A method to determine integrated steroid levels in wildlife claws

Area of Science:

• Endocrinology
• Wildlife Biology
• Conservation Science

Background:

• Glucocorticoids are vital hormones regulating physiological and behavioral processes throughout life.
• Hormone levels in wildlife are labile, making measurement challenging due to capture and handling stress.
• Developing non-invasive methods for steroid analysis in wildlife is crucial for accurate assessment.

Purpose of the Study:

• To explore a novel method for measuring glucocorticoids in free-ranging chameleons.
• To assess the feasibility of using claw samples for steroid quantification.
• To investigate the relationship between claw corticosterone levels and body size in male chameleons.

Main Methods:

• Collected claw tips from free-ranging chameleons for individual identification and steroid analysis.
• Developed and applied a steroid extraction and quantification method for claw matrix.
• Utilized commercial enzyme immunoassay (EIA) kits for corticosterone measurement.

Main Results:

• Successfully measured corticosterone in small amounts of chameleon claw matrix.
• Found a significant association between claw corticosterone levels and body size in wild male chameleons.
• Demonstrated that claw steroids provide an integrated hormonal level reflecting the period of claw growth.

Conclusions:

• Chameleon claw testing offers a promising, non-invasive matrix for wildlife biomonitoring.
• This method overcomes the challenges associated with stress-induced hormone level fluctuations.
• Claw corticosterone analysis can provide valuable insights into the physiological status and environmental responses of wildlife.