However, due to the lack of significant changes in fecal hormone metabolite profiles, further investigation of the excretory dynamics of corticosteroids during acute and chronic stress is warranted.Įmerging evidence from the preclinical and human research suggests sex differences in response to different types of stress exposure, and that developmental timing, reproductive status, and biological sex are important factors influencing the degree of HPA activation/function. This study provides a direct measurement of the physiologic response of clinically healthy killer whales to a stress event. For serum chemistry, significant deviations from baseline levels were seen for the majority (20/37) of measured parameters. Significant differences between pre-test levels and the stress test stage were observed for counts of white blood cells and absolute neutrophils, consistent with a stress leukogram. Concentrations of fecal corticosteroid metabolites did not change significantly during the stress test. Circulating corticosteroids significantly increased during the stress test and returned to pre-treatment concentrations within 24 h, indicating hypothalamic-pituitary-adrenal-axis activation. Paired blood and feces were tested for cortisol, corticosterone, aldosterone, and their metabolites and hematological and serum chemistry parameters. A stress test was performed in 13 zoo-based killer whales (Orcinus orca) whereby animals were elevated out of the water on a rising lift-bottom platform for 20 min. The importance of home range size suggests that maintaining or improving habitats that promote smaller home ranges would likely facilitate a lower stress response by hens, which should benefit Sage-Grouse survival and reproduction.Ĭomparisons of circulating and excreted corticosteroid profiles during a biological stress response could provide more data concerning the timing and magnitude of acute hormone changes in different sample matrices. Concentrations of corticosterone increased with home range size but decreased with reproductive effort and temperature. We collected 36 fecal samples from 22 radio-collared hens during the brood-rearing season (24 May–26 July) in southwestern Idaho 2017–18. We used remotely sensed data to estimate vegetation cover within hens’ home ranges and accounted for factors that influence FCORTm in other vertebrates, such as age and weather. We evaluated relationships between habitat use in a landscape modified by juniper expansion and annual grasses and corticosterone metabolite levels (stress responses) in feces (FCORTm) of female Sage-Grouse. Expansion of juniper (Juniperus spp.) trees and invasion of annual grasses into sagebrush (Artemisia spp.) ecosystems have contributed to habitat degradation for Greater Sage-Grouse (Centrococercus urophasianus (Bonaparte, 1827) hereafter, “Sage-Grouse”), a species of conservation concern throughout its range. Ecological conditions for many animal species have deteriorated as a function of invasive plants and habitat fragmentation. Measurement of physiological responses can reveal effects of ecological conditions on an animal and correlate with demographic parameters. This is the first step towards standardizing the methods for assessing stress by measuring fecal glucocorticoid metabolites in snakes. Since the collected fecal samples contain 75% undigestible materials by weight, these results support our hypothesis that removing these materials will improve extraction methods for a more reliable measurement of corticosterone. The results indicated that the samples with the undigestible materials removed had a 95% increase in overall yield (p < 0.01). These extracts were then used to quantify FGM concentrations using a corticosterone EIA kit. Fecal samples were collected from Pituophis species and FGMs were extracted by two different sample collection methods: (1) fecal sample containing undigested materials and (2) fecal samples with undigested materials removed. While many factors can influence FGM levels, we aimed to standardize and improve these methods in snakes. While there are many benefits to this methodology, there are also recognized limitations, including the apprehensive interpretation of results. Measuring fecal glucocorticoid metabolites (FGM) has recently become a sought-after method for assessing stress in animals.
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