Spaciotemporal relations between quetzal abundance and cloud forest habitat characteristics in El Triunfo Biosphere Reserve, Mexico

We carried out an intensive and systematized sampling of the spider fauna of the tropical mountain cloud forest (TMCF) in El Triunfo Biosphere Reserve, Chiapas, Mexico, in order to analyze their composition, species richness, abundance, and proportion of undescribed species, and to compare these results with those found in other TMCFs. We sampled ten plots in two seasons (dry and rainy) using different sampling techniques on two strata (ground and understory). A total of 7,432 specimens were collected corresponding to 28 families, 78 genera and 111 morphospecies. A high proportion of total species (58.6%) were undescribed species. For 11 species originally described from a single sex, we found the other sex. Five species and one genus were new records for the Mexican spider fauna. Understory stratum had higher numbers of species and individuals than ground stratum, and there was a high species turnover, with only 17% of the total species shared between strata. The spider fauna of El Triunfo shows similarities with other TMCFs (especially that on the same mountain range) concerning the identities of dominant and species-rich families, family and genera composition, the presence and relevance (in abundance or richness) of families that are uncommon in lowland tropical habitats (Linyphiidae and Theridiosomatidae), and in the high proportion of undescribed species. However, there is a high species turnover among sites (only 16% species shared), even at relatively short distances, that seems derived in part from the relative high proportions of endemic species. Our results suggest that high abundance of Theridiosomatidae and Linyphiidae, together with high species richness of this last family, could be used as conservation indicators for the Mexican TMCFs. The high numbers of undescribed species in the analyzed TMCFs, and their relatively high endemicity levels, support that TMCFs could be regarded as hotspots for the order Araneae.

The Cryptotis goodwini species group of small-eared shrews (Eulipotyphla, Soricidae) includes at least 12 species discontinuously distributed in the cloud forests from southern Mexico to Honduras. Its taxonomy is still under study, with several species described only in the last decade. Previous genetic studies have highlighted that a population from El Triunfo Biosphere Reserve in Chiapas, Mexico, previously assigned to C. goodwini, is evolutionarily divergent from the other known species. However, the available specimens from this region have not been examined rigorously. Herein, I use morphological and biogeographic analyses to evaluate the taxonomic status of this population. The results confirm that it is an independent lineage, which I describe here as a new species endemic to Mexico. Overall, this is the largest shrew within the C. goodwini group. Its morphological and genetic distinction is probably due to long-term geographic isolation in the mountains of El Triunfo. I present what is now the first and only record of C. goodwini (sensu stricto) for Mexico. Finally, I identify some priority regions to direct field surveys on the C. goodwini species group to better understand its richness and distribution.

Human activities are one of the most critical threats to wildlife. Therefore, understanding human-wildlife interactions is key to designing and applying sound conservation strategies. We identified wild animals relevant for people in El Triunfo Biosphere Reserve, southern Mexico considering four types of interactions: Use, affect (either positive or negative), and conflict. Twenty-eight workshops and 670 wildlife-human experiences with 58 taxa were recorded. The most relevant species were Odocoileus virginianus, Tapirus bairdii, Panthera onca, Pharomachrus mocinno, and Bothriechis bicolor. Positive affect was the most frequent interaction reported (46%), followed by use (20%), conflict (17%), and negative affect (16%). Negative affect and conflicts were mainly related to fear and damage by native predators. Species use was relatively infrequent (20%). We propose that conservation strategies be directed according to the species and their specific interactions.

Abstract:Plant–animal mutualistic interactions through ecological network systems and the environmental conditions in which they occur, allow us to understand patterns of species composition and the structure and dynamics of communities. We evaluated whether flower morphologies with different pollination syndromes (ornithophilous and non-ornithophilous) are used by hummingbirds and whether these characteristics affect the structure (core-peripheral species) of hummingbird networks. Observations were made in flowering patches, where plant–hummingbird interactions were recorded at three altitudes (300–2500 m) during three seasons (dry, rainy and post-rainy) from 2015 to 2016 at El Triunfo Biosphere Reserve, Chiapas, Mexico. We recorded 15 hummingbird species interacting with 58 plant species, and the greatest number of interacting hummingbird species (11; 14) and plant species (28; 40) were found at middle altitudes and during the dry season, respectively. In all study sites, most of the plant species visited by hummingbirds had an ornithophilous syndrome (67%) at high altitudes (22 plant species) and during the dry season (26 plant species), but more individual hummingbirds visited non-ornithophilous plant species. The hummingbird species at high altitudes exhibited the greatest level of specialization towards plants (H2′ = 0.74), but the networks of plant-hummingbird interactions were generalist (H2′ = 0.25); i.e. visiting plants with both syndromes, at low altitudes. The core generalist hummingbird species remained constant with altitude and season, but the core generalist plant species varied between different altitudes and seasons according to the phenology of the species.

