Influence of the number of calves and lactating adult females in a herd on the adrenocortical activity of free-ranging Asian elephants

2019 ◽  
Vol 46 (8) ◽  
pp. 679 ◽  
Author(s):  
Sanjeeta Sharma Pokharel ◽  
Polani B. Seshagiri ◽  
Raman Sukumar
Keyword(s):  
National Parks ◽  
Body Condition ◽  
Adult Female ◽  
Ecological Factors ◽  
Herd Size ◽  
Asian Elephants ◽  
Adrenocortical Activity ◽  
Adult Females ◽  
Stress Levels ◽  
Free Ranging

Abstract ContextPhysiological stress has the potential to influence animal population persistence. The endangered Asian elephant (Elephas maximus) is involved in intense conflict with humans in many parts of its range, which likely leads to stress for individuals and groups, with consequences for population survival. Thus, it is important to understand how the elephants’ stress levels are influenced by socio-ecological factors when not directly exposed to human-induced threats, and to use this understanding to improve conservation and management strategies. AimsThe present study was designed to provide baseline information on the link between socio-ecological factors and stress levels of undisturbed populations of elephants. The main aim was to determine the influence of a number of factors – herd size, season, number of calves and adult females present in a herd and their lactational status and body condition – on the adrenocortical activity of free-ranging adult female Asian elephants living in protected forests (without any direct exposure to human-induced threats), by measuring their faecal glucocorticoid metabolite (fGCM) levels. MethodsA total of 145 fresh faecal samples were collected from 123 identified adult female elephants inhabiting Bandipur and Nagarahole National Parks of southern India, between the years 2013 and 2015. fGCM levels were measured by employing a group-specific standardised 11-oxoetiocholanolone enzyme immunoassay (EIA). A generalised linear mixed-effects model (GLMM) was used to assess the influence of socio-ecological factors on fGCM levels of adult female elephants. Key resultsWhen fGCM levels were analysed with a GLMM, the following patterns were observed: fGCM levels were negatively correlated with the number of adult females (herd size) and positively correlated with the number of calves in a herd and active lactational status of an adult female. fGCM levels of adult female elephants were higher during the dry season (February to May) than wet season (August to December) and negatively correlated with body condition scores. ConclusionsAdrenocortical activity of female elephants is significantly influenced by the number of calves and adult females present in the herd, seasonality and lactational status. ImplicationsIt is important to consider the influence of multiple ecological and social correlates when assessing and interpreting the adrenocortical activity of Asian elephants. Our findings highlight the importance of maintaining the social structure of elephants in the wild to avoid detrimental effects on their physiological health. Insights from such assessments could be used to evaluate the stress in elephants that are involved in direct conflicts with humans to take appropriate management decisions for mitigating conflicts.

Social capital and physiological stress levels in free-ranging adult female rhesus macaques

2011 ◽  
Vol 102 (1) ◽  
pp. 76-83 ◽  
Author(s):  
L.J.N. Brent ◽  
S. Semple ◽  
C. Dubuc ◽  
M. Heistermann ◽  
A. MacLarnon
Keyword(s):  
Social Capital ◽  
Adult Female ◽  
Physiological Stress ◽  
Rhesus Macaques ◽  
Female Rhesus ◽  
Stress Levels ◽  
Free Ranging ◽  
Female Rhesus Macaques

scholarly journals Ecological role of hunting in population dynamics and its implications for co-management of the Porcupine caribou herd

Rangifer ◽  
2000 ◽  
Vol 20 (5) ◽  
pp. 71 ◽  
Author(s):  
Thomas A. Hanley ◽  
Donald E. Russell
Keyword(s):  
Population Dynamics ◽  
Monitoring System ◽  
Body Condition ◽  
Population Model ◽  
Census Data ◽  
Herd Size ◽  
The Past ◽  
Adult Females ◽  
Herd Dynamics

At a present population size of 160 000 animals, the Porcupine caribou herd has been subjected to an annual harvest rate of 2% for the past couple of decades. We modeled potential sensitivity of herd population dynamics to hunting and used that relation as a basis for a herd monitoring system. Maximum number of adult cows that could be harvested without causing a subsequent decline in herd size was calculated as a function of total number of adult cows in the herd and recruitment of calves to yearling age-class. Maximum cow harvest, therefore, is a threshold above which hunting has destabilizing effects on herd dynamics. Actual harvest in relation to theoretical maximum harvest provides a basis for prediction of herd sensitivity to hunting. Maximum harvest is a linear function of recruitment. Herd dynamics are especially sensitive to low recruitment, however, when combined with low herd size. The two relations involving recruitment and herd size provide the basis for predicting herd dynamics and sensitivity to hunting. Herd size is best estimated by aerial census, while an index of recruitment can be predicted by monitoring autumn body condition of adult females. Body condition can be estimated on the basis of a few simple metrics measured by hunters in the field. The hunters' data on body composition, combined with aerial census data on herd size, provide a useful tool for managers and co-management boards to devise policies and regulations to manage the herd. The population model and monitoring system can operate on the Internet and be accessible to all users in villages within the range of the Porcupine caribou herd.

