We investigated movement patterns in a high-density population of Eurasian badgers (Meles meles) to explore how the costs and benefits of dispersal and other forms of movement differed among individuals in the population. We analyzed a 17-year data set comprising 5,255 trapping events for members of a population of Eurasian badgers at Wytham Woods, Oxford, United Kingdom. For a subset of badgers with a sufficient trapping history, we were able to identify dispersal events. Permanent dispersal was not common. Of 267 badgers 1st trapped as young and caught on a minimum of 4 occasions spanning 400 days or more, the majority (75.8%) were never captured at more than 2 social groups. Only 51 (19.1%) of these animals satisfied our definition of dispersal; 96 (35.8%) were never captured outside of their natal social group. Male badgers moved between groups more than did females and accumulated more wounds in the process. Dispersing males tended to move to larger groups and to groups with a preponderance of females, but dispersal rate did not change as the density of the population increased. However, evidence of extraterritorial matings suggests that inbreeding may be alleviated without dispersal. We consider the implications of these findings for the mating system and social behavior of the badger.

Direct observations of small foxes are rare because of their secretive nature and nocturnal activity patterns. We observed 10 adult (≥1-year-old) San Joaquin kit foxes (Vulpes macrotis mutica) at night over a 7-month period that included the mating season to quantify the types, rates, and durations of social interactions. Of 191 interactions between members of this seasonally breeding, socially monogamous species, 52 were with adult foxes in the same social group, 43 with adult foxes from other known social groups, 48 with juveniles (<1 year old), and 48 with unknown foxes. Most interactions (n = 173), especially those between pair-mates, between females, and with juveniles, were affiliative. Agonistic encounters were rare (n = 18) and occurred mostly between males of different social groups and with unknown foxes. Interaction rates with social group members, most of which were pair-mates (88%), peaked in the months before the annual mating season, whereas those with non–social group foxes, most of which represented potential extrapair copulation partners (79%), peaked later and more sharply. The duration of interactions with adult social and non–social group foxes was highest during the mating season. Increased social interactions at this time may help foxes strengthen bonds with pair-mates and become familiar with potential extrapair partners.

We tested the influence of a change in food resource distribution on space use and diet of coyotes (Canis latrans). We focused on 2 facets of space use: maintenance of home ranges by residents, and establishment of home ranges by immigrants after a coyote removal program. The study was conducted on 2 populations of coyotes in southern Texas. In both populations, a clumped, high-quality food source was added to randomly selected feeding stations to measure the influence of food distribution and abundance on home-range patterns, trespassing rates, and consumption of native prey. In established home ranges, coyotes visited and foraged at stations regularly and were found closer to stations during the treatment period. Although there was no overall treatment effect on home-range size (F = 1.66, d.f. = 5, P = 0.15), home ranges without supplemental food remained stable in size, whereas home ranges that had received supplemental food increased during the posttreatment period (t = 2.09, d.f. = 1, P = 0.04). Core areas showed a similar trend; there was no overall treatment effect (F = 1.51, d.f. = 2, P = 0.24); however, core areas of home ranges that received supplemental food were smaller than those of controls during the treatment period (t = 2.71, d.f. = 1, P < 0.01). There were no statistical differences in occurrence of any species, such as small mammals or white-tailed deer (Odocoileus virginianus), in scats of treatment versus control coyotes. Coyotes within the study site after removals were located closer to feeding stations during treatment than posttreatment (F = 8.83, d.f. = 1, P < 0.02, n = 897) periods, yet home-range size with supplemental food was larger than home-range size during the posttreatment period. Our findings suggest that a resource other than food influences coyote spatial patterns.

