First record of leucism in Mantled Howler Monkeys Alouatta palliata (Gray 1849)

The existence of chromatic aberrations such as leucism or albinism is the result of inbreeding in isolated populations of wild local fauna and is associated with environmental stressors. This anomaly may reduce survival rates. There are many cases of leucism in wildlife, but overall, it is considered very rare. In neotropical primates, there have been records of leucism but previously, in howler monkeys was unknown. In this article, we report for the first time leucistic young individuals of Mantled howler monkeys Alouatta palliata, subspecies A. p. aequatorialis in an isolated remanent of tropical dry forest in southwestern Ecuador, namely Cerro Blanco Protective Forest. In total, we found two individuals, we named them Albita (a female) and Japu (a male). We also include a spatial analysis of the covert forest loss between 2000 to 2020. The report of individuals with leucism, may imply inbreeding because of isolated populations. Thus, immediate management strategies must be considered to significantly increase connectivity with other populations of howler monkeys.

Co-structure analysis and genetic associations reveal insights into pinworms (Trypanoxyuris) and primates (Alouatta palliata) microevolutionary dynamics

Background In parasitism arm race processes and red queen dynamics between host and parasites reciprocally mold many aspects of their genetics and evolution. We performed a parallel assessment of population genetics and demography of two species of pinworms with different degrees of host specificity (Trypanoxyuris multilabiatus, species-specific; and T. minutus, genus-specific) and their host, the mantled howler monkey (Alouatta palliata), based on mitochondrial DNA sequences and microsatellite loci (these only for the host). Given that pinworms and primates have a close co-evolutionary history, covariation in several genetic aspects of their populations is expected. Results Mitochondrial DNA revealed two genetic clusters (West and East) in both pinworm species and howler monkeys, although population structure and genetic differentiation were stronger in the host, while genetic diversity was higher in pinworms than howler populations. Co-divergence tests showed no congruence between host and parasite phylogenies; nonetheless, a significant correlation was found between both pinworms and A. palliata genetic pairwise distances suggesting that the parasites’ gene flow is mediated by the host dispersal. Moreover, the parasite most infective and the host most susceptible haplotypes were also the most frequent, whereas the less divergent haplotypes tended to be either more infective (for pinworms) or more susceptible (for howlers). Finally, a positive correlation was found between pairwise p-distance of host haplotypes and that of their associated pinworm haplotypes. Conclusion The genetic configuration of pinworm populations appears to be molded by their own demography and life history traits in conjunction with the biology and evolutionary history of their hosts, including host genetic variation, social interactions, dispersal and biogeography. Similarity in patterns of genetic structure, differentiation and diversity is higher between howler monkeys and T. multilabiatus in comparison with T. minutus, highlighting the role of host-specificity in coevolving processes. Trypanoxyuris minutus exhibits genetic specificity towards the most frequent host haplotype as well as geographic specificity. Results suggest signals of potential local adaptation in pinworms and further support the notion of correlated evolution between pinworms and their primate hosts.

The Primate Cultural Significance Index: applications with Popoluca Indigenous people at Los Tuxtlas Biosphere Reserve

Background The study of the cultural significance (CS) of biodiversity provides key information to develop conservation strategies consistent with traditions and perceptions of human communities. In Los Tuxtlas Biosphere Reserve (TBR) in Mexico, the mantled howler monkeys (Alouatta palliata mexicana) and the black-handed spider monkeys (Ateles geoffroyi vellerosus) have historically coexisted with Popoluca Indigenous Peoples. This study sought to determine how the presence of a natural protected area (TBR location) and a range of sociodemographic factors (gender, age, origin, language proficiency, education level, religion) relate to the CS held by the Popoluca Indigenous People in relation to these two endangered primate species. Methods The first Primate Cultural Significance Index (PCSI) was designed as a composed index of 11 cultural variables (sub-indices) and was applied randomly to a representative size sample of people over 15 years old in two Popolucas communities, one within the TBR (Piedra Labrada = 81 people) and another outside (Los Mangos = 91). U Mann–Whitney tests were used to compare the PCSI between communities and Generalized Linear Models (GLM) to evaluate the sociodemographic factors of participants that influenced the sub-indices in the PCSI. Results The cultural significance of spider monkeys held by the Popolucas was higher for the community within the TBR than for the community outside, while for howler monkeys it was higher outside. For both primate species across the two communities, the most relevant sub-indices were (1) interest in conservation and (2) touristic significance of primates. Sociodemographic factors of participants influenced nine sub-indices of cultural significance out of the possible 10 sub-indices applied for each primate species. The demographic factors that most influenced each sub-index for both species were location and gender. Conclusions The main differences found between communities may be linked to the conservation and sustainable development programs promoted by the reserve, as well as the greater persistence of Popolucan ancestral traditions within the boundaries of the reserve. We recommend that conservation efforts should focus on people less interested about primate conservation (women, non-natives and residents outside the reserve), and turn to the leadership of people more interested (native men who reside inside the reserve).

