Behavioral modifications lead to disparate demographic consequences in two sympatric species

Life‐history theory suggests species that typically have a large number of offspring and high adult mortality may make decisions that benefit offspring survival in exchange for increased adult risks. Such behavioral adaptations are essential to understanding how demographic performance is linked to habitat selection during this important life‐history stage. Though studies have illustrated negative fitness consequences to attendant adults or potential fitness benefits to associated offspring because of adaptive habitat selection during brood rearing, equivocal relationships could arise if both aspects of this reproductive trade‐off are not assessed simultaneously. To better understand how adaptive habitat selection during brood rearing influences demographics, we studied the brood survival, attendant parental survival, and space use of two sympatric ground‐nesting bird species, the northern bobwhite (hereafter: “bobwhite”; Colinus virgininanus) and scaled quail (Callipepla squamata). During the 2013–2014 breeding seasons, we estimated habitat suitability across two grains (2 m and 30 m) for both species and determined how adult space use of these areas influenced individual chick survival and parental risk. We found the proportion of a brood's home range containing highly suitable areas significantly increased bobwhite chick survival (β = 0.02, SE = 0.006). Additionally, adult weekly survival for bobwhite was greater for individuals not actively brooding offspring (0.9716, SE = 0.0054) as compared to brooding adults (0.8928, SE = 0.0006). Conversely, brood habitat suitability did not influence scaled quail chick survival during our study, nor did we detect a survival cost for adults that were actively brooding offspring. Our research illustrates the importance of understanding life‐history strategies and how they might influence relationships between adaptive habitat selection and demographic parameters.     

Range‐wide multilocus phylogeography of the red fox reveals ancient continental divergence,minimal genomic exchange and distinct demographic histories

Widely distributed taxa provide an opportunity to compare biogeographic responses to climatic fluctuations on multiple continents and to investigate speciation. We conducted the most geographically and genomically comprehensive study to date of the red fox (Vulpes vulpes), the world's most widely distributed wild terrestrial carnivore. Analyses of 697 bp of mitochondrial sequence in ~1000 individuals suggested an ancient Middle Eastern origin for all extant red foxes and a 400 kya (SD = 139 kya) origin of the primary North American (Nearctic) clade. Demographic analyses indicated a major expansion in Eurasia during the last glaciation (~50 kya), coinciding with a previously described secondary transfer of a single matriline (Holarctic) to North America. In contrast, North American matrilines (including the transferred portion of Holarctic clade) exhibited no signatures of expansion until the end of the Pleistocene (~12 kya). Analyses of 11 autosomal loci from a subset of foxes supported the colonization time frame suggested by mtDNA (and the fossil record) but, in contrast, reflected no detectable secondary transfer, resulting in the most fundamental genomic division of red foxes at the Bering Strait. Endemic continental Y‐chromosome clades further supported this pattern. Thus, intercontinental genomic exchange was overall very limited, consistent with long‐term reproductive isolation since the initial colonization of North America. Based on continental divergence times in other carnivoran species pairs, our findings support a model of peripatric speciation and are consistent with the previous classification of the North American red fox as a distinct species, V. fulva.     

Phylogeography of Heliconius cydno and its closest relatives: disentangling their origin and diversification

The origins of the extraordinary diversity within the Neotropics have long fascinated biologists and naturalists. Yet, the underlying factors that have given rise to this diversity remain controversial. To test the relative importance of Quaternary climatic change and Neogene tectonic and paleogeographic reorganizations in the generation of biodiversity, we examine intraspecific variation across the Heliconius cydno radiation and compare this variation to that within the closely related Heliconius melpomene and Heliconius timareta radiations. Our data, which consist of both mtDNA and genome‐scan data from nearly 2250 amplified fragment length polymorphism (AFLP) loci, reveal a complex history of differentiation and admixture at different geographic scales. Both mtDNA and AFLP phylogenies suggest that H. timareta and H. cydno are probably geographic extremes of the same radiation that probably diverged from H. melpomene prior to the Pliocene–Pleistocene boundary, consistent with hypotheses of diversification that rely on geological events in the Pliocene. The mtDNA suggests that this radiation originated in Central America or the northwestern region of South America, with a subsequent colonization of the eastern and western slopes of the Andes. Our genome‐scan data indicate significant admixture among sympatric H. cydno/H. timareta and H. melpomene populations across the extensive geographic ranges of the two radiations. Within H. cydno, both mtDNA and AFLP data indicate significant population structure at local scales, with strong genetic differences even among adjacent H. cydno colour pattern races. These genetic patterns highlight the importance of past geoclimatic events, intraspecific gene flow, and local population differentiation in the origin and establishment of new adaptive forms.     

