Hunters´ landscape accessibility and daily activity of ungulates in Yasuní Biosphere Reserve, Ecuador

Abstract

Ungulates are one of the most important groups in terrestrial ecosystems across the tropics. Also, ungulates are an important source of protein for people who inhabit tropical forests, and numerous studies have been conducted to evaluate the impact of hunting on the size of ungulate populations. However, little is known about other potential effects of hunting on these species. This study aims to analyze the effect of landscape accessibility to hunters on the daily activities of ungulates in Yasuní Biosphere Reserve, a protected area located in the Amazon region of Ecuador. We compared activity patterns (i. e., distribution of hours of activity along the day) and activity levels (i. e., proportion of hours of the day that an animal is active) for five ungulate species (white-lipped peccary Tayassu pecari, collared peccary Pecari tajacu, red brocket deer Mazama americana, brown brocket deer M. nemorivaga, and tapir Tapirus terrestris) in four sites differing in the degree of access to hunters. To this end, in each of the four study areas, a grid of camera traps was placed within a polygon of approximately 100 km2; traps operated continuously for three to four consecutive months. We recorded the date and time of detection for each species. Daily activity patterns and activity levels were estimated with kernel density analysis for circular data. Our work included a total of 9,506 effective trapping days for the four study sites, resulting in 1,063 separate records of the five ungulate species. In the four study areas, the brown brocket deer and the two species of peccaries concentrated their activity in daytime hours. The red brocket deer was most active in twilight hours, and the tapir was primarily nocturnal. At sites most accessible to hunters, the activity patterns of the collared peccary included a higher proportion of nighttime hours. The red brocket deer also seemed to increase the proportion of nighttime hours of its daily activity. The overall daily activity level was higher in the site with higher accessibility, but was statistically significant only for the collared peccary and the red brocket deer. Our findings include moderate statistically significant evidence suggesting that the access of hunters to the landscape influences the daily activity of ungulates in Yasuní. One species that is clearly affected by the access of hunters is the collared peccary, which becomes more nocturnal and increases its nighttime hours of activity when accessibility to hunters is higher. When our results are compared with other studies, it is evident that the species may display different behavioral responses to hunting, and that these responses may vary with the scale of analysis. This study was limited by sample sizes, which did not allow performing comprehensive analyses for all five species. To further understand the effects of hunting and other human activities on animal behavior, additional studies specifically designed for this purpose should be conducted.