Poster Presentation 64th International Conference of the Wildlife Disease Association 2015

Preliminary investigations into neonate health and cause-specific calf mortality in a declining moose population in northeastern Minnesota (#195)

Tiffany M Wolf 1 2 , Seth Moore 3 , Edmund J Isaac 3
  1. University of Minnesota, St. Paul, MN, USA
  2. Minnesota Zoo, Apple Valley, MN, USA
  3. Grand Portage Band of Lake Superior Chippewa, Grand Portage, Minnesota, USA

The Minnesota moose population (Alces alces), like many along the southern extent of the North American moose range, has been experiencing a precipitous decline in recent years. Ongoing studies of moose on Grand Portage Indian Reservation, MN reveal high levels of disease and reduced condition associated with adult mortality and low annual calf recruitment. Specifically, calf:cow ratios have been steadily declining since 2000. To understand neonate health and causes of calf mortality on Grand Portage Reservation, we studied 19 calves of 16 moose cows from parturition since 2013. The natural mortality rate observed was 79% by November of each study year. Nine (60%) mortalities were a result of predation (bear: n = 5, wolf: n = 4), the majority of which occurred by end of summer. Remaining causes of mortality included stillbirth (n=2), septicemia (n=1), abandonment (n=1), and unknown (n=2). Neonatal health was evaluated in a subset of captured calves (n=13), 48-72 hours post-partum, by complete blood cell count (CBC), serum biochemistry panel, and total serum immunoglobulin (Ig). While general health parameters were mostly within a normal range, maternal antibody transfer as measured by total serum Ig appeared to be marginally sufficient in 5 calves and deficient in 5 calves. Unfortunately, there is a paucity of information on Ig levels in moose calves that are sufficient for immunological protection as calf immune systems develop. Further, our observations of predation as the primary cause of calf mortality is not a reliable indicator of the impact of failure of maternal antibody uptake. These findings clearly demonstrate that most calves are not surviving through their first year, many a result of predation; however, our preliminary research into neonatal health also reveals lower than expected levels of maternal-derived antibody suggesting that compromised health may play a role in calf survival.