Contrasting responses to Pleistocene climate changes: a case study of two sister species Allium cyathophorum and A. spicata (Amaryllidaceae) distributed in the eastern and western Qinghai–Tibet Plateau

It has been hypothesized that species occurring in the eastern and the western Qinghai–Tibet Plateau (QTP) responded differently to climate changes during the Pleistocene. Here, we test this hypothesis by phylogeographic analysis of two sister species, Allium cyathophorum and A. spicata. We sequenced two chloroplast DNA (cpDNA) fragments (accD‐psaI and the rpl16 intron) of 150 individuals, and the nuclear (ITS) region of 114 individuals, from 19 populations throughout the distributional ranges of these species. The divergence between the two species was dated at 779 ‐ 714 thousand years before the present and was likely initiated by the most major glaciation in the QTP. Analysis of chlorotype diversity showed that A. spicata, the species occurring in the western QTP, contains much lower genetic diversity (0.25) than A. cyathophorum (0.93), which is distributed in the eastern QTP. Moreover, multiple independent tests suggested that the A. spicata population had expanded recently, while no such expansion was detected in A. cyathophorum, indicating a contrasting pattern of responses to Pleistocene climate changes. These findings highlight the importance of geographical topography in determining how species responded to the climate changes that took place in the QTP during the Pleistocene.     

Variation in behavioral traits of two frugivorous mammals may lead to differential responses to human disturbance

Human activities can lead to a shift in wildlife species’ spatial distribution. Understanding the specific effects of human activities on ranging behavior can improve conservation management of wildlife populations in human‐dominated landscapes. This study evaluated the effects of forest use by humans on the spatial distribution of mammal species with different behavioral adaptations, using sympatric western lowland gorilla and central chimpanzee as focal species. We collected data on great ape nest locations, ecological and physical variables (habitat distribution, permanent rivers, and topographic data), and anthropogenic variables (distance to trails, villages, and a permanent research site). Here, we show that anthropogenic variables are important predictors of the distribution of wild animals. In the resource model, the distribution of gorilla nests was predicted by nesting habitat distribution, while chimpanzee nests were predicted first by elevation followed by nesting habitat distribution. In the anthropogenic model, the major predictors of gorilla nesting changed to human features, while the major predictors of chimpanzee nesting remained elevation and the availability of their preferred nesting habitats. Animal behavioral traits (body size, terrestrial/arboreal, level of specialization/generalization, and competitive inferiority/superiority) may influence the response of mammals to human activities. Our results suggest that chimpanzees may survive in human‐encroached areas whenever the availability of their nesting habitat and preferred fruits can support their population, while a certain level of human activities may threaten gorillas. Consequently, the survival of gorillas in human‐dominated landscapes is more at risk than that of chimpanzees. Replicating our research in other sites should permit a systematic evaluation of the influence of human activity on the distribution of mammal populations. As wild animals are increasingly exposed to human disturbance, understanding the resulting consequences of shifting species distributions due to human disturbance on animal population abundance and their long‐term survival will be of growing conservation importance.     

Genomic patterns in the widespread Eurasian lynx shaped by Late Quaternary climatic fluctuations and anthropogenic impacts

Disentangling the contribution of long‐term evolutionary processes and recent anthropogenic impacts to current genetic patterns of wildlife species is key to assessing genetic risks and designing conservation strategies. Here, we used 80 whole nuclear genomes and 96 mitogenomes from populations of the Eurasian lynx covering a range of conservation statuses, climatic zones and subspecies across Eurasia to infer the demographic history, reconstruct genetic patterns, and discuss the influence of long‐term isolation and/or more recent human‐driven changes. Our results show that Eurasian lynx populations shared a common history until 100,000 years ago, when Asian and European populations started to diverge and both entered a period of continuous and widespread decline, with western populations, except Kirov, maintaining lower effective sizes than eastern populations. Population declines and increased isolation in more recent times probably drove the genetic differentiation between geographically and ecologically close westernmost European populations. By contrast, and despite the wide range of habitats covered, populations are quite homogeneous genetically across the Asian range, showing a pattern of isolation by distance and providing little genetic support for the several proposed subspecies. Mitogenomic and nuclear divergences and population declines starting during the Late Pleistocene can be mostly attributed to climatic fluctuations and early human influence, but the widespread and sustained decline since the Holocene is more probably the consequence of anthropogenic impacts which intensified in recent centuries, especially in western Europe. Genetic erosion in isolated European populations and lack of evidence for long‐term isolation argue for the restoration of lost population connectivity.     

Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus

Comparative phylogeography offers a unique opportunity to understand the interplay between past environmental events and life‐history traits on diversification of unrelated but co‐distributed species. Here, we examined the effects of the quaternary climate fluctuations and palaeomarine currents and present‐day marine currents on the extant patterns of genetic diversity in the two most conspicuous mangrove species of the Neotropics. The black (Avicennia germinans, Avicenniaceae) and the red (Rhizophora mangle, Rhizophoraceae) mangroves have similar geographic ranges but are very distantly related and show striking differences on their life‐history traits. We sampled 18 Atlantic and 26 Pacific locations for A. germinans (N = 292) and R. mangle (N = 422). We performed coalescence simulations using microsatellite diversity to test for evidence of population change associated with quaternary climate fluctuations. In addition, we examined whether patterns of genetic variation were consistent with the directions of major marine (historical and present day) currents in the region. Our demographic analysis was grounded within a phylogeographic framework provided by the sequence analysis of two chloroplasts and one flanking microsatellite region in a subsample of individuals. The two mangrove species shared similar biogeographic histories including: (1) strong genetic breaks between Atlantic and Pacific ocean basins associated with the final closure of the Central American Isthmus (CAI), (2) evidence for simultaneous population declines between the mid‐Pleistocene and early Holocene, (3) asymmetric historical migration with higher gene flow from the Atlantic to the Pacific oceans following the direction of the palaeomarine current, and (4) contemporary gene flow between West Africa and South America following the major Atlantic Ocean currents. Despite the remarkable differences in life‐history traits of mangrove species, which should have had a strong influence on seed dispersal capability and, thus, population connectivity, we found that vicariant events, climate fluctuations and marine currents have shaped the distribution of genetic diversity in strikingly similar ways.     

Extreme climatic events constrain space use and survival of a ground‐nesting bird

Two fundamental issues in ecology are understanding what influences the distribution and abundance of organisms through space and time. While it is well established that broad‐scale patterns of abiotic and biotic conditions affect organisms’ distributions and population fluctuations, discrete events may be important drivers of space use, survival, and persistence. These discrete extreme climatic events can constrain populations and space use at fine scales beyond that which is typically measured in ecological studies. Recently, a growing body of literature has identified thermal stress as a potential mechanism in determining space use and survival. We sought to determine how ambient temperature at fine temporal scales affected survival and space use for a ground‐nesting quail species (Colinus virginianus; northern bobwhite). We modeled space use across an ambient temperature gradient (ranging from ?20 to 38 °C) through a maxent algorithm. We also used Andersen–Gill proportional hazard models to assess the influence of ambient temperature‐related variables on survival through time. Estimated available useable space ranged from 18.6% to 57.1% of the landscape depending on ambient temperature. The lowest and highest ambient temperature categories (35 °C, respectively) were associated with the least amount of estimated useable space (18.6% and 24.6%, respectively). Range overlap analysis indicated dissimilarity in areas where Colinus virginianus were restricted during times of thermal extremes (range overlap = 0.38). This suggests that habitat under a given condition is not necessarily a habitat under alternative conditions. Further, we found survival was most influenced by weekly minimum ambient temperatures. Our results demonstrate that ecological constraints can occur along a thermal gradient and that understanding the effects of these discrete events and how they change over time may be more important to conservation of organisms than are average and broad‐scale conditions as typically measured in ecological studies.     