scholarly journals Association between stress and bilateral symmetrical alopecia in free-ranging Formosan macaques in Mt. Longevity, Taiwan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chen-Chih Chen ◽  
Ai-Mei Chang ◽  
Ming-Shan Tsai ◽  
Yen-Hua Huang ◽  
Kurtis Jai-Chyi Pei ◽  
...  
Keyword(s):  
Total Population ◽  
Causative Factor ◽  
Population Status ◽  
Adrenocortical Activity ◽  
High Incidence ◽  
Normal Hair ◽  
The Mean ◽  
The Individual ◽  
Free Ranging ◽  
The Impact

AbstractSince 2013, a high incidence of bilateral symmetrical alopecia has been observed in free-ranging Formosan macaques (Macaca cyclopis) in Mt. Longevity, Taiwan. We hypothesized that stress induces alopecia in this population. To verify our hypothesis, we evaluated the histopathological characteristics of skin biopsy and used a validated enzyme immunoassay (EIA) for fecal glucocorticoid metabolite (FGM) analysis, which act as an indicator of stress experienced by the individual. Follicular densities were lower (2.1–3.0 mm2) in individuals with symmetrical alopecia than in those with normal hair conditions (4.7 mm2). Furthermore, anagen to catagen/telogen ratios were lower in individuals with alopecia (0–1.4) than in those with normal hair (4.0). The histopathological characteristics of alopecia were similar to those of telogen effluvium, which indicates that stress is one of the possible etiologies. On the basis of the analytical and biological validation of EIAs for FGM analysis, 11β-hydroxyetiocholanolone was considered suitable for monitoring adrenocortical activity in both sexes of Formosan macaques. The mean concentrations (standard error; sample size) of 11β-hydroxyetiocholanolone were 2.02 (0.17; n = 10) and 1.41 (0.10; n = 31) μg/g for individuals with and without alopecia, respectively. Furthermore, the results of logistic regression analysis show that 11β-hydroxyetiocholanolone (p = 0.012) concentration was positively associated with alopecia. Thus, stress was the most likely to trigger symmetrical alopecia in Formosan macaques in Mt. Longevity. Although stress can decrease the fitness of an individual, considering the population status of Formosan macaques in Taiwan is stable and alopecia was only observed in our study area, which is isolated from other populations, the impact on the total population of Formosan macaque in Taiwan is limited. Nonetheless, stress-induced immunosuppression and alopecia might affect the local abundance and increase zoonosis risk due to frequent human–macaque contact in Mt. Longevity. Future studies are suggested to focus on the causative factor of stress and the effects of stress and alopecia on the health and welfare in the Formosan macaques.

Association Between Stress and Bilateral Symmetrical Alopecia in Free-Ranging Formosan Macaques (Macaca Cyclopis) in A High-Population-Density Area

2021 ◽  
Author(s):  
Chen-Chih Chen ◽  
Ai-Mei Chang ◽  
Ming-Shan Tsai ◽  
Yen-Hua Huang ◽  
Kurtis Jai-Chyi Pei ◽  
...  
Keyword(s):  
Total Population ◽  
High Population Density ◽  
Macaca Cyclopis ◽  
Adrenocortical Activity ◽  
Biological Validation ◽  
High Incidence ◽  
Normal Hair ◽  
The Mean ◽  
The Individual ◽  
Free Ranging

Abstract Since 2013, a high incidence of bilateral symmetrical alopecia has been observed in free-ranging Formosan macaques (Macaca cyclopis) in Mt. Longevity, Taiwan. We hypothesized that stress induces alopecia in this population. To verify our hypothesis, we evaluated the histopathological characteristics of skin biopsy and used a validated enzyme immunoassay (EIA) for fecal glucocorticoid metabolite (FGM) analysis, which act as an indicator of stress experienced by the individual. Follicular densities were lower (2.1–3.0 mm2) in individuals with symmetrical alopecia than in those with normal hair conditions (4.7 mm2). Furthermore, anagen to catagen/telogen ratios were lower in individuals with alopecia (0–1.4) than in those with normal hair (4.0). The histopathological characteristics of alopecia were similar to those of telogen effluvium, which indicates that stress is one of the possible etiologies. On the basis of the analytical and biological validation of EIAs for FGM analysis, 11β-hydroxyetiocholanolone was considered suitable for monitoring adrenocortical activity in both sexes of Formosan macaques. The mean concentrations (standard error; sample size) of 11β-hydroxyetiocholanolone were 2.02 (0.17; n = 10) and 1.41 (0.10; n = 31) μg/g for individuals with and without alopecia, respectively. Furthermore, the results of logistic regression analysis show that 11β-hydroxyetiocholanolone (p = 0.012) concentration was positively associated with alopecia. Thus, stress was the most likely to trigger symmetrical alopecia in Formosan macaques in Mt. Longevity. Although stress can decrease the fitness of an individual, it should not impact the total population of Formosan macaque in Taiwan. Nonetheless, stress-induced immunosuppression might increase zoonosis risk due to frequent human–macaque contact in Mt. Longevity.

