Decreased Baseline Fecal Glucocorticoid Concentrations Associated with Skin and Oral Lesions in Black Rhinoceros (Diceros bicornis)

Abstract

Ulcerative lesions are a health concern for managed black rhinoceros (Diceros bicornis) populations. To examine possible relationships between ex situ variables and adrenal activity with the presence of lesions, facility and socioenvironmental surveys of 25:20 (male:female) black rhinos at 18 zoos were conducted, and fecal samples were collected twice weekly for 1 yr for glucocorticoid metabolite analyses. During the collection period, 5.1 rhinos exhibited skin lesions, 1.0 had oral lesions, and 1.0 had both. All of the rhinos with lesions recovered, except the one with both oral and skin lesions, which died shortly after the end of the study. In general, there were no relationships (P > 0.05) between ex situ variables, or rhino behavior indices, and lesion onset. There also were no differences (P > 0.05) in fecal glucocorticoid variability (+/- SEM) between rhinos with (coefficients of variation [CV] = 57.1 +/- 7.2 ng/g) and without (53.8 +/- 2.3 ng/g) lesions, or in overall mean (+/- SEM) glucocorticoid metabolite concentrations between rhinos with (45.1 +/- 4.0 ng/g) and without (34.6 +/- 2.8 ng/g) lesions. However, baseline mean (+/- SEM) glucocorticoid metabolite concentrations were lower (P < 0.05) in rhinos with lesions (n = 5.1, baseline mean = 29.9 +/- 3.3 ng/g, range: 24.3-84.9 ng/g) than without (n = 19.19 baseline mean = 40.0 +/- 2.4 ng/g, range: 19.4-50.8 ng/g). For a male rhino that developed lesions during the study, the mean glucocorticoid concentrations were lower (P < 0.01) when lesions were present (n = 12, overall = 30.1 +/- 2.4 ng/g, baseline = 28.7 +/- 2.2 ng/g) than prior to lesion onset (n = 75, overall = 36.5 +/- 1.0 ng/g, baseline 35.3 +/- 0.8 ng/g). These results suggest that ulcerative lesions may be associated with changes in adrenal activity, although it is not clear if this is a cause or effect of disease.

“Feelings and Fitness” Not “Feelings or Fitness”–The Raison d'être of Conservation Welfare, Which Aligns Conservation and Animal Welfare Objectives

“…For instance, “stress responses” can also occur in situations actively sought out by animals and which would intuitively appear to be related to positive experiences e.g., hunting, mating ( 91 ). In addition, the responses and responsiveness of the HPA axis can change depending on the pattern and duration of the stressors [e.g., ( 92 , 113 , 161 )], stress may have negative (e.g., reduced reproduction) or positive (e.g., escaping a predator) consequences for fitness ( 75 ), and behavioral strategies may be used instead to “cope” with conditions that are nonetheless unpleasant to the animal, e.g., hiding, expressing abnormal repetitive behaviors ( 114 , 162 ).…”

Effects of natural environmental conditions on faecal glucocorticoid metabolite concentrations in jaguars (Panthera onca) in Belize

“…Non-invasive hormone monitoring (NHM) is widely used in a variety of wildlife species, but requires rigorous testing to ensure the validity of techniques employed to assess steroid metabolites in excreta, such as faeces ( Möstl et al , 2005 ; Palme, 2005 ; Touma and Palme, 2005 ). The applicability of this powerful tool has been demonstrated in several areas of animal research, such as ethology, reproductive physiology and animal health ( Goymann et al , 2001 ; Wielebnowski et al , 2002 ; Brown, 2006 ; Franceschini et al , 2008 ; Dorsey et al , 2010 ). Most of the studies employing NHM, however, are performed in ex situ settings, such as zoos or research centres, where samples can be collected fresh and exposure to environmental conditions is limited.…”

Stress in captive Blue-fronted parrots (Amazona aestiva): the animalists’ tale

“…, 2017) and causing a maladaptation of these animals in the wild (Santos and Lopes, 2006). This unsatisfactory stress response has been already further underlined by some studies that associated low GCM levels in domesticated or captive animals with poor welfare or disease (Dorsey et al. , 2010; Pawluski et al.…”