We evaluated our ability to deliver adequate daily doses of the reproductive inhibitor, nicarbazin, to individually marked resident Canada geese (Branta canadensis). We also evaluated the efficiency of nicarbazin in reducing egg hatchability. The study was conducted prior to and during the egg-laying period at a wildlife sanctuary that has a large, problem-causing population of resident geese that were accustomed to being fed by people. Twenty-eight adult females were marked with individually identifiable neck collars, 24 of which were affixed with radio transmitters. Grit pellets and gelatin capsules containing nicarbazin were fed to these geese from March 17, 2001 through April 26, 2001. We attempted to deliver doses to geese each day. Doses varied among geese throughout the study and within geese daily because all geese were not present at the site each day, and even if present they accepted the bait to varying degrees. Seven of our target birds did receive what we believed to be adequate doses of nicarbazin. We documented that only about 11% of the resident population nested at the sanctuary, while the others nested in remote areas. We were able to locate 5 nests of birds that received adequate doses, but found no significant effect of nicarbazin on the hatchability of their eggs compared to untreated geese. We found that the biggest challenges to orally-fed reproductive inhibitors include the palatability of bait relative to other food sources, reduced feeding during the breeding period, and movements and territoriality associated with nesting.

Bovine tuberculosis (bTB) is a contagious disease capable of infecting wildlife, livestock, and humans. While once common in U.S. livestock, the disease has historically been rare in wildlife. However, in Michigan’s Northeastern Lower Peninsula (NELP), bTB is endemic in white-tailed deer, and evidence suggests transmission to cattle. The disease has also been documented in other wildlife species including raccoons, which frequent areas used by domestic cattle. Such interactions could facilitate transmission of bTB, but whether free-ranging raccoons shed the causative agent, Mycobacterium bovis, is unknown. We trapped raccoons on private and public land in 5 counties in the NELP from which we collected tissue samples, oral/nasal swabs, and fecal samples to determine if raccoons shed M. bovis. Culture results from 2 of 144 usable tissue sample submissions were positive for bTB, suggesting an apparent local prevalence of 1.4%, a decrease from previous estimates. Using currently available culturing techniques, swabs and feces from one tissue culture-positive animal were negative for M. bovis. While this small sample size of positive animals makes definitive conclusions difficult, we believe that although raccoons may serve as a reservoir or a spillover host for bTB, transmission risk to cattle is minimal. Further research into this arena, as well as continued refinement of culturing techniques to detect low levels of M. bovis, is warranted.