Effects of canine heartworm (Dirofilaria immitis) on body condition and activity of free-ranging coyotes (Canis latrans)

2000 ◽  
Vol 78 (6) ◽  
pp. 1042-1051 ◽  
Author(s):  
Benjamin N Sacks ◽  
Karen M Blejwas
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Dirofilaria Immitis ◽  
Canis Latrans ◽  
Infected Group ◽  
Control Group ◽  
Canine Heartworm ◽  
Average Body Mass ◽  
Free Ranging ◽  
Average Body

We used radiotelemetry to study relationships among canine heartworm (Dirofilaria immitis) infection, body condition, and activity of free-ranging coyotes (Canis latrans). Average body mass at death was lower for 17 coyotes in a high-intensity infected group (mean = 33.6 heartworms) than for 18 coyotes in a control group (mean = 3.6 heartworms; p < 0.01). Coyotes in the infected group lost body mass at an average rate of 20% per year relative to the control group (p < 0.01). Bone marrow fat was negatively correlated with heartworm burden (R2 = 0.27; p < 0.01). Average body mass of coyotes at initial capture (i.e., potentially before infection) did not differ between infected and control groups (p = 0.90; 1–β = 0.70). Activity was negatively correlated with heartworm burden during the last 2 months of life (R2 = 0.30; p < 0.01), but no correlation was found 2–4 months before death. Activity of the infected group (n = 13) declined over time (p = 0.01), whereas no difference in activity was observed in the control group (n = 13; p = 0.50). Our findings indicate that heartworm infection reduced body condition and activity of coyotes but that nutritional status did not significantly affect susceptibility to infection.

Spatial variability in the social organisation of the yellow-bellied glider (Petaurus australis) near Ravenshoe, north Queensland

2001 ◽  
Vol 49 (4) ◽  
pp. 397 ◽  
Author(s):  
Ross L. Goldingay ◽  
Darren G. Quin ◽  
Sue Churchill
Keyword(s):  
Adult Female ◽  
Social System ◽  
Dominant Male ◽  
Female Group ◽  
Sexually Dimorphic ◽  
Adult Males ◽  
Adult Females ◽  
The Social ◽  
Natal Home ◽  
Petaurus Australis

A detailed study was conducted over a 12-month period of 10 yellow-bellied glider groups at Nitchaga Creek in north Queensland. Adult gliders were sexually dimorphic in body size and were characterised by yellow ventral fur, which is consistent with southern populations. Gliders lived in groups of 3–6 individuals that occupied exclusive areas of about 50 ha. The structure of glider groups varied enormously: five contained one adult pair, three contained one adult male and 2–3 adult females, and two initially contained 2–3 adult males and one adult female but then persisted as bachelor groups after the death or disappearance of the adult female. Group size changed during the year as offspring matured and as individuals died. One male glider dispersed about 1 km from its natal home-range and became the dominant male in a nearby group. Young were born throughout the year, with a peak in the number of pouch-young in June. This study has confirmed the highly variable social system of the yellow-bellied glider, which appears to be mediated by local resource abundance.

scholarly journals Birth season glucocorticoids are related to the presence of infants in sifaka ( Propithecus verreauxi )

2009 ◽  
Vol 276 (1663) ◽  
pp. 1855-1863 ◽  
Author(s):  
Diane K. Brockman ◽  
Amy K. Cobden ◽  
Patricia L. Whitten
Keyword(s):  
Stress Responses ◽  
Physiological Stress ◽  
Ecological Factors ◽  
Adult Males ◽  
Birth Season ◽  
Propithecus Verreauxi ◽  
Group Stability ◽  
Dispersal Events ◽  
Free Ranging ◽  
Plural Breeding

The responses of plural breeding mammals to environmental stressors are little understood in free-ranging populations, but recent studies of singular breeders suggest that ecological factors and social milieu influence the variable physiological stress responses observed among individuals. Our previous studies examining faecal glucocorticoid (fGC)–behaviour interactions in plural breeding male sifaka ( Propithecus verreauxi ) show that fGC elevations coincide with specific dispersal events, particularly the eviction of subordinates by resident alpha males. This study examined the utility of fGC assays for assessing the stress responses of male sifaka to demographic changes in the population during the birth season. Analyses were based on 889 faecal samples collected over five birth seasons from 124 adult males residing in 55 different groups at Beza Mahafaly, Madagascar. Results show that fGC levels in males are unrelated to age, residence, group stability or rank, but are significantly and positively correlated with the presence of infants, annual elevations in weekly mean fGC concentrations in males paralleling increasing numbers of infants born annually in the population. These data are the first to show that in seasonal plural breeding species such as sifaka, elevated fGC in males reflects specific events related to reproduction rather than states or social context during the birth season.

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