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1.
Am J Biol Anthropol ; 183(1): 60-78, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37607125

RESUMO

OBJECTIVES: The investigation of morphological variation in animals is widely used in taxonomy, ecology, and evolution. Using large datasets for meta-analyses has dramatically increased, raising concerns about dataset compatibilities and biases introduced by contributions of multiple researchers. MATERIALS AND METHODS: We compiled morphological data on 13 variables for 3073 individual mouse lemurs (Cheirogaleidae, Microcebus spp.) from 25 taxa and 153 different sampling locations, measured by 48 different researchers. We introduced and applied a filtering pipeline and quantified improvements in data quality (Shapiro-Francia statistic, skewness, and excess kurtosis). The filtered dataset was then used to test for genus-wide sexual size dimorphism and the applicability of Rensch's, Allen's, and Bergmann's rules. RESULTS: Our pipeline reduced inter-observer bias (i.e., increased normality of data distributions). Inter-observer reliability of measurements was notably variable, highlighting the need to reduce data collection biases. Although subtle, we found a consistent pattern of sexual size dimorphism across Microcebus, with females being the larger (but not heavier) sex. Sexual size dimorphism was isometric, providing no support for Rensch's rule. Variations in tail length but not in ear size were consistent with the predictions of Allen's rule. Body mass and length followed a pattern contrary to predictions of Bergmann's rule. DISCUSSION: We highlighted the usefulness of large multi-researcher datasets for testing ecological hypotheses after correcting for inter-observer biases. Using genus-wide tests, we outlined generalizable patterns of morphological variability across all mouse lemurs. This new methodological toolkit aims to facilitate future large-scale morphological comparisons for a wide range of taxa and applications.


Assuntos
Cheirogaleidae , Animais , Feminino , Humanos , Tamanho Corporal , Variações Dependentes do Observador , Confiabilidade dos Dados , Reprodutibilidade dos Testes
2.
Front Physiol ; 14: 1251042, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37745231

RESUMO

Feast-fast cycles allow animals to live in seasonal environments by promoting fat storage when food is plentiful and lipolysis when food is scarce. Fat-storing hibernators have mastered this cycle over a circannual schedule, by undergoing extreme fattening to stockpile fuel for the ensuing hibernation season. Insulin is intrinsic to carbohydrate and lipid metabolism and is central to regulating feast-fast cycles in mammalian hibernators. Here, we examine glucose and insulin dynamics across the feast-fast cycle in fat-tailed dwarf lemurs, the only obligate hibernator among primates. Unlike cold-adapted hibernators, dwarf lemurs inhabit tropical forests in Madagascar and hibernate under various temperature conditions. Using the captive colony at the Duke Lemur Center, we determined fasting glucose and insulin, and glucose tolerance, in dwarf lemurs across seasons. During the lean season, we maintained dwarf lemurs under stable warm, stable cold, or fluctuating ambient temperatures that variably included food provisioning or deprivation. Overall, we find that dwarf lemurs can show signatures of reversible, lean-season insulin resistance. During the fattening season prior to hibernation, dwarf lemurs had low glucose, insulin, and HOMA-IR despite consuming high-sugar diets. In the active season after hibernation, glucose, insulin, HOMA-IR, and glucose tolerance all increased, highlighting the metabolic processes at play during periods of weight gain versus weight loss. During the lean season, glucose remained low, but insulin and HOMA-IR increased, particularly in animals kept under warm conditions with daily food. Moreover, these lemurs had the greatest glucose intolerance in our study and had average HOMA-IR values consistent with insulin resistance (5.49), while those without food under cold (1.95) or fluctuating (1.17) temperatures did not. Remarkably low insulin in dwarf lemurs under fluctuating temperatures raises new questions about lipid metabolism when animals can passively warm and cool rather than undergo sporadic arousals. Our results underscore that seasonal changes in insulin and glucose tolerance are likely hallmarks of hibernating mammals. Because dwarf lemurs can hibernate under a range of conditions in captivity, they are an emerging model for primate metabolic flexibility with implications for human health.