Social correlates of variation in urinary oxytocin concentrations of mantled howler monkeys Alouatta palliata (Gray, 1849) (Primates: Atelidae): A preliminary assessment

There is growing evidence that non-human primate sociality is linked to proximate neuroendocrine mechanisms. Arginine vasopressin, endorphins, and oxytocin may be involved in such mechanisms. Here, we perform a preliminary analysis of the social correlates of variation in urinary oxytocin concentrations in mantled howler monkeys (Alouatta palliata). From January to December 2017, we studied 13 adult mantled howler monkeys belonging to two groups. We recorded the occurrence of social interactions (547.5 observation hours); assessed proximity among group members (2,194 instantaneous recordings); and collected 172 urine samples. Urine samples were assayed (ELISA) for oxytocin concentrations, which were corrected for specific gravity, resulting in 54 analyzed samples. Hormone concentrations increased by approximately 62% when individuals were involved in affiliative interactions. With respect to when no affiliative interactions occurred, urinary oxytocin concentrations were higher when dyads with a low-quality social relationship affiliated. These results agree with previous contentions that this hormone is linked to participation in affiliative interactions. Convergence between these and results from other taxa supports the hypothesis that the biological mechanisms that allow for primate sociality are shared among species.

Amenazas que enfrentan los monos congo (Alouata palliata) en Costa Rica e iniciativas de conservación para el bienestar y una coexistencia sana con la especie

El mono congo (Alouatta palliata) es una de las cuatro especies de primates de Costa Rica cuyo estatus de conservación la ubica como especie en peligro de extinción. La principal amenaza que enfrentan los monos congo es la pérdida del hábitat y la fragmentación del bosque situación que expone a sus poblaciones a problemas relacionados con el aislamiento, la pérdida de conectividad en el paisaje y un ambiente modificado por infraestructuras de origen antropogénico. Se expone la relevancia de atender la problemática que experimentan los monos congo en pro de su bienestar mediante el trabajo interinstitucional coordinado, la aplicación de la robusta legislación costarricense y el conocimiento ecológico existente de la especie.

A preliminary assessment of allostatic load in male mantled howler monkeys

Allostatic load refers to the wear and tear of the organism associated with the repeated activation of mechanisms that allow for homeostasis. Although allostasis (i.e., maintaining stability through change) is achieved through the orchestration of multiple systems, assessments of allostatic load in wildlife have usually relied on the measurement of single or few physiological mediators. In the present study, we aimed at constructing an allostatic load index (ALI) for male mantled howler monkeys (Alouatta palliata) based on seven physiological mediators (C-peptide, triiodothyronine, glucocorticoids, testosterone, amount of activity, foraging effort, and participation in agonistic interactions). We then examined if variation in this ALI was associated with social, ecological, and abiotic challenges. For five years, we studied ten adult males belonging to two groups. We assessed physiological mediators via behavioral observations (3,364 hours of samplings), and both urine (1,500 assayed samples) and fecal (1,500 assayed samples) sampling. We calculated an ALI based on mediator specific risk scores. Seasonality, encounters with extragroup males, mating, and centrality were positively related with male allostatic load, though only the first two had significant effects on ALI. ALI reflected the physiological and behavioral responses of males to social, ecological, and abiotic challenges. It remains for future research to determine if the observed trends correspond to normal fluctuations in mechanisms that allow male mantled howler monkeys to cope with their environment.

Abnormal pelage color in mantled howler monkey (Alouatta palliata mexicana) in Veracruz, México

El leucismo es una despigmentación total o parcial del pelaje, mientras que el albinismo es la pérdida total de pigmentos en el cuerpo entero; las condiciones anormales de la carencia del pigmento se deben a la expresión de genes recesivos. Se realizó una expedición ad libitum en el Ejido Álvaro Obregón, al suroeste de Nuevo Cantón, municipio de Uxpanapa, Veracruz en diciembre de 2019. Presentamos el primer registro de un individuo de mono aullador de manto (Alouatta palliata mexicana) con coloración no convencional (probablemente leucismo o albinismo), observado en una tropa silvestre en la región del Valle de Uxpanapa, Veracruz, México. La coloración de la mucosa oral y palpebral no muestran pigmentación y pueden ser resultado de la expresión de genes recesivos en el individuo, por lo que realizar estudios más profundos sobre la expresión de genes recesivos ampliaría la comprensión del fenómeno.