Seasonally dry tropical forest mammals: Adaptations and seasonal patterns

Abstract

Seasonally dry tropical forests have one of the most extreme climates within tropical ecosystems. Mammals that inhabit tropical dry forests must be capable of dealing with high temperatures, low precipitation in the dry season, and large fluctuations in the availability of food and water throughout the year. The extreme abiotic conditions characteristic of seasonally dry forests create unique challenges for mammals in these ecosystems. Herein, we review the diverse mechanisms that are used by mammals to deal with these extreme abiotic conditions. Physiological adaptations include changes in body temperature, torpor, hibernation, fat storage, water conservation, and delayed reproduction including delayed fertilization, implantation, and embryonic development. Behavioral adaptations include dietary flexibility to utilize seasonally available food resources, changes in home range or foraging activity patterns, long- and short-distance migration to occupy dry forests only seasonally, movement to other areas during periods of food scarcity, changes in activity and foraging times, and changes in the seasonality of reproduction. Forest destruction and habitat fragmentation are the most serious problems affecting mammals in seasonally dry tropical forests today. Habitat destruction can impact distribution, abundance, and ecology of mammals. With the increased value of land for agriculture and human occupation, the habitat matrix bordering seasonally dry tropical forests is being degraded, removing buffer zones that provided critical habitat. Larger species, especially dietary specialists and predators, are the first to disappear from fragmented habitats, causing a ripple effect through communities. Several species of generalists have increased their distribution and abundance in fragmented habitats. Much recent research has focused on the ecology of dry forest mammals, yet mammals in this ecosystem remain much more poorly understood than those found in wet forests. Basic and comparative research is critically needed to elucidate the role mammals play in dry forests because these species have impacts on the structure and function of dry forests, as well as other ecosystems.