3.
Int J Parasitol Parasites Wildl ; 20: 138-152, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36845223

RESUMO

Sucking lice live in intimate association with their hosts and often display a high degree of host specificity. The present study investigated sucking lice of the genus Lemurpediculus from six mouse lemur (Microcebus) and two dwarf lemur (Cheirogaleus) species endemic to the island of Madagascar, considered a biodiversity hotspot. Louse phylogenetic trees were created based on cytochrome C oxidase subunit I (COI), elongation factor 1α (EF1α) and internal transcribed spacer 1 (ITS1) sequences. While clustering according to host species was generally observed for COI and ITS1, suggesting high host specificity of the examined lice, EF1α sequences alone did not distinguish between lice of different Microcebus species, possibly due to rather recent divergence. As bootstrap support for basal tree structure was rather low, further data are necessary to resolve the evolutionary history of louse-mouse lemur associations. Three new species of sucking lice are described: Lemurpediculus zimmermanni sp. Nov. From Microcebus ravelobensis, Lemurpediculus gerpi sp.nov. from Microcebus gerpi, and Lemurpediculus tsimanampesotsae sp. nov. from Microcebus griseorufus. These new species are compared with all known congeneric species and identifying features are illustrated for all known species of Lemurpediculus.

4.
Zoo Biol ; 42(2): 209-222, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36251585

RESUMO

Captive wildlife benefit from ecologically informed management strategies that promote natural behaviors. The Duke Lemur Center has pioneered husbandry programs rooted in species' ecology for a diversity of lemurs, including housing social groups in multiacre forest enclosures. We systematically document the foraging and ranging patterns of Coquerel's sifakas (Propithecus coquereli) living in these forest enclosures. Coquerel's sifakas are seasonal frugo-folivores that exhibit striking feeding flexibility in the wild. They are also one of the few members of the Indriidae family to persist in captivity. During all-day follows in the spring and summer of 2 consecutive years, we tracked the behavior of 14 sifakas in six forest enclosures. The sifakas' ranging and foraging patterns reflected those of wild sifakas in western Madagascar: On average, DLC sifakas occupied 3-day home ranges of 1.2 ha, traveled 473 m/day, and spent 26% of their time foraging for wild foodstuffs. The sifakas foraged most for young and mature leaves, fruits, nuts, and flowers from 39 plant species, especially red maple (Acer rubrum), tulip poplar (Liriodendron tulipifera), black locust (Robinia pseudoacacia), grapevine (Vitis rotundifolia), hickory (Carya spp.), and white oak (Quercus alba). Foraging patterns varied across seasons, enclosure areas, and groups, potentially reflecting differences in phenology, microhabitats, and individual preferences. While demonstrating that captive-bred primates express wild-like behaviors under ecologically relevant conditions, our results underscore the feeding flexibility of the Coquerel's sifaka. Captive wildlife exhibiting the range of species-specific behaviors are key resources for ecological research and might be best suited for future reintroductions.


Assuntos
Indriidae , Lemur , Strepsirhini , Animais , Animais de Zoológico , Melhoramento Vegetal , Primatas , Florestas , Madagáscar
5.
Org Lett ; 24(37): 6810-6815, 2022 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-36082943

RESUMO

Efficient methodologies for synthesizing enantiopure α-deuterated derivatives of serine, cysteine, selenocysteine, and 2,3-diaminopropanoic acid have been developed. H/D exchange was achieved by deprotonation of a chiral bicyclic serine equivalent followed by selective deuteration. Additionally, diastereoselective additions of thiols, selenols, and amines to a chiral bicyclic dehydroalanine in deuterated alcohols allowed site-selective deuteration at the Cα atom of cysteine, selenocysteine, and 2,3-diaminopropanoic acid derivatives. A deuterated analogue of carbocysteine, a drug for the treatment of bronchiectasis, was synthesized.


