The 4 known species of northern shrew-opossums, Caenolestes (Paucituberculata: Caenolestidae), are restricted to the northern Andes of South America. Five specimens of a new species of Caenolestes were collected in Sangay National Park on the eastern slopes of the Andes in Ecuador. Review of museum specimens revealed 6 additional specimens of this species, here named Caenolestes sangay. All specimens were collected in cloud forest habitats from 2,050 to 3,500 m above sea level along a recently constructed highway. The new species appears to be uncommon. Inadequate sampling on the eastern slopes of the Andes limits our understanding of the distributional limits of the new species, but it occurs in a region of high endemism. New roads and land conversion threaten mature habitats near the type locality. The new species is medium sized with a narrow antorbital vacuity. It is distinguished from congeners by its large major palatine foramen and a diastema between I4 and C, among other characters. A phylogeny of Caenolestidae based on molecular and morphological characters shows a sister-group relationship between Lestoros and Rhyncholestes and indicates that the new species is likely closest to C. caniventer.

Las 4 especies conocidas de ratones marsupiales, Caenolestes (Paucituberculata: Caenolestidae), están restringidas a los hábitats asociados con los Andes del norte de América del Sur. Cinco especímenes de una nueva especie de Caenolestes fueron colectados en el Parque Nacional Sangay en la Cordillera Oriental de Ecuador. Una revisión de especímenes de museo reveló 6 especímenes adicionales de esta especie nueva, aquí descrita como Caenolestes sangay. Todos los especímenes fueron colectados en hábitats de bosque nublado entre los 2,050 y 3,500 m sobre el nivel del mar a lo largo de una carretera recientemente construida. La nueva especie parece ser poco común. El muestreo inadecuado especialmente en la cordillera oriental limita nuestro entendimiento de los límites distribucionales de esta nueva especie, sin embrago esta es una región de alto endemismo. Nuevas vías y conversión de tierras amenazan a los hábitats que se encuentran cerca de la localidad tipo. La nueva especie es de tamaño mediano con una vacuidad anteorbital angosta. Esta especie se distingue por el tamaño grande de su foramen palatino mayor y el espacio entre el I4 y C, entre otros caracteres. Se presenta una filogenia de Caenolestidae basada en caracteres moleculares y morfológicos, mostrando una relación de grupos hermanos entre Lestoros y Rhyncholestes e indicando que la nueva especie es probablemente cercana a C. caniventer.

The southern pocket gopher, Thomomys umbrinus, traditionally has been divided into as many as 5 genetically defined subclades based on chromosomal and allozymic data. Recent molecular analyses have resurrected 2 species from within these clades: 1 from the Pacific coastal lowlands (T. atrovarius), and another from the highlands of the Sierra Madre Occidental (T. sheldoni). In this study, multilocus genetic analyses of 3 mitochondrial and 5 nuclear genes reveal a previously unrecognized 3rd species apparently restricted to the Sierra del Nayar of northeastern Nayarit, Mexico. In addition to molecular and chromosomal studies of this new species, cranial morphology is analyzed to help distinguish it from its congeners. This taxon, T. nayarensis, is described herein, and a key to distinguishing the 3 species of Thomomys in northeastern Nayarit is provided.

La tuza sureña, Thomomys umbrinus, tradicionalmente ha sido dividida hasta en 5 subclados, definidos genéticamente con base en datos cromosómicos y de aloenzimas. Análisis moleculares recientes han resucitado 2 especies a partir de estos clados: 1 especie de las tierras bajas de la costa del Pacífico (T. atrovarius), y otra de las tierras altas de la Sierra Madre Occidental (T. sheldoni). En este estudio, análisis genéticos multilocus de 3 genes mitocondriales y 5 genes nucleares revelan una 3ra especie no descrita previamente, y aparentemente restringida a la Sierra del Nayar del noreste de Nayarit. Además de los estudios moleculares y cromosómicos de esta nueva especie, la morfología craneal es analizada para ayudar a distinguirla de sus congéneres. Este taxon, T. nayarensis, se describe aquí, y se proporciona una clave taxonómica para distinguir las 3 especies de Thomomys en el noreste de Nayarit.

