Northern Prairie Wildlife Research Center
D. Tommy King and Mark E. Tobin, U.S. Department of Agriculture, Animal and Plant Health Inspection Services, Wildlife Services, National Wildlife Research Center, Mississippi Research Station, P.O. Drawer 6099, Mississippi State University, Mississippi State, MS 39762 USA
We evaluated two techniques for attaching transmitters to double-crested cormorants (Phalocrocorax auritus). We captured and housed 12 cormorants in a 0.4-ha enclosure that contained a 0.04-ha pond stocked with catfish (Ictalurus punctatus) fingerlings. We randomly assigned four cormorants to each of three treatment groups (patagial tag and backpack harness attachments and a control group). The patagial transmitters were plastic cattle ear tags with solar powered transmitters glued to the dorsal surface. The backpack transmitters were attached using a teflon ribbon body harness. Weight loss varied among treatment groups (P = 0.004), with weight loss for birds in the control and backpack groups greater than for birds in the patagial tag group (P < 0.05). Only one bird lost >10 % of its body weight during the 9-day test. There were no significant differences among groups in amount of time spent foraging (P = 0.6174), diving (P = 0.7530), or preening (P = 0.4320). We conclude that both backpack and patagial tag transmitters are applicable for use on double-crested cormorant.