Population dynamics of the narwhal Monodon monoceros: an initial assessement (Odontoceti: Monodontidae)

• Published in: Journal of Zoology
• Main Author: Kingsley, Michael
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1989
• Subjects: Monodon monoceros; narwhal*
• Online Access: http://dx.doi.org/10.1111/j.1469-7998.1989.tb02576.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1469-7998.1989.tb02576.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1989.tb02576.x; https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1469-7998.1989.tb02576.x

A simplified population equation for Monodon Pnonoceros shows that current estimates of the values of the life history variables are inconsistent with the hypothesis of a stationary population. Instantaneous adult mortality must be less than 0,10/yr, not the published estimate of 12–13%/yr, for accepted values of the other variables to be consistent with stationarity. For sustainable harvest, permissible exploitation rates are no larger than 3–4%/yr, and instantaneous natural mortality must then be well below 10%/yr. Present uncertainty in the values of survival rates, both of adults and young, contributes twice as much to uncertainty in population growth rate as does uncertainty in reproductive rates.