Reducing sampling error in faecal egg counts from black rhinoceros (Diceros bicornis)

Area of Science:

• Veterinary Parasitology
• Wildlife Health Management
• Conservation Biology

Background:

• Faecal egg counts (FECs) are crucial for non-invasive parasite load assessment in wildlife.
• Potential errors in FECs stem from laboratory techniques, sample storage, and sampling methods.
• Understanding sampling error is vital for accurate parasite burden estimation in host populations.

Purpose of the Study:

• To evaluate the impact of delayed dung sample collection on FECs in black rhinoceros.
• To determine the optimal number of samples required for reliable estimation of mean parasite abundance.
• To enhance the cost-effectiveness and efficiency of sampling strategies for black rhinoceros populations.

Main Methods:

• Investigated strongyle-type nematodes and Anoplocephala gigantea eggs in black rhinoceros dung.
• Assessed FECs from dung samples collected up to six hours after defecation.
• Utilized statistical methods to estimate the sample size needed for robust parasite abundance data.

Main Results:

• Dung sample collection up to six hours post-defecation did not significantly affect FECs.
• A minimum of nine samples were required to substantially improve confidence intervals for mean parasite abundance.
• Sampling timing and sample size influence the reliability of FEC data.

Conclusions:

• FECs in black rhinoceros are reliable when samples are collected within six hours of defecation.
• A minimum of nine samples per host population is recommended for accurate parasite abundance assessment.
• Optimized sampling protocols improve the efficiency and reliability of FECs in wildlife health monitoring.