Wind turbine-associated bat mortality is occurring at unanticipated rates, yet our understanding of the causes of these fatalities is limited. The prominent proximate causes of bat deaths at wind turbines are direct collision (i.e., blunt-force trauma) and barotrauma. The objectives of this study were to use veterinary diagnostic procedures to determine the lesions associated with bats killed by wind turbines and investigate relationships between patterns of injuries and proximate causes of death. A majority of the bats (74%; 29 of 39) examined by radiology had bone fractures; most of these fractures were in the wings and none was in the hind limbs. Visual inspection resulted in 33% fewer detected bone fractures when compared with radiology results. Bats dropped from a turbine nacelle (91.44 m) to determine extent and type(s) of bone fracture did not show signs of significant bone damage. Approximately one-half (52%; 12 of 23) of bats whose ears were examined had mild to severe hemorrhaging in the middle or inner ears (or both). None of the bats found during this study had any pre-existing disease. It is difficult to attribute individual fatalities exclusively to either direct collision or barotrauma. Gross necropsy, histopathology, and radiology complement each others' deficiencies and together give the best insight into cause of death. Delayed lethal effects after nonlethal contact with wind turbines are poorly understood and difficult to quantify by mortality searches alone but can result in underestimating bat mortality caused by wind energy facilities.

Edible dormice (Glis glis) are exposed temporally and spatially to a tremendous variation in food resources. This variation strongly influences reproduction; in edible dormice reproduction is tightly linked to the availability of energy-rich seeds. Although most dormice reproduce in full mast years of beech or oak, entire populations skip reproduction in years without seed production; however, nearly 50% of all years are intermediate mast years, during which only part of the dormouse population reproduces. We investigated how the beech mast pattern, local habitat characteristics, and individual traits (body mass and age class) influence whether individual female edible dormice invest in reproduction in intermediate mast years. Our field study, conducted during 2006–2009 in the Vienna Woods, revealed that in intermediate mast years the probability of females reproducing increased with the age of trees but not with the proportion of beech trees within their home ranges. Mean litter size was larger in years with higher seed availability and also increased with the mean age of trees within the home range of the dormice. More adult than yearling females reproduced, but this effect was modulated by yearly and local variation in food availability. Whether a female edible dormouse reproduces in an intermediate mast year depends mainly on the local food availability and age of the individual.

Food resources and predation play important roles in determining small mammal population dynamics. These factors also can interact as individuals under predation pressure make trade-offs between access to food resources and exposure to predators. Fires consume food sources and reduce cover, which increases exposure to predators. For species that occur in areas with frequent fire, it is instructive to consider how all of these factors interact to affect populations of interest. We examined how supplemental feeding, mammalian predator exclusion, and prescribed fire affected survival, abundance, and reproduction of cotton mice (Peromyscus gossypinus) and oldfield mice (P. polionotus) in a longleaf pine ecosystem. Burning and predator exclusion interacted to affect survival of cotton mice; survival was similar in predator exclosures and controls in nonburning periods and in controls following prescribed burns but increased in exclosures following burns. Rates of transitions to reproductive states (which for females includes lactation or gravidity and for males, descent of testes) decreased in burn years but increased with the combination of feeding and predator exclusion. Supplemental feeding increased abundances. Among oldfield mice, survival and abundance were greater in predator exclusion areas than in controls. Supplemental feeding and the interaction of feeding and predator exclusion also increased abundances. During peak breeding seasons during which burning occurred rates of transitions to reproductive states declined to such an extent that reproductive transition rates in these seasons were lower than during nonpeak breeding seasons.

The genus Rhipidomys (sigmodontine rodents in the tribe Thomasomyini) is a poorly known radiation of Neotropical mice with few studies addressing their systematics and geographic distribution. We describe 2 new species of Rhipidomys (climbing mice) from southeastern Brazil. One of these species is known only from the type locality and 2 additional sites in the southeastern part of Minas Gerais, north of the Serra da Mantiqueira mountain complex. The other species occurs to the south of this mountain range in eastern Rio de Janeiro and São Paulo states, including coastal islands. These species can be distinguished from each other and from their congeners by morphological and molecular traits, and the new species from south of the Serra da Mantiqueira has a unique chromosomal complement of 2n  =  44 and FN  =  48, 49, or 50. Phylogenetic analysis of cytochrome-b sequences also revealed an additional unnamed clade of Rhipidomys from central and eastern Brazil, which is closely related to R. cariri from northeastern Brazil. A formal description of this clade requires additional morphological analyses, including specimens from the Guianas and other central Brazilian localities. In addition, the Amazonian species R. macconnelli and R. wetzeli appear as highly divergent from all other species included in the analysis. Finally, intraspecific morphological variation in species from mesic enclaves (brejos) in northeastern Brazil indicates the need for further taxonomic revision of R. mastacalis, R. macrurus, R. cariri, and Rhipidomys sp.