Non‐concordant phylogeographical patterns of three widely codistributed endemic Western Balkans lacertid lizards (Reptilia,Lacertidae) shaped by specific habitat requirements and different responses to Pleistocene climatic oscillations

The Balkan Peninsula is a hot spot for European herpetofaunal biodiversity and endemism. The rock climbing lizards Dalmatolacerta oxycephala and Dinarolacerta mosorensis and the ground‐dwelling Dalmatian wall lizard Podarcis melisellensis are endemic to the Western Balkans, and their ranges largely overlap. Here, we present a comparative phylogeographical study of these three species in the area of their codistribution in order to determine the level of concordance in their evolutionary patterns. Phylogenetic analyses were performed based on two mitochondrial genes (cytochrome b and 16S rRNA), and a molecular clock approach was used to date the most important events in their evolutionary histories. We also tested for correlations regarding genetic differentiation among populations and their geographical distances. For all three species, a significant correlation between genetic and geographical distances was found. Within D. oxycephala, two deeply separated clades (‘island’ and ‘mainland clade’), with further subdivision of the ‘mainland clade’ into two subclades (‘south‐eastern’ and ‘north‐western’), were found. High sequence divergences were observed between these groups. From our data, the time of separation of the two main clades of D. oxycephala can be estimated at about 5 mya and at about 0.8 mya for the two subclades of the mainland clade. Within D. mosorensis, coalescence time may be dated at about 1 mya, while D. mosorensis and D. montenegrina separated around 5 mya. The results imply the existence of complex palaeo‐biogeographical and geological factors that probably influenced the observed phylogeographical patterns in these lacertid species, and point to the presence of numerous glacial/interglacial refugia. Furthermore, the observed cryptic genetic diversity within the presently monotypic species D. oxycephala prompts for a revision of its taxonomic and conservation status.     

Winter survival of North American grassland birds is driven by weather and grassland condition in the Chihuahuan Desert

Populations of grassland birds that overwinter in the Chihuahuan Desert are declining more rapidly than other grassland birds, and survival during the non‐breeding season may have a strong influence on population trends of these species. Habitat loss and deterioration due to desertification may be contributing to these declines, and the winter ecology of grassland birds under these changing environmental conditions remains relatively unexplored. To fill this information gap, we estimated the survival of two grassland‐obligate sparrows, Baird's Sparrows (Ammodramus bairdii) and Grasshopper Sparrows (A. savannarum), on their wintering grounds in the Chihuahuan Desert, and investigated the role of habitat structure and weather on survival rates. We deployed radio‐transmitters on Baird's (N = 49) and Grasshopper (N = 126) sparrows near Janos, Chihuahua, and tracked birds from November to March during the winters of 2012–2013 and 2013–2014. Causes of mortality included avian predators, mammals, and possibly weather. We estimated an overall weekly winter survival probability of ? = 92.73% (95% CI[s] = 88.63–95.44%) for Baird's Sparrows in 2012–2013. We estimated a weekly winter survival probability of ? = 93.48% (95% CI[s] = 90.29–96.67%) and ? = 98.78% (95% CI[s] = 97.88–99.68%) for Grasshopper Sparrow in 2012–2013 and 2013–2014, respectively. Weekly winter survival was lower with colder daily minimum temperatures for both species and in areas with taller shrubs for Grasshopper Sparrows, with the shrubs potentially increasing predation risk by providing perches for Loggerhead Shrikes (Lanius ludovicianus). Our results highlight the need to maintain healthy grass structure in wintering areas to provide birds with food, protection from predators, and adequate cover from inclement weather. Our results also demonstrate that the presence of shrubs can lower winter survival, and suggest that shrub encroachment into the winter habitat of these sparrows may be an important driver of their population declines. Shrub removal could increase survival of wintering sparrows in the Chihuahuan Desert by reducing availability of perches for avian predators, thus reducing predation risk.     

Temporal,spatial and ecological dynamics of speciation among amphi‐Beringian small mammals

Aim

Quaternary climate cycles played an important role in promoting diversification across the Northern Hemisphere, although details of the mechanisms driving evolutionary change are still poorly resolved. In a comparative phylogeographical framework, we investigate temporal, spatial and ecological components of evolution within a suite of Holarctic small mammals. We test a hypothesis of simultaneous divergence among multiple taxon pairs, investigating time to coalescence and demographic change for each taxon in response to a combination of climate and geography.

Location

Beringia, the nexus of the northern continents.

Methods

We used approximate Bayesian computation methods to test for simultaneous divergence among eight pairs of taxa, using cytochrome b gene sequences. We calculated coalescence times for eastern and western components of each pair and for the combined pairs, and relate dates to Quaternary climatic periodicity and combinations of environmental events and physical barriers. Population growth and expansion statistics were used to test evolutionary responses among taxa, including range shifts, persistence or periodic extirpation. Species distribution models (SDMs) for each taxon were used to predict their geographical ranges during the present interglacial, Last Glacial Maximum and previous interglacial.

