Comparative Seed Dispersal Effectiveness of Sympatric Alouatta guariba and Brachyteles arachnoides in Southeastern Brazil1

I compared the effectiveness of sympatric brown howlers (Alouatta guariba) and muriquis (Brachyteles arachnoides) as seed dispersers in terms of quantitative and qualitative attributes. I hypothesized that differences in feeding and behavioral patterns between these large‐bodied folivorous/frugivorous primates would lead to dissimilarities in their effectiveness as endozoochoric seed dispersal agents. The study was carried out in a semideciduous forest fragment of Fazenda Barreiro Rico, southeastern Brazil. Through behavioral sampling of frugivory and defecation events as well as analyses of fecal samples, I determined that A. guariba dispersed fewer species and produced a lower proportion of dung with intact seeds than B. arachnoides. There was no difference between the number of seeds in fecal samples of A. guariba and B. arachnoides. These primates affected to a similar degree both germination percentage and latency to germination of seeds they ingested or removed the pulp from. Howlers and muriquis were also similar in carrying seeds away from the parent trees. Contrary to muriquis, howlers defecated seeds under the canopy of conspecific lianas, where seeds are expected to suffer high mortality rates, and voided seeds predominantly in a clumped pattern. B. arachnoides was a more effective seed disperser when compared to A. guariba in some attributes evaluated, but not in others. Given the interspecific variation in recruitment patterns of tropical plants and the loss of frugivorous bird species at the study site, the differences between howlers and muriquis in their abilities as seed dispersers may crucially influence the composition and maintenance of seedling diversity.     

Diet of Southern Muriquis in Continuous Brazilian Atlantic Forest

We systematically collected data on feeding behavior for one group of 33–39 southern muriquis (Brachyteles arachnoides) in Parque Estadual Carlos Botelho (PECB), São Paulo State, Brazil (37,432.45 ha of continuous Atlantic Forest), between January and December 1995. We determined food item consumption from instantaneous scans of behavior. Fruits were the most eaten food items in all 12 mo (40–80% of scan in every mo, average = 71.3%). Muriquis ate young leaves more than mature leaves or flowers. Our results are consistent with previous findings at the same and neighboring forest sites that southern muriquis have a consistently frugivorous diet when inhabiting less disturbed habitats, but contrast with previous observations on oppportunistic frugivory in muriqui populations inhabiting fragmented forests. Sustained high levels of frugivory probably result from year-round availability of fruit within large continuous forests.     

Genetic diversity and population history of a critically endangered primate, the northern muriqui (Brachyteles hypoxanthus)

Social, ecological, and historical processes affect the genetic structure of primate populations, and therefore have key implications for the conservation of endangered species. The northern muriqui (Brachyteles hypoxanthus) is a critically endangered New World monkey and a flagship species for the conservation of the Atlantic Forest hotspot. Yet, like other neotropical primates, little is known about its population history and the genetic structure of remnant populations. We analyzed the mitochondrial DNA control region of 152 northern muriquis, or 17.6% of the 864 northern muriquis from 8 of the 12 known extant populations and found no evidence of phylogeographic partitions or past population shrinkage/expansion. Bayesian and classic analyses show that this finding may be attributed to the joint contribution of female-biased dispersal, demographic stability, and a relatively large historic population size. Past population stability is consistent with a central Atlantic Forest Pleistocene refuge. In addition, the best scenario supported by an Approximate Bayesian Computation analysis, significant fixation indices (Φ_ST = 0.49, Φ_CT = 0.24), and population-specific haplotypes, coupled with the extirpation of intermediate populations, are indicative of a recent geographic structuring of genetic diversity during the Holocene. Genetic diversity is higher in populations living in larger areas (>2,000 hectares), but it is remarkably low in the species overall (θ = 0.018). Three populations occurring in protected reserves and one fragmented population inhabiting private lands harbor 22 out of 23 haplotypes, most of which are population-exclusive, and therefore represent patchy repositories of the species'' genetic diversity. We suggest that these populations be treated as discrete units for conservation management purposes.     

