Publications by EEOB faculty in 19 Jan - 31 Jan 2014

February 3, 2014

The presence of neighbors influences defense against predators in a cooperatively breeding cichlid

Jennifer K. Hellmann and Ian M. Hamilton. 2014. Behavioral Ecology in press. DOI: 10.1093/beheco/aru001

Abstract Although behavior is often examined in a dyadic or group context, behavioral interactions are also influenced by the broader social context. Interactions with neighboring groups may provide information about the local environment or may offer important reproductive opportunities. Considering the potential fitness consequences of intergroup interactions, particularly for territorial species that have long-term relationships with neighboring groups, we expect individuals will alter their behavior based on access to surrounding groups. We used a cooperatively breeding cichlid Neolamprologus pulcher to determine if individuals vary their response to a predator when neighbors were present versus absent. We found no difference in dominant behavior between neighbor present and neighbor absent treatments, but subordinates increased their defense against the predator when neighbors were present, particularly when the neighbor was unfamiliar. Subordinates may change their behavior when neighbors are present in order to signal to or cooperate with neighboring individuals but may also be responding to the change in intragroup dynamics that can result from the presence of neighboring conspecifics. This study illustrates the importance of considering the effect of neighboring groups on individual behavior, given that intergroup dynamics can influence behaviors that do not directly involve conspecific interactions.

Hamilton lab


Religious tradition of conservation associated with greater abundance of a keystone tree species in rural Western Rajasthan, India

Jonathan C. Hall and Ian M. Hamilton. 2014. Journal of Arid Environments 103, 11--16. DOI: 10.1016/j.jaridenv.2013.12.007

Abstract Land-use and land-cover change in the Thar Desert region of Rajasthan threatens the persistence of many ecologically and economically important species. The Bishnoi people of Rajasthan have religiously protected a keystone tree species, Prosopis cineraria, locally known as the Khejeri tree, for over five centuries. We conducted the first comparative study that tests the widely held assumption that Bishnoi presence is positively associated with P. cineraria abundance in nineteen villages in rural Rajasthan. We also evaluated the influence of land area type, human and livestock population, and income on measured Khejeri tree abundance. Villages with Bishnoi had significantly more P. cineraria and had significantly higher incomes than villages without Bishnoi despite no significant differences in land area, human population, or livestock population between village classes. We found no direct associations between Khejeri tree abundance and village demographics suggesting P. cineraria abundance is a function of environmental and socio-economic factors. Within this context we discuss the role of Bishnoi protection of Khejeri trees in maintaining important ecosystem functions and supporting human prosperity.

Hamilton lab