Assuntos
Carbocisteína , Selenocisteína , Álcoois , Aminas , Cisteína , Serina , beta-Alanina/análogos & derivados
6.
Arch Bronconeumol ; 58(2): T150-T158, 2022 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-35971814

RESUMO

In this fifth phase of development, the contents of the Spanish Asthma Management Guidelines (GEMA), which include versions 5.0 and 5.1, have undergone a thorough review. The aim here is to set the main changes in context. These could be summarized as follows: DIAGNOSIS: new FENO cut-off and severity classification based on treatment needed to maintain control; INTERMITTENT ASTHMA: a more restrictive concept and treatment extended to include a glucocorticoid/adrenergic combination as needed; MILD ASTHMA: glucocorticoid/adrenergic therapy as needed as an alternative in case of low therapeutic adherence to conventional fixed-dose steroids; SEVERE ASTHMA: readjustment of phenotypes, incorporation of triple therapy in a single inhaler, and criteria for selection of a biologic in severe uncontrolled asthma; OTHERS: specific scoring in childhood asthma, incorporation of certain organizational aspects (care circuits, asthma units, telemedicine), new sections on COVID-19 and nasal polyposis.


Assuntos
Asma , COVID-19 , Adrenérgicos/uso terapêutico , Asma/tratamento farmacológico , Glucocorticoides/uso terapêutico , Humanos
7.
Mol Ecol ; 31(19): 4901-4918, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35880414

RESUMO

Madagascar's Central Highlands are largely composed of grasslands, interspersed with patches of forest. The historical perspective was that Madagascar's grasslands had anthropogenic origins, but emerging evidence suggests that grasslands were a component of the pre-human Central Highlands vegetation. Consequently, there is now vigorous debate regarding the extent to which these grasslands have expanded due to anthropogenic pressures. Here, we shed light on the temporal dynamics of Madagascar's vegetative composition by conducting a population genomic investigation of Goodman's mouse lemur (Microcebus lehilahytsara; Cheirogaleidae). These small-bodied primates occur both in Madagascar's eastern rainforests and in the Central Highlands, making them a valuable indicator species. Population divergences among forest-dwelling mammals will reflect changes to their habitat, including fragmentation, whereas patterns of post-divergence gene flow can reveal formerly wooded migration corridors. To explore these patterns, we used RADseq data to infer population genetic structure, demographic models of post-divergence gene flow, and population size change through time. The results offer evidence that open habitats are an ancient component of the Central Highlands, and that widespread forest fragmentation occurred naturally during a period of decreased precipitation near the last glacial maximum. Models of gene flow suggest that migration across the Central Highlands has been possible from the Pleistocene through the recent Holocene via riparian corridors. Though our findings support the hypothesis that Central Highland grasslands predate human arrival, we also find evidence for human-mediated population declines. This highlights the extent to which species imminently threatened by human-mediated deforestation may already be vulnerable from paleoclimatic conditions.


Assuntos
Cheirogaleidae , Lemur , Animais , Cheirogaleidae/genética , Humanos , Madagáscar , Metagenômica , Floresta Úmida
8.
FEMS Microbiol Ecol ; 98(7)2022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35679092

