Social interactions do not drive territory aggregation in a grassland songbird
Understanding the drivers of animal distributions is a fundamental goal of ecology and informs habitat management. The costs and benefits of colonial aggregations in animals are well established, but the factors leading to aggregation in territorial animals remain unclear. Territorial animals might aggregate to facilitate social behavior such as (1) group defense from predators and/or parasites, (2) cooperative care of offspring, (3) extra-pair mating, and/or (4) mitigation of extra-pair mating costs through kin selection. Using experimental and observational methods, we tested predictions of all four hypotheses in a tallgrass prairie in northeast Kansas, United States. Grasshopper Sparrow (Ammodramus savannarum) males formed clumps of territories in some parts of the site while leaving other apparently suitable areas unoccupied. Despite substantial sampling effort (653 territories and 223 nests), we found no support for any hypothesized social driver of aggregation, nor evidence that aggregation increases nest success. Our results run counter to previous evidence that conspecific interactions shape territory distributions. These results suggest one of the following alternatives: (1) the benefits of aggregation accrue to different life‐history stages, or (2) the benefits of territory aggregation may be too small to detect in short‐term studies and/or the consequences of aggregation are sufficiently temporally and spatially variable that they do not always appear to be locally adaptive, perhaps exacerbated by changing landscape contexts and declining population sizes. Check it out here!
(Ecology 2019, coauthors: S.M. Munguía, E.J. Williams, and W.A. Boyle)
The impact of maternal hormones on the growth and development of birds
(fondly known on Twitter as project #GrowBirdGrow)
We are investigating the ways in which the hormones passed from mom to egg ultimately influence the growth and behavior of bird embryos, chicks, and juveniles. Keep checking in using the @GrowBirdGrow Twitter as I update everyone on our progress!
The role of brood parasitism in shaping nestling growth and development strategies
(fondly known on Twitter as project #PrairieBabies)
In my master’s research, I seek to identify the effect(s) of Brown-headed Cowbird (Molothrus ater) brood parasitism on the growth and development of nestlings of three grassland-obligate host species: Grasshopper Sparrow (Ammodramus savannarum), Dickcissel (Spiza americana), and Eastern Meadowlark (Sturnella magna). Previous work on nestling development has illustrated the importance of perceived nest predation risk (e.g. Cheng and Martin 2012) and food availability (e.g. Ricklefs 1993)—in order to identify the variation explained by cowbird parasitism, we need to quantify the effect(s) of and interactions between food availability and predation risk as well. We will locate nests of each of the host species and identify the perceived predation risk, the food available to the nestlings, and the presence and risk of cowbirds at subsets of the total nests. We will then relate these factors to the skeletal growth, development (eyes opening, movement capacity), feather growth, and fat/muscle gain of the host nestlings, which we will calculate from nestling measurements taken every other day. At the conclusion of this study we hope to advance our knowledge of the impact of cowbirds, identify the development strategies that produce highest nest and post-fledge success in cowbird-dominated systems, and provide insight on the past and future evolution of cowbird hosts.
Population biology of Red-winged Blackbirds on the Lake Erie Islands
The Lake Erie Islands (Ohio, USA) provide important stopover habitat for migrating songbirds, but little research has been done to assess the quality of the island habitat for residential breeding songbirds. In order to evaluate habitat quality, we used a mist net mark-recapture technique at five different sites in the Bass Islands, focusing our analysis on the Red-winged Blackbirds (Agelaius phoeniceus) due to their relative abundance. When the health of the blackbirds was compared at each location using a weight on tarsus length index, we found no significant difference in the health of the birds among the locations. The proportion of second-year (SY) to after-second-year (ASY) birds was significantly different than the expected proportion in each community, with second-year birds being much more prevalent in the locations studied. This possibly indicates that the more experienced breeding adults are avoiding our sites due to poor habitat quality. In addition, we observed a 380% increase in the prevalence of pox infections in Red-winged Blackbirds from 2012 to 2013, though more research is needed to assess the effect the infection has on the survivorship of the breeding birds on the islands. (This research project was completed as part of a summer REU program at The Ohio State University's Stone Laboratory with Dr. James Marshall).
The Ideals of Female Sanctity in Merovingian and Carolingian Vitae
My undergraduate history research explored the ways that "holiness" was expressed in texts from Merovingian and Carolingian Gaul (5th-8th century, modern-day France). These saints' lives, or vitae, were written to commemorate the lives of and campaign for the canonization of deceased individuals. As such, they do not provide us with stories of historical reality, but rather give us insight into the values of the writers at the time. Therefore, I use vitae of female saints (especially the pretty awesome St. Radegund and St. Genovefa) to explore the ways gender identity interacted with religion; what language and motifs were acceptable ways to portray women's holiness? How did that change over time? How did gender and religion interact with other sociopolitical realities at the time? Ultimately I argued that these vitae portray a shift from warrior-like, action-based valor stories to passive, introspective piety as time progressed. This change mirrored the rise of the Church in Gaul; in the early Merovingian dynasty the spreading Church valued miraculous visible saints of all genders, representing the power of Christianity to the masses as the Church expanded. By the end of the Carolingian dynasty Christianity was firmly established in Gaul--at this point the Church did not need saints who showcased the incredible power of the religion, but rather saints who exhibited quiet, pious deference to the Church hierarchy. Please note that I have not revised this in years-- there are likely problematic references to a gender binary throughout the text. Read it here by clicking on the purple box!
St. Radegund, public domain image found here