Akodontini is the 2nd most diverse tribe of Sigmodontinae, which in turn is one of the most speciose groups of muroid rodents. This tribe is among the most poorly understood Neotropical taxa, with most taxonomic problems concentrated in Andean species, especially those inhabiting the northern Andes. Here, applying morphological, morphometric, and phylogenetic analyses (based on 1 mitochondrial and 1 nuclear gene), we review the systematic and taxonomic status of the Bogotá akodont, Akodon bogotensis Thomas, 1895, and the Ecuadorean akodont, A. latebricola (Anthony, 1924) (Cricetidae: Sigmodontinae). Morphometric and morphological analyses give evidence of the morphological distinctiveness of A. latebricola and A. bogotensis. Specifically, these small-sized species present a unique combination of characters that includes soft, grizzled to dark chestnut dorsal fur; dark brown manus, pes, and tail; slender and proportionally long rostra; indistinct zygomatic notches; narrow, backward-sloping zygomatic plates; wedge-shaped infraorbital foramina; proportionally short incisive foramina; inflated braincase and auditory bullae; and opposite molar cusps. In agreement with these morphological results, phylogenetic analyses placed latebricola outside the tribe Akodontini. Based on these results, we propose and describe a new genus for latebricola and bogotensis.

Akodontini es la segunda tribu más diversa de Sigmodontinae, que a su vez es uno de los grupos de roedores muroideos con mayor riqueza de especies. Esta tribu es también uno de los taxones neotropicales menos conocidos, con la mayoría de los problemas taxonómicos concentrados en las especies andinas, especialmente aquellas que habitan los Andes del Norte. En este trabajo, utilizando análisis morfológicos, morfométricos y filogenéticos (basados en 1 gen mitocondrial y 1 nuclear), revisamos el estatus sistemático y taxonómico del akodonte bogotano, Akodon bogotensis Thomas, 1895, y del akodonte ecuatoriano, A. latebricola (Anthony, 1924) (Cricetidae: Sigmodontinae). Los análisis morfométricos ponen en evidencia la peculiaridad morfológica de A. latebricola y A. bogotensis. Específicamente, estas especies de pequeño tamaño presentan una combinación única de caracteres que incluye un pelaje dorsal suave de coloración grisácea a café oscuro rojizo, patas y cola oscuras, rostro delgado y proporcionalmente largo, hendiduras cigomáticas no discernibles, placas zigomáticas delgadas e inclinadas hacia atrás, forámenes infraorbitales anchos en forma de cuña, forámenes incisivos proporcionalmente cortos, caja craneal y bulas auditivas infladas y molares con cúspides opuestas. En concordancia con estos resultados morfológicos, análisis filogenéticos ubican a latebricola fuera de la tribu Akodontini. Basados en estos resultados, proponemos y describimos un nuevo género para latebricola y bogotensis.

Understanding how diversity is partitioned across the landscape provides perspectives on the environmental processes that have influenced the evolutionary history of organisms. We analyzed spatial demography, historical biogeography, and niche divergence of the western jumping mouse (Zapus princeps) using molecular sequence data from mitochondrial and nuclear DNA recovered from 7 of the 11 subspecies in western North America. Phylogeographic structure within Z. princeps was partitioned across 5 clades (Boreal, Northern Sierra, Southern Rockies, Southern Sierra, and Uinta). Two lineages detected in the Sierra Nevada of California (Northern Sierra and Southern Sierra) were more closely allied to Z. trinotatus than to other lineages of Z. princeps and species distribution models mirror these phylogenetic signatures by detecting wide overlap in niches for Sierran jumping mice and Z. trinotatus as compared to other Z. princeps. Four southern lineages are deeply divergent and limited to disjunct mesic and montane habitats within the xeric southwestern United States, whereas the 5th lineage is widespread, extending from Wyoming to Alaska and reflecting expansion northward following deglaciation, a common pattern in boreal mammals.

