Antonio Santos-Moreno

Ecological Traits of Phyllostomid Bats Associated with Sensitivity to Tropical Forest Fragmentation in Los Chimalapas, Mexico

Certain ecological traits of bats may be associated with sensitivity to the fragmentation of their habitat, but the relative importance of this is unclear and has been poorly studied in tropical environments. We evaluated the relationship between six ecological traits of phyllostomid bats (body mass, trophic level, vertical foraging area, natural abundance in continuous forest, wing aspect ratio, and relative wing loading) and three measures of sensitivity to habitat fragmentation (species prevalence, change in abundance index, and nestedness ranking) in a fragmented forest in Los Chimalapas, Mexico. Ecological traits were obtained from 20 bat species for a period of 2 years, and their relationship with measures of sensitivity to fragmentation was analyzed using Generalized Linear Models. The analysis suggests that naturally non-abundant species (e.g., Salvins Big-eyed Bat [Chiroderma salvini]) have a greater risk of population decline because of habitat fragmentation. In contrast, abundant species such as Jamaican Fruit-eating Bat (Artibeus jamaicensis) will likely be less affected. The identification of these traits in studies of tropical bat conservation is fundamental to determine species-specific decline risk due to habitat fragmentation.

NOTEWORTHY RECORDS OF TWO RARE MAMMALS IN SIERRA NORTE DE OAXACA, MEXICO

Abstract We made an intensive survey of small mammals in the Sierra Norte de Oaxaca region, in Oaxaca, México. We recorded the presence of 2 interesting species: water mouse (Rheomys mexicanus) and river otter (Lontra longicaudis annectens). The locality for the river otter represented the highest altitude recorded in México for this species. The locality for the water mouse is the fourth known in all of its range and the second record in Sierra Norte.

Abundance and activity patterns of medium-sized felids (Felidae, Carnivora) In Southeastern Mexico

Abstract We compared abundance and activity patterns of medium-sized felids in the neotropics. We used 29 camera traps to record species in the region of Los Chimalapas, Oaxaca, Mexico, during 2011–2013. We estimated population size with the capture-recapture model (Cormack-Jolly-Seber model). We assessed the differences in activity patterns between species through the Mardia-Watson-Wheeler test. Leopardus pardalis, Leopardus wiedii, and Puma yagouaroundi were recorded by cameras. The population size of L. wiedii was high in comparison with L. pardalis, which presented a medium abundance compared to other regions. Puma yagouaroundi individuals were relatively rare, likely due to a difference in habitat selection. We provide evidence that in the southeastern region of Mexico there is a significant L. wiedii population despite the presence of L. pardalis.

Responses of phyllostomid bats to forest cover in upland landscapes in Chiapas, southeast Mexico

ABSTRACT Forests are a key habitat for bats, but tend to be lost and fragmented in some agri-environment schemes. We studied the effects of forest cover change on phyllostomid bats in agricultural landscapes with increment of open areas in an upland region in Chiapas, southeast Mexico. We tested whether with forest cover increase there is a directly proportional response on assemblage species diversity measures, on the capture success and body condition of particular ensembles. Depending on the spatial analysis window, and presumably on vagility, we found positive and significant associations with the sanguivore ensemble’s capture success, as well as with the nectarivore and shrub frugivore ensembles’ body condition. We support the idea that appropriate amounts of forest over small geographic extents may propitiate favorable environments for some phyllostomids, which can also provide important ecological services. Furthermore, the arrangement of ecologically similar species proved to be valuable for exploring adaptive traits, and adequate for conservation strategies of species-rich taxa.

Cavity Occupancy by Lowland Paca (Cuniculus Paca) in the Lacandon Rainforest, Chiapas, Mexico

Habitat occupancy is a good indicator of wildlife behavior and interactions with their environment. We used camera traps to study the use of cavities by lowland paca (Cuniculus paca) in three sites in the Lacandon Rainforest of Chiapas, Mexico. To understand the biotic, environmental, physical, anthropic, and behavioral elements that affect spotted lowland paca, the cameras recorded lowland paca activity in front of 29 cavities. Monitoring occurred continuously in cavities near permanent natural water bodies, underneath roots of trees, or inside hollow logs. These cavities were more frequently found in Montes Azules Biosphere Reserve (MABR), where hunting pressure was low. The daily occupancy and permanence of lowland paca in these cavities were associated with the presence of its offspring. There were no offspring recorded in cavities alongside rivers within grazing areas. This suggests the potential existence of a sink-source type of metapopulation, where community reserves and MABR would serve as source habitat, while riparian corridors would be sink habitat for this species. Lowland pacas used these locations, which were scattered through the study area, so long as hunting was moderate and riparian corridors with safe cavities in large trees were well preserved.

Band size, activity pattern and occupancy of the coati Nasua narica (Carnivora, Procyonidae) in the Southeastern Mexican rainforest

Abstract The White-nosed coati or tejon, Nasua narica, is relatively common within terrestrial mammal communities though little information on its population ecology has been gathered in certain regions. This study evaluates the band size, activity pattern and occupancy of N. narica at Los Chimalapas, in the eastern region of the state of Oaxaca, Mexico, a biodiverse region. It is expected that band size will be greater and activity time will differ from that of predators. Camera traps were used to record the species (2011–2013) in a rainforest at Southeastern Mexico. Band size and activity pattern were calculated based on photographic records. Activity pattern was compared between seasons and with that of predators. The spatial distribution of activity, as well as relationship to the proximity of water, populated areas, crops and the presence of predators, was evaluated with occupancy models. Average band size was 9.03±0.52 individuals. As expected, N. narica presented principally diurnal activity and its activity patterns did not differ seasonally, but differed significantly from those of its predators. The occupancy probability of N. narica was 0.66 and the detection probability was higher in proximity to the nearby village. The population of N. narica at Los Chimalapas may be considered similar to other regions, particularly the band size; predator activity patterns may be an important factor in the activity of N. narica, but not in its occupancy.

