchelli ◽  
Declining Populations ◽  
Habitat Enhancement ◽  
Connochaetes Taurinus ◽  
Plains Zebra

Declines and persistent low densities of plains ungulates during 1960–1994 in Etosha National Park (Etosha) compromise Namibia's efforts to develop a wildlife- and tourist-based economy and maintain its national biodiversity. Plains ungulates are blue wildebeest (Connochaetes taurinus), plains zebra (Equus burchelli), springbok (Antidorcas marsupialis), and gemsbok (Oryx gazella). We tested the hypothesis that plains ungulate populations were well below their food-resource ceiling (FRC) and predicted that widely variable rainfall (food production) would have no significant effect on birth and survival rates; alternatively, ungulates regulated near their FRC would display strong responses to variable rainfall through negative feedback on fertility, yearling recruitment, and mortality. Data supported the hypothesis that Etosha's populations were well below their FRC. The pregnancy rate of springbok was high during drought. Recruitment of all four species was not positively related to rainfall. Mortality was not negatively related to rainfall, and high mortality did not occur during droughts. Given the high recruitment of Etosha's stable or declining populations, we hypothesize that high adult and yearling mortality resulting from anthrax and predation was the primary process preventing population growth. Management aimed at maintaining or increasing the numbers of Etosha's plains ungulates currently need not emphasize habitat enhancement.

scholarly journals Natural mortality amoung four common ungulate species on Letaba Ranch, Limpopo Province, South Africa

Koedoe ◽  
2002 ◽  
Vol 45 (1) ◽  
Author(s):  
H.P. Cronje ◽  
B.K. Reilly ◽  
I.D. Macfadyen
Keyword(s):  
National Park ◽  
Limpopo Province ◽  
Mortality Data ◽  
Panthera Pardus ◽  
Lycaon Pictus ◽  
Tragelaphus Strepsiceros ◽  
Connochaetes Taurinus ◽  
Wild Dogs ◽  
Respective Species ◽  
Aepyceros Melampus

Five years of mortality data of impala Aepyceros melampus, blue wildebeest Connochaetes taurinus, buffalo Syncerus caffer and kudu Tragelaphus strepsiceros have been used to describe the minimum mortality profiles of the respective species in an open savanna system with the full compliment of predators. Predation is the principle cause of natural mortalities on the study site, Letaba Ranch, which is adjacent to the Kruger National Park. The principle cause of impala mortality are leopards Panthera pardus and wild dogs Lycaon pictus. Lion Panthera leo were major contributors to the mortality of wildebeest and buffalo. Anthrax Bacillus anthracis was the main cause of kudu mortality.

A keystone predator at risk? Density and distribution of the spotted hyena (Crocuta crocuta) in the Etosha National Park, Namibia

2009 ◽  
Vol 87 (10) ◽  
pp. 941-947 ◽  
Author(s):  
Martina Trinkel
Keyword(s):  
National Park ◽  
Spatial Relationship ◽  
Crocuta Crocuta ◽  
Spotted Hyena ◽  
Migratory Species ◽  
Mathematical Correlation ◽  
Equus Burchelli ◽  
Spotted Hyenas ◽  
The Status ◽  
Connochaetes Taurinus

For wildlife management and conservation biology, it is important to be able to estimate the status and distribution of animals and to monitor their population trends. In the Etosha National Park, Namibia, there is a lack of knowledge about numbers and distribution of spotted hyenas ( Crocuta crocuta (Erxleben, 1777)) and factors regulating their population. To estimate hyena density and distribution, tape-recorded vocalizations (call-ups) were performed to attract hyenas in the central and eastern parts of Etosha. Eighty-five adult and subadult hyenas responded to the calls, with most of them responding in an area with high density of migratory ungulates, principally springbok ( Antidorcas marsupialis (Zimmermann, 1780)), wildebeest ( Connochaetes taurinus (Burchell, 1823)), and Burchell’s zebra ( Equus burchelli (Gray, 1824)). These migratory species are the main prey of spotted hyenas in Etosha. There was a strong spatial relationship between hyena density and migratory prey biomass. Based on this mathematical correlation, I estimated 203 ± 79 hyenas, i.e., 2.7 ± 1.1 hyenas/100 km2, in the central and eastern parts of Etosha. Applying this correlation to the western part of the park, it was possible to estimate 339 ± 176 spotted hyenas, corresponding to an overall density of 2.1 ± 1.0 hyenas/100 km2, in the whole Etosha National Park.

