El Triunfo Biosphere Reserve Research Articles

Influence of human emotions on conservation attitudes toward relevant wildlife species in El Triunfo Biosphere Reserve, Mexico

Influence of human emotions on conservation attitudes toward relevant wildlife species in El Triunfo Biosphere Reserve, Mexico

Revisiting the phenology of El Triunfo cloud forest, Mexico, 30 years later

Abstract 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.

Feelings, conflicts, and use: wildlife-human interactions in El Triunfo Biosphere Reserve, Mexico

ABSTRACT 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.

Predation of oak acorns by Baird's tapir in one of the last remnants of mountain cloud forest in Southern Mexico

The consumption of fruits and seeds by mammals can have a strong impact on the regeneration of tropical forests. Our knowledge of this biotic interaction has steadily increased recently but it remains fragmentary. This is largely due to most of the studies focusing on a small proportion of the diverse mammals and plants involved in these interactions and to the fact most commonly used methods provide just partial information about the whole seed dispersal/predation process. The use of camera traps has opened the opportunity to greatly improve our knowledge of the intricacies of frugivory and seed predation by increasing the likelihood to record very secretive animal species and providing detailed accounts of their behavior. Based on camera trap data we report acorn consumption of Quercus benthamii and Q. sapotifolia by the threatened Baird's tapir (Tapirus bairdii). This study was conducted in the largest remnant of Mountain cloud forest in Mexico, located in El Triunfo Biosphere Reserve (ETBR) in the state of Chiapas. Despite the fact that ten mammal species were recorded in the focal trees, only two of them (T. bairdii and Sciurus deppei) were documented exhibiting acorn consumption. We obtained 82 videos showing the consumption of Q. benthamii acorns by tapirs (sampling effort = 133 camera trap days, n = 8 trees) with an average of 6.04 ± 3.56 (± sd) minutes spent on this activity. In comparison, we only obtained one video of a tapir consuming Q. sapotifolia acorns (sampling effort = 264 camera trap days, n = 5 trees) during 35 s. Consumption of these Quercus species by tapir was not previously reported. Moreover, our study is the first (to our knowledge) to show video-recorded evidence of the interaction between tapirs and Quercus trees. Due to tapirs' large body size, the consumption of acorns might be an important source of mortality for some Quercus species (e.g., Q. benthamii).

A new species of small-eared shrew (Soricidae, Cryptotis) from El Triunfo Biosphere Reserve, Chiapas, Mexico

Abstract 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.

Consumption of arthropods by hummingbirds in the Sierra Madre de Chiapas, Mexico

An organism's morphological features can determine the type of prey they consume due to adaptive advantages in capturing them, for example, the shape and length of the bill in birds. Hummingbirds have been considered specialists in nectar consumption. However, they have been documented to also be important insectivores in ecosystems. In this study, we evaluated arthropod consumption by hummingbirds in relation to their bill and capture strategies. We theorized that hummingbirds with short-medium bills (9-11 bill length to body mass cube root ratio) capture a higher proportion of non-flying arthropods, as they have a lower linear speed of closure of the bill tip relative to the base, while species with long bills (13-14) capture mainly flying arthropods. The study was conducted in El Triunfo Biosphere Reserve, Chiapas, southeastern Mexico from 2015 to 2016, where seven hummingbird species that captured arthropods, their strategies of capture, and the type of prey consumed were recorded. We also analyzed the stomach contents (n = 72 stomachs) collected in the Sierra Madre de Chiapas. We calculated the frequency of occurrence of arthropods and their diversity, as well as the breadth of the feeding niche and the bill-prey relationship of 15 hummingbird species. The Green-throated Mountain-gem ( Lampornis viridipallens) and Rivoli's Hummingbird ( Eugenes fulgens) presented the highest richness of arthropod consumption. Arthropod prey belonged to eight orders, where Hymenoptera and Diptera were the most frequent. The most recorded capture strategies were on the substrate in sustained flight (37.5%) and hovering in sustained flight (33.3%). A positive association was found between the type of arthropods consumed and the morphological traits of the hummingbirds, non-flying arthropods were captured by hummingbirds with short-medium bills, while hummingbirds with long bills captured flying arthropods. Morphological adaptations for food resource use are a trait that determines food selection, capture, and handling success.