The Jico crested-tailed mouse (Habromys simulatus) is an arboreal rodent endemic to Mexico, with only 2 known extant populations restricted to montane cloud forests in the states of Hidalgo and Oaxaca. The habitat of this species has been reduced and fragmented as a result of anthropogenic activities, isolating populations and likely decreasing their sizes. We evaluated the effects of such isolation by analyzing the genetic diversity and structure of H. simulatus using 10 microsatellite loci. DNA was obtained from 52 samples from both populations. Despite the isolated and fragmented nature of the species, we found high levels of genetic diversity (H_Nei  =  0.732), similar to those reported in other endangered species with fragmented distributions. Genetic differentiation was significant (F_ST  =  0.178) and number of migrants was negligible (NmF_ST  =  0.196), a result supported by an assignment test and a factorial correspondence test. Molecular analysis of variance showed that 82% of genetic variation was distributed within populations, not unexpected given that each of the individuals' genotypes was distinct. Individuals within each population were mostly unrelated. The smallest population showed evidence of genetic bottleneck. We found evidence of detrimental genetic processes such as allelic fixation, genetic drift, and inbreeding. Our results strongly suggest that each of the 2 populations is a unique genetic entity that must be considered a distinct evolutionary unit. Unfortunately, both populations are at high risk of extinction, primarily due to habitat loss and population decline.

Management agencies and quantitative ecologists need robust estimates of population density. The best way of converting population estimates of livetrapped small mammals to population density is not clear. We estimated population density on livetrapping grids with 4 estimators applied to 3 species of boreal forest and 3 species of tundra rodents to test for relative differences in density estimators. We used 2 spatial estimators proposed by Efford (2009) and 2 traditional boundary-strip estimators designed for grid livetrapping. We analyzed mark–recapture data from 104 trapping sessions from the boreal forest at Kluane, Yukon (n  =  4,818 individuals), and 56 trapping sessions from tundra areas of Herschel Island and Komakuk Beach in northern Yukon (n  =  1,327 individuals). For boreal forest rodents on average both boundary-strip methods produced density estimates larger than Efford's maximum-likelihood (ML) estimator by as much as 50% at all population densities up to 25 animals/ha. For tundra rodents both boundary-strip methods produced density estimates smaller than Efford's ML at low density (<1.5/ha) and larger than Efford's ML density by 36–63% at high density (25/ha). Efford's inverse prediction estimator produced larger density estimates than the ML estimator by 4% for the boreal forest and 32% for the tundra rodents. Relationships were high between all the estimators, such that trends in density could be inferred from all methods. Determining the bias in population density estimators in small mammals will require data from populations spatially closed and completely enumerated. For our small mammals Efford's ML estimator typically provided density estimates smaller than those produced by conventional boundary-strip estimators.

We evaluated evolutionary relationships of taxa within silky pocket mice of the Perognathus fasciatus species group, composed of 3 species, P. fasciatus, P. flavescens, and P. apache. These species are distributed throughout the Great Plains, Wyoming Basin, Colorado Plateau, and northern Chihuahuan Desert biogeographic regions in North America. We tested a previously postulated hypothesis of Pleistocene species divergence and introgression by analyzing mitochondrial DNA (mtDNA) and amplified fragment length polymorphisms (AFLPs). Both mtDNA and AFLP data support several genetic lineages in the fasciatus species group that are geographically structured. Molecular clock estimates reject a Pleistocene speciation hypothesis in favor of a deeper, more complex evolutionary history of initial divergence in the Miocene followed by secondary diversification beginning in the middle Pliocene and progressing through the Pleistocene. Results support recognition of an additional species within the group. Temporal and spatial congruence between the mtDNA clades in the fasciatus species group and other codistributed species of Perognathus appear to support a hypothesis of concerted diversification throughout the Chihuahuan Desert, Colorado Plateau, and Great Plains.