Climatic conditions have changed within the cloud forests of southern Mexico, but the effects of these changes on tree phenology are not well understood. Our study aimed to determine relationships between seasonal patterns of flowering and fruiting and the annual and long-term changes in temperature and rainfall in El Triunfo Biosphere Reserve, Mexico. Flowering and ripe fruiting intensity and fruit number were recorded for 158 trees of 21 zoochorous species during 17 months in 2019–2021. Circular statistics, synchronization calculations, and generalized linear mixed models were used to determine phenological patterns and relationships between phenophases and temperature, rainfall, and solar radiation. Flowering was most closely associated (negatively) with rainfall, whereas ripe fruiting was positively associated with solar radiation. We compared recent fruiting seasonality with phenological data collected in 1991–1993. The mean date of community fruiting in 2019–2020 was earlier (April 4) than in 1992 (May 1) and 1993 (May 13). Community fruit number in 2020–2021 decreased in comparison to 2019–2020. Our results suggest that decadal trends of increasing minimum daily temperature and an earlier and wetter wet season influenced the timing of community fruiting phenology, and fruit numbers varied greatly between years, possibly impacting resource availability for frugivores in El Triunfo.

ABSTRACTSoil seed banks from four Mexican lower montane forests were studied. These forests are in the transition zone between neartic and Neotropical floristic regions. Soil seed bank characteristics were biased toward the dominant – temperate or tropical – phytogeographical affinity. The northern site (El Cielo Biosphere Reserve, Tamaulipas) had the lowest seed density, 720 seeds m−2. The eastern (Rancho La Mesa, Veracruz), western (Sierra de Manantlán Biosphere Reserve, Jalisco) and southern (El Triunfo Biosphere Reserve, Chiapas) sites all had much higher seed densities (2291, 2901, and 2341 seeds m−2, respectively). Germinated tropical species seeds were more abundant than temperate species seeds at all four sites, and were higher for southern and intermediate sites when compared with the northern site. On the basis of family, El Cielo appears to be different. The tropical family Melastomataceae was absent from this northern site, whereas it represented >30% of total germinated seeds at the other three sites. Trees were the most abundant life form at the southern site but were particularly poorly represented in the eastern and northern sites. Herbs were very abundant in the eastern, western and northern sites but were poorly represented in the seed bank of the southern site. The four seed banks differ between themselves and resemble seed banks of neither temperate deciduous nor tropical forests. In some ways they are unique, at least with respect to floristic composition, seed density, and life form representation.

Anthropogenic activities are increasingly encroaching into wildland areas, heightening interactions between human and carnivore communities. Area-based conservation measures, such as protected areas (PAs), employ different management strategies via land-use designations to mitigate anthropogenic pressures and reduce human-wildlife conflicts in shared landscapes. Here, we assessed carnivore diel activity and temporal activity overlap in and around El Triunfo Biosphere Reserve (REBITRI) in Chiapas, Mexico, along a land-use designation gradient. We deployed 33 camera traps along the gradient, leveraging the reserve’s core and buffer zones, and private lands surrounding the reserve. We calculated activity overlap between species to detect changes in interspecific competition and predator-prey interactions along the gradient. In total, we detected 14 carnivores in the core zones, 10 in the buffer zone, and 9 on private land across the 4777 trap-night survey. Significant shifts in single-species diel activity between the buffer zones and private land were detected for margay (Leopardus wiedii) and grey fox (Urocyon cinereoargenteus). Activity overlap was the highest in the buffer zone for all predator-prey pairs, and two competitor pairs, suggesting reduced diel niche partitioning in this land-use designation due to varied anthropogenic pressures. Our findings contribute to assessing PA efficacy and understanding carnivore activity in multiple-use landscapes where anthropogenic pressures are ubiquitous.

An integrative analysis of threats affecting protected areas in a biodiversity stronghold in Southeast Mexico

The influence of cash and technical assistance on household-level outcomes in payments for hydrological services programs in Chiapas, Mexico

I. Abstract We describe the spatial distribution, population structure, and fecundity of Ceratozamia matudai in two populations in the El Triunfo Biosphere Reserve, in Chiapas, Mexico. Three random plots of 20 × 20 m were laid out in a cypress forest habitat of the cycad and six plots in a cloud forest habitat on Mount Ovando. The aggregated spatial pattern of C. matudai showed a clumped local distribution on shallow soils on steep slopes. Individuals between the sites showed differences in leaf production, trunk diameter, height, and growth pattern. A population structure with an inverse “J” curve was obtained in both sites. Emergence of male and female cones appears to be synchronous in both populations, with a predominance of male cones recorded.

Reproductive biology and vocalizations of the Homed Guan (Oreophasis derbianus) were studied in the El Triunfo Biosphere Reserve in Chiapas, Mexico. The nest and eggs are described here for the first time. The Horned Guan apparently has a polygynous mating system. Males make at least five different kinds of vocalizations. Females produce seven or eight different types of calls, which are guttural compared with those of males. One female took 2.81 (± 0.40) incubation recesses daily during 16 days of observation, and individual recesses averaged 32.9 (± 13.1) min. Incubation sessions averaged 191 min ± 44.6. The incubation period was estimated to be 35-36.5 days. Likely predators of Homed Guan eggs are described. Suggestions for the conservation of this species and its habitat are presented