Emballonura semicaudata occurs in the southwestern Pacific and populations on many islands have declined or disappeared. One subspecies (E. semicaudata rotensis) occurs in the Northern Mariana Islands, where it has been extirpated from all but 1 island (Aguiguan). We assessed genetic similarity between the last population of E. s. rotensis and 2 other subspecies, and examined genetic diversity on Aguiguan. We sampled 12 E. s. rotensis, sequenced them at 3 mitochondrial loci, and compared them with published sequences from 2 other subspecies. All 12 E. s. rotensis had identical sequences in each of the 3 regions. Using cytochrome-b (Cytb) data E. s. rotensis was sister to E. s. palauensis in a clade separate from E. s. semicaudata. 12S ribosomal RNA (12S) sequences grouped all E. s. semicaudata in 1 clade with E. s. rotensis in a clade by itself. Genetic distances among the 3 subspecies at Cytb were smallest between E. s. palauensis and E. s. rotensis. Distance between E. s. semicaudata and the other 2 subspecies was not different from the distance between E. s. semicaudata and the full species E. raffrayana. A similar relationship was found using the 12S data. These distances are larger than those typically reported for mammalian subspecies using Cytb sequence and within the range of sister species.

The breeding population of the endangered Florida panther (Puma concolor coryi) is confined to the southern portion of the Florida peninsula. During the 20th century, a combination of isolation and small population size resulted in increased inbreeding. This ultimately led to a genetic restoration program in 1995 to alleviate correlates of inbreeding depression and avert extinction of the Florida panther. Genetic restoration involved the release of 8 female Texas pumas into the wild Florida population, a management initiative that has significantly improved the outlook for recovery. It is unknown whether genetic restoration changed the distinctive cranial morphology of the Florida panther; and whether some metrics that were historically used to differentiate Florida panthers from other subspecies of P. concolor are still valid. We used a high-resolution digital imaging system to compare cranial morphology from several groupings of Florida panthers that were defined by genetic restoration to elucidate any morphological changes this event may have had on cranial profile. Our results indicated that cranial measurements of Florida panthers were not significantly altered by genetic restoration.

In territorial species, competitive asymmetries can result in the uneven distribution of food resources as high-quality individuals force young or subordinates to occupy smaller or lower-quality sites, or both. However, spatiotemporal variation in the production of resources also can influence an individual's ability to monopolize resources and, consequently, affect survival. We examined how spatial and temporal variation in food supply affects the distribution of resources among territorial food-hoarding red squirrels (Tamiasciurus hudsonicus) by mapping cone production over 62.5 ha of white spruce (Picea glauca) forest and measuring the interrelationships between territory size, cone supply, and survival during 4 years of low cone abundance in Yukon, Canada. Territory size and cone production within a territory varied 10- and 520-fold, respectively, with juvenile squirrels occupying smaller territories with fewer cones. Because of small-scale heterogeneity in the distribution of cones, territory size explained low to moderate amounts of the variation in territory-wide cone production within (r_s = 0.49–0.69) and across (r_s = 0.31) years. Furthermore, spatial heterogeneity in cone production varied across years such that territory location was not useful for predicting relative food availability from one year to the next. Perhaps as a consequence of this heterogeneity, the number of cones within an individual's hoard was only weakly correlated with territory size (r_s = 0.42) and not correlated with territory-wide cone production. Hoard size better predicted overwinter survival than did territory size, whereas cone production on a territory was not predictive of survival. We suggest that caution be used in equating territory size with food supply because small-scale spatial heterogeneity can weaken this relationship, particularly in food-hoarders. Spatiotemporal variation in food abundance, in turn, may cause high-quality territories in one year to be low-quality territories in other years, which will limit the ability of individuals to assess the long-term quality of territories at the time of settlement.

Little is known about the macrohabitat associations of rodents and shrews in prairie landscapes because of the logistic constraints of conventional trapping. We used the remains of 60,972 small mammals in owl pellets to assess factors affecting small mammal composition across 4.3 million hectares of the northern Great Plains of North America. Cropland with clay soils was dominated by deer mice (Peromyscus maniculatus), whereas areas with higher proportions of native grassland and moderately sandy soils supported communities with more sagebrush voles (Lemmiscus curtatus). Areas with clay soils and higher annual precipitation were associated with higher proportions of house mice (Mus musculus), meadow voles (Microtus pennsylvanicus), and shrews (Blarina brevicauda and Sorex species), whereas drier areas with sandier soils and lower annual precipitation were dominated by olive-backed pocket mice (Perognathus fasciatus) and northern grasshopper mice (Onychomys leucogaster). Contrary to extrapolations of previous smaller-scale efforts, soil texture was the primary landscape feature driving small mammal composition in our study, whereas agricultural cropland significantly altered the composition of these assemblages. These associations demonstrate the importance of considering macrohabitats encompassing entire populations.

