The Philippine archipelago hosts an exceptional diversity of murid rodents that have diversified following several independent colonization events. Here, we report the discovery of a new species of rodent from Mt. Kampalili on eastern Mindanao Island. Molecular and craniodental analyses reveal this species as a member of a Philippine “New Endemic” clade consisting of Tarsomys, Limnomys, and Rattus everetti (tribe Rattini). This new species of “shrew-mouse” is easily distinguished from its relatives in both craniodental and external characteristics including a long, narrow snout; small eyes and ears; short, dark, dense fur dorsally and ventrally; stout body with a tapering, visibly haired tail shorter than head and body length; stout forepaws; bulbous and nearly smooth braincase; narrow, tapering rostrum; short incisive foramina; slender mandible; and narrow, slightly opisthodont incisors. This new genus and species of murid rodent illustrates that murids of the tribe Rattini have exhibited greater species and morphological diversification within the Philippines than previously known and provides evidence that Mt. Kampalili represents a previously unrecognized center of mammalian endemism on Mindanao Island that is deserving of conservation action.

The taxonomy of the South American river dolphins of the genus Inia has been a focus of intense debate. While traditionally it is thought to be composed of a single species with three geographically structured subspecies (Inia geoffrensis geoffrensis, I. g. humboldtiana, and I. g. boliviensis), recent molecular studies have highlighted substantial differentiation, suggesting the existence of two species (I. geoffrensis and I. araguaiaensis). Despite this evidence, the recognition of the specific status of these taxa has been hindered by inconsistent morphological diagnoses. Here, we aim to provide evidence for the morphological differentiation (or lack thereof) between subspecies and putative species. We employ geometrics and traditional morphometrics to measure skull variation to support efforts of integrative taxonomy. Our results show that morphometric diversity within the group is inconsistent with a single taxon. Morphometric evidence supports the traditional differentiation of three distinct morphotypes within the analyzed sample. These morphotypes largely correspond to described subspecies I. g. geoffrensis, I. g. humboldtiana—the latter differing from the former by size—and I. g. boliviensis, which differs from the remaining groups by shape. Furthermore, morphometric data show no differences between I. g. geoffrensis and a newly proposed species, I. araguaiaensis. Given the conservation importance of this genus and the different threats they are subject to, we strongly suggest an urgent integrative taxonomic treatment of the group to better protect these singular cetaceans.

A taxonomia dos golfinhos de água doce da América do Sul pertencentes ao gênero Inia têm sido foco de intenso debate. Enquanto tradicionalmente considera-se a existência de uma única espécie e três subespécies (Inia geoffrensis geoffrensis, I. g. humboldtiana, and I. g. boliviensis), estudos moleculares recentes evidenciam diferenciação substancial, sugerindo a existência de mais de uma espécie (I. geoffrensis and I. araguaiaensis). Apesar desta evidência, o reconhecimento do status específico desses táxons tem sido limitado pela presença de diagnoses morfológicas inconsistentes. Nosso objetivo no presente trabalho é proporcionar evidências para a diferenciação morfológica (ou a sua ausência) entre as subespécies e as possíveis espécies. Utilizamos morfometria geométrica e tradicional para medir a variação do cranio de forma a sustentar esforços de taxonomia integrativa. Nossos resultados mostram que a diversidade morfométrica dentro do grupo é inconsistente com um único táxon. A evidência morfométrica aponta a diferenciação tradicional de três morfotipos distintos dentro da amostra analisada. Esses morfotipos correspondem em grande parte às subespecies I. g. geoffrensis, I. g. humboldtiana, que diverge da primeira através do seu tamanho, e I. g. boliviensis, que diverge das demais através de sua forma. Ademais, dados morfométricos não mostram diferenças entre Inia g. geoffrensis e a espécie recém proposta, I. araguaiaensis. Dada a importância para conservação desse gênero e as diferentes ameaças às quais estão sujeitos, nós sugerimos enfaticamente um tratamento de taxonomia integrativa para o grupo, de forma a melhor proteger esses cetáceos singulares.

In many long-lived mammalian species, association patterns between individuals have been found to influence sociality, behavioral traits, survival, and longevity. In common bottlenose dolphins (Tursiops truncatus), the early stages of development are of particular importance as associations experienced as dependent calves may influence future association patterns. While behavioral characteristics associated with the transition from a dependent calf state to an independent juvenile state have been documented, there are limited studies that examine associations between these time periods. This study aims to document association longevity for bottlenose dolphins as they transition from calves to juveniles and determine the extent to which kinship plays a role in the development of these associations. Using social network analysis, a generalized linear mixed model (GLMM), and a tiered association scale, we found 53.7% of associations were retained from the calf to the juvenile phase. GLMM results indicated that preferred associates (half-weight index [HWI] > 0.178) from the calf state were 3.6 times more likely to associate in the juvenile state (0.178 > HWI > 0) and 5.67 times more likely to be preferred associates in the juvenile state compared to nonpreferred calf associates. The majority of juveniles, 76.92%, maintained a low–moderate to moderate level association (0.089–0.54) with their mother, and a few retained their mother as their top associate. Kin were preferred associates in 46.15% of cases and found to be the top juvenile associate in 26.92% of cases. Identifying continuity in associations, particularly from the calving state to the juvenile state, is imperative as mammalian association patterns may influence community structure, disease transmission, reproductive success, and predict survival.

