Retention of transmitter attachments on black cockatoos (Calyptorhynchus spp.).

Despite the widespread use of telemetry to track the movements of many different avian species, there are few published studies describing tracking methods for large psittacine birds. Due to their powerful bills and inquisitive demeanours, large parrots may damage valuable transmitters and confound telemetry studies. We undertook a captive trial of three attachment methods (collar, harness and tail-mount) and a novel weak-link harness design for black cockatoos (Calyptorhynchus latirostris, C. baudinii and C. banksii naso). Mean retention times for the transmitter packages ranged from 44 to 384 days. There was no skin or feather damage to the birds associated with transmitter attachments. The results showed sufficient transmitter retention times to allow for the collection of valuable movement and survival data, with no obvious ill effects on animal welfare, and are a first step towards using transmitters on wild cockatoos.

Acoustic and radio-transmitter retention in common carp (Cyprinus carpio) in New Zealand

Common carp (Cyprinus carpio) are notoriously difficult to monitor in water temperatures above 20°C using telemetry owing to transmitter expulsion. To reduce transmitter loss, radio transmitters were anchored to the pelvic girdle and a polymer coating was applied to acoustic transmitters to reduce tissue irritation in two tank trials. Ten dummy transmitters were surgically implanted in each of four groups of adult koi carp, a highly coloured strain of C. carpio. Water temperatures ranged between 7 and 24°C. After 365 days, the control and test groups of each trial had similar expulsion rates (P ≥ 0.30; two-tailed Fisher’s exact probability test). Expulsion rates for uncoated acoustic transmitters were 60% (n = 6), coated acoustic transmitters 50% (n = 5), unanchored radio transmitters 60% (n = 6) and anchored radio transmitters 90% (n = 9). Expulsions occurred 15–362 days after implantation as a result of ulcers at or near the surgical wound. Bacterial infection of the wound appears to be the primary mechanism for transmitter expulsion.