Many female small mammals face limited food availability during lactation. These dams may have to choose between altering the amount of maternal behavior they provide to their young, reducing the size of their litter, or not adjusting their behavior or litter size. How females allocate energy to maternal investment may depend on the energy costs of different lactation stages. We hypothesized that the amount of time female voles provided maternal behavior would differ if they were deprived of food during early, middle, or late lactation. We tested this hypothesis by placing lactating female meadow voles (Microtus pennsylvanicus) into 1 of 4 groups: dams that underwent a 30% caloric restriction during days 1–7 of lactation, those that were food restricted on days 8–14, those that were food restricted on days 15–21, and dams that did not undergo food restriction during lactation. Dams that were not food restricted spent more time engaged in maternal behavior than dams that were food restricted during lactation. Dams that were food restricted during days 8–14 of lactation displayed the most pronounced decline in maternal behavior relative to dams that were restricted during days 1–7 or days 15–21 of lactation. This effect was most dramatic in the amount of time that dams spent licking their pups. Reduced licking of pups may affect the mother–pup bond, inducing pups to possibly develop deficits in their social and sexual behavior as adults. The results also suggest that when they are faced with a food shortage, particularly during the 1st week of lactation, lactating female meadow voles do not reduce the size of their litter but do show a decrease in maternal behavior toward pups.

The role of so-called pest species in alternatively causing, or responding to, changing rangeland conditions remains contentious. Most scientists have concluded that high densities of plateau pikas (Ochotona curzoniae) on the Qinghai-Tibet Plateau, China, are a response to sparsely vegetation conditions, but demographic studies to support this hypothesis are lacking. During February–July 2009 we captured, weighed, and released plateau pikas monthly on 16 plots arrayed along a continuum of vegetation cover and pika density, both of which reflected differing land use for livestock management. We estimated apparent survival of adults using the Cormack–Jolly–Seber approach and recruitment of juveniles using the Pradel approach (in program MARK), modeling both as functions of habitat conditions, including vegetation cover. The probability of an adult pika captured in February being alive and present where initially captured in late July was ∼0.04; male and female survival rates were similar. Best-supported models of survival included vegetation cover and an index of late winter pika density; survival was negatively related to percent vegetation cover. Pika body condition varied monthly, and was negatively associated with percent vegetation cover during February–May, but positively associated in June. Pikas living where yaks had reduced vegetation cover displayed no lower recruitment, and higher survival, than where vegetation cover was higher. Thus, our results support the hypothesis that high pika density is a response to, rather than a cause of, “rangeland degradation.” Reducing undesired high pika densities will require addressing root causes of undesirable rangeland conditions.

Northern grasshopper mice (Onychomys leucogaster) have been implicated as a potential reservoir for plague, which causes local extinction of black-tailed prairie dog (Cynomys ludovicianus) colonies. To identify mechanisms by which grasshopper mice could facilitate plague spread, we measured burrow use, movements, and flea burdens of mice in colonies in northern Colorado. At the microhabitat scale, powder-tracked mice (n = 41) used both prairie dog mounds and burrows extensively, entering an average of 5.3 burrows per 100 m traveled. Burrow use did not differ between active and inactive mounds, or vary with mouse age, sex, or reproductive status. Radiotracking revealed that mice occupied larger ranges (X̄ = 3.84 ha) than reported off colonies, which we estimated would overlap 12–23 prairie dog coterie territories. Mice also harbored high flea burdens (8.1 fleas/mouse), including fleas associated with prairie dogs, which we attributed to their frequent use of burrows. Our results support the contention that, at high population densities observed in colonies, grasshopper mice facilitate plague spread by transporting infected fleas between burrows across prairie dog social boundaries represented by coterie territories.

It is crucial to understand how Neotropical leaf-nosed bats select fruits, because their choices strongly affect the seed dispersal process, especially of pioneer plants. We tested the hypothesis of hierarchical fruit selection by phyllostomid bats at the levels of the bat genus and species by combining a literature database with field experiments. Considering our database for the whole Neotropics, Artibeus bats focus on Ficus (Moraceae) and Cecropia (Cecropiaceae), Carollia bats on Piper (Piperaceae), and Sturnira bats on Solanum (Solanaceae). Results from a field experiment in Brazil corroborated those preferences, because bats of those 3 genera selected 1st the fruits of their preferred plant genera, even when secondary fruits were offered in higher abundance. In another field experiment in Panama, we observed that 2 sympatric Carollia species, although focusing on the same plant genus, prefer different Piper species. Literature records for the whole range of the 2 Carollia species show that they have strongly nested diets. Our findings corroborate the hypothesis that frugivorous phyllostomids do not forage opportunistically, and, moreover, segregate their diets hierarchically at the genus and species levels.