En muchas especies de mamíferos longevos, se ha descubierto que los patrones de asociación entre individuos influyen en la sociabilidad, los rasgos de comportamiento, la supervivencia y la longevidad. En los delfines mulares comunes (Tursiops truncatus), las primeras etapas de desarrollo son de particular importancia ya que las asociaciones experimentadas como delfinatos dependientes pueden influir en los patrones de asociación futuros. Mientras que se han documentado las características de comportamiento asociadas con la transición de un estado de cría dependiente a un estado juvenil independiente, hay estudios limitados que examinan las asociaciones entre estos períodos de tiempo. Este estudio tiene como objetivo documentar la longevidad de la asociación de los delfines mulares a medida que pasan de crías a jóvenes y así determinar hasta que punto el parentesco juega un papel en el desarrollo de estas asociaciones. Utilizando el análisis de redes sociales, un modelo lineal mixto generalizado (GLMM) y una escala de asociación escalonada, encontramos que el 53,7% de las asociaciones se retuvieron desde la fase de delfinato hasta la fase juvenil. Los asociados preferidos (HWI > 0.178) en el estado juvenil que se mantuvieron desde el estado de delfinato tenían 3.6 veces más probabilidad de asociarse y 5.67 veces más probabilidad de ser un asociado preferido en el estado juvenil (P < 0.0001). La mayoría de los jóvenes, el 76,92%, mantuvieron una asociación de nivel bajo-moderado a moderado (0,089–0,54) con su madre, y unos pocos mantuvieron a su madre como su principal asociada. Los delfines con parentesco fueron asociados preferidos en el 46,15% de los casos y se encontró que eran los principales asociados juveniles en el 26,92% de los casos. Es imperativo identificar la continuidad de estas asociaciones, particularmente desde el estado de delfinato hasta el estado juvenil, ya que los patrones de asociación de los mamíferos pueden influir en la estructura de la comunidad, la transmisión de enfermedades, el éxito reproductivo y predecir la supervivencia.

Em muitas espécies de mamíferos de vida longa, descobriu-se que os padrões de associação entre os indivíduos influenciam a sociabilidade, as características comportamentais, a sobrevivência e a longevidade. Em golfinhos-nariz-de-garrafa comuns (Tursiops truncatus), os estágios iniciais de desenvolvimento são de particular importância, pois as associações vividas como filhotes dependentes podem influenciar os padrões de associação futuros. Embora as características comportamentais associadas à transição de um estado de filhote dependente para um estado de juvenil independente tenham sido documentadas, estudos que examinam as associações entre esses períodos de tempo são limitados. Este estudo tem como objetivo documentar a longevidade da associação em golfinhos-nariz-de-garrafa durante a transição de filhotes para juvenis, e determinar até que ponto o parentesco influencia no desenvolvimento dessas associações. Usando a análise de redes sociais, um modelo linear generalizado misto (GLMM) e uma escala de associação em camadas, descobrimos que 53,7% das associações foram retidas desde a fase de filhote até a fase juvenil. Associados preferidos (HWI > 0,178) no estado juvenil que foram mantidos desde o estado de filhote tiveram 3,6 vezes mais chances de se associarem e 5,67 vezes mais chances de serem um associado preferencial no estado juvenil (P < 0,0001). A maioria dos juvenis, 76,92%, mantiveram uma associação de nível baixo-moderado a moderado (0,089–0,54) com a própria mãe, e alguns mantiveram a mãe como principal associado. Parentes foram os associados preferidos em 46,15% dos casos e considerados os principais associados de juvenis em 26,92% dos casos. Identificar a continuidade nas associações, particularmente do estado de filhote ao estado juvenil, é imperativo, pois os padrões de associação em mamíferos podem influenciar a estrutura da comunidade, a transmissão de doenças e o sucesso reprodutivo, e prever sobrevivência.

The gray wolf, Canis lupus, once inhabited much of the northern hemisphere worldwide; however, persecution drove its populations almost to extinction. In North America, diverse conservation programs have been implemented in the last decades to recover its populations in the wild, many of them guided by the historical distribution of the gray wolf subspecies. Over time, several authors have proposed different subspecies classifications. Nevertheless, most of them are mutually inconsistent regarding the number and distribution of subspecies, creating controversy when implementing conservation programs. This study used niche-based distribution models and cluster analysis to explore the bioclimatic profiles of C. lupus across North America and compare them with different subspecies classifications to identify environmental correlatives that support the proposed designations. Our cluster analysis results indicate that the optimal number of climatic groups was five, designated as Northern, Eastern, Western, Coastal, and Southern groups, with transitional overlap boundaries located at their peripheries, indicating climatic gradients between them and supporting the idea of intergrading zones. The geographic ranges of these groups mismatched to a different extent with all subspecies delimitations. In general, the boundaries of putative subspecies did not match the climatic patterns of North America. Our results may contribute to the recovery programs underway for this carnivore by identifying suitable areas for the release of individuals from specific lineages. New approaches to characterizing the intraspecific variation of the gray wolf should include all evidence available, including genetic, morphological, and ecological information.