Results

Multiple divergence events across Beringia were primarily coincident with extreme glacial cycles of the late Quaternary. Structure within Beringia is spatially consistent with at least three environmental barriers arising at different times: the Kolyma Uplands, Bering Strait and portions of the Bering Isthmus. Levels of divergence varied substantially, indicating evolutionary processes spanning deep and shallow time‐scales. The different demographics among taxa reflect their distinct ecological responses. SDMs predicted regional distributional changes through time and different spatial responses among taxa.

Main conclusions

Beringia predominantly constituted a dispersal corridor during the early Quaternary and a major centre of endemism in the late Quaternary. Coincident with severe glacial cycles, small mammal species were ‘caught’ in Beringia and diversified over multiple climatic phases. Relative genetic differentiation across Beringia appears to be related to ecological differences reflecting a gradual adaptation to Beringian environments through time. Some methodological constraints associated with resolving recent (late Quaternary) isolation events or drawing inferences from a single locus are discussed.     

Quaternary range and demographic expansion of Liolaemus darwinii (Squamata: Liolaemidae) in the Monte Desert of Central Argentina using Bayesian phylogeography and ecological niche modelling

Until recently, most phylogeographic approaches have been unable to distinguish between demographic and range expansion processes, making it difficult to test for the possibility of range expansion without population growth and vice versa. In this study, we applied a Bayesian phylogeographic approach to reconstruct both demographic and range expansion in the lizard Liolaemus darwinii of the Monte Desert in Central Argentina, during the Late Quaternary. Based on analysis of 14 anonymous nuclear loci and the cytochrome b mitochondrial DNA gene, we detected signals of demographic expansion starting at ~55 ka based on Bayesian Skyline and Skyride Plots. In contrast, Bayesian relaxed models of spatial diffusion suggested that range expansion occurred only between ~95 and 55 ka, and more recently, diffusion rates were very low during demographic expansion. The possibility of population growth without substantial range expansion could account for the shared patterns of demographic expansion during the Last Glacial Maxima (OIS 2 and 4) in fish, small mammals and other lizards of the Monte Desert. We found substantial variation in diffusion rates over time, and very high rates during the range expansion phase, consistent with a rapidly advancing expansion front towards the southeast shown by palaeo‐distribution models. Furthermore, the estimated diffusion rates are congruent with observed dispersal rates of lizards in field conditions and therefore provide additional confidence to the temporal scale of inferred phylogeographic patterns. Our study highlights how the integration of phylogeography with palaeo‐distribution models can shed light on both demographic and range expansion processes and their potential causes.     

Mitochondrial introgressive hybridization following a demographic expansion in the tomato frogs of Madagascar,genus Dyscophus

Madagascar is a biodiversity hotspot with a unique fauna and flora largely endemic at the species level and highly threatened by habitat destruction. The processes underlying population‐level differentiation in Madagascar's biota are poorly understood and have been proposed to be related to Pleistocene climatic cycles, yet the levels of genetic divergence observed are often suggestive of ancient events. We combined molecular markers of different variability to assess the phylogeography of Madagascar's emblematic tomato frogs (Dyscophus guineti and D. antongilii) and interpret the observed pattern as resulting from ancient and recent processes. Our results suggest that the initial divergence between these taxa is probably old as reflected by protein‐coding nuclear genes and by a strong mitochondrial differentiation of the southernmost population. Dramatic changes in their demography appear to have been triggered by the end of the last glacial period and possibly by the short return of glacial conditions known as the 8K event. This dramatic change resulted in an approximately 50‐fold reduction of the effective population size in various populations of both species. We hypothesize these species' current mitochondrial DNA diversity distribution reflects a swamping of the mitochondrial genetic diversity of D. guineti by that of D. antongilii previous to the populations' bottlenecks during the Holocene, and probably as a consequence of D. antongilii demographic expansion approximately 1 million years ago. Our data support the continued recognition of D. antongilii and D. guineti as separate species and flag D. guineti as the more vulnerable species to past and probably also future environmental changes.     

