Assessing stress physiology within a conservation breeding program for an endangered species

Area of Science:

• Veterinary Medicine
• Wildlife Conservation Biology
• Animal Physiology

Background:

• Conservation breeding programs manage species both in situ (in natural habitats) and ex situ (outside natural habitats).
• Understanding physiological changes in managed species is crucial for maximizing conservation outcomes.
• Previous studies indicated differences in hair glucocorticoid concentrations among managed Vancouver Island marmots (VIMs).

Purpose of the Study:

• To assess the neutrophil to lymphocyte (N:L) ratio as a physiological stress metric in VIMs across different management groups.
• To compare stress levels between captive, pre-release, post-release, and wild VIM populations.
• To investigate the influence of age, sex, and sampling month on the N:L ratio within each population.

Main Methods:

• Utilized over 1000 blood samples collected since the inception of the VIM conservation breeding program.
• Analyzed the neutrophil to lymphocyte (N:L) ratio as a biomarker for physiological stress.
• Compared N:L ratios across four distinct VIM populations: captive, pre-release, post-release, and wild.

Main Results:

• In situ (wild) VIM populations exhibited a significantly higher N:L ratio compared to ex situ (managed) populations.
• The wild environment appears to be more physiologically challenging for VIMs than managed care settings.
• The influence of age and sex on N:L ratio varied significantly across the different populations, with age being most impactful in wild VIMs and sex in ex situ populations.

Conclusions:

• The N:L ratio provides valuable insights into the physiological stress experienced by VIMs in different environments.
• Wild VIMs face greater physiological challenges than those in managed conservation programs.
• Further post-release monitoring is recommended to fully understand the role of physiology in VIM survival rates and to refine conservation strategies.