scholarly journals A rapid loss of stripes: the evolutionary history of the extinct quagga

2005 ◽  
Vol 1 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Jennifer A Leonard ◽  
Nadin Rohland ◽  
Scott Glaberman ◽  
Robert C Fleischer ◽  
Adalgisa Caccone ◽  
...  
Keyword(s):  
South African ◽  
Dna Sequences ◽  
Evolutionary History ◽  
Climate Changes ◽  
Rapid Loss ◽  
Mt Dna ◽  
Pleistocene Climate ◽  
Equus Burchelli ◽  
History Of ◽  
Plains Zebra

Twenty years ago, the field of ancient DNA was launched with the publication of two short mitochondrial (mt) DNA sequences from a single quagga ( Equus quagga ) museum skin, an extinct South African equid ( Higuchi et al . 1984 Nature 312 , 282–284). This was the first extinct species from which genetic information was retrieved. The DNA sequences of the quagga showed that it was more closely related to zebras than to horses. However, quagga evolutionary history is far from clear. We have isolated DNA from eight quaggas and a plains zebra (subspecies or phenotype Equus burchelli burchelli ). We show that the quagga displayed little genetic diversity and very recently diverged from the plains zebra, probably during the penultimate glacial maximum. This emphasizes the importance of Pleistocene climate changes for phylogeographic patterns in African as well as Holarctic fauna.

DAILY ACTIVITY OF JUVENILE JAVAN GIBBON (Hylobates moloch AUDEBERT 1798) IN GUNUNG HALIMUN SALAK NATIONAL PARK

Zoo Indonesia ◽  
2020 ◽  
Vol 29 (1) ◽  
Author(s):  
Ivanna Febrissa ◽  
Dones Rinaldi
Keyword(s):  
Daily Activity ◽  
National Park ◽  
Sampling Method ◽  
Food Resource ◽  
Daily Activities ◽  
Risk Of Extinction ◽  
Conservation Effort ◽  
Hylobates Moloch ◽  
Species Population ◽  
Javan Gibbon

Javan gibbon (Hylobates moloch) is one of endemic primates in Java Island, which listed as endangered and facing the high risk of extinction. Conservation efforts need to be taken immediately in regard to the decrease of this species population. One of aspects that support conservation effort is data on daily activity of this species. The aim of this study was to determine the daily activities of Javan gibbon juvenile at Citalahab Forest Gunung Halimun Salak National Park. We used focal sampling method to collect behavioral data and recording the activity of each individual Javan gibbon by continuous recording. Average time the daily activities of the three groups is 9 hours 56 minutes. Percentage of daily activity from the highest to the lowest is the resting (36.21%), feeding (33.33%), moving (23.05%), socializing (4.94%) and undetected (2.47%). Mostly social activities that do by javan gibbon is play with most frequently performed is wrestling. Javan gibbon in Cikaniki – Citalahab used 11 species as food resource. There are four types of trees used as sleeping tree over the research. The dominant tree strata for sleeping tree is strata A (over 30 m).

scholarly journals Charlson Comorbidity Index Predicts 5-Year Survivorship of Surgically Treated Hip Fracture Patients

2018 ◽  
Vol 9 ◽  
pp. 215145931880644 ◽  
Author(s):  
Lei Jiang ◽  
Andrew Chia Chen Chou ◽  
Nivedita Nadkarni ◽  
Caris En Qi Ng ◽  
Yun San Chong ◽  
...  
Keyword(s):  
Surgical Treatment ◽  
Hip Fracture ◽  
Charlson Comorbidity Index ◽  
Demographic Data ◽  
Survival Rates ◽  
Predictive Ability ◽  
Fracture Pattern ◽  
Mortality Data ◽  
Comorbidity Index

