Wildlife Cameras Reveal Activity Patterns in Threatened Crawfish Frogs

摘要

Crawfish Frogs (Lithobates areolatus) are obligate crayfish burrow dwellers with small home ranges (0.05 m2) and strong philopatry. Using wildlife cameras, we monitored the behavior of adults and juveniles at a high-resolution time scale (down to 5-min intervals) around-the-clock and across years, from 2009–2013 at Hillenbrand Fish and Wildlife Area-West in Greene County, Indiana, USA. We found that Crawfish Frogs demonstrated a consistent pattern of seasonal activity. Peaks of highest activity occurred in May and September when frogs were active around-the-clock (circumdiel). Early spring and late fall lulls were due to frogs being predominately diurnal; the summer plateau was due to frogs being predominately nocturnal. Individual frogs were strictly diurnal or strictly nocturnal depending on the season. We assessed the activity of these frogs in relation to environmental variables, including ambient temperature, vapor pressure gradient between the atmosphere and frog skin (a measure of evaporative water loss in frogs), and precipitation. Activity was best explained by daily temperature and vapor pressure gradient. Our results suggest that Crawfish Frogs will alter their activity patterns in response to changing environmental conditions, such as temperature and vapor pressure gradient. Although we examined changes across seasons, this behavioral plasticity may also provide them with resilience to changes associated with climate change.