The population of black howler monkeys (Alouatta pigra) at the Lamanai Archaeological Reserve in northwestern Belize was studied for a total of 11.5 months during 2 wet and 2 dry seasons between October 1993 and May 1995. We estimated home-range size and range overlap of troops in order to examine territoriality, and tested the null hypothesis that the population is uniformly distributed throughout the reserve in order to examine habitat use. Home-range sizes were similar to those at Bermudian Landing, Belize, but smaller than those at Tikal, Guatemala. Mean home-range size was estimated as 15.3 ha with 52% overlap based on a 1.0-ha grid. There was no evidence for territoriality. Population distribution was generally uniform, but ruin sites appeared to be preferred habitat and edge habitat was least frequented.

The wild boar (Sus scrofa) is a large, sexually dimorphic ungulate that exhibits a life-history tactic different from what would be predicted for a mammal of its size. In particular, litter size is larger and adult survival usually lower in wild boars than in other species of comparable size. We used capture–mark–recapture methods to model survival in a Mediterranean population (S. s. majori) of wild boars during an 8-year period, using a large sample of individually tagged animals of known age, to investigate demographic patterns and the effects of variable environmental conditions (e.g., summer droughts), which are believed to have a strong impact on the demography of this species. Contrary to the predictions based on our current knowledge of life-history theory, survival of wild boars differed less among age classes and between sexes than has been reported in other large mammals. As predicted from current theories on sexual selection, the impact of environmental factors was stronger on males than on females. This study documents for wild boars a life-history tactic different from the accepted model for large ungulates but similar to the tactic observed in small terrestrial mammals.

The long-term viability of small, isolated populations has been questioned in light of stochasticity and bottlenecks. Following a drought in northwestern Montana in 2003, the pronghorn (Antilocapra americana) of the National Bison Range experienced a demographic bottleneck. We used information theoretic approaches to examine the influence of sex, age, genetic variation, summer lactation, mate-search effort by females, and mating effort by males on subsequent winter survival and spring fecundity. Survival of males was influenced by age, whereas survival of females was influenced by prior energy expenditure and genetic variation, implicating inbreeding depression as the mechanism. Fecundity of females also was influenced by prior energy expenditure and genetic variation, with heterosis as the apparent mechanism. Our results agree with those of other studies that have emphasized the need to maintain genetic variation and limit inbreeding in small, isolated populations, and to account for stochasticity in population viability assessments and long-term management planning.

Nutritional restriction during growth can have short- and long-term effects on fitness; however, animals inhabiting uncertain environments may exhibit adaptations to cope with variation in food availability. We examined changes in body mass in free-ranging female caribou (Rangifer tarandus) by measuring mass at birth and at 4, 11, and 16 months of age to evaluate the relative importance of seasonal nutrition to growth, the persistence of cohort-specific variation in body mass through time, and compensatory growth of individuals. Relative mean body mass of cohorts did not persist through time. Compensatory growth of smaller individuals was not observed in summer; however, small calves exhibited more positive change in body mass than did large calves. Compensation occurred during periods of nutritional restriction (winter) rather than during periods of rapid growth (summer) thus differing from the conventional view of compensatory growth.

The red-tailed phascogale (Phascogale calura) is an endangered dasyurid from southwestern Western Australia that has been bred in captivity since 2001. It is an annual breeder that has a restricted breeding period, and males only participate in a single breeding season. We examined the reproductive biology of female red-tailed phascogales, assessing methods for detection of estrus, variation in the timing of breeding in captivity across facilities and years, and reproductive success. Body mass and pouch changes were useful indicators of estrus, whereas assays for fecal estradiol and progesterone did not allow for accurate prediction of ovulation. Females mated with multiple males and matings occurred over a period of at least 5 days, with females storing sperm in the lumen and crypts of the oviduct. Births tended to occur in July at Alice Spring Desert Park, with births at Adelaide Zoo occurring from early June to late August. The predictable births at Alice Springs are similar to those observed with Antechinus, but with flexibility remaining in the reproductive strategy of the species as observed at Adelaide. Of the 146 breeding females at Alice Springs, 127 females produced 846 pouch young, of which 68% were weaned. A female bias was observed in weaned young. Information gained from this study has been incorporated into the captive-breeding program for this species.