Migration and isolation during the turbulent Ponto‐Caspian Pleistocene create high diversity in the crustacean Paramysis lacustris

The Ponto‐Caspian brackish‐water fauna inhabits estuaries and rivers of the Black, Azov and Caspian seas and is fragmented by higher salinity waters and a major interbasin watershed. The fauna is known for the high levels of endemism, complex zoogeographic histories, and as a recent source of successful invasive species. It remains debated whether the Black and Azov Sea brackish‐water populations survived unfavourable Pleistocene conditions in multiple separate refugia or whether the two seas were (repeatedly) recolonized from the Caspian. Using microsatellite and mtDNA markers, we demonstrate deep among‐ and within‐basin subdivisions in a widespread Ponto‐Caspian mysid crustacean Paramysis lacustris. Five genetic clusters were identified, but their relationships did not reflect the geography of the region. The Azov cluster was the most distinct (4–5% COI divergence), despite its geographic position in the corridor between Black and Caspian seas, and may represent a new species. In the northern Black Sea area, the Dnieper cluster was closer to the Caspian cluster than to the neighbouring Danube–Dniester–Bug populations, suggesting separate colonizations of the Black Sea. Overall, the data implied a predominant gene flow from the east to the Black Sea and highlight the importance of Caspian Sea transgressions in facilitating dispersal. Yet, the presence of distinct lineages in the Black Sea points to the persistence of isolated refugial populations that have gained diagnostic differences under presumably high mutation rates and large population sizes. The unfavourable Pleistocene periods in the Black Sea therefore appear to have promoted diversification of the brackish‐water lineages, rather than extirpated them.     

Nuclear locus divergence at the early stages of speciation in the Orchard Oriole complex

As two lineages diverge from one another, mitochondrial DNA should evolve fixed differences more rapidly than nuclear DNA due to its smaller effective population size and faster mutation rate. As a consequence, molecular systematists have focused on the criteria of reciprocal monophyly in mitochondrial DNA for delimiting species boundaries. However, mitochondrial gene trees do not necessarily reflect the evolutionary history of the taxa in question, and even mitochondrial loci are not expected to be reciprocally monophyletic when the speciation event happened very recently. The goal of this study was to examine mitochondrial paraphyly within the Orchard Oriole complex, which is composed of Icterus spurius (Orchard Oriole) and Icterus fuertesi (Fuertes' Oriole). We increased the geographic sampling, added four nuclear loci, and used a range of population genetic and coalescent methods to examine the divergence between the taxa. With increased taxon sampling, we found evidence of clear structure between the taxa for mitochondrial DNA. However, nuclear loci showed little evidence of population structure, indicating a very recent divergence between I. spurius and I. fuertesi. Another goal was to examine the genetic variation within each taxon to look for evidence of a past founder event within the I. fuertesi lineage. Based on the high amounts of genetic variation for all nuclear loci, we found no evidence of such an event – thus, we found no support for the possible founding of I. fuertesi through a change in migratory behavior, followed by peripheral isolates speciation. Our results demonstrate that these two taxa are in the earliest stages of speciation, at a point when they have fixed differences in plumage color that are not reflected in monophyly of the mitochondrial or nuclear DNA markers in this study. This very recent divergence makes them ideal for continued studies of species boundaries and the earliest stages of speciation.     

Patterns of diversification in two species of short‐tailed bats (Carollia Gray, 1838): the effects of historical fragmentation of Brazilian rainforests

The small‐sized frugivorous bat Carollia perspicillata is an understory specialist and occurs in a wide range of lowland habitats, tending to be more common in tropical dry or moist forests of South and Central America. Its sister species, Carollia brevicauda, occurs almost exclusively in the Amazon rainforest. A recent phylogeographic study proposed a hypothesis of origin and subsequent diversification for C. perspicillata along the Atlantic coastal forest of Brazil. Additionally, it also found two allopatric clades for C. brevicauda separated by the Amazon Basin. We used cytochrome b gene sequences and a more extensive sampling to test hypotheses related to the origin and diversification of C. perspicillata plus C. brevicauda clade in South America. The results obtained indicate that there are two sympatric evolutionary lineages within each species. In C. perspicillata, one lineage is limited to the Southern Atlantic Forest, whereas the other is widely distributed. Coalescent analysis points to a simultaneous origin for C. perspicillata and C. brevicauda, although no place for the diversification of each species can be firmly suggested. The phylogeographic pattern shown by C. perspicillata is also congruent with the Pleistocene refugia hypothesis as a likely vicariant phenomenon shaping the present distribution of its intraspecific lineages. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 527–539.