É crucial entender como morcegos filostomídeos neotropicais selecionam frutos, porque as escolhas deles influenciam fortemente o processo de dispersão de sementes, especialmente de plantas pioneiras. Testamos a hipótese de seleção hierárquica de frutos por morcegos filostomídeos nos níveis do gênero e espécie de morcegos, através de uma combinação de um banco de dados e experimentos de campo. Considerando o nosso banco de dados para toda a região Neotropical, morcegos Artibeus focam em Ficus (Moraceae) e Cecropia (Cecropiaceae), morcegos Carollia em Piper (Piperaceae) e morcegos Sturnira em Solanum (Solanaceae). Os resultados de um experimento de campo no Brasil corroboraram essas preferências, pois morcegos desses 3 gêneros selecionaram os frutos dos seus gêneros preferidos em primeiro lugar, até mesmo quando frutos secundários foram oferecidos em maior abundância. Em outro experimento de campo no Panamá, observamos que 2 espécies simpátridas de Carollia, apesar de focarem no mesmo gênero de plantas, preferem espécies de Piper diferentes. Registros da literatura para toda a área de distribuição geográfica dessas duas espécies de Carollia mostram que elas têm dietas fortemente aninhadas. Nossas descobertas corroboram a hipótese de que filostomídeos frugívoros não forrageiam de maneira oportunista e, além disso, segregam suas dietas hierarquicamente nos níveis do gênero e da espécie.

Island vertebrate consumers of marine crustaceans and fish are particularly susceptible to seasonal fluctuations of oceanographic conditions. The endemic fish-eating myotis (Myotis vivesi) is restricted to a few insular ecosystems in the Gulf of California, where it feeds on both marine and terrestrial prey; yet it is unknown whether its diet covaries with marine primary productivity. We determined the relative contribution of marine and terrestrial food sources to the diet of the fish-eating myotis to test the hypothesis that seasonal changes in oceanic primary productivity would dictate general feeding patterns of this bat species. We predicted that marine food would predominate in the diet of the bat during winter followed by an increase in importance of terrestrial food sources as summer approached. We measured amount of feces deposited in the day roost per bat and extrapolated this value to estimate amount of feces deposited in 1 year by the fish-eating myotis population in Partida Norte Island. Carbon and nitrogen stable isotope analysis of bat blood and examination of food remains in feces showed that marine food was the main source of nutrients for fish-eating myotis throughout the year. Importance of terrestrial food was marginal during most of the year, with a modest increase in summer. Estimated annual feces production was up to 1,518 kg. Because of its predominantly marine feeding habits, fish-eating myotis transfer allochthonous nutrients to islands where they roost, subsidizing the nutrient and energy economy of the islands.

Los vertebrados insulares que se alimentan de crustáceos y peces marinos son particularmente susceptibles a las fluctuaciones estacionales de las condiciones oceanográficas. El murciélago endémico myotis pescador (Myotis vivesi) está restringido a los ecosistemas insulares del Golfo de California, donde se alimenta de presas marinas y terrestres; sin embargo, no se sabe si su dieta varía con la productividad primaria marina. Nosotros estimamos la contribución relativa de fuentes de alimento marinas y terrestres en la dieta del myotis pescador para poner a prueba la hipótesis de que los cambios estacionales en la productividad primaria oceánica determinan los patrones generales de alimentación de esta especie. Se predijo que los alimentos de origen marino predominan en la dieta del murciélago durante el invierno, y que la importancia de los alimentos de origen terrestre aumenta conforme se acerca el verano. Además, se midió la cantidad de heces fecales depositadas en los refugios diurnos por cada individuo y se extrapoló este valor para estimar la cantidad depositada en un año por la población de myotis pescador en la Isla Partida Norte. Los análisis de isótopos estables de carbono y nitrógeno de la sangre de murciélagos y el examen del contenido de restos de alimentos en las heces demostraron que el alimento marino fue la principal fuente de nutrientes proteinas a lo largo del año para el myotis pescador. La importancia de las fuentes de alimento terrestre fue marginal durante todo el año, con un incremento modesto en el verano. La producción anual de heces estimada fue de hasta 1,518 kg. Debido a sus hábitos alimentarios predominantemente marinos, el myotis pescador transfiere nutrientes alóctonos a las islas donde se refugia, subsidiando ási la economía de nutrientes y energía de estas.