Rates of metabolism and body temperatures were measured as a function of ambient temperature in 6 species of cuscuses, including 5 species of Phalanger and 1 species of Spilocuscus from Papua New Guinea. These species had basal rates that are typical of marsupials. Basal rate of metabolism correlated with activity level, with active species having basal rates that averaged 18% greater than inactive species. Body mass and activity level accounted for 96.6% of the variation in phalangerid basal rates. The uniformity in marsupial basal rate, independent of body mass, reflects a form of reproduction that cannot exploit high basal rates. Montane species tended to have lower thermal conductances than generally found in species limited to low altitudes.

Locomotion in land and water requires different adaptations, hence semiaquatic mammals must deal with conflicting demands of the 2 environments. Semiaquatic rodents of the tribe Oryzomyini are considered semiaquatic mostly based on habitat use and morphology, but locomotory specializations were not yet determined for most species of the group. We compared water absorption of the fur and swimming behavior between 2 species of oryzomyine water rats (Nectomys) and 2 terrestrial species of Cerradomys. We used adult rodents captured in the wild but acclimated to laboratory conditions. Water absorption rate was determined by the relative increase in body mass after a 5-min swimming session. Animals were videotaped swimming in an aquarium to determine gaits, body posture, maneuverability, and speed. Water absorption rate was significantly lower in semiaquatic species, with no significant difference between sexes. Bipedal paddling was the more frequently used gait by all 4 species, but semiaquatic species were faster and maintained a more hydrodynamic body posture, with a short gliding phase during the gait cycle. Only semiaquatic species were capable of floating effortlessly, and used the swimming bound, a gait similar to the half bound of terrestrial locomotion. Submerged swimming was the fastest swimming gait, used by 1 terrestrial and 1 semiaquatic species. The better performance during bipedal swimming of semiaquatic water rats was related to the improved buoyancy provided by reduced water absorption of the fur, which seemed to represent an important adaptation to move in the water without compromising locomotion on land.

The suitability of a habitat to an animal includes food availability, physical and climatic factors, population interactions, and safety from predators. Mappings of vegetation, soils, and microclimates across ecological landscapes have become standard and important tools for assessing an animal's habitat. More elusive to the researcher, yet of equal importance to the animal, has been the ability to map the predation risk perceived by an animal. Laundré et al., in developing the concept, defined the landscape of fear as the spatial map of the animal's predation cost of foraging. We mapped this landscape of predation costs by measuring the use of depletable food patches (yielding giving up densities [GUDs]) arranged as a grid across the landscape of interest. The landscapes of fear for 3 colonies of Cape ground squirrels (Xerus inauris) in Augrabies Falls National Park, South Africa, revealed large and distinct spatial variation in predation costs that appeared to be governed primarily by proximity to burrows and open sight lines. By converting the GUDs into quitting harvest rates (joules per minute), we believe we have translated the animals' perceptions of risk into a physical map whose contours across the landscape represent lines of equal foraging costs. Among the 3 colonies only 3–22% of the space resulted in low foraging costs (<2,500 J/min), whereas 31–92% of the sampled areas represented very high foraging costs (>5,000 J/min).

We collected long-term indices of mammalian abundance at 2 sites in the Great Basin: Curlew Valley in northern Utah, and the Idaho National Laboratory in southeastern Idaho. Abundance patterns were examined for 1 predator, the coyote (Canis latrans), and its prey community including 9 species of rodents and 3 species of lagomorphs. Our results suggest cycles with a period of 10–11 years among the main prey species, Lepus californicus. Responses of C. latrans to prey fluctuations were variable among study areas, with abundance levels of coyotes remaining high during declines in prey populations in Curlew Valley. Abundance indices were generally low for all species of rodents except Peromyscus maniculatus. Although many of the rodents demonstrated consistent biannual fluctuations, we could not statistically confirm multiseasonal cyclic patterns. Population levels of coyotes seem to reflect a combination of factors including abundance of both monitored species of prey and alternate prey groups, and human harvest.

