The efficacy of interventions to protect crops from raiding elephants.

Both African elephants (Loxodonta spp.) and the Asian elephant (Elephas maximus) across their range come into conflict with people because of their crop-raiding behavior, which presents profound impediments to farmer livelihoods. In response, a series of interventions, designed to reduce elephant crop raiding have been applied. Based on an extensive review of elephant crop-raiding studies published over a 31-year period, we identified four primary categories of interventions including: (i) detection efforts; (ii) preemptive measures; (iii) fencing and trenches; and (iv) deterrent techniques. The interventions reported to be most effective involved chili peppers (i.e., fences, spray, and briquettes) and crop guarding coupled with deterrents. The extent to which these interventions can be applied more widely is unclear as only two studies examined efficacy across sites in more than one country. Thus, future inquiry should evaluate the ability of effective interventions, or indeed a combination of interventions, to be applied across the range of elephants to reduce crop raiding at scale.

Effects of food availability on serum insulin and lipid concentrations in free-ranging baboons.

The relationship between food availability and metabolic physiology was studied in groups of free-ranging baboons (Papio spp.) living in the Amboseli National Park and the Masai Mara National Reserve of Kenya. Three groups subsisted entirely on natural forage, while two other groups lived near tourist facilities and often consumed food wastes from these lodges. The refuse provided a very accessible food source with relatively high caloric density. Consumption of the refuse was associated with reduced locomotion. Sexually mature individuals from all five groups were sedated surreptitiously in the early morning and blood samples were collected. Compared to animals foraging exclusively in the wild, animals that supplemented their diet with the refuse items had two- to threefold elevations in serum insulin concentrations, as well as increased total cholesterol (C), HDL-C, and VLDL+LDL-C levels. No sex differences in physiological measures were observed except in body mass. Elevated serum insulin, and cholesterol and lipoprotein concentrations influence the development of cardiovascular disease and have been shown to be subject to dietary manipulation and exercise under controlled conditions. The present results suggest potentially deleterious effects of a highly accessible, calorically dense food source, and associated reduction of physical activity for baboons living in an otherwise natural environment.

Body size and fatness of free-living baboons reflect food availability and activity levels.

We used morphometric techniques and isotope-labeled water to investigate the influence of abundant, accessible food and resultant low activity levels on body size and fatness in free-living adolescent and adult baboons as compared to animals in the same population that experienced more typical, wild-feeding conditions. Females that had access to abundant food from a nearby garbage dump averaged 16.7 kg body mass, 50% more than their wild-feeding counterparts in adjacent home ranges. Little of the difference was due to lean mass: the animals with an accessible abundance of food averaged 23.2% body fat in contrast to 1.9% for the wild-feeding animals. Significant differences between feeding conditions were found for all measured skinfolds and for upper arm circumference but not for linear measurements. Differences between feeding conditions were less for males than for females, perhaps reflecting persistent effects of nutritional conditions during the first eight years of life before dispersal from the group of birth. The difference in fatness between feeding conditions was similar to the difference between humans with frank obesity and those that are considered lean, but in both cases the percentages of body fat in the baboons were considerably less than those observed in humans. In levels of fatness, the relatively sedentary animals resembled their counterparts in group-housed captive conditions. © 1993 Wiley-Liss, Inc.

Resource base, parity, and reproductive condition affect females' feeding time and nutrient intake within and between groups of a baboon population.

We examined within- and between-group differences in aspects of feeding and nutrient intake among adult females of a single population of baboons (Papio cynocephalus) in Amboseli National Park, Kenya. Differences in time spent feeding, daily energy and protein intake and feeding efficiency (nutrient intake per minute spent feeding) reflected differences in resource base, reproductive condition and parity. Baboons that partially fed from a lodge garbage dump spent less than half the time feeding than those that were feeding totally in the wild. During this greatly reduced feeding time, the garbage-feeding group had a similar daily energy intake and only a slightly lower daily protein intake relative to wild-feeding baboons. Consequently, the feeding efficiency of the semi-provisioned baboons was appreciably higher than that of the non-provisioned baboons. For the totally wild-feeding baboons, samples were large enough to permit analyses of feeding time and nutrient intake during different reproductive states and parity. Females spent more time feeding and had higher daily energy and protein intake when they were pregnant or lactating than when they were sexually cycling. Nulliparous females spent more time feeding than their multiparous counterparts. The daily energy intake of nulliparous females was higher than that of their multiparous counterparts, but their daily protein intakes did not differ significantly. Pregnant or lactating and nulliparous females had higher feeding efficiency than their sexually cycling and multiparous counterparts. The two nulliparous females in the garbage-feeding group spent more time feeding but did not take in more energy or protein per day than their multiparous counterparts.

Differences in daily life between semiprovisioned and wild-feeding baboons.

Activity budgets and social aspects of feeding, among the adult females in a group of semiprovisioned baboons that fed from a garbage dump were compared with those of adjacent wild-feeding groups in Amboseli National Park, Kenya, during the dry seasons of 1984 and 1985. Statistically significant differences were found in time spent feeding, distance travelled, and the relationship between dominance rank and time spent feeding. The garbage-feeding animals fed for 20% of the time and rested for almost 50%, in contrast to approximately 60% and 10%, respectively, for the wild-feeding animals. Speed of travel, length of day-route, and home range size were greatly reduced for the garbage-feeding animals. Use of sleeping trees and day route were highly regular in contrast to the unprovisioned group. At the garbage dump, time spent feeding was correlated with dominance rank among the adult females of this study. This was not the case for feeding on wild foods. Human enriched food sources offer the opportunity to study limiting factors and relationships between ecology and behavior. However, these conditions lead to human-animal conflicts that may be to the animals' long-term detriment. Conservation and management implications are discussed.