Introduction: This study aims to assess the correlation of the age-adjusted Charlson comorbidity index (ACCI) with 5-year mortality in a surgically treated hip fracture population. Materials and Methods: A retrospective analysis was performed on 1057 patients aged 60 years and above who underwent surgery for hip fracture with a minimum of 5-year follow-up (92.2% 5-year follow-up rate) in a tertiary hospital. Manual review of patients’ electronic hospital records was performed to record demographic data, comorbidities, and length of stay. Mortality data were extracted from the hospital’s electronic medical records and corroborated with the National Electronic Health Record. Results: Of the 1057 patients, 283 (26.8%) were male. The majority of patients were 80 years of age and above (42.5%), with the oldest patient operated on age 102 with a mean age of 77.8 (8.6) years. Four hundred eighteen (39.5%) patients sustained extracapsular intertrochanteric fractures. The mean follow-up duration was 8 years and 3 days with an overall survivorship of 37.2%. A multiple regression model constructed with ACCI, age, gender, and fracture pattern demonstrated satisfactory predictive ability with a concordance statistic of 0.68. Patients with a higher ACCI category (≥6) had an increased 5-year mortality rate (41.8%) with an odds ratio of 13.6 (6.7-31.8, P < .001) compared to those with an ACCI category of 3 and below (89.3%). Discussion: The study demonstrates that ACCI correlated with 5-year mortality after surgical treatment of hip fracture. This information is pertinent in the counseling of patients with regard to their midterm survival following hip fracture surgery and may inform policy makers of the varied midterm survival rates in patients with differing ACCI scores and educate the allocation of health-care resources. Conclusion: The ACCI correlates with 5-year mortality after surgical treatment of hip fracture.

Sex of the foetus determines the time of weaning of the previous offspring of captive plains zebra (Equus burchelli)

2007 ◽  
Vol 105 (1-3) ◽  
pp. 192-204 ◽  
Author(s):  
Jan Pluháček ◽  
Luděk Bartoš ◽  
Miroslava Doležalová ◽  
Jitka Bartošová-Víchová
Keyword(s):  
Equus Burchelli ◽  
Plains Zebra

Impacts of recolonizing gray wolves (Canis lupus) on survival and mortality in two sympatric ungulates

2018 ◽  
Vol 96 (7) ◽  
pp. 760-768 ◽  
Author(s):  
J.A. Dellinger ◽  
C.R. Shores ◽  
M. Marsh ◽  
M.R. Heithaus ◽  
W.J. Ripple ◽  
...  
Keyword(s):  
Canis Lupus ◽  
Mule Deer ◽  
Survival Rates ◽  
Odocoileus Hemionus ◽  
Mortality Rates ◽  
Adult Survival ◽  
Mortality Data ◽  
Gray Wolf ◽  
Gray Wolves ◽  
Large Predators

There is growing recognition that humans may mediate the strength and nature of the ecological effects of large predators. We took advantage of ongoing gray wolf (Canis lupus Linnaeus, 1758) recolonization in Washington, USA, to contrast adult survival rates and sources of mortality for mule deer (Odocoileus hemionus (Rafinesque, 1817)) and white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) in areas with and without wolf packs in a managed landscape dominated by multiple human uses. We tested the hypothesis that the addition of wolves to the existing predator guild would augment predator-induced mortality rates for both ungulates. Source of mortality data from adult mule deer and white-tailed deer, respectively, revealed that wolf-related mortality was low compared with that inflicted by other predators or humans. Predator-caused mortality was largely confined to winter. There was little effect of wolf presence on adult deer mortality rates, and there was no difference in mortality between the two deer species relative to wolf-free or wolf-occupied sites. Although this study occurred early in wolf recovery in Washington, our results differ from those demonstrated for gray wolves in protected areas. Thus, we encourage further investigation of effects of direct predation by recolonizing large carnivores on prey in human-dominated landscapes.

Effects of food, kinship, and density on the longevity of spiderlings

2021 ◽  
pp. 741-751
Author(s):  
Marta Luciane Fischer ◽  
Lays Cherobim Parolin ◽  
Felipe Marcel Neves ◽  
German Antonio Villanueva-Bonilla ◽  
João Vasconellos-Neto
Keyword(s):  
Population Density ◽  
Laboratory Experiments ◽  
Survival Rates ◽  
Food Resource ◽  
Behavioral Characteristic ◽  
Risk Of Predation ◽  
Large Populations ◽  
Main Factors ◽  
Conspecific Tolerance ◽  
Loxosceles Laeta