In general, urbanization negatively impacts wildlife, including bats. However, most urban ecology studies have been conducted in forested biomes and responses of grassland fauna to urbanization are poorly understood. Grasslands are flat, largely treeless, and represent challenging environments to insectivorous bats, which need vertical landscape elements for roosts and often prefer to forage in clutter or along edges. Grasslands may be even less hospitable to bats where agriculture is the dominant land use, as in the Great Plains of North America where intensive pesticide use and livestock grazing are likely detrimental to insects. Compared to agricultural areas that surround them, cities in the Great Plains offer greater structural complexity and an absence of agriculture. We investigated the hypothesis that urbanization benefits bats in the Canadian Prairies by increasing access to insect prey and foraging habitat. In 2007 and 2008, we used sticky traps to sample availability of nocturnal insects, and echolocation detectors to record foraging activity by bats, in and around the city of Calgary, Alberta, Canada. Our data did not support our predictions. Insect biomass and diversity were greatest in rural areas, and foraging activity by bats was influenced more by temperature than by urbanization. Although urbanization does not seem to benefit insects or their bat predators, we found no evidence that it is detrimental to bats in prairie grasslands.

Interactions between cetacean species are common events that can lead to the formation of mixed-species groups, which have been reported in both captive and wild odontocetes. However, mixed groups containing Indo-Pacific humpback dolphin (Sousa chinensis) and the finless porpoise (Neophocaena phocaenoides) rarely have been seen, and detailed interactions between these 2 species have been limited. For the first time, this paper describes wild Indo-Pacific humpback dolphins assisting a finless porpoise (N. p. sunameri) calf in Xiamen waters, China. A group of 8 humpback dolphins amicably herded a finless porpoise calf for more than 3 h. The humpback dolphins accompanied the finless porpoise calf and took turns pushing the calf out of the water to breathe. This paper provides a detailed behavioral description of these interactions, and we discuss the potential causes of this event.

Repeated stressful events can negatively impact overall health by continuous stimulation of the hypothalamic–pituitary–adrenal axis, which leads to depletion of glucose stores and suppression of immune and reproductive function. The influence of stressors on survivability is particularly salient for coyote (Canis latrans) populations, because understanding how coyotes cope with stressors may provide relevant context on coyote adaptation to urbanized ecosystems. Our objectives were to physiologically validate fecal glucocorticoid metabolite (FGM) analysis in coyotes by performing an adrenocorticotropic hormone (ACTH) challenge in 12 captive individuals (6 treatment and 6 control) housed at the United States Department of Agriculture National Wildlife Research Center Predator Research Facility in Millville, Utah; to quantify potential changes in FGM output due to diurnal variation and sex; and to determine the effects of 2 anthropogenic events (placement of a novel cooling fan and state holiday celebrations) on the coyotes' stress responses (via FGM production). Results demonstrated that in response to the ACTH injection, treatment animals (3 males and 3 females) displayed FGM concentration peaks ≥ 5-fold (range: 5- to 30-fold) above their preinjection means approximately 8 h after injection, which was a greater (P = 0.037) response than control animals. FGM output was lowest for morning fecal samples compared with midday (P = 0.001) and evening (P < 0.001) samples. Within the evening period, FGM output for male samples tended to be higher (P = 0.056) than for female samples, although not significant. The anthropogenic events elicited FGM concentration peaks ≥ 5-fold above pre-event means for several of the study animals occurring approximately 12 and 9 h later, respectively. This study is the 1st to physiologically validate the measurement of stress physiology using FGM analysis in coyotes and demonstrate the impact of anthropogenic events on their stress response. Furthermore, this work provides a foundation for future studies of FGMs, stress, and anthropogenic effects in wild and captive systems.

