Determinants of reproduction in young bighorn ewes (ovis canadensis)
McKenzie, Nancy Kae
The factors affecting reproductive strategies in long-lived species comprise one of the most important yet least understood components of population ecology. My research examined how the probability of reproduction in young (2- to 5-year-old) bighorn ewes was affected by individual body mass, resource availability and age. I investigated whether the probability of reproduction was simply a function of individual body mass (suggesting a fixed threshold physiological constraint), a mass-age interaction (suggesting an age-dependent physiological constraint) or a function of both mass and resource availability (suggesting a true and flexible reproductive strategy, in particular if heavy ewes did not reproduce at low resource availability). Body mass, resource availability and age are all determinants of reproduction in young bighorn ewes. Contrary to several earlier studies of ungulates, I found that mass during early development explained only a small part of individual variability in reproduction; there was no single body mass above which all ewes conceive".--Résumé abrégé par UMI.
- Sciences – Mémoires