El lobo gris, Canis lupus, habitó gran parte del hemisferio norte en todo el mundo; sin embargo, su persecución condujo a sus poblaciones casi a la extinción. En Norteamérica, se han implementado diversos programas de conservación en las últimas décadas para recuperar algunas de sus poblaciones silvestres, muchos de éstos apegándose a la distribución histórica de sus subespecies. No obstante, a lo largo del tiempo, diversos autores han propuesto diferentes esquemas subespecíficos para el lobo gris en Norteamérica que, en su mayoría, son inconsistentes entre sí en términos del número del número de subespecies comprendidas y de la distribución geográfica de las mismas, generando así controversias en cuanto a la implementación de programas de conservación. En este estudio utilizamos modelos de distribución de nichos de especies y análisis de conglomerados para explorar los perfiles bioclimáticos de C. lupus en Norteamérica y compararlos con los diferentes esquemas de subespecies, con el objetivo de identificar correlaciones ambientales que respalden dichos esquemas. Nuestros resultados del análisis de conglomerados indican que el número óptimo de grupos climáticos es cinco, denominados: Grupos del Norte, Este, Oeste, Costero y Sur. Los grupos mostraron áreas de sobrelapamiento en sus periferias, sugiriendo gradientes climáticos entre ellos, corroborando el concepto de zonas de transición. Las distribuciones de estos grupos no coincidieron con las de las subespecies reconocidas históricamente, lo que sugiere que los límites históricos de las subespecies no siguen los patrones climáticos de Norteamérica. Este trabajo puede contribuir a los programas de recuperación que existen para esta especie mediante la identificación de lugares adecuados para la liberación de individuos de linajes particulares. Los nuevos enfoques para caracterizar y entender la variación intraespecífica del lobo gris deben incluir toda la evidencia disponible, incluyendo información genética, morfológica y ecológica.

American marten (Martes americana) in Interior Alaska are at the northwestern limit of their North American range. To investigate factors that may be associated with reproduction we determined the cementum age and the presence or absence of blastocysts in 118 female martens for 3 years (2012, 2014, and 2016) in two regions. For each marten we collected fur samples and measured steroid hormone concentrations (cortisol, testosterone, and progesterone) and stable isotopes (δ¹⁵N and δ¹³C values, a proxy for diet). These parameters reflect the diet and endocrine activity between June and October when fur is grown. We also collected two claws from a subset of 39 female marten from one region in 2012 and 2014. Progesterone concentrations were measured in one whole claw and from a second claw divided into proximal (recent growth) and distal sections. Differences in the probability of blastocysts being present were associated with geographic region and sample year suggesting that reproduction in female marten varies on a fine scale. We found the that presence of blastocysts was positively associated with marten age and δ¹⁵N values in fur but negatively associated with fur cortisol concentrations. These findings suggest that the likelihood a female marten will reproduce in a given year is influenced, in part, by the proportion of protein in their diet and stressors encountered during late summer and fall, months before active gestation begins.

Monitoring variation in population features such as abundance and density is essential for evaluating and implementing conservation actions. Camera trapping can be important for assessing population status and trends and is increasingly used to generate density estimates through capture–recapture models. Moreover, success in using this technique can vary seasonally given shifting animal distributions and camera encounter rates. Notwithstanding these potential advantages, a gap still exists in our understanding of the performance of such models for estimating density of cryptic Neotropical terrestrial carnivores with low encounter rate probability with cameras. In addition, scanty information is available on how sampling design can affect the accuracy and precision of density estimates for Neotropical carnivores. We evaluate the performance of spatially explicit versus nonspatial capture–mark–recapture models for estimating densities and population size of ocelots (Leopardus pardalis) within an Atlantic Forest fragment in Brazil. We conducted two spatially concurrent surveys, a random camera-trap deployment covering the entire study area and a systematic camera-trap deployment in a small portion of the study area, where trails and unpaved roads were located. We obtained 244 photographs of ocelots in the Rio Doce State Park from April 2016 to November 2017, using 54-double camera stations spaced approximately 1.5 km apart (random placement) totaling 4,320 trap-nights and 15-double camera stations spaced from 0.3–10 km apart (systematic placement) totaling 1,200 trap-nights. Using the random placement design, ocelot density estimates were similar during the dry season, 14.0 individuals/km² (± 5.6 SE, 6.6–30.0, 95% CI) and 13.78 individuals/km² (± 4.25 SE, 5.4–22.1, 95% CI) from spatially explicit capture–recapture and nonspatial models, respectively. Using the systematic placement design spatially explicit models had smaller and less precise ocelot density estimates than nonspatial models during the dry season. Ocelot density was 12.4 individuals/100 km² (± 5.0 SE, 5.8–26.7, 95% CI) and 19.9 individuals/km² (± 5.2 SE, 9.7–30.1, 95% CI) from spatially explicit and nonspatial models, respectively. During the rainy season, we found the opposite pattern. Using the systematic placement design, spatial-explicit models had higher and less precise estimates than nonspatial models. Ocelot density was 24.6 individuals/100 km² (± 13.9 SE, 8.7–69.4, 95% CI) and 11.89 individuals/km² (± 3.93 SE, 4.19–19.59, 95% CI) from spatially explicit and nonspatial models, respectively. During the rainy season, we could not compare models using the random placement design due to limited number of recaptures to run nonspatial models. In addition, a single recapture yielded an imprecise population density estimate using spatial models (high SE and large 95% CIs), thus precluding any comparison between nonspatial and spatially explicit models. We demonstrate relative differences and similarities between the performance of spatially explicit and nonspatial capture–mark–recapture models for estimating density and population size of ocelots and highlight that both types of capture–recapture models differ in their estimation depending on the sampling design. We highlight that performance of camera surveys is contingent on placement design and that researchers need to be strategic in camera distribution according to study objectives and logistics. This point is especially relevant for cryptic or endangered species occurring at low densities and having low detection probability using traditional sampling methods.

