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In the monogamous and biparental California mouse (Peromyscus californicus), paternal care is critical for maximal offspring survival. Animals form pair bonds and do not engage in extrapair matings, and thus female evaluation of paternal quality during courtship is likely to be advantageous. We hypothesized that male endocrine or behavioral response to courtship interactions would be predictive of future paternal behavior. To test this hypothesis, we formed 20 pairs of California mice, and evaluated their behavior during the first hour of courtship interactions and again following the birth of young. We also collected blood from males at baseline, 1-hr after pairing, 3-weeks paired, and when young were four days old to measure testosterone (T). We found that male T-response to courtship interactions predicted future paternal behavior, specifically the amount of time he huddled over young when challenged by the temporary removal of his mate. Males that mounted T increases at courtship also approached pups more quickly during this challenge than males who had a significant decrease in T at courtship. Proximity of the male and female during courtship predicted paternal huddling during a 1-hr observation, and a multiple regression analysis revealed that courtship behavior was also predictive of birth latency. We speculate that male T-response to a female in P. californicus is an honest indicator of paternal quality, and if detectable by females could provide a basis for evaluation during mate choice. KeywordsMonogamy; paternal care; testosterone; courtship; mate choice; Peromyscus Courtship behavior has been described in a wide variety of taxa including birds, reptiles, insects, amphibians and fish (Adkins-Regan, 1981;Lindzey and Crews, 1986;Sturtevant, 1915;Wagner, 1989;Wootton, 1984). Courtship behaviors themselves are diverse, but it is generally accepted that courtship serves as a tool to assess a potential mate and determine whether to proceed with the act of mating (Adkins-Regan, 2005). Although courtship can provide basic information regarding sex and species of the signaler, it can also be used to evaluate a potential partner for desired qualities. An animal may select a mate on the basis of direct benefits such as nuptial gifts or access to resources, or indirect benefits including good genes or offspring defense (Andersson, 1994). Classically, females have been considered the "choosy sex"; due to the contribution of costly ova and in many cases larger parental *Corresponding author. Department of Psychology, University of Wisconsin-Madison, 1202 W Johnson Street, Madison, WI 53706., Fax: 608-262-4029, Telephone: 608-262-7550, edgleason@wisc.edu (E.D. Gleason). Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note...

Maternal behaviour has profound, long-lasting implications for the health and well-being of developing offspring. In the monogamous California mouse (Peromyscus californicus), care by both parents is critical for offspring survival. We tested the hypothesis that similar to maternal care in rodents, paternal huddling and grooming (HG) behaviour can be transmitted to future generations via behavioural mechanisms. In California mice, testosterone maintains paternal HG behaviour. In the present study, we randomly assigned a group of male California mice to castration or sham-operated conditions and allowed them to raise their offspring normally. Adult sons of these males were paired with a female, and they were observed interacting with their own offspring. We found that like their fathers, the sons of castrated males huddled and groomed their young at lower levels than the sons of sham-operated fathers. The sons of castrates also retrieved pups more frequently. When both parents were present, the sons of castrates also showed a trend towards engaging in less exploratory behaviour. These data support the hypothesis that paternal behaviour, like maternal behaviour, can be transferred to future generations via epigenetic mechanisms and suggest that in a biparental species both parents contribute to offspring behavioural development.

The mammalian brain and central nervous system are especially dependent on the omega-3 (n-3) fatty acid docosahexaenoic acid (DHA) for normative signaling and function, and research suggests that n-3 fatty acid deficiencies are one contributing factor in the increasing prevalence of depressive disorders. However, the reasons for which n-3 fatty acids and mood are connected remain unknown. Atrophy in the hippocampus is one of the most significant neuroanatomical findings in depressed patients, and current therapies for depression tend to increase hippocampal neurogenesis. We recently discovered that the fat-1 transgenic mouse, which has enriched levels of DHA in the brain because it can convert n-6 to n-3 fatty acids, exhibits increased hippocampal neurogenesis. This finding suggests a mechanism by which omega-3 could influence depression and mood; here we expand on the argument that n-3 fatty acids, and DHA in particular, may help prevent and treat depression by virtue of their effects on neurogenesis in the hippocampus. Because DHA can be obtained through the diet, increasing DHA intake in depressed patients or those at risk for depression may be one way of managing the disease and perhaps providing aid to those who have not been able to achieve remission via pharmacological means.