Early paternal retrieval experience influences the degree of maternal retrieval behavior in adult California mice offspring.

In biparental species like the California mouse (Peromyscus californicus), paternal presence and care contributes to offspring survival with lasting consequences on brain development and social behavior. Paternal retrieval behavior may be particularly important since it protects young from dangers outside of the nest. We have previously shown that paternal retrievals influence social behavior of adult female and male offspring, as well as the expression of hormones associated with parental behavior. In male offspring, paternal retrieval influences future parenting, but whether paternal retrievals affect maternal behavior in adulthood is unclear. Here, we manipulated the experience of paternal retrieval during development and then assessed maternal behavior of adult female offspring. We did not detect group differences in maternal behavior during undisturbed observation or following pup displacement. However, following pup displacement we observed a moderate positive correlation between paternal retrievals experienced in development and maternal retrievals performed in adulthood. Further analysis revealed that the likelihood of females being a high or low retriever is influenced by their developmental experience. These findings suggest that although female California mice engage in similar levels of maternal behavior regardless of paternal care environment, there may be variation in retrieval behavior that is informed by paternal retrieval experience.

Assessing the risk of ships striking large whales in marine spatial planning.

Marine spatial planning provides a comprehensive framework for managing multiple uses of the marine environment and has the potential to minimize environmental impacts and reduce conflicts among users. Spatially explicit assessments of the risks to key marine species from human activities are a requirement of marine spatial planning. We assessed the risk of ships striking humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and fin (Balaenoptera physalus) whales in alternative shipping routes derived from patterns of shipping traffic off Southern California (U.S.A.). Specifically, we developed whale-habitat models and assumed ship-strike risk for the alternative shipping routes was proportional to the number of whales predicted by the models to occur within each route. This definition of risk assumes all ships travel within a single route. We also calculated risk assuming ships travel via multiple routes. We estimated the potential for conflict between shipping and other uses (military training and fishing) due to overlap with the routes. We also estimated the overlap between shipping routes and protected areas. The route with the lowest risk for humpback whales had the highest risk for fin whales and vice versa. Risk to both species may be ameliorated by creating a new route south of the northern Channel Islands and spreading traffic between this new route and the existing route in the Santa Barbara Channel. Creating a longer route may reduce the overlap between shipping and other uses by concentrating shipping traffic. Blue whales are distributed more evenly across our study area than humpback and fin whales; thus, risk could not be ameliorated by concentrating shipping traffic in any of the routes we considered. Reducing ship-strike risk for blue whales may be necessary because our estimate of the potential number of strikes suggests that they are likely to exceed allowable levels of anthropogenic impacts established under U.S. laws.