RESUMO

The gut microbiome can mediate host metabolism, including facilitating energy-saving strategies like hibernation. The dwarf lemurs of Madagascar (Cheirogaleus spp.) are the only obligate hibernators among primates. They also hibernate in the subtropics, and unlike temperate hibernators, fatten by converting fruit sugars to lipid deposits, torpor at relatively warm temperatures, and forage for a generalized diet after emergence. Despite these ecological differences, we might expect hibernation to shape the gut microbiome in similar ways across mammals. We, therefore, compare gut microbiome profiles, determined by amplicon sequencing of rectal swabs, in wild furry-eared dwarf lemurs (C. crossleyi) during fattening, hibernation, and after emergence. The dwarf lemurs exhibited reduced gut microbial diversity during fattening, intermediate diversity and increased community homogenization during hibernation, and greatest diversity after emergence. The Mycoplasma genus was enriched during fattening, whereas the Aerococcaceae and Actinomycetaceae families, and not Akkermansia, bloomed during hibernation. As expected, the dwarf lemurs showed seasonal reconfigurations of the gut microbiome; however, the patterns of microbial diversity diverged from temperate hibernators, and better resembled the shifts associated with dietary fruits and sugars in primates and model organisms. Our results thus highlight the potential for dwarf lemurs to probe microbiome-mediated metabolism in primates under contrasting conditions.


Assuntos
Cheirogaleidae , Microbioma Gastrointestinal , Hibernação , Torpor , Animais , Microbioma Gastrointestinal/genética , Mamíferos , Açúcares
9.
Arch. bronconeumol. (Ed. impr.) ; 58(2): 150-158, feb. 2022. tab, ilus, graf
Artigo em Inglês, Espanhol | IBECS | ID: ibc-203029

RESUMO

La quinta fase de la Guía Española para el Manejo del Asma (GEMA) que incluye las versiones 5.0 y 5.1, ha efectuado una profunda revisión de su contenido. El presente texto tiene como objetivo contextualizar los principales cambios. Estos se podrían resumir en: DIAGNÓSTICO: nuevo punto de corte de óxido nítrico en aire exhalado (FENO) y clasificación de gravedad basada en el tratamiento necesario para mantener el control; ASMA INTERMITENTE: concepto más restrictivo y tratamiento ampliado a combinación de glucocorticoide/adrenérgico a demanda; ASMA LEVE: tratamiento con glucocorticoide/adrenérgico a demanda como alternativa si baja adhesión terapéutica a esteroide fijo clásico; ASMA GRAVE: reajuste de los fenotipos, incorporación de la triple terapia en un solo inhalador y criterios para la selección del fármaco biológico en asma grave no controlada; OTROS: puntualizaciones concretas en asma infantil, incorporación de determinados aspectos organizativos (flujos entre niveles asistenciales, unidades de asma y telemedicina), nuevas secciones de COVID-19 y de poliposis nasal.


In this fifth phase of development, the contents of the Spanish Asthma Management Guidelines (GEMA), which include versions 5.0 and 5.1, have undergone a thorough review. The aim here is to set the main changes in context. These could be summarized as follows: DIAGNOSIS: new FENO cut-off and severity classification based on treatment needed to maintain control; INTERMITTENT ASTHMA: a more restrictive concept and treatment extended to include a glucocorticoid/adrenergic combination as needed; MILD ASTHMA: glucocorticoid/adrenergic therapy as needed as an alternative in case of low therapeutic adherence to conventional fixed-dose steroids; SEVERE ASTHMA: readjustment of phenotypes, incorporation of triple therapy in a single inhaler, and criteria for selection of a biologic in severe uncontrolled asthma; OTHERS: specific scoring in childhood asthma, incorporation of certain organizational aspects (care circuits, asthma units, telemedicine), new sections on COVID-19 and nasal polyposis.


Assuntos
Humanos , Ciências da Saúde , Asma , Estado Asmático , Medicina Baseada em Evidências
10.
Physiol Biochem Zool ; 95(2): 122-129, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34986077