A new species of Lachesilla (Psocodea: Psocomorpha: Lachesillidae) in the L. texcocana species group, from El Triunfo Biosphere Reserve, Chiapas, Mexico

A species of Lachesilla, in the L. texcocana species group, endemic to El Triunfo Biosphere Reserve, Chiapas, Mexico, is described and illustrated. Based on female characters (male is unknown), it is close to L. gamma García-Aldrete, from which it differs in the shape and size of the underlying pigmented area of the subgenital plate. It is the third species of the L. texcocana species group recorded in the state of Chiapas.

COI mtDNA barcoding and morphology for the description of a new species of ricinuleid of the genus Pseudocellus (Arachnida: Ricinulei: Ricinoididae) from El Triunfo Biosphere Reserve, Chiapas, Mexico

A new species of epigean ricinuleid of the genus Pseudocellus Platnick, 1980 from El Triunfo Biosphere Reserve, Chiapas, Mexico is described. DNA barcoding utilizing mitochondrial cytochrome c oxidase subunit 1 (CO1) and morphology were used for species delimitation. Molecular analyses and species delimitation included four methods: 1) General Mixed Yule Coalescent model (GMYC), 2) Automatic Barcode Gap Discovery (ABGD), 3) Bayesian Poisson Tree Process (bPTP), and 4) Assemble Species by Automatic Partitioning (ASAP). All molecular methods and morphology were consistent in delimiting and recognizing the new species described herein. The average interspecific genetic distance (p-distance) among analyzed species of Pseudocellus was 11.6%. The species is described based on adult males and females: Pseudocellus giribeti sp. nov. This is the seventh species described from Chiapas, which holds the highest number of ricinuleids species for the country. The total number of described species of Pseudocellus from Mexico increases to 21, having the highest species diversity of known ricinuleids worldwide.

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

Protected areas (PAs) are one of the main strategies to preserve tropical biodiversity. However, their viability is compromised by the impacts of a variety of threats. To gain a more integrated view of how different threats affect them, individually and in combination, we analyzed the spatial distribution of forest loss (2010–2015), human density, incidence of fires, and mining activities in four PAs (Cordón Pico Loro-Paxtal: CPL, El Triunfo Biosphere Reserve: ETBR, La Sepultura Biosphere Reserve: SEBR and La Frailescana: LF) located in the biodiversity stronghold of the Sierra Madre de Chiapas (SMC), Mexico. We integrated these threats in a Human Pressure Index (HPI, ranging from 0 to 1, where 1 is the highest human pressure). We found that the SEBR and LF were affected mainly by forest loss (13.43% and 11.67% forest area lost, respectively) and fire incidence (between 0.02-0.73 and 0–0.81 fire hotspots/km2, respectively). On the other hand, the ETBR and CPL had lower forest loss and fire incidence but higher mining presence (16.2% and 84.8% of their area involving this activity, respectively), and population density (on average 0.6 and 8.6 inhabitants/km2, respectively). The highest HPI values (>0.6) occurred in the northern and the southern extremes of the study area encompassing 42.6%, 54.5% and 54.1% of the extent of the SEBR, LF, and CPL, respectively, putting in high risk important areas to maintain landscape connectivity. Despite occurring in the same region (SMC) focal PAs are affected differently by the assessed threats. A nonintegrated analysis of threats affecting PAs in biodiversity strongholds such as the SMC risks producing a biased view of their intensity, reducing the possibility to planning more effective conservation strategies.