We used nitrogen isotope analysis from pectoral muscle of the Egyptian fruit bat Rousettus aegyptiacus (Chiroptera: Pteropodidae) to determine intrapopulation variation in sources of dietary protein throughout the year in northern Israel. In Mediterranean climates, winter and summer are stable seasons, whereas spring and fall are transitional seasons. Number of species of fruit-bearing plants is higher during the transitional periods, and we therefore predicted that intrapopulation variation would be higher during spring than in winter and summer; we made no prediction for fall because sample size was small. We also reconstructed sources of dietary protein for each individual using nitrogen isotope ratios (δ¹⁵N) to determine whether individuals foraged on the same sources of food within each season. Intrapopulation variation in δ¹⁵N was significantly higher in spring (δ¹⁵N range: 9.7–17.5‰) compared to winter (8.8–11.1‰) and summer (9.5–11.2‰), suggesting that individuals during this period varied more in their use of protein sources. Dietary reconstruction revealed intrapopulation partitioning among the bats in the use of plant food items, and interspecific partitioning among plants in their dependence on dispersal by bats.

We investigated food habits and relationships between food resource abundance and activity of bats. We identified prey remains in guano collected from 337 individuals in the Oregon Coast Range. Guano analyses indicated that 2 species, long-legged myotis (Myotis volans) and Townsend's big-eared bat (Corynorhinus townsendii), consumed predominantly Lepidoptera; 4 species, California myotis (M. californicus), little brown myotis (M. lucifugus), Yuma myotis (M. yumanensis), and silver-haired bat (Lasionycteris noctivagans), consumed predominantly smaller insects likely of aquatic origin (Diptera and Trichoptera); and the remaining 4 species, long-eared myotis (M. evotis), fringed myotis (M. thysanodes), big brown bat (Eptesicus fuscus), and hoary bat (Lasiurus cinereus), consumed predominantly larger invertebrates of terrestrial origin (Lepidoptera, Coleoptera, Hemiptera, and Araneae). We hypothesized that bat activity in riparian areas would be correlated with abundance of preferred insect prey and used an information-theoretic approach to determine whether variability in bat activity was more strongly associated with captures of all insects, of taxa most frequently occurring in the diet, or of particular size classes of insects. We found strong associations between activity of small Myotis species and number of captures of small insects, but activities of larger Myotis species and of non-Myotis species were not associated with numbers of insects of any category.

Monitoring the dynamics and status of populations of harbor seals (Phoca vitulina richardii) requires efficient methods for estimating population parameters from mark–resight data. We used a test set of photographs from 182 individuals identified by flipper tags, scars, or unique pelage markings to test whether individuals could be identified accurately by their ventral pelage markings; to document efficiency and misidentification error rate associated with a computer-assisted photograph-matching system; and to test for bias in mark–recapture survival estimates resulting from misidentification errors. Pelage patterns of seals that were not of dark-intermediate or intermediate color phase were unique and stable from birth until 6–8 years, and from year to year as adults. The computer-assisted system greatly improved efficiency of photograph matching: 93.3% of good photographs and 69.9% of all photographs ranked 1st, and 95.2% of good photographs ranked in the top 0.3% of the ordered list for visual checking. Additional visual matching error averaged <3.0% for good photographs, and overall misidentification error rate was low at 1.8%, due to the availability of multiple photographs for matching. Inclusion of poor-quality photographs reduced ranking success by ∼20% and increased additional visual matching error up to 20%. Bias in survival estimates was −7.0% for a misidentification rate of 8.8%, but was ≤1.1% for misidentification rates of <2.7%, achieved by restricting data to only good photos. Our study suggests that estimation of misidentification error rate, inclusion of only high-quality photographs, or use of models that account for misidentification error, are required to prevent bias in mark–recapture survival estimates when using data from natural-marking studies.