Cannibalism is a behavioral characteristic found in a wide variety of animal groups. Although the rates of cannibalism can vary from one group to another, studies indicate that the main factors contributing to an increase in the frequency of such behavior are the availability of food, population density, the behavior and availability of victims, and environmental stress. We carried out different laboratory experiments to assess whether different factors such as the presence or absence of food among siblings and non-siblings, and at different densities among conspecific and heterospecific individuals, affect longevity of recently emerged Brazilian brown recluse (Loxosceles intermedia Mello-Leitão, 1934) and Chilean recluse (Loxosceles laeta (Nicolet, 1849)) spiderlings during periods of starvation. The results revealed that the survivorship of L. laeta during starvation was significantly higher than that of L. intermedia and that the addition of conspecific individuals increased survival rates by 1.5- and 1.6-fold, respectively. The tolerance of conspecifics differed between the two species, and generally, cannibalism was not observed, probably due to the risk of predation and limited consumption by weakened spiders, which coincided with the continued availability of endogenous vitelline reserves, thus indicating that the use of these spiderlings as a food resource may act to regulate starvation in more resistant spiders. The greater longevity and conspecific tolerance of L. laeta may be important factors contributing to the establishment of large populations of this spider in restricted areas, whereas for L. intermedia, hunger probably functions as a trigger for dispersal.

P4672Current outcome of chronic thromboembolic pulmonary hypertension in Spain

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
P Martinez Santos ◽  
A Aurtenetxe Perez ◽  
M J Lopez Gude ◽  
J A Barbera ◽  
M Lopez Meseguer ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Survival Rates ◽  
Real Life ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Invasive Procedure ◽  
Percutaneous Treatment ◽  
Mortality Data ◽  
Balloon Pulmonary Angioplasty ◽  
Thromboembolic Pulmonary Hypertension ◽  
The Impact

Abstract Background Chronic thromboembolic pulmonary hypertension (CTEPH) treatment has evolved over the last decade. Increasing evidence regarding new therapeutic developments has shown clinical benefit among these patients in different scenarios. However, there is scarce information about the long-term impact of these achievements in a real-life population on a national scale. We aimed to analyze the impact of current CTEPH therapies on survival in Spain. Methods We prospectively collected epidemiological, clinical and prognostic data from CTEPH patients consecutively included in the Spanish REHAP registry from January 1, 2007, to December 31, 2017. All-cause mortality data were gathered during this period. Results Eight hundred thirteen patients were included. The mean age was 61 (15) years and 58.1% were women. Out of the 813 patients, 537 (66%) were referred to an expert PH-center. Overall, 245 (30.1%) patients were selected for surgery and 52 (6.4%) for percutaneous treatment and 452 (60.5%) received medical treatment exclusively with specific PH drugs. Survival rates of patients who underwent an invasive procedure (pulmonary thrombendarterectomy or balloon pulmonary angioplasty) were remarkably high. Figure 1. Cumulative survival from date Conclusions Patients who underwent pulmonary thrombendarterectomy or balloon pulmonary angioplasty associated a better outcome. Acknowledgement/Funding We gratefully acknowledge all investigators of the REHAP Registry. We express our gratitude to Actelion, Ferrer, GlaxoSmithKline (GSK) and Merck Sharp

scholarly journals The effect of stress and season on some Haematological and Biochemical parameters of three antelope species in the Kalahari Gemsbok National Park

Koedoe ◽  
1984 ◽  
Vol 27 (2) ◽  
Author(s):  
F Le R Fourie ◽  
M. T Van Ouwerkerk
Keyword(s):  
Biochemical Parameters ◽  
National Park ◽  
Blood Parameters ◽  
Optimal Range ◽  
Drug Induced ◽  
Seasonal Study ◽  
Active Pursuit ◽  
Connochaetes Taurinus ◽  
Antidorcas Marsupialis

A seasonal study of some haematological and biochemical parameters of three antelope species (springbok Antidorcas marsupialis, oryx Oryx gazella and blue wildebeest Connochaetes taurinus) was conducted during January, April and June in the Kalahari Gemsbok National Park. A communal increase in two blood parameters during April was observed in all three species studied. These increases correlated with optimal range conditions. Active pursuit of individuals as well as drug induced immobilisation proved to place animals under stress influencing haematograms extensively.

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