Fruit diet of Alouatta guariba and Brachyteles arachnoides in Southeastern Brazil: comparison of fruit type, color, and seed size

Fruit is an important food resource for neotropical primates. In this study I compare the fruit diet of sympatric brown howlers (Alouatta guariba) and southern muriquis (Brachyteles arachnoides). Feeding behavior was studied over 12 months and fruit species consumed were identified and assigned to the categories fruit type, fruit color, and seed size. Observed-fruit feeding records were compared with expected records determined from local availability of the fruit of the tree species. I also determined dietary overlap. Fruit consumption occupied 8 and 12% of the feeding time of A. guariba and B. arachnoides, respectively. Fruit from eight tree species were consumed by the former and fruit from twenty-two species by the latter. Patterns of fruit selection of A. guariba and B. arachnoides varied widely. Although howlers and muriquis converge behaviorally by selecting fruit with common attributes (fleshy/unprotected, violet and brown/black-colored), unlike A. guariba, B. arachnoides fed on immature seeds of fleshy/protected and dry fruit. Large seeds were ingested, and defecated intact, by B. arachnoides only. There was little overlap of fruit diet even within categories that had been selected by both, suggesting that dietary divergence is occurring at the interspecific level. Different resource exploitation probably mediates the coexistence of A. guariba and B. arachnoides in low diversity, semideciduous forests, where the environment imposes narrow limits on primate food choices.     

Functional Redundancy and Complementarities of Seed Dispersal by the Last Neotropical Megafrugivores

Background

Functional redundancy has been debated largely in ecology and conservation, yet we lack detailed empirical studies on the roles of functionally similar species in ecosystem function. Large bodied frugivores may disperse similar plant species and have strong impact on plant recruitment in tropical forests. The two largest frugivores in the neotropics, tapirs (Tapirus terrestris) and muriquis (Brachyteles arachnoides) are potential candidates for functional redundancy on seed dispersal effectiveness. Here we provide a comparison of the quantitative, qualitative and spatial effects on seed dispersal by these megafrugivores in a continuous Brazilian Atlantic forest.

Methodology/Principal Findings

We found a low overlap of plant species dispersed by both muriquis and tapirs. A group of 35 muriquis occupied an area of 850 ha and dispersed 5 times more plant species, and 13 times more seeds than 22 tapirs living in the same area. Muriquis dispersed 2.4 times more seeds in any random position than tapirs. This can be explained mainly because seed deposition by muriquis leaves less empty space than tapirs. However, tapirs are able to disperse larger seeds than muriquis and move them into sites not reached by primates, such as large forest gaps, open areas and fragments nearby. Based on published information we found 302 plant species that are dispersed by at least one of these megafrugivores in the Brazilian Atlantic forest.

Conclusions/Significance

Our study showed that both megafrugivores play complementary rather than redundant roles as seed dispersers. Although tapirs disperse fewer seeds and species than muriquis, they disperse larger-seeded species and in places not used by primates. The selective extinction of these megafrugivores will change the spatial seed rain they generate and may have negative effects on the recruitment of several plant species, particularly those with large seeds that have muriquis and tapirs as the last living seed dispersers.     

New World primates,new frontiers: Insights from the woolly spider monkey,or muriqui (Brachyteles arachnoides)

Despite over 25 years of intensive research, much of our knowledge of primate behavior has been limited to a small number of Old World, semiterrestrial species. With the exception of chimpanzees, these species share consistent patterns of behavior, including aggressive competition between males, male dominance over females, male dispersal and female kin groups, that have come to characterize the Order Primates. However, as research has expanded to include a number of newly studied species, such generalizations about primate behavior are no longer appropriate. Data presented on the wooly spider monkey, or muriqui (Brachyteles arachnoides), provide examples of the ways in which traditional views of primate behavior are being reconsidered. In muriquis, and in several other New World monkeys, female kin groups do not occur because females disperse from their natal groups. In addition, aggressive competition between males is virtually absent; and, female muriquis appear to be codominant with males. Constraints on sexual dimorphism may help to explain why muriquis (and other New World primates) differ so fundamentally from the better known semi-terrestrial Old World monkeys.Logo of the 1988 International Primatological Society.     

Activity Patterns of <Emphasis Type="Italic">Brachyteles arachnoides</Emphasis> in the Largest Remaining Fragment of Brazilian Atlantic Forest

Time is an important currency for primate energetics, reproduction, and survival. Here, we describe the activity budgets of a group of southern muriquis (Brachyteles arachnoides) inhabiting the largest continuous fragment of Brazilian Atlantic Forest (210,000 ha) in Parque Estadual Carlos Botelho (24°44´–15´S, 47´46–10 W), in the southern region of São Paulo State. We collected instantaneous scan sampling data to assess monthly, seasonal, and between-year differences in time allocation for the different activities for 2 complete, nonconsecutive years—1995 and 2002—and compare these with measures of food availability. Over the 2 yr, the group rested on average for 48%, fed for 28%, traveled for 22.5%, and socialized for 1.5% of daylight hours. On a monthly basis, resting correlated negatively with traveling in 1995, and strongly negatively correlated with feeding for both years. Feeding correlated negatively with traveling in 2002, with significantly more time spent traveling during periods of higher young leaf availability. Season was a major influence on activity: the group rested more during the hotter, rainy austral summer season, whereas feeding occurred more frequently in the cooler, drier winter season. We found no consistent associations between food availability and the time that southern muriquis spent in most activities. We suggest that these southern muriquis, like many other large-bodied and atelin primates, minimize energy expenditure while maximizing energy intake, which may be associated with their ability to be folivorous when their preferred fruit foods are less available. They thus adopt a flexible energetic strategy for coping with variable climatic conditions rather than being constrained by food availability.     

