We developed an individual-based study of harbor seals in northeast Scotland, whereby data were collected during daily photo-identification surveys throughout the pupping seasons between 2006 and 2011. However, a consequence of observing seals remotely meant that information on sex, maturity-stage, or breeding status was not always available. To provide unbiased estimates of survival rates we conditioned initial release of individuals on the selleck inhibitor first time sex was known to estimate sex-specific survival rates, while a robust design multistate model accounting for uncertainty in breeding status was used
to estimate reproductive rate of multiparous and ≥3-yr-old females. Survival rates were estimated at 0.95 (95% CI = 0.91–0.97) for females and 0.92 (0.83–0.96) for males, while reproductive rate was estimated at 0.89 (0.75–0.95) for multiparous and 0.69 (0.64–0.74) for ≥3-yr-old females. Stage-based population
modeling indicated that this population should be recovering, even under the current shooting quotas implemented by the recent management plan. “
“To examine the factors influencing birth site selection and territory location in Australian fur seals (Arctocephalus pusillus doriferus), habitat variables (slope, substrate, and elevation) were quantified in seven zones within a breeding colony on Kanowna Island (39º15′S, 146º18′E), southeastern Australia. Distribution across the colony was not uniform with zones at low elevations (i.e., close to water) being preferred areas, having earlier occupancies and Selleck Ibrutinib greater female densities. Body length of females and territorial adult males was assessed using laser-metrics. Average female length increased throughout the breeding season, within
zones and across the colony, with larger females arriving to 上海皓元医药股份有限公司 give birth later. Larger females also occupied areas of lower elevation close to water. Adult male body length had no influence on territory size, but was positively correlated with the number of females in harems (r2 = 0.70, P < 0.05) and female length (r2 = 0.87, P < 0.01) within harems. By monopolizing larger females, adult males may enhance their reproductive success as these individuals are more likely to give birth and have greater weaning success. "
“Estimates of fossil sirenian body size are important for understanding niche partitioning among possibly sympatric species. Because of the paucity of complete fossil skeletons, we explored the utility of three morphometric predictors of body size: (condylobasal skull length [BSL]; occipital condyle width [OCW]; and foramen magnum width [FMW]) in extant sirenians—Florida manatees (Trichechus manatus latirostris) and dugongs (Dugong dugon)—and then applied these to obtain estimates of body size in extinct sirenian taxa. Condylobasal length of the skull is a more accurate predictor of body size in extant Florida manatees and dugongs than are width of the occipital condyles or width of the foramen magnum.
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