First records of hypopigmentation disorders in the Peters’ ghost-faced bat Mormoops megalophylla (Chiroptera, Mormoopidae)

Abstract The pigmentation process can be affected throughout development and result in aberrant pigmentation. This can derive not only from genetic mutations, but also from other sources like infectious diseases that result in color patterns which are different from those characteristic of each species. In bats, most pigmentation abnormalities have been observed in the families Phyllostomidae and Vespertilionidae, probably because they are the largest families in number of species and have been exceptionally well studied. For the Mormoopidae family only two cases are known. This paper documents the first case of hypopigmentation disorder in the bat Mormoops megalophylla throughout its range, recorded in two specimens captured in the state of Oaxaca, México.

Analysis of the contribution of landscape attributes on the genetic diversity of Artibeus jamaicensis Leach, 1821

It is commonly assumed that bats, due to their flight capacity, are not affected by landscape attributes across small geographic extensions. However, recent studies with phyllostomids have found evidence of negative responses, such as decreasing genetic diversity with decreasing forest amount, specifically in areas dominated by agricultural land. The purpose of this study was to evaluate if landscape composition and configuration could be influencing the genetic diversity of a common frugivorous bat: Artibeus jamaicensis. We worked in an area characterized by the presence of extensive agricultural land, with a trend towards open spaces of high contrast with forests. Through mtDNA control region sequences, we inferred high levels of genetic diversity in the surveyed landscapes. In order to determine a possible relationship between genetic diversity and landscape attributes, we employed a multivariate exploratory analysis that allowed us to determine the independent contribution of each variable, in a hierarchical model. We found a negative relationship between genetic diversity and total forest edge, which is a variable that reflects the degree of fragmentation. This procedure can be implemented in population genetics, allowing the incorporation of spatially explicit variables.

Effect of intrinsic and extrinsic factors on the variability of echolocation pulses of Myotis nigricans (Schinz, 1821) (Chiroptera: Vespertilionidae)

Abstract Bats may exhibit plasticity in echolocation pulses as response to intrinsic and extrinsic factors, and the estimation of the magnitude of such variation can provide confidence in acoustic monitoring. Myotis nigricans (Schinz, 1821) is a widely distributed but relatively understudied Neotropical species for which, during fieldwork, we found maternity colonies in the Lagunas de Montebello National Park, in Chiapas, South-east Mexico, and no previous information in the area. Therefore, we aimed to provide an acoustic characterization on the basis of intraspecific variability for its recognition using bat detectors. For this purpose, we examined the moulding of shape, frequency-based and time-based acoustic parameters, specifically by the effect of age group (sub-adults vs. adults) and acoustic environment (open space vs. background vegetation). By graphic comparison of echolocation pulses between acoustic environments, we observed changes in shape by an increase in bandwidth and steeper modulation along background vegetation. Statistically, on univariate basis, we did not find a significant effect of age group, but we did of acoustic environment, specifically on highest frequency (higher average), duration (shorter average) and interpulse interval (shorter average) along background vegetation. On multivariate basis, we confirmed shorter average interpulse interval along background vegetation. The overall classification accuracy was relatively high (82.22%): 80% in open space and 84% along background vegetation. Our work reinforces previous knowledge about sound constraints imposed by vegetation clutter, and provides a reliable framework for acoustic monitoring of this species across structurally variable, and hence acoustically variable, environments in the area.

Abundance, density and habitat use of lowland paca (Cuniculus paca, Rodentia: Cuniculidae) in the Lacandon Rainforest, Chiapas, Mexico

In this study, the effect of relevant variables (availability of food and cavities, competition, predation, and hunting pressure) on the relative abundance and population density of the spotted lowland paca (Cuniculus paca) was assessed. In addition, habitat use of this species at three sites with different land use regime (Montes Azules Biosphere Reserve, community reserves, and anthropic sites) in the Lacandon Rainforest, Chiapas, Mexico was analysed. From the perspective of the source-sink systems, it was predicted that pacas selectively would use the habitat with higher food and cavity availability (source habitats), where higher densities were expected. Twelve transects were located in three sites with different land use regimes, where food availability and potential cavities used by pacas were assessed. Along these transects, 4 camera-traps were deployed every 200 meters to estimate the relative abundance of pacas and their potential competitors and predators. Photo-captured individuals were identified to estimate population density and seasonal variation in habitat use. Generalized linear models (GLM) were constructed to analyse the effects of several variables on paca abundance and density. A relative abundance of 0.05 and 0.08 paca photographs/100 camera-days were recorded in the dry and the rainy season, respectively. A density of 54 pacas/km2 was estimated in both seasons. The availability of cavities was the only variable that showed a significant effect on paca density (P = 0.04 for the dry season, and P = 0.006 for the rainy season). Community reserves were used in the dry season more than expected from their availability in the study area (x2 = 28.8; P = 0.0001). In the rainy season, all three sites were used by paca in proportion to their availability. Our results suggest that the cavities used as refuges by pacas drive their population dynamics, and constitute a key habitat resource for them in the study area. We propose that the Ejidal Reserve and Montes Azules Biosphere Reserve may be source habitats supporting higher paca densities and greater availability of adequate cavities to protect adults and their offspring. On the other hand, areas transformed into croplands and grasslands for livestock production would represent sink habitats with lower paca densities, less availability of adequate cavities, and absence of offspring. The long-term conservation and habitat management of pacas in transformed landscapes will probably rely on the distribution and connectivity between and within the different habitat types available in the study area.