The “living fossil,” Dromiciops gliroides (monito del monte), is an endemic marsupial inhabiting the temperate rain forests of South America. It is cavity-dependent and faces high energetic costs associated with thermoregulation during the austral winter. Although D. gliroides is well known for seed dispersal in temperate rain forests, its ecology, behavior, and long-term population dynamics have received little attention. We monitored a population of D. gliroides and studied variation in abundance and density and seasonal changes in body mass and body condition index (BCI). In addition, we monitored activity and communal nesting with camera traps and nest boxes, respectively. Over 4 years we documented a mean population density of 26 (95% confidence interval  =  19–32) individuals/ha. We found significantly greater body mass and BCI for females than for males, suggesting different energetic strategies during the prehibernation period. Animals were nocturnal and active until dawn. Communal nesting occurred during summer and early fall, but torpor by single individuals and small groups was increasingly frequent during winter. Communal nesting could be a key behavioral strategy affecting survival. However, given the greater frequency in warm seasons and groups composed of postreproductive females and juveniles, communal nesting might be more related to parental care associated with kin selection than to thermoregulation.

Southern flying squirrels (Glaucomys volans) are seasonally gregarious and rely on the thermoregulatory benefits of well-constructed nests and presence of nest mates to survive harsh winter conditions. Prior work has shown that kinship components are important to how winter aggregations form in captivity and that relatedness between individuals is higher than expected in undisturbed populations examined in the field. Over the course of 2 falls, 2006 and 2007, we created related and unrelated groups in a laboratory colony at Wake Forest University. We presented each group type with related and unrelated individuals as intruders. Once formed, aggregations persisted when presented with an intruder squirrel. Squirrels from existing aggregations were found in the same nest box 98% of the time. Factors of relatedness and familiarity were crucial in determining whether the intruder was accepted into an existing aggregation or nested alone. We found that related groups were more tolerant of truly novel (unrelated unfamiliar) intruders and more likely to incorporate them into the aggregation than were unrelated groups. Unrelated groups never accepted unrelated unfamiliar intruders in 2006, whereas some were accepted in 2007 due to increased colony-wide familiarity. Acceptance of intruders was dependent on relatedness. Intruders were more likely to be found in an aggregation when either the existing group was composed of kin or the intruder was related to at least one group member. We also found effects of familiarity of individuals on the choice of nest mates.

Although cases of pilfering food are reported commonly in the mammal literature, the factors affecting pilfering rates among individuals and between populations within the same species remain relatively unknown. We measured individual pilfering rates in 2 populations of highly territorial larder-hoarding red squirrels (Tamiasciurus hudsonicus) in Kluane, Yukon, Canada. One population received artificial food supplementation (where all individuals had ad libitum food) and had a 2-fold higher density than the control population. We knew the age, relatedness, and spatial relationship of all individuals in each population, and we had a measure of the food resources (cones) cached by each individual and their fates through the study. Results from experimental removal of territory owners suggested that younger squirrels with smaller food caches were more likely to pilfer when provided the opportunity. However, using a mark–recapture study of marked spruce cones under natural conditions, we found that few individuals (14%) pilfered, and stolen cones represented only 0.3% of total cones that were larder-hoarded. Pilfering occurs at a much lower rate in Kluane than reported for red squirrels in other regions and is less than rates reported for scatter-hoarding species.

The tassel-eared squirrel (Sciurus aberti) is dependent on ponderosa pine (Pinus ponderosa) for food and cover and is likely to be affected by management treatments intended to restore currently dense ponderosa pine forests to presettlement, more-open stand structure. We used radiotelemetry to determine how restoration treatments affected habitat use by tassel-eared squirrels. Mean 50% fixed kernel core areas and 85% fixed kernel home ranges were significantly smaller in winter (core  =  1.1 ha; home range  =  5.1 ha) than nonwinter (core  =  3.48 ha; home range  =  13.81 ha), and squirrels selected untreated forests and areas with high (51–75%) canopy cover for these winter areas. During nonwinter core areas and home ranges expanded to include treated areas with high canopy cover (51–75%). Squirrels placed the majority of winter nests in areas with >51% canopy cover and high (0.0601–0.0819 kg/m³) crown bulk density. Given the apparent importance of denser, untreated patches and treated areas with canopy cover of 51–75% in winter, we suggest retaining some areas with these characteristics where it is compatible with other forest management objectives.