Diversity of epiphyte ferns along an elevational gradient in El Triunfo Biosphere Reserve, southern Mexico – Erratum

Diversity of epiphyte ferns along an elevational gradient in El Triunfo Biosphere Reserve, southern Mexico – Erratum

Diversity of epiphyte ferns along an elevational gradient in El Triunfo Biosphere Reserve, southern Mexico

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.

Spiders (Arachnida: Araneae) of the tropical mountain cloud forest from 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.

Bayesian nonparametric inference for the overlap of daily animal activity patterns

The study of the interaction among species is an active area of research in Ecology. In particular, it is of interest to evaluate the overlap of their ecological niches. Temporal activity is one of the niche’s axes most commonly used to explore ecological segregation among animal species, and many contributions focus on the overlap of this variable. Once the information of the temporal activity is obtained in the wild, the data is treated as a random sample. There exist different methods to estimate the overlap. Specifically, in the case of two species, one possibility is to estimate the density of the temporal activity of each species and then evaluate the overlap between these density functions. This leads naturally to the analysis of circular data. Most of the procedures currently in use impose some rather restrictive assumptions on the probabilistic models used to describe the phenomena, and only provide approximate measures of the uncertainty involved in the process. In this article, we propose a Bayesian nonparametric approach which incorporates a well-defined noninformative prior. We take advantage of the data structure to define such a prior in terms of the predictive distribution. To the best of our knowledge, this is a novel approach. Our procedure is compared with a well-known method using simulated data, and applied to the analysis of real camera-trap data concerning two mammalian species from the El Triunfo biosphere reserve (Chiapas, Mexico).

Pollination syndromes and interaction networks in hummingbird assemblages in El Triunfo Biosphere Reserve, Chiapas, Mexico

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.

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

This paper examines whether and how payments for hydrological services (PHS) programs implemented on communal lands in Mexico result in household-level conservation and human wellbeing outcomes. We first use evaluation methods to establish the impact of PHS by comparing outcomes across seven communities enrolled, and one community not enrolled, in PHS. Second, we exploit variations in PHS program design across the enrolled communities to test the role of cash and technical assistance on outcomes. Data come from a 2016 cross-sectional survey of 261 households around El Triunfo Biosphere Reserve, in Chiapas, Mexico. We find that households enrolled in PHS implement more conservation actions and that some own more assets than similar households not enrolled in PHS. We find that asset ownership is positively correlated with a household’s payment amount and that conservation practices are related to amount of assistance received. We also measure perceived equity and benefits for households enrolled in PHS and find that perceptions are correlated with both payment and assistance, and strongly influenced by community organization. Our results provide evidence that common-property PHS contracts can change household-level conservation and human wellbeing outcomes, but that these changes are dependent on the type of external motivator and community organization.

Diet and Feeding Behavior of the Horned Guan (Oreophasis derbianus) In Mexico

ABSTRACT.— The Horned Guan (Oreophasis derbianus) is endemic to humid montane forests of southern Mexico and Guatemala. This species is considered endangered because of their small populations, the loss and fragmentation of habitat, illegal trade, and overexploitation by subsistence hunters. We update information about the species' diet and foraging behavior by integrating the results generated during two and a half decades of research on the Horned Guan's ecology at the El Triunfo Biosphere Reserve, in Chiapas, Mexico, with additional published information compiled from other areas. Based on nearly 450 hrs of direct observations of free-ranging guans and 530 discrete feeding events, we found that during the breeding season Horned Guans feed primarily on fruits from six species of plants and leaves from one species. Horned Guans were not observed eating animal matter, corroborating its specialized frugivore-folivore habits. Our study increases the known plant taxa found in the Horned Guan's diet in El Tri...

