Juan Carlos Serio-Silva

The role of Ficus (Moraceae) in the diet and nutrition of a troop of Mexican howler monkeys, Alouatta palliata mexicana, released on an island in southern Veracruz, Mexico

We analysed the selection of tree species consumed by an isolated troop of Mexican howler monkeys (Alouatta palliata mexicana) released in a translocation programme on Agaltepec Island, in Catemaco Lake, Veracruz, Mexico. During November 1989-December 1996, howlers used 36 of the 63 tree species present on the island as food. Selection ratios indicated that six Ficus species (particularly F. pertusa) were among the seven most important food species. Data on time spent feeding showed that the six Ficus species were among the eight most important food species for the monkeys. Howlers spent 64.2% of their feeding time on Ficus products with F. pertusa being consumed significantly more often than foods from other Ficus species. However, monkeys fed on only one third of the 81 adult Ficus trees on the island. No significant differences were found in various food constituents (water, ash, fibre, protein, carbohydrates, lipids) of the six Ficus and two other abundant species in the habitat, whether across species, plant parts (young leaves, mature leaves, fruits), or between seasons (wet, dry). Monkeys consumed Ficus fruits rather the leaves. Fruits showed a much higher energy content per g dry weight than leaves. We also estimated the average daily biomass of leaves and fruits of Ficus spp. consumed by howlers and their energetic contribution to the daily diet of these monkeys. We suggest that some of these tendencies to frugivory reflect the abundance of Ficus trees within the home ranges of the howlers; when few fig trees are present, folivory is the dominant tendency, whereas when many fig trees are present, frugivory is dominant.

Interacting effects of forest fragmentation and howler monkey foraging on germination and disperal of fig seeds

We studied changes in germination rates In a large forest fragment with ‘regularly’ distributed Ficus individuals the howler monkeys move away from and dispersal distance of seeds of Ficus perforata and F. lundelli dispersed by howler monkeys (Alouatta palliata the seed source, increasing the probability that the seeds are desposited on a tree other than Ficus, which is mexicana), in a small (40 ha) ‘disturbed’ and a larger (>600 ha) ‘preserved’ tropical rainforest in southern important for the germination and future development of a hemiepiphytic species. In a small forest fragment Veracruz, Mexico. The interaction between A. p. mexicana and Ficus (Urostigma) spp. is beneficial for the interacting with trees distributed in clumps howlers repeatedly use the same individual trees, and faeces containing seeds species and has important implications for their conservation. Howler monkeys gain from the ingestion of may be dropped on unsuitable trees more often. These are key issues when addressing conservation policies for an important food source, germination rates of Ficus seeds are improved by passage through the monkeys’ fragmented forests. digestive tract, and the seeds are more likely to be deposited in a site suitable for germination and develop

Resource Use in a Landscape Matrix by an Arboreal Primate: Evidence of Supplementation in Black howlers (Alouatta pigra)

Across the tropics, landscapes of continuous rain forest are being replaced by forest fragments embedded in a matrix of pastures and farmlands. This conversion has endangered many species, including arboreal primates. Species vary, however, in how they are able to supplement their diets from the matrix, although this is rarely studied in primates. We studied two groups of black howlers (Alouatta pigra) for a total of 1156 h, one inhabiting a smaller fragment (0.4 ha) and the other a larger fragment (20 ha). monkeys inhabiting the smaller fragment spent more time in the matrix than in the habitat fragment, spending 50 % of their time (335 of 667 h) in an abandoned mango (Mangifera indica) plantation, 8.8 % in scattered trees, and 0.2 % in pastures. In contrast, monkeys in the larger fragment spent 75 % of their time (368 of 489 h) in the forest fragment and only 25 % of their time in the matrix. Feeding in the matrix accounted for 53 % and 12 % of the foraging time for groups in the smaller and larger fragments respectively. We suggest that Alouatta pigra can use resources in the matrix to supplement their diet by means of crop raiding or taking other resources in many fragmented landscapes and that this may be true also for many fragment-dwelling primates. It is important to include a consideration of the matrix in conservation planning, considering both the total resources available to primates and the consequences of crop raiding for farmers.

