The reliability of latex weak links on radio collars used to track eastern grey kangaroos (Macropus giganteus)

Telemetry neck collars are commonly used to collect spatial data on free ranging animals. Two major challenges in application are entanglement prevention and retrieval of the collars after the study. Weak links made of a degradable material that breaks down while deployed on the animal are a potential solution to reduce entanglement and prevent the need to capture or sedate animals for retrieval. However, weak links can perform inconsistently depending on an animal’s behaviour and environmental factors such as heat and humidity. A study of disease in eastern grey kangaroos (Macropus giganteus) in Victoria, Australia, provided an opportunity to test the performance of 35 radio collars fitted with a latex weak link between May and July 2022. At the conclusion of the study, 20 collars were manually removed from euthanised animals, and 15 detached in the field; all of these broke at the weak link. Of the 15 detached collars, 10 dropped from live animals due to degradation between 106 and 208 days (mean = 147 days) after deployment, four kangaroos were found dead and their collars were retrieved nearby and one dropped immediately after attachment. The performance of the device in this study demonstrates the utility of weak links as a cheap and simple remote detachment tool to prevent entanglement and achieve remote detachment of neck collars during animal tracking studies.