The recent co-occurrence of red wolves (Canis rufus) and coyotes (Canis latrans) in eastern North Carolina provides a unique opportunity to study prey partitioning by sympatric canids. We collected scats from this region and examined them for prey contents. We used fecal DNA analysis to identify which taxa deposited each scat and multinomial modeling designed for mark–recapture data to investigate diets of sympatric red wolves and coyotes. Diets of red wolves and coyotes did not differ, but the proportion of small rodents in the composite scats of both canids was greater in the spring than in the summer. White-tailed deer (Odocoileus virginianus), rabbits (Sylvilagus spp.), and small rodents were the most common diet items in canid scats. The similarity of diet between red wolves and coyotes suggests that these 2 species may be affecting prey populations similarly.

A spatial gradient in the interactions between American minks (Neovison vison) and muskrats (Ondatra zibethicus) occurs in the Hudson's Bay Company fur harvest returns of Canada. Evidence for strong dependence of minks on muskrats exists in northwestern Canada, whereas evidence for weaker interactions exists in central and eastern Canada. We tested the hypothesis that minks consume fewer muskrats and more alternative prey in some areas, using fur records from 56 Hudson's Bay posts. Both muskrats and small microtines were found to explain mink dynamics, with small microtines and other alternative prey gaining importance in the eastern portion of our study area. Mink fur returns exhibited a range of cycle lengths from 2.6 to 13 years encompassing typical small microtine periodicities of 3–5 years and typical muskrat periodicities of 8–13 years. A time lag of 0 years occurred between mink and muskrat harvest data frequently in the eastern portion of our study area, hypothesized to be a result of minks consuming alternative prey. To biologically verify small microtines as a potential prey source, we modeled mink and muskrat population dynamics assuming small microtines were an alternative prey by modifying the Turchin and Hanski (1997) model. Simulated mink and muskrat time series replicated observed periodicity and time-lag range, suggesting that minks can be generalist predators and consume alternative prey. Finally, we examined species richness and land cover as potential drivers of mink prey-switching, but were unable to find support for either hypothesis, suggesting that additional environmental- or competition-related interactions influence mink population dynamics.

Conservation concern for fishers (Pekania [Martes] pennanti) in the Pacific states has highlighted a need to develop cost-effective methods of monitoring reproduction in extant and reintroduced fisher populations. We evaluated the efficacy of nipple size as a predictive index of weaning success for females with known reproductive histories from 3 study areas in California. We captured and radiocollared 91 female fishers on 146 occasions between 2004 and 2011 and measured the width and height of all 4 nipples and quantified reproductive status via radiotelemetry. We classified each radiomarked female into 1 of 3 reproductive classes (nonbreeders, attempted breeders, and current breeders) based on our telemetry observations during the den season prior to capture. We used a modified random forests (RF) procedure to account for repeated measures of individual females sampled in multiple years. Our modified RF procedure correctly classified reproductive class for 130 (89%) and 131 (90%) of our 146 observations using raw and weighted vote totals, respectively. We calculated Cohen's kappa of 0.80 and 0.81 using raw and weighted vote totals, respectively, indicating strong model performance. We conclude that nipple sizes of female fishers measured during a livetrapping effort can be used as a cost-effective index of the weaning rates of adult female fishers.

Space use and habitat selection of mammals are determined by the distribution and availability of critical resources. Such information on space use and habitat selection is necessary for the conservation and management of wild populations. We revealed the determinants of habitat use for 12 common palm civets (Paradoxurus hermaphroditus) within a matrix of human-modified habitats in Sabah, Borneo. Although studies within natural forests have reported that space use of common palm civets is mainly determined by fruit availability, we hypothesized that space use in our study area might be affected by other factors because the habitat characteristics have been largely modified from those of natural habitats. Our results showed that, for both males and females, space use is largely affected by fruit availability. Specifically, the 95% minimum convex polygon home range was negatively affected by the presence of a fruit-rich oil palm plantation in the ranging area. In forest, civets increased home-range size during the fruiting season of specific pioneer plants; they visited the fruiting trees of those plants outside the ranging area of the nonfruiting season. However, availability of day-beds also influenced the ranging pattern of civets. During the day, civets used the oil palm plantation less frequently than expected from habitat availability and often retreated to adjacent forest or forest fragments. When resting in the plantation, they selected palm trees with dense mats of ferns and larger numbers of leaves, and often reused these trees. Our results indicate that fruit availability and suitable day-bed sites may be important for the survival of common palm civets in human-modified habitats and should be preserved or restored for civet conservation.