O monitoramento da variação nas características da população, como abundância e densidade, é essencial para avaliar e implementar ações de conservação. O armadilhamento fotográfico pode ser importante para avaliar a ocupação ou tendência populacional e é cada vez mais usado para gerar estimativas de densidade por meio de modelos de captura e recaptura. O sucesso em usar esta técnica pode variar sazonalmente, devido às distribuições dos animais em movimento e às taxas de encontro com as câmeras. Avaliamos o desempenho relativo de modelos espacialmente explícitos versus não explícitos de captura-marcação- recaptura para estimar densidades e tamanho populacional de jaguatiricas (Leopardus pardalis) dentro de um fragmento de Mata Atlântica no Brasil. Nós realizamos duas amostragens de armadilhas fotográficas espacialmente simultâneas, uma aleatória cobrindo toda a área de estudo e uma sistemática em uma pequena parte da área de estudo, onde estavam localizadas trilhas e estradas não pavimentadas. Obtivemos 244 fotografias de jaguatiricas no Parque Estadual do Rio Doce (RDSP) de abril de 2016 a novembro de 2017, usando 54 estações com duas câmeras cada espaçadas a aproximadamente 1,5 km de distância (amostragem aleatória), totalizando 4.320 noites de armadilhamento e 15 estações com duas câmeras cada espaçadas de 0,3 a 10 km de distância (amostragem sistemática), totalizando 1.200 noites de armadilhamento. Usando a amostragem aleatória, estimamos a densidade de jaguatirica durante a estação seca em 14,0 indivíduos/km² (± 5,6 EP – erro padrão, 6,6–30,0 95% IC – intervalo de confiança) e 13,78 indivíduos/km² (± 4,25 EP, 5,4–22,1 95% IC), a partir do modelo espacialmente explícito de captura-recaptura (SECR) e modelos não espaciais, respectivamente. O uso de modelos não espaciais na amostragem sistemática apresentou estimativas de densidade de jaguatiricas mais altas e mais precisas durante a estação seca. A densidade de jaguatirica foi de 12,4 indivíduos/100 km² (± 5,0 EP, 5,8–26,7 95% IC) e 19,87, indivíduos/km² (± 5,2 EP, 9,7–30,1 95% IC) dos modelos espacialmente explícito e não espaciais, respectivamente. Para a estação chuvosa, observamos um padrão inverso. Modelos espaciais tiveram uma estimativa maior e menos precisa. A densidade de jaguatirica foi de 24,6 indivíduos/100 km² (± 13,9 EP, 8,7–69,4, 95% IC) e 11,89 indivíduos/km² (± 3,93 EP, 4,19–19,59, 95% IC) dos modelos SECR e não espaciais, respectivamente. Não foi possível comparar os modelos durante a estação chuvosa devido ao limitado número de recapturas necessárias para executar os modelos não espaciais. Demonstramos as diferenças e semelhanças relativas entre o desempenho de modelos de captura-marcação-recaptura espacialmente explícitos e não espaciais para estimar a densidade e o tamanho da população de jaguatiricas e destacamos que ambos os tipos de modelos diferem em suas estimativas, dependendo do tipo de amostragem. Este ponto é especialmente relevante para espécies enigmáticas ou ameaçadas que ocorrem em baixas densidades e com baixa probabilidade de detecção usando métodos de amostragem tradicionais.

Weasels are small mustelid carnivores that play an important role as predators of small mammals in a wide array of ecosystems. However, their response to land use, such as forest harvest for timber products, is seldom the subject of focused research and management projects. Both the American ermine, also known as the short-tailed weasel (Mustela richardsonii), and the long-tailed weasel (Neogale frenata) are native to Maine, United States, where commercial timber harvesting is widespread. The effects of this forest disturbance on weasels are poorly understood, so to contribute toward filling this knowledge gap, we conducted a 4-year, large-scale field study: specifically, our objective was to assess the effects of forest disturbance caused by timber harvest on occupancy patterns of ermines and long-tailed weasels occupancy patterns in Maine. We collected data from 197 survey sites (three camera traps each) over 4 years and analyzed over 7,000 images of weasels using dynamic false-positive occupancy models. We found that American ermines were widely distributed across the state (naïve occupancy at 54% of sites), while long-tailed weasels were rarer (naïve occupancy at 16% of sites). Both species responded positively to forest disturbance, with higher occupancy probabilities as disturbance increased, especially at the larger scales. American ermines were more likely to occupy stands with a higher percentage of conifer trees, while no such relationship was found for long-tailed weasels. We conclude that current forest harvest practices in Maine are not detrimental to weasel populations, but that the two species warrant continued monitoring.