We reinvestigated the phylogeny of all 15 species of Marmota to resolve a conflict between 2 published analyses, one by Kruckenhauser et al. and another by Steppan et al., regarding the Olympic marmot (M. olympus) and to improve resolution in the genus. We acquired fresh samples of M. olympus, combined all available data on mitochondrial DNA (cytochrome b [Cytb] and ND3/ND4), new sequences for ND3/ND4, and 2,000 base pairs (bp) of the nuclear RAG1 gene. All analyses indicate that M. olympus is a much older, rather than more recent, offshoot of the widespread hoary marmot (M. caligata) or Vancouver Island marmot (M. vancouverensis). The mitochondrial data and some RAG1 results are largely congruent, but RAG1 differs on several points, including: the subgenus Marmota appears paraphyletic to Petromarmota, with reciprocally monophyletic Palearctic and Nearctic clades; and the long-tailed marmot (M. caudata) and Menzbier's marmot (M. menzbieri) are not sister species, suggesting mitochondrial introgression. Asia was colonized by Marmota from North America at approximately 4.6 million years ago (mya), followed by rapid diversification of several major lineages. M. olympus diverged from the M. caligata–M. vancouverensis lineage at approximately 2.6 mya, whereas M. vancouverensis and M. caligata diverged at only about 0.4–1.2 mya. M. olympus might have survived in isolation on the Olympic Peninsula in a nunatak refugium throughout a series of glacial maxima.

Evolution of the marsupial forelimb complex is argued to be constrained by the functional requirements of the newborn's crawl to the teat. This constraint is often used to explain why marsupials are limited in their diversity relative to eutherians. However, despite the constraint's importance to mammalian evolution, one of its fundamental corollaries, that marsupials exhibit less forelimb specialization than eutherians, has not been tested explicitly. We used morphometric analyses of mammalian limbs to test 2 hypotheses concerning their specialization: marsupials have less-specialized forelimbs than eutherians, and marsupials tend to specialize their hind limbs rather than forelimbs and eutherians their forelimbs rather than hind limbs. In support of the 1st, marsupial forelimbs are more similar among functional groups, display smaller morphospaces, and have lower morphologic divergence from the average mammalian state than eutherian forelimbs. In support of the 2nd, marsupial hind limbs are more dissimilar than forelimbs and display higher morphological divergence, but the opposite is true for eutherians. Results suggest fundamental differences in the mechanistic underpinnings of limb specialization in marsupials and eutherians and support a constraint on the marsupial forelimb complex, and possibly the mammalian hind limb.

The effects of forest type and disturbance on specific reproductive traits are unknown for many forest-dwelling mammals. We assessed whether differences in forest type and disturbance influenced key reproductive traits of an arboreal marsupial, the common brushtail possum (Trichosurus vulpecula), in Tasmania, Australia. Trapping was conducted in spring–summer and autumn–winter during 2007–2008 at 6 dry Eucalyptus forest sites (3 regenerating and 3 relatively undisturbed) in southeast Tasmania and 4 wet Eucalyptus forest sites (2 regenerating and 2 relatively undisturbed) in the northeast. We aged pouch young and assessed the body condition of back young. We milked females captured during the late stage of lactation and compared the nutritional composition of milk among sites. Births occurred slightly earlier at the northern sites than at those in the south. Female body mass and offspring body condition and survival were similar across sites. Milk composition also was similar across sites, but possums in dry, undisturbed forest, primarily at 1 site, produced milk with significantly higher fat content; however, we found no evidence of a difference in body condition or survival of young that could be attributed to a difference in milk quality. Although forest type and disturbance influence demography and breeding frequency in the brushtail possum populations we studied, these population-level differences are not linked to variations in the reproductive traits examined here. We conclude that the brushtail possum is a physiologically resilient species, and the ability of individual females to reproduce successfully is relatively insensitive to forest type or habitat disturbance.

Riparian ecosystems serve as movement and dispersal corridors; however, the factors that determine their use by multiple species of carnivores remain unknown. Two hypotheses can explain carnivore presence in riparian ecosystems. Higher riparian plant richness, diversity, and structure provide the resources used by carnivores (resting sites, cover, and food). Alternatively, areas with higher water availability allow species to withstand water loss and thermal gradients in the high summer temperatures. In southern Portugal we surveyed 70 transects 2 km long along riparian ecosystems during the wet winter months and again in the dry summer months, recording signs of carnivore species and the environmental context in which they occurred (vegetation descriptors, surrounding landscape, and waterway type and condition). Five carnivore species used riparian ecosystems (stone marten [Martes foina], Eurasian badger [Meles meles], common genet [Genetta genetta], Egyptian mongoose [Herpestes ichneumon], and red fox [Vulpes vulpes]). Riparian ecosystems had a diverse and heterogeneous plant community with a mix of obligate riparian, Mediterranean sclerophyllous, and exotic species. Most carnivore species responded to water channel type and standing water availability in both seasons, except for the stone marten in the wet season, which uses areas with rich riparian vegetation. Our results suggest that the use of riparian ecosystems is linked to water availability that provides water, prey, and external temperature regulation.