RESUMO

AbstractHibernation, a metabolic strategy, allows individuals to reduce energetic demands in times of energetic deficits. Hibernation is pervasive in nature, occurring in all major mammalian lineages and geographical regions; however, its expression is variable across species, populations, and individuals, suggesting that trade-offs are at play. Whereas hibernation reduces energy expenditure, energetically expensive arousals may impose physiological burdens. The torpor optimization hypothesis posits that hibernation should be expressed according to energy availability. The greater the energy surplus, the lower the hibernation output. The thrifty female hypothesis, a variation of the torpor optimization hypothesis, states that females should conserve more energy because of their more substantial reproductive costs. Contrarily, if hibernation's benefits offset its costs, hibernation may be maximized rather than optimized (e.g., hibernators with greater fat reserves could afford to hibernate longer). We assessed torpor expression in captive dwarf lemurs, primates that are obligate, seasonal, and tropical hibernators. Across 4.5 mo in winter, we subjected eight individuals at the Duke Lemur Center to conditions conducive to hibernation, recorded estimates of skin temperature hourly (a proxy for torpor), and determined body mass and tail fat reserves bimonthly. Across and between consecutive weigh-ins, heavier dwarf lemurs spent less time in torpor and lost more body mass. At equivalent body mass, females spent more time torpid and better conserved energy than did males. Although preliminary, our results support the torpor optimization and thrifty female hypotheses, suggesting that individuals optimize rather than maximize torpor according to body mass. These patterns are consistent with hibernation phenology in Madagascar, where dwarf lemurs hibernate longer in more seasonal habitats.


Assuntos
Cheirogaleidae , Hibernação , Torpor , Animais , Temperatura Corporal , Metabolismo Energético , Feminino , Masculino , Mamíferos , Estações do Ano , Cauda
11.
Arch Bronconeumol ; 58(2): 150-158, 2022 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-34167859

RESUMO

In this fifth phase of development, the contents of the Spanish Asthma Management Guidelines (GEMA), which include versions 5.0 and 5.1, have undergone a thorough review. The aim here is to set the main changes in context. These could be summarized as follows: DIAGNOSIS: new FENO cut-off and severity classification based on treatment needed to maintain control; INTERMITTENT ASTHMA: a more restrictive concept and treatment extended to include a glucocorticoid/adrenergic combination as needed; MILD ASTHMA: glucocorticoid/adrenergic therapy as needed as an alternative in case of low therapeutic adherence to conventional fixed-dose steroids; SEVERE ASTHMA: readjustment of phenotypes, incorporation of triple therapy in a single inhaler, and criteria for selection of a biologic in severe uncontrolled asthma; OTHERS: specific scoring in childhood asthma, incorporation of certain organizational aspects (care circuits, asthma units, telemedicine), new sections on COVID-19 and nasal polyposis.

12.
Folia Primatol (Basel) ; 92(5-6): 284-295, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34702792

RESUMO

Madagascar's biodiversity is imperiled by habitat loss and degradation. Furthermore, species may be locally extirpated due to targeted hunting or disease. Translocating at-risk individuals to areas devoid of the species may be an effective conservation intervention. The aye-aye, Daubentonia madagascariensis, is uniquely susceptible to hunting pressure due to a cultural superstition. In June 2018, we reintroduced two aye-ayes in the Anjajavy Reserve, a dry deciduous forest in northwestern Madagascar. The translocated individuals, an adult female and juvenile offspring, were rescued from a neighboring forest that was subjected to pressure from fires and logging. We safely secured and transported the aye-ayes to Anjajavy and put them in a quarantine enclosure, where they were subjected to biomedical and behavioral monitoring. After release in the adjacent, protected forest, we conducted postrelease monitoring of the adult female using radio-tracking and scan sampling to determine ranging and activity patterns. We conducted behavioral observations from October 2018 to February 2019 and collected sleeping site data from October 2018 to September 2019. The female aye-aye fed on local resources including Canariumsp. seeds. During the study period, the aye-aye used 31 nests, occupied a home range of approximately 85 ha and traveled, on average, at a pace of 320 m/h. Our findings are comparable with published data on wild aye-ayes in other regions of Madagascar and provide support for future reintroductions of adult aye-ayes, and potentially other endemic species to the natural and protected habitats of Anjajavy.


