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Stress Levels

Decent Essays
Wildlife researchers would like to accurately quantify stress levels in animals so that species reactions to potential stressors in the environment can be documented and predicted. To analyze stress, it is necessary to obtain some form of body fluid or sample. Researchers face the problem that their presence in the ecosystem may bias stress measurements (Romano et al. 2010). There are direct and indirect methods of obtaining samples; researchers must choose a method that will not bias the stress levels of their study species while obtaining a representative sample of the population. The technique used will depend on the study, the species, whether the impact of acute or chronic stressors are being examined, and on the extent of…show more content…
2011)
-Salivary glucocorticoid is highly stable. Samples can be stored at room temperature for several days or up to 4 weeks before analysis is performed (Sheriff et al. 2011)
-A controlled number of samples can be collected across short time intervals - unlike excrement and blood , unlimited samples can be taken when the researcher is ready, doesn’t have to wait for the animal to urinate or to recover from previous bleeding.
Cons:
-Trapping the animal is required to obtain a saliva sample - may bias stress levels
-Concentrations of glucocorticoids in saliva are 10-60% of those found in plasma depending on the species. (Sheriff et al. 2014)
-Sampling for saliva could potentially lead to being bitten by the animal

3. Excrement
Pros:
-Trapping the animal is not required to obtain an excrement sample
-Non invasive sample
-Fecal samples can be preserved in cold environments (Creel et al. 2002)
-Fecal glucocorticoid levels are not prone to researcher-induced biases introduced by handling due to the delay time of a stressor and its appearance in the feces (Kersey et al. 2014)
-Both wet and dry samples can be used and both usually correlate well (Sheriff et al. 2011)

Cons:
-Excrement is potentially harmful to investigator
-Excrement analysis is species limited (Creel et al. 2002)
-The amount of excrement collected in the field can vary
-It cannot provide as many physiological indices
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