Las comadrejas son pequeños mustélidos carnívoros que juegan una función importante como depredadores de pequeños mamíferos en un amplio conjunto de ecosistemas. Sin embargo, su respuesta al uso de la tierra, como la explotación forestal para productos madereros, rara vez es objeto de proyectos de investigación y gestión específicos. Tanto el armiño americano, conocido como comadreja de cola corta (Mustela richardsonii), como la comadreja de cola larga (Neogale frenata) son especies nativas del Estado de Maine, en EE. UU., donde la tala comercial de madera está bastante extendida. Los efectos que tiene este tipo de perturbación del bosque sobre las comadrejas son poco conocidos, por lo que, para contribuir a llenar este vacío en el conocimiento, realizamos un estudio de campo a gran escala por cuatro años: específicamente, nuestro objetivo fue evaluar los efectos de la perturbación del bosque causada por la extracción de madera sobre los patrones de ocupación del armiño y la comadreja de cola larga en Maine. Colectamos datos en 197 sitios de estudio (con tres cámaras trampa por sitio) durante cuatro años y analizamos más de 7,000 imágenes de comadrejas usando modelos de ocupación dinámicos falso-positivo. Encontramos que el armiño americano está distribuido ampliamente en todo el estado (ocupación ingenua en 54% de los sitios), mientras que la comadreja de cola larga es menos común (ocupación ingenua en 16% de los sitios). Ambas especies han respondido positivamente a la perturbación del bosque, con mayores probabilidades de ocupación a medida que la perturbación aumenta, especialmente a mayor escala. El armiño americano mostró más probabilidades de ocupar espacios con mayores porcentajes de coníferas, aunque no se encontró tal relación para la comadreja de cola larga. Concluimos que las prácticas actuales de extracción forestal en Maine no son perjudiciales para las poblaciones de comadrejas, pero ambas especies requieren de monitoreo continuo.

Humans interact with wildlife regularly, mostly without conflict. Interactions between humans and bears, however, have a history of conflict. Using data from female black bears in two populations, we compared behaviors related to a series of hypotheses about habituation and food supplementation via research feeding. We livetrapped bears in the southern boreal forests and cove forests of the Pisgah National Forest, North Carolina, in barrel traps or modified leg-hold snares and outfitted them with very high frequency (VHF) transmitters, for 95 bear-years of data. In the southern boreal forests of Superior National Forest, Minnesota, we habituated bears and outfitted them with VHF collars supplemented with GPS units, for 42 bear-years. Some human residents of the Superior study area fed local black bears and we established a research feeding site. Bears in both populations avoided roads and habituated: Superior bears avoided houses where they were not fed; the study site for Pisgah bears (no habituation or feeding) had too few houses to test for avoidance. Bears in both populations gained weight faster during their active seasons when wild foods were abundant. Habituated, supplemented Superior bears averaged a smaller proportion of a day active, longer activity bouts, and less sinuous movements than did not-habituated or supplemented Pisgah bears. The bears in the two populations did not differ with respect to distances traveled per 2 h or mean lengths of activity bouts. The abundance of wild foods affected time active, distance traveled, and sinuosity of travel by not-habituated or supplemented Pisgah bears. Females in breeding condition in both populations were more active, had longer activity bouts, traveled further, and had more linear travel in spring and early summer while females with cubs pushed these activities into late summer and autumn. This timing pattern for bout length, distance moved, and sinuosity was less pronounced for habituated and research-fed Superior bears than for not-habituated or supplemented Pisgah bears. Thus, habituation to a small number of researchers appeared to not affect many behaviors of bears in our habituated and research-fed Superior population; research feeding appeared to affect some behaviors in a manner consistent with a food supply that had low annual variance. Because we have samples of one for each treatment (one site with habituation and feeding, one site without), our results do not establish that differences documented between the populations were caused by the differences in habituation and feeding. The effects of habituation, research feeding, or other forms of food supplementation on backcountry behaviors of black bears need broader testing across the range of black bears.

Los seres humanos interactúan rutinariamente con fauna silvestre, mayormente sin conflictos. Sin embargo, las interacciones entre humanos y osos históricamente sí tienen un historial de conflicto. Usando datos de hembras en dos poblaciones de oso negro, comparamos comportamientos relacionados con una serie de hipótesis sobre habituación a seres humanos y suplementación alimenticia por medio de alimentación durante programas de investigación. Usando trampas de barril o trampas de lazo para piernas, capturamos osos de forma no letal en el sur de los bosques boreales y en bosques de ensenada del ecosistema Apalache, y les pusimos collares con transmisores de muy alta frecuencia (transmisores VHF), los cuales resultaron en datos sobre 95 años-oso. Sometimos a los osos del sur de los bosques boreales en Minnesota a un régimen de habituación y les pusimos collares VHF suplidos con aparatos GPS, resultando en datos sobre 42 años-oso. Los osos de ambas poblaciones evitaron las carreteras. Los osos bajo régimen de habituación y con alimentos suplementados evitaron aquellas casas sin alimentación suplementaria. El ámbito de estudio de los osos independientes (sin habituación o alimentación suplementaria) tenía demasiadas pocas casas para poder llevar a cabo un análisis con respecto al comportamiento de evitar casas. Los osos de ambas poblaciones aumentaron de peso más rápidamente en su temporada activa, cuando abundaban los alimentos silvestres. Los osos alimentados pasaban en activo una menor parte del día en promedio, pero recorrían mayores distancias por periodos de dos horas, evidenciaron periodos de actividad más largos y recorridos más sinuosos que los osos independientes. La abundancia de alimentos silvestres afectó el tiempo pasado en activo, la distancia recorrida, y la sinuosidad de los recorridos de los osos independientes; sin embargo, nuestros análisis carecieron de poder estadístico suficiente para aceptar las hipótesis nulas predicando la falta de efectos en los osos con comida suplementada. Las hembras en condición reproductiva de ambas poblaciones eran más activas, mostraron periodos de actividad más largos y recorridos más largos y más lineales durante la primavera y comienzo del verano, mientras las hembras con oseznos extendieron estas actividades hasta el final del verano y otoño. Este patrón de periodos de actividad, distancia recorrida y sinuosidad de recorrido era menos marcado en los osos con alimentación suplementada que en osos independientes. Así, la habituación a un reducido número de investigadores no parece haber afectado el comportamiento de los osos, mientras que la alimentación con propósitos de investigación pareció afectar algunos comportamientos de una manera que es consistente con un suministro de alimentos de baja variación anual. Nuestros resultados no establecen una relación efecto-causa porque teníamos muestras de uno para cada tratamiento distinto (un sitio con habituación y alimentación suplementada, un sitio sin ellos). Los efectos de la habituación, la alimentación por investigación u otras formas de suplementación alimentaria en los comportamientos de los osos negros en zonas campestres requieren pruebas más amplias en toda la distribución de osos negros.