Assuntos
Conservação dos Recursos Naturais , Strepsirhini , Animais , Ecossistema , Feminino , Comportamento de Retorno ao Território Vital , Caça , Madagáscar
13.
Primates ; 62(6): 887-896, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34541622

RESUMO

Habitat fragmentation is one of the major types of anthropogenic change, though fragmented landscapes predate human intervention. At present, the Central Highlands of Madagascar are covered by extensive grasslands interspersed with small discrete forest patches of unknown antiquity. Ankafobe, an actively protected site, comprises two such fragments of 12 and 30 ha, respectively, known to harbor three lemur species and other endemic wildlife. At this location, we conducted a survey of resident Goodman's mouse lemurs, Microcebus lehilahytsara, to determine baseline behavioral and ecological conditions for this isolated population. By studying primates in forest fragments, investigators can characterize the effects of shrinking habitats and decreasing connectivity on species diversity and survival, thus providing a glimpse into the potential resilience of species in the face of anthropogenic disturbance. Investigating the behavioral ecology of Goodman's mouse lemurs across their geographic range could help us understand their metabolic and ecological flexibility and predict species long-term survival prospects. We conducted night transect walks, using capture techniques and telemetry, to track eight radio-collared individuals. Preliminary density estimates based on a limited number of sightings (n = 18) were 2.19 ind/ha, and home range assessments ranged between 0.22 and 3.67 ha. Mouse lemurs traveled an average of 425 m nightly during the 5-h tracking periods and primarily fed on fruits of the mistletoe Bakerella clavata. The finding that Goodman's mouse lemurs apparently thrive in the seasonally cold and arid forest fragments in the Central Highlands indicates that they may be among the most tolerant and adaptable lemur species in Madagascar. These results point towards an exciting research program that focuses on ecological tolerance as a mechanism for long-term species survival.


Assuntos
Cheirogaleidae , Lemur , Animais , Ecossistema , Florestas , Madagáscar
14.
Acta amaz ; 51(3): 234-243, set 2021.
Artigo em Inglês | LILACS | ID: biblio-1353527

RESUMO

La pérdida y fragmentación del hábitat causada por la deforestación es un importante impulsor antropogénico de cambios sobre la biodiversidad en la selva amazónica. Sin embargo, la magnitud y dirección de los efectos sobre la composición y distribución de las especies aún es incomprendida. Evaluamos las respuestas de cuatro grupos taxonómicos - aves, anfibios, abejas de orquídeas y escarabajos peloteros - a la pérdida y fragmentación del hábitat, tanto a nivel de especies como de ensamblaje, en la Amazonía norte ecuatoriana. Tomamos muestras de quince parcelas de 250 m de largo en remanentes de bosque de tierra firme. Calculamos un índice de fragmentación del paisaje (fragindex), que considera la cobertura forestal continua, densidad del borde y el aislamiento en el paisaje, y nueve métricas de configuración del paisaje para analizar las respuestas de especies y ensamblajes. Más del 80% de las especies de aves, anfibios o abejas de orquídeas y el 60% de los escarabajos peloteros se vieron afectados negativamente por la pérdida y fragmentación del hábitat. La composición por especies se vio significativamente afectada por las diferencias en la cobertura forestal y la conectividad, mientras que la forma y el área de los parches de bosque determinaron la magnitud y la dirección del efecto en las respuestas de las especies. Por lo tanto, los cambios en la configuración del paisaje de la Amazonía ecuatoriana deben minimizarse para disminuir los efectos de la pérdida y fragmentación del hábitat sobre la presencia de especies y la composición de los ensambles. (AU)


Assuntos
Florestas , Espécies em Perigo de Extinção , Conservação dos Recursos Naturais
15.
Anim Microbiome ; 3(1): 39, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006323

