"Relationship between carbon stocks and structural diversity in humid and subhumid tropical forest of Mexico "

"Two structural-diversity and two biodiversity indexes and carbon stocks were determined at eight humid and sub-humid tropical forest sites between 20-120 yrs-old in southeastern Mexico. The dbh of all trees > 10 cm was measured and species were identified in 131 randomly located plots of different sizes. Results for the number of species (S), Shannon (H'), biomass-species (BS) and abundance-biomass-species (ABS) indexes were related to Mg C ha-1 and the age of the sites. Values found were: S, 27-109; H', 3.9-5.31; BS, 7.39-16.0; ABS, 9.87-18.2; Mg C ha-1, 39.7-130.7. The relationships between BS and ABS to C and the age of the sites were linear and positive, showing that stand structure directly influenced carbon storage. The relationship between site age and C was remarkably high (R2 = 0.79). Humid forests showed higher values of C than the sub-humid forests (104.4 vs. 70.6, t=2.07, P=0.04) but their structural diversity was similar (BS, 11.25 vs. 8.3, P = 0.134; ABS, 13.9 vs. 10.6, P = 0.135). It is concluded that forestry management (of tree diameter) may be a factor that can favor more carbon storage in secondary forest regrowth as it starts to reach maturity.

Jaguar (Panthera onca) and puma (Puma concolor) diets in Quintana Roo, Mexico

A study was carried out for two years in Northwest Quintana Roo, México, using scat analysis to determine the diet and prey preferences of pumas and jaguars. Cat species and gender were determined using molecular techniques (rapid classificatory protocol: polymerise chain reaction, RCP–PCR), and prey abundance was estimated from camera trapping. The scats contained remains from 16 wild mammal species, but there was no evidence of livestock or other taxa. The diet breadths of jaguar (0.32) and puma (0.29) indicated a high degree of prey specialization, which combined with their dietary overlap (Pianka index 0.77) suggested competition between them. However, both felids showed a preference for red brocket deer Mazama temama, and frequently consumed collared peccaries Pecari tajacu. The importance of such large ungulates in the felids' diets is similar to the expected patterns of wild meat consumption in rural areas of the Northern Yucatan Peninsula. Therefore, future conservation management plan initiatives should involve local rural communities in the management of sustainable hunting, considering these ungulates are also the felid prey species. Resumen La dieta del jaguar (Panthera onca) y del puma (Puma concolor) en Quintana Roo, en México. El estudio se realizó durante dos años en el noroeste de Quintana Roo, en México y se utilizó el análisis de excrementos para determinar la dieta y las preferencias de presas del puma y del jaguar. Se utilizaron técnicas moleculares para identificar la especie de félido y el sexo (protocolo de clasificación rápida: reacción en cadena de la polimerasa, RCP–PCR), y se estimó la abundancia de presas mediante el método de trampeo fotográfico. Los excrementos contenían restos de 16 especies de mamíferos salvajes, pero no se encontraron restos de ganado ni de otros taxones. La amplitud de la dieta del jaguar (0,32) y del puma (0,29) indica que son especies con un alto grado de especialización, lo cual, junto con el traslape de las dietas (índice de Pianka = 0,77) sugiere que ambos félidos compiten entre sí. Asimismo, ambos mostraron preferencia por el venado temazate, Mazama temama, y frecuentemente consumieron pecarí de collar, Pecari tajacu. La importancia de la presencia de este tipo de ungulados en la dieta de los félidos se corresponde con la pauta esperada de consumo de carne de caza en las zonas rurales del norte de la península de Yucatán. Por lo tanto, las futuras iniciativas encaminadas a planificar la conservación de ambos félidos deberían hacer partícipes a las comunidades rurales en la gestión de la cacería sustentable, considerando que estos ungulados también son presas de los félidos

Coexistence of jaguars (Panthera onca) and pumas (Puma concolor) in a tropical forest in south–eastern Mexico

The biological ranges of the jaguar (Panthera onca) and puma (Puma concolor) overlap in the Yucatan Peninsula, corresponding to the most important population of jaguars in Mexico. The goal of this study in the El Eden Ecological Reserve (EER) was to investigate the factors that permit these two predators to coexist in the dense vegetation of medium–stature tropical forest and secondary forest in the north–eastern Yucatan Peninsula. We assessed their spatial and temporal overlap using Pianka’s index, and evaluated their habitat use by applying occupancy models. A total sampling effort of 7,159 trap–nights over 4 years produced 142 independent photographic records of jaguars, and 134 of pumas. The felids showed high to very high overlap in their use of different vegetation (0.68–0.99) and trail types (0.63–0.97) and in their activity patterns (0.81–0.90). However, their peak activity patterns showed some temporal separation. Time of day, particularly for peak activity time, was the best predictor to explain the coexistence of the felids in this habitat. While occupancy models showed that the presence of potential prey species and vegetation type could predict the presence of felids in the study area. Natural disturbances during 2010 (hurricane) and 2011 (fire) drastically changed habitat use and activity patterns, resulting in pumas and jaguars adjusting their resource–use and activity pattern through a strategy of mutual evasion

