Antiphonal vocal bouts associated with departures in free-ranging African elephant family groups (Loxodonta africana)

Bioacoustics ◽  
2012 ◽  
Vol 21 (3) ◽  
pp. 215-224 ◽  
Author(s):  
C. E. O'Connell-Rodwell ◽  
J. D. Wood ◽  
M. Wyman ◽  
S. Redfield ◽  
S. Puria ◽  
...  
Keyword(s):  
Loxodonta Africana ◽  
African Elephant ◽  
Free Ranging ◽  
Family Groups

Effects of poaching on bull mating success in a free ranging African elephant (Loxodonta africana) population in Tarangire National Park, Tanzania

2007 ◽  
Vol 9 (2) ◽  
pp. 247-255 ◽  
Author(s):  
D. R. S. Ishengoma ◽  
A. M. Shedlock ◽  
C. A. H. Foley ◽  
L. J. Foley ◽  
S. K. Wasser ◽  
...  
Keyword(s):  
Mating Success ◽  
National Park ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Tarangire National Park ◽  
Free Ranging

scholarly journals Vaccination against GnRH may suppress aggressive behaviour and musth in African elephant (Loxodonta africana) bulls - a pilot study

2010 ◽  
Vol 81 (1) ◽  
Author(s):  
H. M. De Nys ◽  
H. J. Bertschinger ◽  
J. A. Turkstra ◽  
B. Colenbrander ◽  
R. Palme ◽  
...  
Keyword(s):  
Pilot Study ◽  
Aggressive Behaviour ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Gland Secretion ◽  
Vaccine Adjuvant ◽  
Free Ranging ◽  
The Relationship ◽  
Temporal Gland Secretion ◽  
Cortisol Metabolites

Aggressive behaviour and musth are constant problems in captive and sometimes in free-ranging African elephant bulls. Aggressive bulls are difficult and musth bulls almost impossible to manage without severely restricting their movement either by leg-chaining or using tranquillisers. This study investigated the relationship between faecal androgen metabolites (FAM) and faecal cortisol metabolites (FCM) concentrations and aggressive behaviour and tested a GnRH vaccine as a means of down-regulating aggressive behaviour and musth in 1 free-ranging and 5 captive elephant bulls. The bulls were non-aggressive (n = 3), aggressive (n = 2) or in musth (n = 1) at the onset of the study. The bulls were injected with a GnRH vaccine-adjuvant combination 3 or 4 times at 3- to 7-week intervals. Behaviour, FAM and FCM concentrations were measured during every week prior to vaccination until 4 months after the last vaccination. FAM concentrations were positively correlated with aggressive behaviour before the 1st vaccination. Androgen production, as reflected by FAM concentrations, was down-regulated in 3 of the 6 immunised bulls. At least 2 bulls and possibly a 3rd showed behavioural improvement following GnRH vaccination and in all 3 temporal gland secretion ceased. No further aggressive behaviour was observed until the end of the study in any of the bulls. The results of this 1st GnRH immunisation study suggest that it could be a useful method to control aggressive behaviour and musth in African elephant bulls.

scholarly journals Tusklessness and tusk fractures in free-ranging African savanna elephants (Loxodonta africana)

2007 ◽  
Vol 78 (2) ◽  
Author(s):  
G. Steenkamp ◽  
S.M. Ferreira ◽  
M.N. Bester
Keyword(s):  
Genetic Drift ◽  
Founder Effect ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Annual Rainfall ◽  
Founder Population ◽  
African Savanna ◽  
History Of ◽  
Free Ranging ◽  
Selective Culling

The incidence of tusklessness varies between free-ranging African elephant populations. Sex-linked genetic drift predicts 2 outcomes - the condition becomes fixed and sex-specific incidences diverge when populations are small and/or heavily poached. By contrast, for large and intact populations, tusklessness diminishes and there is no variation between sexes. We tested these predictions by comparing sex-specific incidences between 15 populations: a small one with a skewed founder effect towards tusklessness; 5 that had experienced intense levels of poaching; 2 that had been subjected to non-selective culling and 7 that are relatively pristine. Patterns of rainfall were studied of tusk fractures amongst these populations to correct for any effect that acquired tusklessness may have on our predictions. The incidence of tusk fractures was related to annual rainfall, but the mechanism that leads to an increase of the condition in drier areas was not clear. Incidences of tusk fractures in free-ranging populations implied that the frequency of acquired bilateral tusklessness is low and should not affect our results. All males had tusks. Tusklessness in females was high in the small skewed founder population and some of those where there was a history of poaching. The incidence is expected to decline if the residual population is large.

Articular cartilage in the knee joint of the African elephant,Loxodonta africana, Blumenbach 1797

2007 ◽  
Vol 269 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Gunter F. Egger ◽  
Kirsti Witter ◽  
Gerald Weissengruber ◽  
Gerhard Forstenpointner
Keyword(s):  
Articular Cartilage ◽  
Knee Joint ◽  
Loxodonta Africana ◽  
African Elephant

scholarly journals Changes in African Elephant (Loxodonta africana) faecal steroid concentrations post-defaecation

Bothalia ◽  
2018 ◽  
Vol 48 (1) ◽  
Author(s):  
Judith T. Webber ◽  
Michelle D. Henley ◽  
Yolanda Pretorius ◽  
Michael J. Somers ◽  
Andre Ganswindt
Keyword(s):  
Reproductive Function ◽  
Loxodonta Africana ◽  
African Elephant ◽  
Sample Collection ◽  
Male And Female ◽  
Freeze Dried ◽  
Metabolite Concentrations ◽  
Endocrine Status ◽  
In The Wild ◽  
Sun And Shade

Background: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection and processing may influence steroid concentrations, as faecal bacterial enzymes can alter steroid composition post-defaecation.Objectives: This study investigated changes in faecal glucocorticoid (fGCM), androgen (fAM) and progestagen (fPM) metabolite concentrations in faeces of a male and female African elephant (Loxodonta africana) post-defaecation and the influence of different faeces-drying regimes.Method: Subsamples of fresh faeces were frozen after being dried in direct sun or shade for 6, 20, 24, 48 and 72 h and 7 and 34 days. A subset of samples for each sex was immediately frozen as controls. Faecal hormone metabolite concentrations were determined using enzyme immunoassays established for fGCM, fAM and fPM monitoring in male and female African elephants.Results: Hormone metabolite concentrations of all three steroid classes were stable at first, but changed distinctively after 20 h post-defaecation, with fGCM concentrations decreasing over time and fPM and fAM concentrations steadily increasing. In freeze-dried faeces fGCM concentrations were significantly higher than respective concentrations in sun-dried material, which were in turn significantly higher than fGCM concentrations in shade-dried material. In contrast, fAM concentrations were significantly higher in sun- and shade-dried faeces compared to freeze-dried faeces. Higher fPM concentrations were also found in air-dried samples compared to lyophilised faeces, but the effect was only significant for sun-dried material.Conclusion: The revealed time restriction for collecting faecal material for hormone monitoring from elephants in the wild should be taken into account to assure reliable and comparable results. However, if logistics allow a timely collection, non-invasive hormone measurement remains a powerful and reliable approach to provide information about an elephant’s endocrine status.

Sign in / Sign up

Export Citation Format

Share Document