RESUMO

BACKGROUND: Captive animals, compared to their wild counterparts, generally harbor imbalanced gut microbiota owing, in part, to their altered diets. This imbalance is particularly striking for folivores that fundamentally rely on gut microbiota for digestion, yet rarely receive sufficient dietary fiber in captivity. We examine the critically endangered Coquerel's sifaka (Propithecus coquereli), an anatomically specialized, rather than facultative, folivore that consumes a seasonal frugo-folivorous diet in the wild, but is provisioned predominantly with seasonal foliage and orchard vegetables in captivity. Using amplicon and metagenomic sequencing applied to fecal samples collected from two wild and one captive population (each comprising multiple groups), we clarify how dietary variation underlies the perturbational effect of captivity on the structure and function of this species' gut microbiota. RESULTS: The gut microbiota of wild sifakas varied by study population, most notably in community evenness and in the abundance of diet-associated microbes from Prevotellaeceae and Lachnospiraceae. Nevertheless, the differences among wild subjects were minor compared to those evident between wild and captive sifakas: Unusually, the consortia of captive sifakas were the most diverse, but lacked representation of endemic Bacteroidetes and metagenomic capacity for essential amino-acid biosynthesis. Instead, they were enriched for complex fiber metabolizers from the Firmicutes phylum, for archaeal methanogens, and for several metabolic pathways putatively linked to plant fiber and secondary compound metabolism. CONCLUSIONS: The relatively minor differences in gut microbial structure and function between wild sifaka populations likely reflect regional and/or temporal environmental variability, whereas the major differences observed in captive conspecifics, including the loss of endemic microbes, but gain in low-abundance taxa, likely reflect imbalanced or unstable consortia. Indeed, community perturbation may not necessarily entail decreased community diversity. Moreover, signatures of greater fiber degradation indicate that captive sifakas consume a more fibrous diet compared to their wild counterparts. These results do not mirror those typically reported for folivores and herbivores, suggesting that the direction and strength of captivity-induced 'dysbiosis' may not be universal across species with similar feeding strategies. We propose that tailored, species-specific dietary interventions in captivity, aimed at better approximating naturally foraged diets, could functionally 'rewild' gut microbiota and facilitate successful management of diverse species.

16.
PLoS One ; 16(5): e0251027, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33956885

RESUMO

Ecuador is one of the most biodiverse countries in the world, but faces severe pressures and threats to its natural ecosystems. Numerous species have declined and require to be objectively evaluated and quantified, as a step towards the development of conservation strategies. Herein, we present an updated National Red List Assessment for amphibian species of Ecuador, with one of the most detailed and complete coverages for any Ecuadorian taxonomic group to date. Based on standardized methodologies that integrate taxonomic work, spatial analyses, and ecological niche modeling, we assessed the extinction risk and identified the main threats for all Ecuadorian native amphibians (635 species), using the IUCN Red List Categories and Criteria. Our evaluation reveals that 57% (363 species) are categorized as Threatened, 12% (78 species) as Near Threatened, 4% (26 species) as Data Deficient, and 27% (168 species) as Least Concern. Our assessment almost doubles the number of threatened species in comparison with previous evaluations. In addition to habitat loss, the expansion of the agricultural/cattle raising frontier and other anthropogenic threats (roads, human settlements, and mining/oil activities) amplify the incidence of other pressures as relevant predictors of ecological integrity. Potential synergic effects with climate change and emergent diseases (apparently responsible for the sudden declines), had particular importance amongst the threats sustained by Ecuadorian amphibians. Most threatened species are distributed in montane forests and paramo habitats of the Andes, with nearly 10% of them occurring outside the National System of Protected Areas of the Ecuadorian government. Based on our results, we recommend the following actions: (i) An increase of the National System of Protected Areas to include threatened species. (ii) Supporting the ex/in-situ conservation programs to protect species considered like Critically Endangered and Endangered. (iii) Focalizing research efforts towards the description of new species, as well as species currently categorized as Data Deficient (DD) that may turn out to be threatened. The implementation of the described actions is challenging, but urgent, given the current conservation crisis faced by amphibians.