Protocolo estandarizado para el seguimiento poblacional del pavón, Oreophasis derbianus: propuesta de métodos de campo y analíticos

La estimación robusta del tamaño poblacional de especies de fauna silvestre es un requisito fundamental en estudios ecológicos y en el diseño e implementación de estrategias de conservación. Sin embargo, en varios casos, estas estimaciones carecen de exactitud, precisión, representatividad y comparabilidad. Esto ha ocasionado que la información generada para las poblaciones de una determinada especie sea difícilmente generalizable y que su aplicación sea limitada. Éste es el caso del pavón, Oreophasis derbianus, un ave endémica de Mesoamérica y en peligro de extinción. En este trabajo presentamos una propuesta de protocolo de muestreo en campo y métodos analíticos estandarizados para el estudio poblacional de esta especie. La propuesta está basada en nuestra experiencia en el estudio de la especie y en la aplicación de la teoría del muestreo de distancias. El propósito de este protocolo estandarizado es generar datos de campo de calidad para obtener estimaciones robustas de la abundancia poblacional de O. derbianus. Este protocolo lo desarrollamos y evaluamos principalmente en la Reserva de la Biosfera El Triunfo, en Chia­pas, México, pero también fue replicado en otras tres localidades en México y Guatemala. Su desarrollo y evaluación incluyó muestreos mensuales en campo durante casi diez años y la impartición de talleres de capacitación teórico-prácticos a personal de campo para la adecuada implementación de este protocolo. Como resultado de esta experiencia, definimos una serie de li­neamientos básicos y factibles que proponemos sea un estándar como métodos de muestreo y analíticos de las poblaciones de O. derbianus para asegurar la calidad y comparabilidad de los datos generados en campo. Finalmente, presentamos estimaciones de la densidad poblacional de O. derbianus en las cuatro localidades estudiadas y discutimos el significado de su variación espacial y temporal en el contexto de esta propuesta.

Potential Links Between Certified Organic Coffee and Deforestation in a Protected Area in Chiapas, Mexico

This study considers organic coffee certification and deforestation in the El Triunfo Biosphere Reserve of Chiapas, Mexico. Land reform, dating back to the revolution, has created a complex context for measuring land use change. The locally improved price of organic production, maintained yield, and plantation growth rate—twice that of conventional producers—raise questions about potential deforestation. While consumers believe organic does not deforest, no measurements are taken during inspection. As communal land privatizes without an established baseline for land use change, improved organic certification inspections are needed to verify good practices and advance forest conservation in the coffee sector.

Density, Abundance and Activity Patterns of the EndangeredTapirus Bairdiiin One of its Last Strongholds in Southern Mexico

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.

Listado de plantas endémicas y en riesgo de la reserva de la biosfera El Triunfo, Chiapas, Méxic

Se presenta una revisión de las especies de plantas vasculares y no vasculares endémicas y en riesgo de la Reserva de la Biosfera El Triunfo. A partir de un listado del inventario florístico que incluye 2,990 especies y 12,835 registros de herbario, se revisó la inclusión de especies en la Norma Oficial Mexicana (NOM-059-SEMARNAT-2010) y la Lista Roja de la Unión Internacional para la Conservación de la Naturaleza y se determinó su nivel de endemismo de acuerdo con su distribución geográfica. Se obtuvo un listado con 347 especies endémicas, de los cuales: 5.9% son endémicas a la reserva, 23.9% a Chiapas y 27.6% a Chiapas y Guatemala. De las 244 especies listadas en alguna categoría de riesgo, la norma oficial Mexicana refiere: 28 sujetas a protección, 36 amenazadas y 11 en peligro de extinción. La Lista Roja de la Unión Internacional para la Conservación de la Naturaleza reconoce: 29 especies casi amenazadas, 74 vulnerables, 63 en peligro y 16 en peligro crítico. El número de especies endémica y en riesgo representan 17% de la flora de la reserva y 4.2% de la flora de Chiapas. El bosque mesófilo de montaña fue el ecosistema con mayor número de especies en riesgo y endémicas. La Reserva de la Biosfera El Triunfo tiene una gran biodiversidad y protege un importante número de especies endémicas y en riesgo.