Ecological invasions of generalist species often are facilitated by anthropogenic disturbance. Coyotes (Canis latrans) have benefitted from anthropogenic changes to North American ecosystems and have experienced a dramatic range expansion since the early 19th century. The region east of the Mississippi River has been colonized via 2 routes that have converged in the mid-Atlantic region during the past few decades. Coyotes using the northern route of expansion show molecular evidence of admixture with the Great Lakes wolf (GLW). We used noninvasive molecular techniques to detect the geographic origins of the recent coyote colonization of northern Virginia as a representative of the mid-Atlantic region and to detect signatures of admixture with GLWs. Of 455 individual canid scats screened, we sequenced a variable 282-base pair fragment of the mitochondrial control region from 126 coyote scats, assigned individual identities to samples using 6 microsatellite loci, and conducted phylogeographic analyses by comparing our sequences to previously published haplotypes. In 39 individuals identified in our scat surveys we detected 7 mitochondrial DNA haplotypes, all of which have been previously reported in diverse surrounding geographic localities. Phylogeographic analyses indicate multiple sources of colonization of northern Virginia. One common haplotype detected in northern Virginia is of wolf origin, indicating the presence of admixed coyotes and GLWs from the north.

The Iberian lynx (Lynx pardinus) is the most endangered wild feline species and the only feline listed as critically endangered by the International Union for the Conservation of Nature. Successful conservation actions rely on accurate knowledge of the species' distribution and decline. Anecdotal unverified reports have overestimated the distribution of the Iberian lynx and misrepresented the severity of its decline. We reconstructed the Iberian lynx range from 1940 to 2000 using only records verified with indisputable physical evidence. We collected data from the 2 major scientific vertebrate collections in Spain, trophies registered by hunting authorities, and miscellaneous private collections. Of 320 lynxes collected during 1940–2007, 261 contained adequate date and location information for this study. The overall species range in 1940 included 15 subpopulations occupying 65 verified 10- × 10-km grid cells. Three large subpopulations (Montes de Toledo, eastern Sierra Morena, and Doñana) accounted for 86.6% of records. The species had a steady decline from 1940 until the 1990s, when lynxes remained in only 2 isolated subpopulations. Our reconstruction of verified lynx distributions since 1940 illustrates how most local extinctions occurred before disease outbreaks among prey, previously assumed to be the principal cause of lynx declines. Rabbit diseases alone cannot account for observed lynx declines, and we suggest that human-caused mortality from direct hunting and indiscriminate predator control programs likely played a larger role in the species' decline. Our verified maps provide a more accurate history of the Iberian lynx distribution in Spain than was available previously. Ideally, this information can help managers outline priority areas for conservation and reintroduction programs to reinforce and restore important subpopulations.

The biology of the Steller sea lion (Eumetopias jubatus) has been the subject of intense scientific investigation. This is primarily due to the rapid decline of population size in the western part of the species' range since the 1970s and the subsequent Threatened and Endangered species listings that had direct impact on the management of one of the world's largest fisheries. The Steller sea lion has emerged as an indicator species representing the environmental health of the North Pacific Ocean and Bering Sea. In this study, to better understand the historical processes that have culminated in the extant populations of E. jubatus, a large genetic data set consisting of 3 mitochondrial regions for >1,000 individuals was analyzed from multiple phylogeographic and demographic perspectives. The results describe the role of climate change in shaping the population structure of E. jubatus. Climatically associated historical processes apparently involved differential demographic responses to ice ages (and putative glacial vicariance) dependent on population size. Ice ages during times of small effective population size promoted restricted gene flow and fragmentation, and ice ages occurring during times of large population size promoted gene flow and dispersal. These results illustrate that effective population size has a profound effect on how species respond to climate change, an observation with obvious implications for large mammals and endangered species under the present conditions of imminent anthropogenically caused climate change. In addition, the results confirm previous observations of strongly biased historic and contemporary gene flow involving dispersal from west to east. Furthermore, phylogenetic patterns in combination with available fossil data suggest the potential of an Asian origin of E. jubatus. The results of this study provide a detailed scenario for the history that has shaped contemporary populations of E. jubatus.

