Richard E. Bodmer

Effects of hunting in habitat fragments of the Atlantic forests, Brazil.

This study evaluates the impact of hunting on mammalian and avian species in Atlantic forest fragments of the Mata de Planalto in the State of Sao Paulo, Brazil. Colonists who farm on the edge of fragments also hunt for subsistence within fragments. Hunters commonly take the two peccary species, tapir, brocket deer, armadillos and agoutis. Primates are rarely hunted in this region. Effects of hunting on species were measured by changes in relative abundance of species between four sites with similar sizes (approximately 2000 ha each), but different hunting pressures (two slightly hunted and two heavily hunted). In addition, one large protected area (35 000 ha) was also censused. Species abundances were measured during 18 months along 2287 km of line transects. Abundances of tapirs, brocket deer, white-lipped peccaries, armadillos and coatis decreased between slightly hunted and heavily hunted sites. Abundances of collared peccaries, agoutis, primates and guans did not show any trends with hunting pressure. Extirpations of tapirs and white-lipped peccaries at heavily hunted sites suggest that in forest remnants encroached by people, hunting exacerbates effects of fragmentation, such as genetics and demographics, and is probably the most important factor in emptying these forests of large species over the short-term.

Strategies of seed dispersal and seed predation in Amazonian ungulates

Amazonian ungulates, which include the red brocket deer, grey brocket deer, collared peccary, white-lipped peccary, and lowland tapir, consume large quantities of fruit and maximize nutritional gain by exploiting both pulp and seed. Amazonian ungulates often disperse seeds over short distances by spitting them out during mastication. The lowland tapir is the only ungulate that frequently disperses intact seeds through the digestive tract. Brocket deer destroy most of the seeds they consume by digesting them with rumen microbes, while peccaries crack seeds using their resistant teeth, strong jaw musdes, and thick skull bones. Defensive strategies of seeds include strength, chemical toxins, mast fruiting, fibrous lignin, and size variation. Brocket deer and peccaries have pregastric fermentation that may detoxify some secondary compounds of seeds. Small seeds occasionally pass intact through brocket deer and peccary guts. However, strong palm seeds that avert many mammalian predators are often destroyed by ungulates. The fibrous lignin that protects seeds of Jessenia bataua (Palmae) appears to be effective against ungulates which may explain its abundance in the study area. AMAZONIAN UNGULATES CONSUME large quantities of fruit. Fruit constitutes 81 percent of the diet of red brocket deer (Mazama americana), 87 percent of grey brocket deer (M. gouazoubira), 59 percent of collared peccary (Tayassu tajacu), 66 percent of white-lipped peccary (T. pecarn) (Bodmer 1989) and 33 percent of lowland tapir (Tapirus terrestnis) (Bodmer 1990a). Much of the fruit consumed by these large-bodied terrestrial herbivores consists of residual fruit production (those fruits not consumed by arboreal animals that reach the forest floor) and to a lesser extent fruits of subcanopy plants. Therefore, ungulates do not have access to the full range of fruits which are available to arboreal frugivores, such as primates, fruit bats, and birds (Eisenberg & McKay 1974). Plants produce pulpy fruits to attract animal vectors, which, in turn, disperse seeds. Seeds are protected against predators by physical characteristics such as hardness or spines, chemical toxins, and saturation strategies via mast fruiting (Janzen 1971, Waller 1979, Kiltie 1982, Bell 1984, Dirzo & Dominguez 1986). However, ungulates maximize nutritional intake from forest fruits by exploiting the entire fruit resource, including protected seeds (Kiltie 1981, Smythe 1986). This paper examines the extent of seed dispersal and seed predation in Amnazonian ungulates, the various ways in which ungulates disperse seeds, and their adaptations for seed predation. The paper also examines the various ways seeds protect themselves from predators and how brocket deer, peccaries, and tapir overcome these seed defenses.

Towards Wildlife Management in Tropical Forests

Hunting is ubiquitous in tropical forests around the world, and meat from wildlife species is an important source of animal protein for rural populations. Ungulates, primates, and rodents provide most of the biomass consumed, but a wide variety of wildlife species are limited for both subsistence and commerce. Across the tropics, tens of millions of animals and millions of metric tons of meat are hunted and consumed each year. Is this harvest sustainable? Available information and the use of simple sustainability models suggest it is not. The supply of wildlife is limited, a anmal production of large mammals in tropica forests is low when compared to other ecosystems, The demand is increasing as tropical forests become more accessible to hunters, effective human population densities increase, people become more sedentary, traditional hunting practices change, the meat trade becomes more commercial, and demand increases for wild meat from urban centers. If wildlife populations are to be sustained, then management institutions, be they government or community-based, need to be strengthened.

Responses of ungulates to seasonal inundations in the Amazon floodplain

Terrestrial ungulates use different strategies to cope with widespread annual flooding of the Amazon basin. Red brocket deer (Mazama americana) and collared peccary (Tayassu tajacu) retreat to floodplain islands and shift from a frugivorous to a woody browse diet. However, both white-lipped peccary (Tayassu pecari) and lowland tapir (Tapirus terrestris) diets are unaffected by inundations; in the case of white-lipped peccary because they migrate into and out of flooded areas and in the case of lowland tapir because of their semi-aquatic nature. These strategies of white-lipped peccary and lowland tapir enable them to exploit the greater fruit production of flooded forests more frequently than brocket deer and collared peccary.

