Linde E. T. Ostro

The use of camera traps for estimating jaguar Panthera onca abundance and density using capture/recapture analysis

Across their range jaguars Panthera onca are important conservation icons for several reasons: their important role in ecosystems as top carnivores, their cultural and economic value, and their potential conflicts with livestock. However, jaguars have historically been difficult to monitor. This paper outlines the first applica- tion of a systematic camera trapping methodology for abundance estimation of jaguars. The methodology was initially developed to estimate tiger abundance in India. We used a grid of camera traps deployed for 2 months, identified individual animals from their pelage patterns, and estimated population abundance using capture-recapture statistical models. We applied this methodology in a total of five study sites in the Mayan

Feeding Ecology of the Black Howler Monkey (Alouatta pigra) in Northern Belize

We studied the feeding ecology of the black howler monkey (Alouatta pigra) from March 1994 to April 1995 in the Community Baboon Sanctuary in northern Belize, Central America. Activity and diet composition were recorded using continuous focal animal sampling. Diet composition was compared with the relative abundance of plant parts eaten by the howlers within the study site. The study animals spent an average of 24.4% of their time feeding, 61.9% resting, and approximately 9.8% traveling. In contrast to previously published reports on A. pigra, we found the diet composition to be similar to that of other Alouatta species (conforming to the folivore/frugivore profile), with 41% of feeding time spent eating fruit, 45% foliage, and 11% flowers. This contrast may indicate a wide degree of dietary flexibility that allows A. pigra to inhabit a variety of habitat types. We suggest that a high level of resource abundance throughout the year makes the Community Baboon Sanctuary excellent habitat for Alouatta pigra. Am. J. Primatol. 45:263–279, 1998.

Spatial and Temporal Interactions of Sympatric Jaguars (Panthera onca) and Pumas (Puma concolor) in a Neotropical Forest

Abstract We used extensive camera-trap surveys to study interindividual interactions among individually recognizable jaguars (Panthera onca) and plain-colored pumas (Puma concolor). Timed location data from a network of 119 trap stations in the Cockscomb Basin of Belize provide the 1st evidence of interspecific avoidance calibrated against intraspecific interactions among jaguars. Camera trapping has advantages over radiotelemetry in its potential to provide data on the complete array of individuals within the study area. The 23 individually identified male jaguars showed high levels of overlap in ranges, with up to 5 different males captured at the same location in the same month. Low levels of avoidance between individuals and a high flux of individuals contributed to low consistency in home-range ownership over the long term (3 months to 2 years). Jaguars and pumas had similar nocturnal activity schedules. Both species used similar habitats within the Cockscomb Basin, indicated by a high correlation in capture rates per location between species. Apart from their overall spatial similarities, jaguars and pumas avoided using the same location at the same time. This interspecific segregation was detectable over and above the spatial and temporal segregation of individual jaguars.

Ranging behavior of translocated and established groups of black howler monkeys Alouatta pigra in Belize, Central America

Control apparatus featuring a condition sensor, a first relay responsive to a signal from the condition sensor, the first relay being in a first state in the absence of a signal from the condition sensor and being switched to a second state in response to a signal from the condition sensor, a control relay adapted to be switched between first and second states, circuitry responsive to an operation request for switching the control relay from the first state to the second state after a time interval, and clamping circuitry operative in response to the detection of the first relay in its second state during the time interval to clamp the first relay in the second state and the control relay in the first state, overriding the influence of the condition sensor on the first relay.

Phytochemical and mineral components of foods consumed by black howler monkeys (Alouatta pigra) at two sites in Belize

We analyzed the chemical composition of the diets of eight groups of free-ranging black howler monkeys (Alouatta pigra) in Belize, Central America. The study groups were located in two different forests: the Community Baboon Sanctuary (CBS) and the Cockscomb Basin Wildlife Sanctuary (CBWS). Two of the study groups were translocated from the CBS to CBWS 3 months into the study, and we compared the diets of groups in the two forests. Young and mature leaves, fruits, flowers, and fig samples (n = 144) were analyzed for water content, crude and available protein, fiber, simple sugars, and minerals. Statistically significant differences were found among the plant parts in all measures except acid-detergent fiber. Dietary foliage in CBS was higher in water content and protein but lower in simple sugars than dietary foliage in CBWS. We suggest that changes in the selection of plant parts by primates may be related to differences in the nutritional content of those parts. These data may be useful in developing optimal diets for captive howler monkeys. Zoo Biol 19:95–109, 2000.

A Geographic Information System Method for Estimating Home Range Size

We developed a new technique to quantify home ranges by using coordinate-based data that were collected at small time intervals and entered into a Geographic Information System (GIS). We used this technique (digitized polygons [DP]) and 4 other established methods to estimate home range sizes of groups of black howler monkeys (Alouatta pigra). We calculated the size of the area used by the study groups during the study period. The DP method used all available data points, excluded lacunae within home ranges, and accounted for spread of the group. The DP estimates of home range size were compared with 4 widely used methods: minimum convex polygon (MCP), grid-cell (GC), 95% harmonic mean (HM), and 95% adaptive kernel (AK). Sizes of home ranges ranged from 1 to 62 ha. Results of all procedures were strongly correlated (P < 0.001), although each gave very different estimates of home range sizes. The DP estimates were smaller than AK (P < 0.039) and MCP (P < 0.002) estimates and consistently (although not significantly) larger than GC methods (P = 0.99). There was no statistically significant or consistent difference between DP and HM estimates. Digitized polygons required the investigator to select path width and size of lacunae to exclude, but these decisions can be based upon biological information. This method may be the most appropriate technique to determine home range size with autocorrelated location data that can be converted to day-range paths.

Shifts in Social Structure of Black Howler (Alouatta pigra) Groups Associated with Natural and Experimental Variation in Population Density

We examined variation in the group structure of black howlers (Alouatta pigra) using the adult composition of 48 social groups. We compared the structure of groups at 5 sites with different population densities and variation in group structure over time with rising population density. In addition, we examined changes in the group structure of monkeys that were translocated from an area of high population density to an area with a much lower population density. We found at low population densities, groups comprised either heterosexual pairs or a single male with two females. At high population densities groups tended to be multimale and often contained >2 adult females. We suggest the relative costs and benefits of dispersal by maturing adults varies with population density, and in Alouatta pigra results in a shift from single to multimale groups of larger size with increasing population density.

The ontogeny of nursing in Babyrousa babyrussa and a comparison with domestic pigs.

3Wildlife Trust, Palisades, New York The nursing behavior of eight babirusa ( Babyrousa babyrussa) infants was studied. Four were from single births and four were from twin births. The age at weaning, the time of day and number of nursing bouts per day, the mean duration of nursing bouts, and whether the offspring or the dam ended nursing bouts were all examined. It was found that although twins are weaned earlier than single offspring, there were no other statistically significant differences in nursing behavior of single and twin offspring. The ontogeny of nursing behavior in this species is described and some comparisons are made between the nursing behavior of babirusa and nursing in the domestic pig (Sus scrofa) and selected suids. Babirusa dams take longer to wean their offspring, allow them to nurse longer, and end nursing bouts less often than domestic pigs. The differences in behavior between babirusa and domestic pig nursing behavior may be related to differences in the number of offspring produced by the two species and the amount of parental investment in each offspring. Zoo Biol 19:253‐262, 2000.