Tick development on sexually-active bull moose is more advanced compared to that of cow moose in the winter tick, Dermacentor albipictus

We performed a complete survey of ticks on 100 cm2 skin samples collected from 30 moose (Alces alces) harvested in 2017 in central and northern Maine, U.S.A. The samples were collected from 15 bulls, 13 cows, and 2 calves in mid-October when moose are breeding and winter ticks (Dermacentor albipictus) quest for a host. We identified only winter ticks with 99.2% in a juvenile stage; 3 adult ticks were found. Unfed nymphs were most common on bulls, whereas most ticks were fed larvae on cows and calves. The mean total count on bull samples was 21 ± 4.4 (range = 0–55) and higher than on cows (6 ± 0.5; range = 2–8). Unlike previous surveys, tick abundance was lowest on calves. Tick abundance was independent of age or weight of adult moose. The higher abundance and more rapid development of winter ticks on adult bulls likely reflects the seasonal influence of increased movements and hormonal cycles associated with reproduction. [Display omitted] •First study that compares tick stages on bulls, cows, and calves during the breeding season.•Tick abundance on calves is low during this time (first report).-tick abundance: bulls >> cows > calves.•There is a developmental lag (first report of occurrence).-post-larvals (nonfed nymphs, fed nymphs, a few adults) dominate on bulls.-unfed and fed larvae dominate on cows and calves.•Tick abundance is independent of moose age and weight.•Only winter ticks (Dermacentor albipictus) were found; no Ixodes in particular.