Exposure to social and ecological adversity during sensitive windows of development often leadto disadvantageous outcomes in adulthood such as reduced social connectedness and shorter lifespan. Consequences of early life adversity can persist across generations. The mother is a crucial component of the early life environment for mammals and plays an important role in shaping offspring development. The mechanisms underlying the associations between early life adversity, adult outcomes, and transgenerational effects are not well established, and the complexities of how early life environments shape the ways offspring prioritize different dimensions of development are only beginning to be understood. This dissertation leverages longitudinal data, detailed behavioral observations, fecal hormone sampling, and noninvasive estimates of infant body size to assess how early life experiences shape development and adult outcomes in a wild population of olive baboons (Papio anubis) in Laikipia, Kenya. Four dissertation papers address: 1) the relationship between a mother’s early life adversity and her maternal effort, physiology, and offspring survival; 2) how the maternal environment shapes the ways developing offspring allocate resources among play, behavioral independence, and growth; 3) the role of interaction style in mediating the relationship between early life adversity and adult female sociability; and 4) the relative importance of female competition over food, mates, and male caretakers. Results of these papers show early life adversity can have lasting consequences on maternal effort and physiology, which in turn shape offspring developmental trajectories. Females who experienced early life adversity were less likely to develop an interaction style that was associated with sociability. Finally, the energetic costs of lactation were the primary driver of female competition, and in light of findings in chacma and yellow baboons, this indicates evolution has finely tuned female baboons’ responses to the social and ecological pressures of their local environments. To better understand the complexities of early life experiences and developmental trajectories, it is important to leverage longitudinal data and create comprehensive models of the maternal environment and infant development.

In most bird species, females disperse prior to their first breeding attempt, while males remain close to the place they were hatched for their entire lives (Greenwood and Harvey (1982)). Explanations for such female bias in natal dispersal have focused on the potential benefits that males derive from knowing the local environment to establish territories, while females search for suitable mates (Greenwood (1980)). However, the variables shaping dispersal decisions appear more complex (Mabry et al. (2013), Végvári et al. (2018)). There are a number of different variables that could act as a driving force behind dispersal including the social mating system, food competition, inbreeding avoidance, predation, and others. Here, we investigate whether females are the dispersing sex in great-tailed grackles, which have a mating system where the males hold territories and the females choose which territory to place their nest in (Johnson et al. (2000)). We used genetic approaches to identify sex biases in the propensity to disperse. In the experiment, we found that the male grackles were less related to each other while the female grackles were more related to each other. Building on that, the average distance between closely related individuals of the male group was longer than the average distance of closely related females. But, the mantel correlograms for the males and females both lack a consistent trend. Overall, the results indicated suggest that the males are the dispersing sex while the females are potentially philopatric and that the average dispersal distance for the grackle is greater than 2000 meters, the size of the sampling range used in the experiment. These results will inform our long-term study on the relationship between behavioral flexibility and rapid geographic range expansion by elucidating which individuals are likely to experience similar conditions across their lives, and which are likely to face new conditions when they become breeders.

Morphological variation among individuals has the potential to influence multiple life history characteristics such as dispersal, migration, reproductive success, and survival (Wilder et al., 2016). Research has shown that individuals that are in better "condition" can disperse or migrate further or more successfully, have greater reproductive success, and survive for longer (Wilder et al., 2016; Heidinger et al., 2010; Liao et al., 2011), particularly in years where environmental conditions are harsh (Milenkaya et al., 2014). An individual's body condition can be defined in various ways, but is most often considered an individual's energetic or immune state (Milenkaya et al., 2014). Since these traits are hard to measure directly, researchers have instead used a variety of morphological proxy variables to quantify condition such as fat score (Kaiser, 1993), weight, ratio of weight to tarsus length (Labocha et al., 2014), a scaled mass index (Peig and Green, 2009), as well as hematological indices for immune system function (Fleskes et al., 2017, Kraft et al., 2019). However, there is mixed support regarding whether these condition indices relate to life history characteristics (Wilder et al., 2016; Labocha et al., 2014), and whether the relationship is linear (Mcnamara et al., 2005; Milenkaya et al., 2014). Additionally, although some researchers use multiple morphological proxy variables for condition (e.g. Warnock and Bishop, 1998), rarely have there been direct comparisons among proxies to validate that they measure the same trait. In this investigation, we define condition as an energetic state and we attempt to measure it by comparing two indices (fat score and the scaled mass index) to validate whether they measure the same trait in our study system, the great-tailed grackle (Quiscalus mexicanus). We found that the morphological proxy variables did not correlate with each other, indicating that they were not measuring the same trait. Further, the proxy variables did not correlate with reproductive success, measured as whether a female had a fledgling and whether a male held a territory containing nests. These results improve our understanding of measures of condition in grackles, and birds in general, and the importance of condition for reproductive success - a necessary component for selection to act.