Mixed-species associations are temporary aggregations of individuals of different species involved in similar activities. Such associations form for foraging, protection against predators, and social advantage. Mixed-species groups in delphinids are frequent in the wild. We aimed to understand the ecological significance of mixed-species group formation by 2 tropical delphinids, the spinner dolphin (Stenella longirostris) and the pantropical spotted dolphin (Stenella attenuata), in waters surrounding the island of Mayotte in the southwestern Indian Ocean. We used sighting data collected year-round from 2004 to 2009. We encountered a total of 67 mixed-species groups (comprising 21% of all groups observed) of spinner and pantropical spotted dolphins around Mayotte. No daily or seasonal variability in the occurrence of associations was detected. Behavioral activities of single- and mixed-species groups differed significantly. Foraging was observed only in single-species groups of pantropical spotted dolphins. Mixed-species groups were larger than single-species groups. When in association, spinner dolphins used deeper waters than while in single-species groups. No evidence of association for social advantage was observed. We suggest that spinner dolphins associate with spotted dolphins for protection against predators when transiting between resting areas.

For species living in seasonal environments the understanding of demographic processes requires identifying the environmental factors during spring and summer that shape phenotypic variation. We assessed the effects of plant phenology and population abundance during spring–summer on variation in autumn body mass among cohorts (1995–2006) of juvenile alpine chamois (Rupicapra rupicapra). We computed several metrics based on the normalized difference vegetation index (NDVI) to assess interannual variation in plant phenology and productivity. Body mass of both sexes decreased similarly during years with late springs (−20%) and with increasing population abundance (−15%), with no interactive effect. Our results also suggested that forage quality more than forage quantity influenced body mass of juveniles. Variation in body mass of juveniles thus can be used as an indicator of the relationship between chamois populations and their environment. This study also demonstrates the utility of satellite-based data in increasing our understanding of the consequences of spring–summer conditions on life-history traits.

We investigated the effects of predation risk on birth-site selection by Rocky Mountain elk (Cervus elaphus nelsoni) during summer in 2002–2004 in northeastern Oregon at macrohabitat (3rd-order selection) and microhabitat (4th-order selection) scales. This study describes vegetative characteristics of birth sites selected by female elk when young <4–5 days old used the hiding strategy and predation sites when most predation events occurred on young >5 days old that used the fleeing strategy. At the macrohabitat scale we observed no evidence that female elk were influenced by predation risk when selecting a birth site on the basis of variables measured in this study. Females chose birth sites with less overhead cover than random sites, suggesting that they might have been influenced more by forage availability than predation risk. At the microhabitat scale females selected birth sites that had more overhead canopy cover and greater visibility at ground level than paired random sites, which suggested that birth-site selection at this scale was influenced by predation risk. Together, these results suggested that female elk selected areas for parturition at the macrohabitat scale that likely had forage to meet high nutritional demands of lactation and at the microhabitat scale selected areas that provided visibility to detect predators and reduce the risk of predation. Predators, mainly cougars (Puma concolor), killed young in areas closer to vegetative edges at the macrohabitat scale and with more visibility at the microhabitat scale. These areas were likely conducive to cougar hunting where sight and cover from forest edges can be important for stalking calves that are traveling with their mothers and family groups.

Fossils of caribou (Rangifer tarandus) and elk-moose (Cervalces scotti) were found in a Wisconsinan–Holocene outwash bog on Kluck Farm, near Bevent, Marathon County, Wisconsin. These caribou fossils are the northernmost records for the state, and the extinct Cervalces the 1st known from the state and northernmost record for the species. The site is located at the mapped ice front of the Green Bay Lobe of the late Wisconsinan Valder's Readvance, which was present between 12,500 and 11,500 years before present. Examination of accelerator mass spectrometry ¹⁴C data indicated that the elk-moose was older than the caribou by 1,600–1,700 years. Matching the radiocarbon dates with those of nearby sites and to their pollen records helps to clarify the nature of climatic conditions and corresponding plant communities at the upper Pleistocene boundary. The pattern of replacement of taiga forest southward and westward of the Green Bay Lobe to warmer, open-range conditions, with invading prairie, pine (Pinus), and deciduous trees, resembles changes that took place earlier, when glaciers and cool climate occurred south of the late Wisconsinan ice fields. Perhaps cursorial carnivores preyed on the large cervids, which were made more visible in openings of the taiga and grassland and by the typical succession expected of boreal wetlands to dry prairie or park-like savanna copses of spruce (Picea), oak (Quercus), and pine.