7 research outputs found
Non-invasive assessment of adrenocortical activity as a measure of stress in giraffe (Giraffa camelopardalis)
Additional file 1: Full dataset in Microsoft Excel workbook format.BACKGROUND : Numbers of giraffes are declining rapidly in their native habitat. As giraffe research and conservation
efforts increase, the demand for more complete measures of the impact of conservation interventions and the
effects of captive environments on animal health and welfare have risen. We compared the ability of six different
enzyme immunoassays to quantify changes in fecal glucocorticoid metabolites (FGM) resulting from three sources:
adrenocorticotropic hormone stimulation test, transport, and time of day that samples were collected.
RESULTS : Two male giraffes underwent ACTH injections; all six assays detected FGM increases following injection
for Giraffe 1, while only three assays detected FGM increases following injection for Giraffe 2. Consistent with other
ruminant species, the two 11-oxoetiocholanolone assays (one for 11,17-dioxoandrostanes and the other for
3α,11-oxo metabolites) measured the most pronounced and prolonged elevation of FGM, while an assay
for 3ÎČ,11ÎČ-diol detected peaks of smaller magnitude and duration. Both of the 11-oxoetiocholanolone assays
detected significant FGM increases after transport in Giraffes 3â7, and preliminary data suggest FGM detected
by the assay for 11,17-dioxoandrostanes may differ across time of day.
CONCLUSIONS : We conclude the assay for 11,17-dioxoandrostanes is the most sensitive assay tested for FGM
in giraffes and the assay for FGM with a 5ÎČ-3α-ol-11-one structure is also effective. 11-oxoetiocholanolone
enzyme immunoassays have now been demonstrated to be successful in a wide variety of ruminant species,
providing indirect evidence that 5ÎČ-reduction may be a common metabolic pathway for glucocorticoids in
ruminants. As FGM peaks were detected in at least some giraffes using all assays tested, giraffes appear to
excrete a wide variety of different FGM. The assays validated here will provide a valuable tool for research
on the health, welfare, and conservation of giraffes.The Association of Friends and Supporters of Goethe University Frankfurt
provided financial support for F. Sicks to travel to Vienna to analyze fecal
samples and von Opel Hessische Zoostiftung supported a studentship for
F. Sicks. One commercial funder [Tierpark Berlin] provided support in the
form of salary for F. Sicks during data analysis and preparation of this
manuscript. The specific role of this author is articulated in the âAuthor
Contributionsâ section.http://www.biomedcentral.com/bmcvetresam2016Anatomy and PhysiologyParaclinical Science
Female tannin avoidance: a possible explanation for habitat and dietary segregation of giraffes ( Giraffa camelopardalis peralta
The impact of Masai giraffe nursery groups on the development of social associations among females and young individuals
Regional Differences in Seasonal Timing of Rainfall Discriminate between Genetically Distinct East African Giraffe Taxa
<div><p>Masai (<i>Giraffa tippelskirchi</i>), Reticulated (<i>G. reticulata</i>) and Rothschild's (<i>G. camelopardalis</i>) giraffe lineages in East Africa are morphologically and genetically distinct, yet in Kenya their ranges abut. This raises the question of how divergence is maintained among populations of a large mammal capable of long-distance travel, and which readily hybridize in zoos. Here we test four hypotheses concerning the maintenance of the phylogeographic boundaries among the three taxa: 1) isolation-by-distance; 2) physical barriers to dispersal; 3) general habitat differences resulting in habitat segregation; or 4) regional differences in the seasonal timing of rainfall, and resultant timing of browse availability. We used satellite remotely sensed and climate data to characterize the environment at the locations of genotyped giraffes. Canonical variate analysis, random forest algorithms, and generalized dissimilarity modelling were employed in a landscape genetics framework to identify the predictor variables that best explained giraffes' genetic divergence. We found that regional differences in the timing of precipitation, and resulting green-up associated with the abundance of browse, effectively discriminate between taxa. Local habitat conditions, topographic and human-induced barriers, and geographic distance did not aid in discriminating among lineages. Our results suggest that selection associated with regional timing of events in the annual climatic cycle may help maintain genetic and phenotypic divergence in giraffes. We discuss potential mechanisms of maintaining divergence, and suggest that synchronization of reproduction with seasonal rainfall cycles that are geographically distinct may contribute to reproductive isolation. Coordination of weaning with green-up cycles could minimize the costs of lactation and predation on the young. Our findings are consistent with theory and empirical results demonstrating the efficacy of seasonal or phenologically dictated selection pressures in contributing to the reproductive isolation of parapatric populations.</p></div