Harnessing the fear animals have of humans has the potential to aid in the conservation of wildlife. Most vertebrates perceive humans as “super predators.” While predator cues are an important nonlethal management tool, the use of human cues for management has rarely been implemented or experimentally tested. Extensive poaching is threatening the persistence of white rhinos (Ceratotherium simum simum), and there is a need to deter them from areas with elevated poaching risks. To investigate the feasibility of harnessing the fear white rhinos have of humans to aid in their conservation, we conducted playback experiments at rhino middens. We broadcasted repeated human (treatment) and bird (control) vocalizations, and measured changes in visitations and antipredator responses. We found that overall rhino visitations did not change in response to controls but decreased by 46% in response to human vocalizations. This pattern appears to be driven by the response of females, who decreased their visitations by 70% in response to human vocalizations, while visitations by males remained unchanged. This difference is likely related to males defending small exclusive territories. Providing evidence that changes in female visitation rates were a function of the perceived fear of white rhinos, we found that both sexes exhibited more vigilance in response to human vocalizations (males 69.5%, females 96%) compared to controls. We also saw a 63% reduction of other herbivores at treatment sites. Our findings provide evidence that the fear of humans can be used to alter the movements and behavior of female white rhinos, critical for population recovery, as well as other large herbivores.

Ecological processes driving female-skewed adult sex ratios (ASRs; males:females) in populations with polygynous mating systems have been addressed theoretically, but empirical support is scarce. The theoretical framework of the female substitution hypothesis (FSH) asserts that a female-skewed ASR at carrying capacity reflects an overall fitness benefit for females and for males competitive in acquiring access to reproductive females. The FSH predicts that as population abundance increases females should acquire forage more efficiently than males, thereby leading to passive displacement of males. The result is declining ASR associated with differential habitat use by both sexes as food resources are depleted by female scramble competition. We characterized the temporal variation in ASR in a Roosevelt elk population inhabiting the Redwood National and State Parks, California, across 24 years, and determined which of two possible ecological mechanisms was the driver of a declining ASR. The first mechanism explored was that increasing female abundance associated with declining forage in the study area led to the passive displacement of males into the study periphery over time. The second mechanism explored was that a declining ASR was precipitated by a lack of males within the study area and the study periphery. Systematic population surveys from a vehicle were done to estimate abundance and ASR as well as assess male abundance in the study periphery. Forage biomass was estimated in quarter-m² plots randomly placed in meadows inhabited by female elk. Our multiple regression analysis revealed an inverse relationship between abundance and ASR indicating density dependence. We found numerous males in the study periphery when females were abundant. Our least squares models indicated declining food resources across years when female abundance increased. Our results showed that the first, and not the second, ecological mechanism examined was responsible for a female-skewed ASR. Our findings provide empirical support for the theoretical framework of the FSH in a nonmigratory population protected from hunting.

Climate change and habitat loss have been identified as the main causes of species extinction. Forest regeneration and protected areas are essential to buffer climate change impacts and to ensure quality habitats for threatened species. We assessed the current and future environmental suitability for the maned sloth, Bradypus torquatus, under both future climate and forest restoration scenarios, using ecological niche modeling. We compared environmental suitability for two Evolutionarily Significant Units (ESUnorth and ESUsouth) using two climate change scenarios for 2070, and three potential forest regeneration scenarios. Likewise, we evaluated the protection degree of the suitable areas resulting from the models, according to Brazilian law: PA—Protected Areas; PPA—Permanent Protection Areas (environmentally sensitive areas in private properties); and LR—Legal Reserves (natural vegetation areas in private properties). Finally, we calculated the deficit of PPA and LR in each ESU, considering the current forest cover. Forest regeneration might mitigate the deleterious effects of climate change by maintaining and increasing environmental suitability in future scenarios. The ESUnorth contains more suitable areas (21,570 km²⁾ than the ESUsouth (12,386 km^2), with an increase in all future scenarios (up to 45,648 km² of new suitable areas), while ESUsouth might have a significant decrease (up to 7,546 km² less). Suitable areas are mostly unprotected (ESUnorth—65.5% and ESUsouth—58.3%). Therefore, PPA and PA can maintain only a small portion of current and future suitable areas. Both ESUs present a high deficit of PPA and LR, highlighting the necessity to act in the recovery of these areas to accomplish a large-scale restoration, mitigate climate change effects, and achieve, at least, a minimum forested area to safeguard the species. Notwithstanding, a long-term conservation of B. torquatus will benefit from forest regeneration besides those minimum requirements, allied to the protection of forest areas.