Agonistic behavior in territorial male California sea lions (Zalophus californianus) may be influenced by multiple factors, including who initiates an interaction and who owns the territory on which an encounter takes place. We studied predictors of the outcomes of agonistic interactions between territorial male California sea lions on 3 islands (Los Islotes, Granito, and San Jorge) in the Gulf of California, Mexico, during the 2005 breeding season. We evaluated both displays and fights among males to examine the hypotheses that initiators of agonistic interactions and that territory owners were more likely to win disputes. The outcomes of agonistic encounters (win or lose) were independent of the types of interaction (displays or fights) by the initiator and, hence, all agonistic interactions were pooled for analyses. We used an overdispersed binomial logistic regression to determine if initiators and resident males were more likely to win an interaction than noninitiators and nonresidents, respectively. We found that initiators of agonistic interactions were more likely to win agonistic disputes. Resident and nonresident males were equally likely to initiate agonistic interactions and were also equally likely to win agonistic disputes. Our results suggest that agonistic interactions among male California sea lions are influenced by which individual initiates the encounter and not by territory ownership.

In northern Patagonia, South American sea lions (Otaria flavescens) are increasing in number after a depletive harvest. There has been an expansion of colonies with an increase in numbers of pups, and changes in social composition and spatial distribution. Using annual counts of 4 different age classes from 1972 to 2007, we found that new colonies change their social composition, transforming from haul-out sites to breeding sites while passing through mixed structures. From this pattern, we hypothesize that at dense breeding sites the shortage of space or the avoidance of intraspecific harassment promotes dispersal by 1st-time breeders to suitable sites nearby. Such mechanisms, along with philopatry and site fidelity, will promote the establishment of new breeding colonies nearer to existing breeding colonies than would be expected by chance. There was significant spatial clustering of new breeding colonies around the 7 focal (established) colonies. This spatial pattern was consistent through time. New breeding colonies were closer to focal colonies than are nonbreeding ones, suggesting a “spill-over” effect, where young individuals choose to breed near established breeders. The colonization mechanism we found suggests that potential areas for population expansion could be closer to areas where growing colonies already exist and highlights the importance of the juvenile age classes and the areas adjacent to colonies in the overall recovery of any population of pinnipeds.

Whistles are narrowband, frequency-modulated sounds produced by many cetaceans. Whistles are extensively studied in delphinids, where several factors have been proposed to explain between- and within-species variation. We examined factors associated with geographic variation in whistles of common bottlenose dolphins (Tursiops truncatus) by assessing the role of ambient noise, noise from boats, and sympatry with other dolphin species, and reviewing and comparing whistle structure across populations in the western and eastern Atlantic Ocean. Whistles of adjacent populations differed, particularly in frequency parameters. A combination of factors may contribute to microgeographic whistle variation, including differences in ambient noise levels (dolphins produced relatively higher frequency whistles in the noisiest habitat), and differences in number of boats present (when multiple boats were present, dolphins whistled with greater frequency modulation and whistles were higher in maximum frequency and longer than when a single boat was present). Whistles produced by adjacent populations were relatively similar in structure. However, for clearly separated populations, the distance between them did not relate directly to whistle structure. We propose that plasticity in bottlenose dolphin whistles facilitates adaptation to local and changing conditions of their habitat, thus promoting variation between populations at different geographic scales.

Standardized measures of behavior can be powerful tools for predicting effects of human activities on natural populations of mammals. We quantified the diurnal activity budget of dusky dolphins (Lagenorhynchus obscurus) in Golfo Nuevo, Argentina, by examining variation in activity as a function of season and age composition of social groups. Observations were made from a research vessel during summer and autumn from 2001 to 2005. Focal group-follow methodology was used. The predominant activity in each social group was recorded using instantaneous sampling, with a 2-min interscan interval. The main daytime activity of dusky dolphins was traveling, followed by milling and feeding. Mother and calf pairs spent more time milling and resting, whereas larger groups of adults and juveniles as well as mixed–age-class groups spent more time traveling and feeding. Although a seasonal pattern of variation in group size and composition was found, little seasonal variation was found in activity budgets, which were almost constant during daylight hours. The activity budget generated by this study provides a baseline for detection of behavioral differences associated with tourism and other human activity in the region.