An Evaluation of the Contemporary Uses and Cultural Significance of Mammals in Mexico

We evaluated current uses of wild mammals by indigenous and mestizo communities in Mexico by extracting data from 59 sources published or produced between 1987–2017, covering data from 240 localities and 3,905 questionnaires. We then calculated a Cultural Value Index (CVI) previously applied to plants to quantify resource use and assess the cultural significance of each mammal. A total of 82 species were reported, and the animals with the highest cultural importance according to their CVI (in brackets) were two species of deer (Odocoileus virginianus [18.32] and Mazama temama [10.04]), as well as the nine-banded armadillo (Dasypus novemcinctus [14.18]), white-nosed coati (Nasua narica [14.75]), collared peccary (Pecari tajaccu [11.90]), northern raccoon (Procyon lotor [11.28]) and spotted paca (Cuniculus paca [9.84]). The most common uses were for food, to reduce the damage or harm they cause, and for medicinal purposes, with O. virginianus, P. lotor, N. narica, and D. novemcinctus frequently hunted for all these reasons. Our analysis also highlighted the hunting of rarer species of national conservation concern, including commercial trading of body parts of the felids Panthera onca, Leopardus pardalis, and Leopardus wiedii. By quantifying the ethnozoological significance of wildlife to indigenous communities, indices such as CVI provide a robust measure of the extent of use and preference for particular species or taxa. This adds to the body of evidence used to develop effective regulations and laws related to harvesting and hunting, and helps promote a more sustainable and long-term approach to the use of natural resources

A Quantitative Method for Evaluating Contemporary Cultural Uses of Birds – A case study from Mexico

This study evaluates the relationship between people and birds in Mexico, a country where high cultural and biological diversity are reflected in the close associations between people and natural resources, recorded since pre-Hispanic times. It systematically reviews 1041 records of cultural use of wild birds in Mexico published between 1996 – 2017, and analyzes patterns of contemporary use of avifauna. It classifies information for 252 birds by grouping uses of species and families into 11 categories and quantifies overall use with a Cultural Value Index (CVI). The data show that birds have a high cultural value as food, pets, and for medicinal uses (312, 235, and 119 records, respectively), particularly in the state of Chiapas. Large edible birds had the highest CVIs and included Plain chachalacas (Ortalis vetula; 9.72), Black-bellied whistling-ducks (Dendrocygna autumnali; 6.65), Crested guams (Penelope purpurascens; 6.25), and Great currasows (Crax rubra; 6.23), with the Cracidae family recorded as favored gamebirds. Conspicuous, brightly-colored birds had high CVIs, including Keel-billed toucans (Ramphastos sulfuratus; 6.50), Red-lored amazons, (Amazona autumnalis; 6.03), and allied species, which were traded or kept as pets despite legal protection. The high CVIs of Barn owls (Tyto alba; 5.45) were related to medicinal uses, and Mourning doves (Zenaida macroura; 5.69) were mainly used as gamebirds. Wild bird populations face increasing pressure from habitat loss and overexploitation. We propose that evaluating the ethnological significance of wildlife with indices like CVIs can quantify the distinctive needs of rural communities, which when combined with information on conservation status can develop more sustainable species management plan

Habitat use of jaguar (Panthera onca) in a tropical forest in northern Quintana Roo, Mexico

The study was carried out in a median stature tropical forest in the north of Quintana Roo during 2008, 2010-2012, using camera traps to record activity and habitat use by jaguar and other vertebrates. Spatial and temporal variations in habitat use, activity patterns, and species associations were analyzed using a chi-squared test (x2). Generalized linear models (GLM) were used to determine which variables influenced the presence of jaguars in the study area. Jaguars were most frequently recorded in acahual (80%) and on roads (66.9%). There were significant differences between years, with selection for particular habitat and trail types in 2008 and 2011 (all χ2 p <0.001). Jaguars were mainly crepuscular-nocturnal (68.5% records). They showed spatial associations with Meleagris ocellata, Dasypus novemncinctus, Mazama temama, Nasua narica, Odocoileus virginianus, Leopardus pardalis, Didelphis spp., and Pecari tajacu. Generalized linear models based on prey, co-predators, and human activity gave the best fit with jaguar occurrence. The felids responded to environmental changes (hurricanes and fires) by modifying their spatial and temporal use of resources

The influence of the lunar cycle on ground-dwelling invertebrates in an Arabian desert

Ground-dwelling, desert invertebrates were sampled using pitfall traps during six consecutive full and new moons to test the hypothesis that the lunar cycle influences catches. Invertebrates were placed in four functional groups: predaceous arthropods, social insects, detritivores, and herbivores. There were significant differences in the abundance and number of taxa of predaceous arthropods between full and new moons. The catch of total arthropods and detritivores was higher on stable gravel substrates than on mobile sand substrates. Fewer predaceous arthropods were active during full moons than new moons, possibly because of the increased risk of vertebrate predation. Substrate was more likely to influence diversity and abundance of non-predaceous invertebrates than moon phase. Both factors must be taken into account when designing sampling regimes for biodiversity assessment in deserts. <br/