Mudanças climáticas e perda de habitat são comumente identificadas como as principais causa de extinção de espécies. A regeneração florestal e as áreas protegidas são essenciais para amortecer os efeitos das mudanças climáticas e garantir habitat de qualidade para espécies ameaçadas. Avaliamos a adequabilidade ambiental atual e futura para preguiça de juba. Bradypus torquatus, tanto sob mudanças climáticas quanto florestais. Comparamos a adequabilidade ambiental em duas unidades evolutivas significativas (UES norte e sul) usando dois cenários de mudança climática para 2070 e três cenários de regeneração florestal potencial. Avaliamos os modelos resultantes quanto ao seu grau de proteção, conforme a legislação brasileira: Áreas Protegidas (AP); Áreas de Proteção Permanente (APP—áreas ambientalmente sensíveis em propriedades privadas); e Reserva Legal (RL—áreas de vegetação natural em propriedades privadas). Por fim, calculamos o déficit de APP e RL em cada UES, considerando a cobertura florestal atual. A regeneração florestal poderá mitigar os efeitos perversos das mudanças climáticas, mantendo e aumentando a futura adequabilidade ambiental. O UESnorte concentra áreas mais adequadas (21.570 km^2; UESsul = 12.386 km^2), com aumento em todos os cenários futuros (até 45.648 km² de novas áreas adequadas). Por outro lado, UESsul pode ter uma queda elevada em áreas adequadas (até 7.546 km² a menos). As áreas adequadas são, em sua maioria, desprotegidas (UESnorte—65,5% e UESsul—58,3%). Ainda assim, APP e AP protegem apenas uma pequena parte de áreas adequadas atuais e futuras. Ambas as UES apresentam alto déficit de APP e RL, evidenciando a necessidade de atuar na recuperação dessas áreas para realizar restaurações em larga escala, mitigar os efeitos das mudanças climáticas e atingir, ao menos, uma área mínima de floresta para preservar a espécie. Contudo, uma conservação de longo prazo de B. torquatus se beneficiará da regeneração florestal além dos requerimentos mínimos, aliada à proteção de áreas florestais.

The island nation of Madagascar is home to three endemic species of Old World fruit bat in the family Pteropodidae: Pteropus rufus, Eidolon dupreanum, and Rousettus madagascariensis, all three of which are IUCN Red Listed under some category of threat. Delineation of seasonal limits in the reproductive calendar for threatened mammals can inform conservation efforts by clarifying parameters used in population viability models, as well as elucidate understanding of the mechanisms underpinning pathogen persistence in host populations. Here, we define the seasonal limits of a staggered annual birth pulse across the three species of endemic Madagascar fruit bat, known reservoirs for viruses of high zoonotic potential. Our field studies indicate that this annual birth pulse takes place in September/October for P. rufus, November for E. dupreanum, and December for R. madagascariensis in central-eastern Madagascar where the bulk of our research was concentrated. Juvenile development periods vary across the three Malagasy pteropodids, resulting in near-synchronous weaning of pups for all species in late January–February at the height of the fruiting season for this region. We here document the size range in morphological traits for the three Malagasy fruit bat species, with P. rufus and E. dupreanum among the larger of pteropodids globally and R. madagascariensis among the smaller. All three species demonstrate subtle sexual dimorphism with males being larger than females. We explore seasonal variation in adult body condition by comparing observed body mass with body mass predicted by forearm length, demonstrating that pregnant females add weight during staggered gestation periods and males lose weight during the nutritionally deficit Malagasy winter. Finally, we quantify forearm, tibia, and ear length growth rates in juvenile bats, demonstrating both faster growth and more protracted development times for P. rufus as compared with E. dupreanum and R. madagascariensis. The longer development period for the already-threatened P. rufus further undermines the conservation status of this species as human hunting is particularly detrimental to population viability during reproductive periods. Our work highlights the importance of longitudinal field studies in collecting critical data for mammalian conservation efforts and human public health alike.

We investigated population responses of Microtus longicaudus to cumulative clear-cutting of coniferous forests and to enhanced understory vegetation in young, fertilized pine stands near Summerland, British Columbia, Canada. We explored if there was a threshold level of habitat quality arising from a given forest disturbance for M. longicaudus to increase to high population levels and potentially fluctuate in abundance over time. Secondly, we asked if these outbreaks were site-specific or part of a long-term pattern. We tested three hypotheses (H) that populations of M. longicaudus would increase in abundance and potentially fluctuate owing to (H₁) the availability of early seral postharvest habitats associated with cumulative clear-cut harvesting; (H₂) woody debris piles on clear-cuts; and (H₃) have higher mean abundance, reproduction, and survival in fertilized forest sites with enhanced understory vegetation. Mean annual and peak abundances of M. longicaudus were significantly different across the four Periods of cumulative forest harvesting with numbers being highest in the first two Periods. Thus, H₁, that long-tailed voles would increase in abundance on new clear-cuts, was partially supported for the first two Periods but not in the later Periods. Constant cattle (Bos taurus) grazing during summer periods over the four decades may have reduced vegetative productivity for voles and damped out population responses on these clear-cut sites, at least in the last two Periods. Woody debris piles on clear-cuts may have increased abundance and generated a population fluctuation, thereby supporting H₂. Enhanced abundance of understory vegetation had no effect on mean abundance, reproduction, or survival of M. longicaudus, and hence did not support H₃. We conclude that it is site-specific disturbances, particularly in forest management, that generate occasional outbreaks of M. longicaudus, and there does not appear to be any long-term pattern to these discordant fluctuations.