We examined the stomach contents of 87 finless porpoises (Neophocaena phocaenoides) in the Ariake Sound–Tachibana Bay area and Omura Bay in western Kyushu, Japan, between 1987 and 1992. Fish (Gobiidae and Atherinidae) were the most numerous and most frequently occurring prey in Omura Bay, whereas both cephalopods (Octopodidae, Sepiidae, Sepiolidae/Sepiidae, and Loliginidae) and fishes (Clupeidae, Engraulidae, and Sciaenidae) were equally important in Ariake Sound–Tachibana Bay. Species compositions in the commercial catch differed between the 2 waters, suggesting that differences in prey availability may explain the geographical variation in diet. Finless porpoises in Ariake Sound–Tachibana Bay showed ontogenetic and seasonal variations in diet. The mean length at weaning was estimated to be 101 cm, corresponding to approximately 6 months of age. Calves fed on small-sized demersal fish and cephalopods. The predominant prey species for sexually mature individuals (including lactating females) consisted of konoshiro gizzard shad (Konosirus punctatus) and cephalopods. Seasonal availability of these organisms may be related to births in the fall–winter season in Ariake Sound–Tachibana Bay. Size-dependent prey selectivity was equivocal. Day–night difference in foraging time was not indicated by the index of stomach fullness.

Elephant-shrews (also called sengis, order Macroscelidea) are small-bodied insectivorous mammals with a strictly African distribution. Fifteen species currently are recognized, of which 9 occur in the southern African subregion. On the basis of molecular, cytogenetic, and morphological evidence, Elephantulus edwardii, the only strictly South African endemic species, is shown to comprise 2 closely related taxa. The new Elephantulus taxon described herein is from the central Nama-Karoo region of Western Cape and Northern Cape Provinces. Important genetic distinctions underpin its delimitation. Sequence data from the mitochondrial cytochrome-bgene and the hypervariable control region as well as 7th intron of the nuclear fibrinogen gene show these 2 taxa to be reciprocally monophyletic. They are separated by 13.8% sequence divergence (uncorrected) based on the 2 mitochondrial segments, and 4.2% based on the nuclear intron sequences. In addition, fixed cytogenetic differences include a centromeric shift, heterochromatic differences on autosomal pairs 1–6, and the number of nucleolar organizer regions. The new species has several subtle morphological and phenotypic characters that distinguish it from its sibling species E. edwardii, the most striking of which is the presence of a tail-tuft, as well as the color of the flanks and the ventral pelage. The abundance, detailed distribution of the new form, and its life-history characteristics are not known, and further studies clearly are needed to determine its conservation status.

Based on a right maxillary with 1st molar recovered in Pleistocene (Ensenadan) deposits from south-central Buenos Aires Province, Argentina, a new genus and species of Oryzomyini (Rodentia, Cricetidae) is named and described. The new taxon is one of the largest known extinct or extant sigmodontines, morphologically related to the marsh rats Holochilus, †Noronhomys, and Pseudoryzomys. It can be differentiated from these taxa by the combination of several traits in the 1st upper molar, in particular a well-developed mesoloph and the free connection of both para- and protoflexus. The occurrence of this sigmodontine suggests warmer and probably moister conditions during deposition times, a hypothesis reinforced by other vertebrates exhumed together (e.g., turtles, coypus, and the giant armadillo †Propraopus).

