Influence of motivation on behaviour in the hermit crab, Pagurus samuelis

Both the need for shelter and the need for food can be motivations that alter animal behaviour. We tested the hypothesis that the hermit crab, Pagurus samuelis, deprived of food, shells, or both will respond differently from control hermit crabs when presented with food and shells concurrently. We measured the number of contacts made with both food and shells, and time elapsed until hermit crabs either began feeding or inserted into shells. We interpreted making few contacts and initiating behaviour quickly to be an indication of short decision time and high motivation; whereas, making many contacts and having long initiation time indicated a long decision time and low motivation to acquire resources. Control (C) hermit crabs made 72% more contacts with food and 53% more contacts with shells than shell-less (S) crabs. Control hermit crabs also made 34% more contacts with food and 35% more contacts with shells than starved and shell-less (StS) hermit crabs. This suggests that S hermit crabs were more motivated to acquire shells than C crabs. In addition, StS hermit crabs chose to insert into provided shells, while hermit crabs remaining in their shells chose to feed. Results indicate that being shell-less is a stronger motivation than being starved, such that finding shelter takes priority over finding food when both are needed. In rocky intertidal environments, resources such as food and shells are likely to be ephemeral. Hermit crabs that are motivated to make appropriate decisions to acquire specific resources may have a distinct advantage over those that are distracted by numerous objects in their environment

Shell and food acquisition behaviors : Evidence for Contextual Decision Hierarchies in hermit crabs

Shell and food acquisition behaviors of the hermit crab, Pagurus samuelis, were examined in response to cues of shell and food availability. Tactile, visual, and chemical cues were presented in a factorial manner, and time was measured between initial contact and either inhabitation of a shell or initiation of feeding. We considered the time difference between initial contact and subsequent behavior to be a measure of hermit crab ‘decision time’. For shell acquisition experiments, treatments that included tactile cues elicited significantly shorter decision times (8.5–117.1 s), than treatments without tactile cues (294.5–765.2 s). In contrast to the shell acquisition experiment, we found that in food acquisition experiments, treatments that included chemical cues elicited significantly shorter decision times (78.4–450.5 s), than those without chemical cues (570.0–778.1 s). Although primary cues elicited the shortest decision times during foraging and shell-seeking, in the absence of the primary cue, secondary cues could still be used to make appropriate decisions, albeit with significantly longer decision times. Therefore we propose that hermit crabs sort environmental information in ‘Contextual Decision Hierarchies’ in order to make accurate and efficient behavioral choices

Surveying Environmental Perspectives among Faculty at an Institution of Christian Higher Education

Environmental degradation and climate change are frequently in the news, but the Christian perspective is often absent or varied. In this study, faculty at an institution of Christian higher education were surveyed to better understand their perspective and to assess if any particular factor (e.g., gender, school affiliation, or political party) can be linked to a particular environmental worldview. Although faculty held neutral positions on half of the questions, they also reported strong agreement to both pro-environment and pro-human statements. Tensions between prioritizing loving ones’ neighbor (anthropocentrism) and embracing Creation stewardship (ecocentrism) can be resolved with a God-centered theocentric worldview