Implications of climatic seasonality on activity patterns and resource use by sympatric peccaries in northern Pantanal

Abstract

We evaluated the effects of climate seasonality from a thermal and water availability perspective on the activity patterns and resource use of Pecari tajacu and Tayassu pecari during wet and dry seasons in the northeastern Brazilian Pantanal. We used camera traps and temperature sensors to record species activity patterns in relation to temperature, established five habitat categories based on flooding intensity and local vegetation characteristics, assessed the activity patterns of each species in dry and wet periods and in artificial water bodies using circular statistical metrics, and calculated niche amplitude and overlap on three axes (temperature, time, and habitat) in both periods. Peccaries shared a strong resemblance in resource use and in their responses to seasonal variations in the tested gradients. The activity patterns of both species exhibited a significant correlation with air temperature on all the evaluated measures, and both species strongly reduced their activity when the air temperature exceeded 35 °C. High temperatures associated with low water availability were most likely responsible for the changes in species activity patterns, which resulted in an increased temporal overlap in habitat use throughout the dry season. However, the peccaries avoided intensively flooded habitats; therefore, the habitat gradient overlap was greater during the wet period. Our results show that an increase in niche overlap on the environmental gradient as a result of climatic seasonality may be partially compensated by a reduction in other niche dimensions. In this case, temporal partitioning appears to be an important, viable mechanism to reduce competition by potentially competing species.

Peer Review #2 of "Achilles heel of a powerful invader: restrictions on distribution and disappearance of feral pigs from a protected area in Northern Pantanal, Western Brazil (v0.1)"

“…in prep. ), gives us support (Hofmann, et al 2015), confirming the absence or rarity of the species in the region.…”

Investigating animal activity patterns and temporal niche partitioning using camera‐trap data: challenges and opportunities

“…Alternative options include angular–linear correlations, as done by Hofmann et al. () in comparing peccary activity time in relation to air temperature. Using an information‐theoretic analysis of species activity, Norris et al.…”

Landscape variables that influence the presence of brocket deer (Mazama sp.) in the Campeche State, México

“…En la región de Calakmul, los temazates prefirieron el bosque inundable en las aéreas con cacería (Reyna-Hurtado y Tanner 2005). En Sudamérica se ha comprobado que los ungulados pueden cambiar su comportamiento cuando los sitios se encuentran inundados (Hofmann et al 2015), y tomar tres tipos de decisiones, vivir de forma subacuática, mantener ámbitos hogareños muy grandes que le permitan migrar a sitios fuera de la inundación o quedarse en el sitio y resguardarse en islas de selva (Husson 1978), esto último se observó en el Amazonas donde M. americana y Pecari tajacu permanecieron durante la temporada de inundación, resguardándose en islas de selva a diferencia de Tapirus terrestris y Tayassu pecari que abandonaron la zona inundable (Bodmer 1990). …”