Howlers Are Able to Survive in Eucalyptus Plantations Where Remnant and Regenerating Vegetation Is Available

Reversing forest loss through reforestation has become a critical strategy to decrease global climate change, and such programs are more likely to be initiated if they can produce a subsequent monetary gain for the host country. As a result, the planting of monocultures of harvestable trees has become widespread and the practice is accelerating. However, little is known about the effect of such reforestation strategies on biodiversity. Here we quantify the demographic patterns of a population of black howlers (Alouatta pigra) living in a 200-ha eucalyptus plantation with connected remnant forests in southeastern Mexico. We compare our results to data from the literature from forest fragments, extensive forest tracts, and different agrosystems. The howler population inhabiting the plantation grew from 69 individuals in 2007 to 77 in 2008 (11.6% growth) and to 84 in 2009 (9.1% growth). During this time the howlers fed extensively on the native vegetation that was growing under the eucalyptus, vines that grew on the plantation trees, and adjacent areas of native secondary growth, but they almost never fed on eucalyptus. Howler density in the plantation was greater than in extensive forest tracts or forest fragments, whereas mean group size was similar to that in the forest tracts and greater than in the fragments and agrosystems. There was no apparent difference in the adult female-to-immature ratio among sites. Our results indicate that plantations that have associated native vegetation can play a positive role in the conservation of this species, but suggest that harvesting regimens must be carefully orchestrated to prevent associated food scarcity.

Potential distribution of Mexican primates: modeling the ecological niche with the maximum entropy algorithm

We developed a potential distribution model for the tropical rain forest species of primates of southern Mexico: the black howler monkey (Alouatta pigra), the mantled howler monkey (Alouatta palliata), and the spider monkey (Ateles geoffroyi). To do so, we applied the maximum entropy algorithm from the ecological niche modeling program MaxEnt. For each species, we used occurrence records from scientific collections, and published and unpublished sources, and we also used the 19 environmental coverage variables related to precipitation and temperature from WorldClim to develop the models. The predicted distribution of A. pigra was strongly associated with the mean temperature of the warmest quarter (23.6%), whereas the potential distributions of A. palliata and A. geoffroyi were strongly associated with precipitation during the coldest quarter (52.2 and 34.3% respectively). The potential distribution of A. geoffroyi is broader than that of the Alouatta spp. The areas with the greatest probability of presence of A. pigra and A. palliata are strongly associated with riparian vegetation, whereas the presence of A. geoffroyi is more strongly associated with the presence of rain forest. Our most significant contribution is the identification of areas with a high probability of the presence of these primate species, which is information that can be applied to planning future studies and then establishing criteria for the creation of areas to primate conservation in Mexico.

Current status of the habitat and population of the black howler monkey (Alouatta pigra) in Balancán, Tabasco, Mexico

We evaluated the habitat and populations of the black howler monkey (Alouatta pigra) in the municipality of Balancán, Tabasco, southeastern Mexico, using a combination of field surveys and remotely sensed data. We identified 21,937 ha of remnant vegetation composed of 1,348 fragments. Fragments separated by up to 200 m were grouped into “clusters” of fragments in accordance with the maximum observed open distance crossed by A. pigra. A total of 11% or 84 of the 772 clusters identified through remote sensing were selected at random, and for these we determined the vegetation type, canopy height, area, and distance to the closest human settlement. In these same 84 clusters, which included a total area of 9,817 ha, from October to June of 2006 we located a total of 1,064 black howler monkeys, including 228 troops and 49 solitary monkeys. A. pigra was found in 62 (74.7%) of all clusters visited, with a cumulative area of 6,032 ha. Troops varied in size from 2 to 15 individuals (average 6.0±2.9 ind/troop). Adults were 67% (n=716) of detected individuals, whereas juveniles were 20.5% (n=218) and infants were 12.5% (n=133). We found black howlers to occur at an ecological density of 10.8 ind/km2, which is low in comparison with A. pigra in other fragmented and conserved sites. We found a statistically significant relationship between the area of clusters and the abundance of howler monkeys (r2=0.2, F=10.47, gl=3, P=0.002). In addition, the probability of finding A. pigra was greater in secondary vegetation, riparian vegetation, tropical dry forest, undisturbed tropical oak forest, and palm forest (F=12, gl=3, P<0.0001), as compared with disturbed tropical oak forest. Our results provide data on the distribution, abundance, and population structure of black howler monkeys in a fragmented landscape in the southeast of Mexico. These data are a necessary prerequisite for conservation planning for this species. Am. J. Primatol. 70:1169–1176, 2008.