Ungulate frugivores and the browser-grazer continuum

Feeding strategies of ungulates are usually classified along a browser grazer continuum which ranges from browsing through to grazing ungulates, but does not accurately include frugivores. However, to understand the evolution of ungulate feeding it is necessary to have a classification that realistically incorporates the full range of ungulate feeding strategies. Such a classification can be described as a linear continuum that ranges from fruit feeders through to browsers and then grazers. Purely frugivorous ungulates are restricted to tropical forests and have consistently small body sizes. Pure grazers on the other hand are absent from tropical forests and are found most commonly in grassland and savannas. Browsing is the most common ungulate feeding strategy and is found in ungulates with a wide range of body sizes and is common in all habitat types. Fruit differs greatly from browses and grasses and adds additional support to the proposed frugivore-browser-grazer classification.

Influence of digestive morphology on resource partitioning in Amazonian ungulates

SummaryResource partitioning of diet and habitat use was studied in the entire Amazonian ungulate community of Northeastern Peru, which comprises the red brocket deer (Mazama americana), grey brocket deer (M. gouazoubira), collared peccary (Tayassu tajacu), white-lipped peccary (T. pecari), and lowland tapir (Tapirus terrestris). Each ungulate species partitioned at least one type of resource from every other species. Digestive morphology had a greater influence on resource partitioning of diet than body size. Neither digestive morphology nor body size were related to segregation of habitats. However, species with similar diets partitioned habitats, whereas species with different diets often used the same type of forest. Increases in habitat breadth of ungulates were positively correlated with increases in dietary breadth.

NICHE PARTITIONING AMONG WHITE-LIPPED PECCARIES (TAYASSU PECARI), COLLARED PECCARIES (PECARI TAJACU), AND FERAL PIGS (SUS SCROFA)

Abstract The introduction of a species into an ecosystem with species already occupying a similar trophic level is predicted to lead to a high degree of niche overlap. The feral pig (Sus scrofa), one of the worlds worst invasive species, was introduced to the Pantanal about 200 years ago and is thought to compete with the native white-lipped peccary (Tayassu pecari) and collared peccary (Pecari tajacu). Resource partitioning between the 3 species was examined, including analysis of fruit items and plants in fecal samples as well as encounter rates in different habitats, to help generate hypotheses about competitive interactions among the species. Overlaps in food resources and habitat use between feral pigs and peccaries were found to be lower than expected. In fact, niche overlap was highest between the native species. Results indicate that currently, feral pigs are not a direct threat to the native peccaries in the study area. Differences in morphology and behavior indicate possible mechanisms of niche partitioning between the species. Feral pigs may, nevertheless, impact the wildlife community in other ways as predators of eggs, by destruction of vegetation through rooting, or by functioning as disease reservoirs. Cattle-ranching activities may favor feral pigs and the current anthropogenic changes in the landscape could lead to changes in competitive dynamics between feral pigs and native species.

Social behavior in fission-fusion groups of red uakari monkeys (Cacajao calvus ucayalii).

Primates living in large groups that divide to forage must have social systems compatible with this mode of living. Uakari monkeys (Cacajao spp.) live in large groups and exhibit a form of fission–fusion grouping, but their social organization is poorly understood. We present some of the first data on social behavior for this genus based on a study on Cacajao calvus ucayalii. They traveled in multimale multifemale groups of highly variable sizes, with bachelor units on the periphery. Adult males were affiliative, and adult females associated with more than one adult male. Adult females typically traveled with their dependent offspring and an older juvenile within the group. In parties of two or more males, individuals engaged in previously unreported display behaviors and acted together to aggressively chase other males. Breeding was seasonal, and mating occurred away from other group members. We speculate on the social organization of C. calvus ucayalii, in which dispersal may be bisexual and peripheral males are affiliative with one another. Affiliated males appear to cooperate in fighting and displaying to other males for access to females during the breeding season. Am. J. Primatol. 71:976–987, 2009.

Diet and Food Choice in Peruvian Red Uakaris (Cacajao calvus ucayalii): Selective or Opportunistic Seed Predation?

Even primates considered dietary specialists tend to eat a combination of fruit pulp, seeds, other plant parts, or animals. Specialist seed predators could either feed on seeds preferentially, or to avoid competition when ripe pulps are scarce. Pitheciin monkeys have specialized dentition that allows them to feed on seeds protected by hard shells, and the upper limit on the hardness of these is likely to be a function of jaw size. We recorded the diet of Peruvian red uakaris (Cacajao calvus ucayalii) on the Yavari River, Peru, to test the prediction that this seed predator would feed on the seeds of hard-shelled fruits preferentially over softer ones in relation to their availability in the forest. We also tested predictions that adult male, adult female, and juvenile diets would differ, with larger individuals eating more hard fruits. Uakaris ate 55.4% seeds, 38.9% pulps and arils, and 5.6% other items, but proportions varied through the year. More pulps, especially from the palm Mauritia flexuosa, were eaten when fruit availability was low, and more hard fruits were positively selected for than softer ones. Juveniles did not open the hardest fruit species opened by adults, and adult males ate harder fruits than females. These results provide evidence that seed eating in some primates has evolved beyond a means of avoiding competition for the ripe pulps typically preferred by many primates. Specialist seeding-eating primates therefore occupy divergent niches that require separate consideration from those of similar-sized primates.

Ungulate biomass in relation to feeding strategy within Amazonian forests

SummaryThe relationship between diet and biomass was examined in the Amazonian ungulates (red brocket deer, grey brocket deer, collared peccary, white-lipped peccary, and lowland tapir) of Northeastern Peru. Tropical forest ungulates have lower biomasses than savanna or grassland ungulates, because in tropical forests the majority of primary production occurs in the canopy, well out of reach from terrestrial herbivores. Within the Amazonian ungulates, species that supplement their diet with animal material, namely the peccaries, obtain a greater crude and metabolic biomass, and higher reproductive rates than the purely herbivorous species. Omnivory appears to help terrestrial herbivores inhabiting closed canopy forests overcome some effects of food limitation.