FECUNDITY OF NORTH AMERICAN MOOSE (ALCES ALCES): A REVIEW

• Main Author: Boer, Arnold H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Lakehead University 1992
• Subjects: Alces alces
• Online Access: http://alcesjournal.org/index.php/alces/article/view/1765

I reviewed the available literature relating moose fecundity to population density and range carrying capacity. Adult pregnancy rates were relatively constant (x̄ = 84.2%, CV = 6.8%) over a broad range of geographic areas, population densities, and winter severities. Yearling pregnancy rates varied between 0 and 93% and twinning rates between 4 and 80%. Yearling pregnancy rates and twinning rates were directly related and changed at approximately the same rate. Both were highly variable and appeared to be sensitive indicators of moose population status relative to carrying capacity. Moose populations above, near, and below K carrying capacity were estimated to produce 0.88, 1.06, and 1.24 calves/adult female at parturition and 0.18, 0.1441, and 0.65 calves/yearling female, respectively. Fetal sex ratio varied widely among studies but the direction of change was inconsistent with respect to population density.