Assuntos
Anfíbios , Espécies em Perigo de Extinção , Animais , Anuros , Bufonidae , Conservação dos Recursos Naturais/métodos , Bases de Dados como Assunto , Ecossistema , Equador , Espécies em Perigo de Extinção/estatística & dados numéricos
17.
Sci Rep ; 11(1): 5740, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33707506

RESUMO

In nature, photoperiod signals environmental seasonality and is a strong selective "zeitgeber" that synchronizes biological rhythms. For animals facing seasonal environmental challenges and energetic bottlenecks, daily torpor and hibernation are two metabolic strategies that can save energy. In the wild, the dwarf lemurs of Madagascar are obligate hibernators, hibernating between 3 and 7 months a year. In captivity, however, dwarf lemurs generally express torpor for periods far shorter than the hibernation season in Madagascar. We investigated whether fat-tailed dwarf lemurs (Cheirogaleus medius) housed at the Duke Lemur Center (DLC) could hibernate, by subjecting 8 individuals to husbandry conditions more in accord with those in Madagascar, including alternating photoperiods, low ambient temperatures, and food restriction. All dwarf lemurs displayed daily and multiday torpor bouts, including bouts lasting ~ 11 days. Ambient temperature was the greatest predictor of torpor bout duration, and food ingestion and night length also played a role. Unlike their wild counterparts, who rarely leave their hibernacula and do not feed during hibernation, DLC dwarf lemurs sporadically moved and ate. While demonstrating that captive dwarf lemurs are physiologically capable of hibernation, we argue that facilitating their hibernation serves both husbandry and research goals: first, it enables lemurs to express the biphasic phenotypes (fattening and fat depletion) that are characteristic of their wild conspecifics; second, by "renaturalizing" dwarf lemurs in captivity, they will emerge a better model for understanding both metabolic extremes in primates generally and metabolic disorders in humans specifically.


Assuntos
Cheirogaleidae/fisiologia , Hibernação/fisiologia , Animais , Comportamento Alimentar , Feminino , Modelos Lineares , Masculino , North Carolina , Fotoperíodo , Temperatura , Fatores de Tempo , Torpor/fisiologia , Redução de Peso
20.
Syst Biol ; 70(2): 203-218, 2021 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32642760

RESUMO

Mouse lemurs (Microcebus) are a radiation of morphologically cryptic primates distributed throughout Madagascar for which the number of recognized species has exploded in the past two decades. This taxonomic revision has prompted understandable concern that there has been substantial oversplitting in the mouse lemur clade. Here, we investigate mouse lemur diversity in a region in northeastern Madagascar with high levels of microendemism and predicted habitat loss. We analyzed RADseq data with multispecies coalescent (MSC) species delimitation methods for two pairs of sister lineages that include three named species and an undescribed lineage previously identified to have divergent mtDNA. Marked differences in effective population sizes, levels of gene flow, patterns of isolation-by-distance, and species delimitation results were found among the two pairs of lineages. Whereas all tests support the recognition of the presently undescribed lineage as a separate species, the species-level distinction of two previously described species, M. mittermeieri and M. lehilahytsara is not supported-a result that is particularly striking when using the genealogical discordance index (gdi). Nonsister lineages occur sympatrically in two of the localities sampled for this study, despite an estimated divergence time of less than 1 Ma. This suggests rapid evolution of reproductive isolation in the focal lineages and in the mouse lemur clade generally. The divergence time estimates reported here are based on the MSC calibrated with pedigree-based mutation rates and are considerably more recent than previously published fossil-calibrated relaxed-clock estimates. We discuss the possible explanations for this discrepancy, noting that there are theoretical justifications for preferring the MSC estimates in this case. [Cryptic species; effective population size; microendemism; multispecies coalescent; speciation; species delimitation.].


Assuntos
Cheirogaleidae , Especiação Genética , Animais , Cheirogaleidae/classificação , Cheirogaleidae/genética , DNA Mitocondrial/genética , Ecossistema , Fósseis , Filogenia
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