MORPHOMETRY OF MOOSE ANTLERS IN CENTRAL BRITISH COLUMBIA

Kenneth Child, Daniel A Aitken, Roy V Rea

Abstract


We analyzed the morphometry of 1,965 sets of antlers from hunter-harvested moose (Alces alces andersoni) taken in the central interior of British Columbia. We describe the variation and age-related changes in antler and brow palm form, number of points on both main and brow palms, maximum spread, height and width of palmations, distance between innermost points on the brow palms, and shaft circumference. Architecturally 25% were cervicorn pole type (PT); 75% were palmicorn with 67% split palm (SP) and 8% full palm (FP). Palmicorn antlers were most common in all age classes. Cervicorn antlers were most common in younger moose (1.5-3.5 years), and rare in moose >4.5 years. Of all antlers collected, 30% had forked brows and 12% had palmated brows. Forked brow palms increased with age; they occurred in 10% of moose 1.5 years old and 40-50% of moose >4.5 years old. The frequency of palmated brow palms increased quickly from 1.5 (2.5%) to 5.5 years (25%), peaked at 13.5 years (40%), before declining in later years. The number of points generally increased from 1.5-7.5 years, and remained stable thereafter. Maximum spread and shaft circumference generally increased from 1.5-13.5 years and decreased thereafter. Maximum antler height and width of main palms increased from 1.5-9.5 years; the first remained stable and the latter declined thereafter. Distance between the inner most points on the brow palms narrowed from 1.5-4.5 years, remained constant to 11.5 years, and then widened thereafter. Antler point counts were the most variable, whereas shaft circumference was the least variable form.

Keywords


Alces alces; antlers; brow palm; full palm; main palm; morphometrics; pole type; split palm; socio-biology

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