Peromyscine mice of the cricetid subfamily Neotominae comprise the most common and speciose assemblage of North American rodents. The composition and phylogenetic relationships within this group have been addressed using multiple character systems but remain unresolved, particularly the branching pattern of deeply rooted lineages. The relationships and status of several taxa formerly included within Peromyscus also are controversial. We present a new phylogenetic hypothesis based on combined mitochondrial and nuclear sequences using cytochrome b, interphotoreceptor retinoid-binding protein, and growth hormone receptor gene sequences, and include all major peromyscine lineages. Bayesian and parsimony approaches recover a congruent, well-resolved phylogeny, wherein Peromyscus forms a monophyletic assemblage only if a number of putative genera are included within it. Onychomys rather than Reithrodontomys is the sister taxon to Peromyscus (within which are included Habromys, Osgoodomys, Megadontomys, Podomys, and Neotomodon). Reithrodontomys in turn is the sister taxon to Isthmomys, and these 2 genera are the nearest outlier to Onychomys plus an expanded concept of Peromyscus, consistent with the recent recognition of this entire group as the tribe Reithrodontomyini. The Baiomyini, Ochrotomyini, and Neotoma (Neotomini) appear as successive outgroups to this clade. Based on these results, we present a systematic review of higher-level relationships among peromyscine rodents.

The genus Hylopetes consists of 8 or 9 species of small flying squirrels. There has been much nomenclatural confusion over 3 of these species: H. platyurus (the gray-cheeked flying squirrel), H. spadiceus (the red-cheeked flying squirrel), and H. lepidus (the pink-cheeked flying squirrel). To address this taxonomic problem, we examined museum specimens and quantified pelage coloration, tail shape, and a number of craniodental characters. A discriminant analysis of craniodental variables discriminated among the 3 species and allocated all specimens correctly (P < 0.00001). We found that simple ratios of craniodental measurements coupled with pelage coloration characters can assist in the identification of these problematic species, although tail shape was not useful for discrimination. Based on our results as well as historical accounts and what is known about the biogeographical patterns of the region, we provide a description and discussion of the distributions for these species.

We phylogenetically analyze 705 base pairs of the cytochrome-b gene and 351 amplified fragment length polymorphism (AFLP) bands from populations of the karyotypically variable Wagner's bonneted bat, Eumops glaucinus, and the Florida bonneted bat, Eumops floridanus (Chiroptera: Molossidae). Three karyotypes have been documented across the range of E. glaucinus, and we report that the karyotype from Cuba is morphologically similar to that from Jamaica. A 4th karyotype is present in specimens from western Ecuador. Three distinct lineages are present in both the cytochrome-b and AFLP trees. One lineage is restricted to western Ecuador and exhibits cytochrome-b divergence values comparable to the values seen between recognized species of Eumops, suggesting that this lineage represents a distinct species. The other 2 lineages are distributed in disjunct areas: Paraguay and Venezuela; and Mexico, the Caribbean, and the United States. Specimens of E. floridanus are morphologically distinct from E. glaucinus, but cannot be distinguished by examination of cytochrome-b or AFLP DNA data. We conclude that there are 4 species in the E. glaucinus complex—E. glaucinus (South America east of the Andes), E. ferox (Caribbean, Mexico, and Central America), E. floridanus in south Florida, and an unnamed taxon in western Ecuador. Speciation is a complex process and no single mechanism, model, concept, or definition is likely to cover all the diverse patterns observed.

On the basis of molecular and morphological evidence, Mormopterus acetabulosus, hitherto considered an endemic to the Mascarene Islands (Mauritius and La Réunion), is shown to comprise 2 closely related taxa. The holotype of M. acetabulosus is from Mauritius and the new taxon described herein is from La Réunion. M. acetabulosus from Mauritius is notably larger than members of this genus from La Réunion, and several soft-part and cranial characters distinguish these 2 taxa. This conclusion is supported by examination of mitochondrial DNA control region data for 141 bats, which shows these 2 groups to be reciprocally monophyletic, separated by an average of 5.01% uncorrected sequence divergence. Two nuclear intron regions (7th intron of the beta fibrinogen gene and thyrotropin) also were included, but showed limited genetic variation and no fixed differences between the 2 taxa. These 2 species of Mormopterus are common on Mauritius and La Réunion, often living in caves or synanthropically, and are not considered a conservation concern.