Background and aims – In the tropics, some studies have found that the richness of epiphytic ferns present a peak at mountain mid-elevations. However, it is not well understood how transitions from tropical to subtropical conditions affect this peak, and even less is known about beta diversity of epiphytic ferns. Thus, the objective is to understand the effect of climatic gradients on the variation of local richness of ferns and beta diversity patterns along an elevational gradient in a mountain system in southern Mexico.Methods – We sampled 32 trees, each in four elevational bands (100–2200 m). Alpha diversity patterns were analysed using linear regression models. We used the Morisita index to quantify species turnover between bands. An additive partitioning approach was used to analyse the degree to which individual trees, plots, and bands contributed to total species richness. We evaluated the influence of climatic variables on species composition via linear regression models.Key results – A total of 30 species in five families were recorded. Each family contributed in different magnitude to the elevational richness pattern, with Polypodiaceae dominating due to its richness and presence along the entire transect. Alpha diversity at the three scales (αtree, αplot, αband) increased with elevation and rainfall, and with decreasing temperature. Species turnover was high along the gradient, but was scale-dependent, with βtransect (65–75%) and βband (14%) with the greatest contributing to total diversity. Although the contribution of the individual trees was lower, it increased with elevation. Conclusions – We emphasize the importance of including different scale levels in analyses of diversity along elevational gradients. In the region, cloud forest on the mountain peaks harbours the highest diversity of epiphytic fern communities. Due to a limited extent of this mountain range, the epiphyte ferns are susceptible to the effects of climate change.

Baird's tapir ( Tapirus bairdii) is one of the most emblematic mammalian species from Mesoamerica. Due to its level of evolutionary distinctiveness and anthropogenic threat this species was recently ranked in 34th position, in terms of its urgency for conservation, among more than 4,000 species of mammals assessed by experts from the Zoological Society of London. Despite its evolutionary and conservation relevance there remain important gaps in knowledge of the basic ecology of this species. Based on camera-trapping data, we estimated Baird's tapir abundance and analyzed its patterns of daily activity and preference for different altitude intervals in El Triunfo Biosphere reserve, one of the last strongholds for this species in southern Mexico. We also applied a recently developed method (Random encounter model) to estimate tapir density without the need of individual identification. Tapir relative abundance was: 1.3 events/100 camera-trap days and density: 0.12 ind./km2. Tapir activity concentrated around dusk (χ2= 21.18, P<0.01) and use of mid-altitude areas was preferred (χ2 = 49, P < 0.001). This study provides data on the ecology of the species and insights on study methods that can have a direct positive impact on its management and conservation.

SummaryThe Azure-rumped Tanager Tangara cabanisi is a threatened species confined to the mountains of the Sierra Madre de Chiapas in Mexico and neighbouring Guatemala. It occurs on the Pacific and Gulf slopes of the mountain range, but most frequently on the former between 1,000 and 1,700 m. The Azure-rumped Tanager's habitat is a medium height (about 30 m tall) humid evergreen broadleaf forest formation containing elements of both mesophilous forest of higher altitudes and tropical forests of the lowlands. Information from field surveys and more general data from vegetation maps was combined using a geographical information system package to extrapolate and predict distribution of potential Azure-rumped Tanager habitat in the Sierra Madre de Chiapas. It is estimated that a maximum of 112,000 ha remain, although the total was probably never greater than 200,000 ha. Fortunately 43,660 ha (39%) of the maximum total is contained within the El Triunfo Biosphere Reserve, a newly decreed protected area that spans both the Pacific and Gulf slopes in the central portion of the mountain range. Most of the suitable habitat is found within the reserve's buffer zone, an area in which there are several small but expanding communities. The effective protection and future status of the species rests heavily on the conservation of this habitat within the reserve and essentially this depends on the collaboration in favour of conservation between the local people and the conservation managers and, ultimately, the development of viable land-use alternatives that are less damaging to the forest ecosystem.

ABSTRACTThe Resplendent Quetzal(Pharomachrus mocinno)is an altitudinal migrant that nests in high elevation cloud forests and migrates toward lower areas during the summer rainy season. It has been suggested that its migratory movements are related to the abundance of ripe Lauraceae fruits. We studied the quetzal diet during two consecutive years, as well as changes in fruit abundance of the plant species on which the bird feeds at El Triunfo Biosphere Reserve, southeastern Mexico. The quetzal was observed feeding on 32 plant species; of these, 24 are new records in its diet. We chose 20 of these 32 species and studied their fruit phenology for two years in order to describe the relationship between fruit and quetzal abundance. Our results showed that quetzal abundance in the breeding area was correlated with the total number of fruiting species, whereas the correlation between quetzal abundance and the number of fruiting Lauraceae species was only marginal. Additionally, a correlation test showed that quetzal abundance was marginally correlated with total fruit availability (total no. of fruits per month); however, the correlation between quetzal abundance and the number of fruits in the Lauraceae was not significant. Our results suggest that the dynamics of food resources may be playing a major role in the quetzal's migratory behavior. Knowing the bird's diet may aid in characterizing the type of habitat adequate for its conservation. Our observations in this respect suggest that conservation efforts to preserve this bird species should concentrate on the protection of its habitat, including both breeding and nonbreeding (migration) locations.