Black howler monkey (Alouatta pigra) activity, foraging and seed dispersal patterns in shaded cocoa plantations versus rainforest in southern Mexico

Recent evidence has shown that primates worldwide use agroecosystems as temporary or permanent habitats. Detailed information on how these primates are using these systems is scant, and yet their role as seed dispersers is often implied. The main objective of this study was to compare the activity, foraging patterns and seed dispersal role of black howler monkeys (Alouatta pigra) inhabiting shaded cocoa plantations and rainforest in southern Chiapas, Mexico. We gathered data on three monkey groups living in shaded cocoa plantations and three groups living in rainforest, using focal sampling, and collecting fecal samples. General activity and foraging patterns were similar in both habitats, with the exception that monkeys in the cocoa habitat spent more time feeding on petioles. Monkeys in shaded cocoa plantations dispersed 51,369 seeds (4% were seeds ≥3 mm width) of 16 plant species. Monkeys in the rainforest dispersed 6,536 seeds (78% were seeds ≥3 mm width) of 13 plant species. Our data suggest that the difference between habitats in the proportion of large versus small seeds dispersed reflects differences in fruit species abundance and availability in cocoa versus forest. Mean seed dispersal distances were statistically similar in both habitats (cocoa = 149 m, forest = 86 m). We conclude that the studied cocoa plantations provide all elements necessary to constitute a long‐term permanent habitat for black howler monkeys. In turn, howler monkeys living in these plantations are able to maintain their functional role as seed dispersers for those native tree and liana species present within their areas of activities. Am. J. Primatol. 76:890–899, 2014.

Primates in Fragments 10 Years Later: Once and Future Goals

In 2010, the Food and Agriculture Organization of the United Nations (FAO) estimated that 16 million hectares of forest per year were lost globally in the 1990s (FAO 2010), and approximately 12.5 million hectares/year were lost in countries with primate populations, an area just smaller than Greece or the US State of Mississippi (Chapman and Peres 2001; Chapman and Gogarten 2012). In contrast, in the last decade (2000–2010), the rate of deforestation has decreased globally by approximately 5.2 million hectares/year, and reforestation and natural expansion of forests in some countries significantly reduced the net loss of forest (FAO 2010). This may be in part due to the lack of resonance in satellite imagery between secondary and primary forest regions, particularly in the tropics. Unfortunately, the increase in forested lands has principally affected temperate regions of Europe and eastern Asia (e.g., China, Japan), but deforestation of most tropical forests has continued steadily (e.g., annual loss: 0.5 % in Africa, 1.2 % in Mesoamerica, 0.5 % in South America, 0.4 % in southeastern Asia; FAO 2011).

Traditional nutritional analyses of figs overestimates intake of most nutrient fractions: a study of ficus perforata consumed by howler monkeys (Alouatta palliata mexicana).

There continue to remain uncertainty concerning the nutritional importance of figs (Ficus spp.) in the primate diet. Although studies have been performed on the nutritional analysis of fig pulp and seed fractions separately, there has not been an attempt to quantify the contribution of animal matter within figs. Here we report nutritional values of figs (Ficus perforata) (Urostigma) consumed by a troop of howler monkeys (Alouatta palliata mexicana). Separate nutritional assays were performed on the pulp, seed, and animal fraction. Whole‐fig analyses significantly exaggerate the concentrations of all nutrients (lipids especially) as seeds, which represent a large proportion of the fig (45%), cannot be digested. Animal matter only represents 1% of the fig, and augments fig protein and lipid content by 0.44 and 0.30%, respectively. This represents the 11 and 9% of the fraction available for digestion. Differences in fig consumption were observed between age and sex classes (P=0.04) and periods of the day (P=0.001); females consumed more figs than males and the highest consumption of figs was observed in the afternoon. F. perforata figs may be an important component of the howler monkeys diet owing to their high content of water and calcium. Am. J. Primatol. 70:432–438, 2008.

Safeguarding biodiversity: what is perceived as working, according to the conservation community?

Dramatic increases in human populations and per capita consumption, climate change, overexploitation of marine and freshwater resources, and deforestation have caused a litany of negative consequences for biodiversity. Such doom-and-gloom scenarios are widely known, frequently cited and frankly depressing. Although accurate assessments of threats have clear value for intervention planning, we believe there is also a need to reflect on successes. Such reflection provides balance to negative scenarios and may shift attention towards constructive, positive action. Here we use a systematic evaluation of 90 success stories provided by conservation scientists and practitioners to explore the characteristics of the projects perceived as being associated with success. Success was deemed to have occurred for 19.4% of the projects simply because an event had occurred (e.g. a law was passed) and for 36.1% of projects quantitative data indicated success (e.g. censuses demonstrated population increase). However, for most projects (63.9%) there was no evaluation and success was defined by the subjective opinion of the respondent. Conservation community members viewed successful projects most often as those being long-term (88%), small in spatial scale (52%), with a relatively low budget (68%), and involving a protectionist approach alone or in combination with another approach. These results highlight the subjectivity of definitions of success in conservation but also the characteristics of conservation efforts that the conservation community perceives as indicative of success.