Notiosorex is the only genus of shrews in North America with particular adaptations for arid habitats such as deserts. Five species currently are recognized in the genus, one of which, Notiosorex evotis, lives in deciduous rain forest from northern Sinaloa to the state of Jalisco in México. Notiosorex evotis originally was described as a subspecies of N. crawfordi; however, it was recently proposed as a valid species based on a discriminant function analysis of craniodental characters. Morphological differentiation between N. evotis populations and sympatric occurrences with N. crawfordi in northern Sinaloa have been recognized. Here, we used a phylogenetic analysis of a mitochondrial gene (Cytb; 1,140 bp) and the nuclear beta fibrinogen intron 7 (β-fib I7; 385 bp), as well as cranial geometric morphometrics, to assess the taxonomic status of N. evotis. We found sequences of N. evotis forming two main subclades: one that includes the populations of the state of Sinaloa, the other including populations of Nayarit and Jalisco. The boundaries between the two groups seem to be related to the ecotonal cline between the Pacific Lowlands province and the Trans-Mexican Volcanic Belt province, which acts as a geographical barrier. The discriminant function analysis revealed clear differences in skull shape between the three species of Notiosorex to the northwest of its distribution. Considering these multiple lines of evidence from our data set, we confirm that N. evotis is a monotypic species. Our results suggest that geometric morphometrics can be used successfully to identify sibling species by shape, especially in groups where determination by craniodental measurements is not possible.

Notiosorex es el único género de musarañas en Norteamérica con adaptaciones especiales para zonas áridas como son los desiertos. Actualmente se reconocen cinco especies en el género, una de las cuales, Notiosorex evotis, vive en el bosque lluvioso caducifolio de México desde el norte de Sinaloa hasta el estado de Jalisco. Notiosorex evotis fue originalmente descrita como subespecie de N. crawfordi; sin embargo, se propuso recientemente como especie válida en base a un análisis discriminante utilizando caracteres craneodentales. Se ha reconocido la diferenciación morfológica entre poblaciones de N. evotis así como ocurrencias simpátricas en el norte de Sinaloa con N. crawfordi. Aquí, utilizamos un análisis filogenético de un gen mitocondrial (Cytb; 1,140 bp) y el gen nuclear intrón 7 de fibrinógeno beta (β-fib I7; 385 bp), junto con morfometría geométrica craneal, para evaluar el estado taxonómico de N. evotis. Encontramos que las secuencias de N. evotis forman dos subclados principales: uno que incluye las poblaciones del estado de Sinaloa, y el otro que comprende las poblaciones de Nayarit y Jalisco. Los límites entre los dos grupos parecen estar relacionados con el cline ecotonal entre la provincia de la Costa del Pacífico y la provincia del Eje Volcánico Transversal, el cual actúa como una barrera geográfica. El análisis de función discriminante reveló claras diferencias en la forma del cráneo entre las tres especies de Notiosorex que constituyen el noroeste de la distribución del género. Teniendo en cuenta estas múltiples líneas de evidencia de nuestro conjunto de datos, confirmamos que N. evotis es una especie monotípica. Nuestros resultados sugieren que la morfometría geométrica es una herramienta útil para discriminar entre especies hermanas en función de su forma, y puede ser utilizada en otros grupos donde no es posible la determinación mediante mediciones craneodentales.

The Lesser Treeshrew, Tupaia minor Günther, 1876, is a small mammal from Southeast Asia with four currently recognized subspecies: T. m. minor from Borneo; T. m. malaccana from the Malay Peninsula; T. m. humeralis from Sumatra; and T. m. sincepis from Singkep Island and Lingga Island. A fifth subspecies, T. m. caedis, was previously synonymized with T. m. minor; it was thought to occur in northern Borneo and on the nearby islands of Banggi and Balambangan. These subspecies were originally differentiated based on pelage color, a plastic feature that has proven to be an unreliable indicator of taxonomic boundaries in treeshrews and other mammals. To explore infraspecific variation among T. minor populations across the Malay Peninsula, Borneo, Sumatra, and smaller islands, we conducted multivariate analyses of morphometric data collected from the hands and skulls of museum specimens. Principal component and discriminant function analyses reveal limited differentiation in manus and skull proportions among populations of T. minor from different islands. We find no morphometric support for the recognition of the four allopatric subspecies and no support for the recognition of T. m. caedis as a separate subspecies on Borneo.

Noninvasive genetic surveys, often conducted by collecting fecal samples, have become a popular tool for surveying wildlife, but have primarily been applied to species with large and conspicuous scat. Although many small mammals are threatened, endangered, or data deficient, noninvasive genetic surveys have rarely been applied due to the challenges of detecting their inconspicuous fecal pellets. As part of a broader study of the endangered salt marsh harvest mouse (Reithrodontomys raviventris), we developed a noninvasive genetic survey technique for the community of small mammals in their putative range. We designed bait stations to passively collect fecal samples from rodents, and developed a multiplex primer set that amplified unique fragment sizes for salt marsh harvest mice and four other sympatric species. We tested the primer set on positive controls and on fecal pellets collected from bait stations at two regularly monitored field sites known to have very different densities of salt marsh harvest mice. The multiplex amplified DNA from all five species, even when all five species were present in a single sample. A positive species identification was made for all field-collected samples, and 43% of these field-collected samples had multispecies detections. The combination of bait stations and genetic species identification proved to be an effective means of noninvasively surveying small mammals in potential salt marsh harvest mouse habitat. The sampling technique should be applicable to a wide variety of small mammals in other systems.