[DOWNLOAD] "Temporal Variation in Sex Allocation of White-Tailed Deer (Report)" by Journal of the Alabama Academy of Science * Book PDF Kindle ePub Free
eBook details
- Title: Temporal Variation in Sex Allocation of White-Tailed Deer (Report)
- Author : Journal of the Alabama Academy of Science
- Release Date : January 01, 2009
- Genre: Engineering,Books,Professional & Technical,
- Pages : * pages
- Size : 176 KB
Description
ABSTRACT For several decades the Trivers-Willard hypothesis has been at the forefront of debates concerning differential investment of females into offspring sex. The main consistency in these debates has been the focus on how female condition influences offspring sex: very few studies have deviated from this line of investigation. We hypothesized that factors other than female condition may influence offspring sex and investigated how conception date influences offspring sex using white-tailed deer (Odocoileus virginianus Zimmerman) as a model. We found that during the first half of the breeding season (prior to 22 Jan) more males were conceived, while more females were conceived during the second half of the breeding season (after 22 Jan). We suggest that time available for development of offspring during their first year is an important factor in determining offspring sex. Offspring born early during the conception period have more time available for development relative to their late-born counterparts, and thus have greater potential for large body size and dominance later in life, important factors in the reproductive success of males. As a result, females conceiving early will maximize fitness by producing male offspring who will have more opportunity for growth prior to their first winter. Females conceiving later should invest in daughters because daughters have less variability in lifetime fitness and greater probability of achieving some measurable reproductive success; late-born sons will be at a competitive disadvantage when breeding. We hypothesize that in species where competition for mates is high and lifetime reproductive success of the sex competing for mates varies considerably, that females who conceive early will maximize fitness by investing in the sex that competes for access to mates.