A Current Perspective on the Historical Geographic Distribution of the Endangered Muriquis (Brachyteles spp.): Implications for Conservation

The muriqui (Brachyteles spp.), endemic to the Atlantic Forest of Brazil, is the largest primate in South America and is endangered, mainly due to habitat loss. Its distribution limits are still uncertain and need to be resolved in order to determine their true conservation status. Species distribution modeling (SDM) has been used to estimate potential species distributions, even when information is incomplete. Here, we developed an environmental suitability model for the two endangered species of muriqui (Brachyteles hypoxanthus and B. arachnoides) using Maxent software. Due to historical absence of muriquis, areas with predicted high habitat suitability yet historically never occupied, were excluded from the predicted historical distribution. Combining that information with the model, it is evident that rivers are potential dispersal barriers for the muriquis. Moreover, although the two species are environmentally separated in a large part of its distribution, there is a potential contact zone where the species apparently do not overlap. This separation might be due to either a physical (i.e., Serra da Mantiqueira mountains) or a biotic barrier (the species exclude one another). Therefore, in addition to environmental characteristics, physical and biotic barriers potentially shaped the limits of the muriqui historical range. Based on these considerations, we proposed the adjustment of their historical distributional limits. Currently only 7.6% of the predicted historical distribution of B. hypoxanthus and 12.9% of B. arachnoides remains forested and able to sustain viable muriqui populations. In addition to measurement of habitat loss we also identified areas for conservation concern where new muriqui populations might be found.     

Diet of a muriqui group (<Emphasis Type="Italic">Brachyteles arachnoides</Emphasis>) in continuous primary forest

The feeding behaviour of a group of free-ranging muriquis (Brachyteles arachnoides) was monitored in the 380 km² Carlos Botelho State Park (PECB), between February 1992 and November 1993. Scan sample data indicated that 59.1% of feeding time was devoted to fruit, 33.2% to leaves, 4.1% to flowers, and 3.6% to other items (twigs, stem and bark). Little seasonal variation was recorded. These results contrast with those of all previous studies of Brachyteles, in which the consumption of leaves was generally double that of fruit. One key difference in comparison with previous studies is that the PECB is part of the largest remaining continuous area of primary Atlantic forest, in the Serra do Mar coastal range. Such intraspecific differences in ecology may have important implications for the conservation of the species.     

Phylogenetic relationships between tuna species of the genus Thunnus (Scombridae: Teleostei): Inconsistent implications from morphology,nuclear and mitochondrial genomes

In order to infer phylogenetic relationships between tuna species of the genus Thunnus, partial sequences of the mitochondrial cytochrome b and ATPase genes were determined in all eight species. Supplemental restriction analysis on the nuclear rRNA gene was also carried out. Pacific northern bluefin tuna (Thunnus thynnus orientalis) was found to have mtDNA distinct from that of the Atlantic subspecies (T. t. thynnus) but very similar to that from the species albacore (T. alaluga). In contrast, no differentiation in nuclear genome was observed between the Atlantic and Pacific northern bluefin tunas. The Atlantic northern bluefin and southern bluefin tunas possessed mtDNA sequences very similar to species of yellowfin tuna group and not so similar to albacore and bigeye tunas which were morphologically assigned to the bluefin tuna group. The molecular data indicate that (1) mtDNA from albacore has been incorporated into the Pacific population of northern bluefin tuna and has extensively displaced the original mtDNA, and (2) albacore is the earliest offshoot, followed by bigeye tuna in this genus, which is inconsistent with the phylogenetic relationships between these tuna species inferred from morphology. Correspondence to: S. Chow     

Persistence of the effect of frugivore identity on post‐dispersal seed fate: consequences for the assessment of functional redundancy

Large frugivores play an important role as seed dispersers and their extinction may affect plant regeneration. The consequences of such extinctions depend on the likelihood of other species being functionally redundant and on how post‐dispersal events are affected. We assess the functional redundancy of two seed dispersers of the Atlantic Forest, the muriqui (Brachyteles arachnoides) and the tapir (Tapirus terrestris) through the comparison of their seed dispersal quality, taking into account post‐dispersal events. We compare tapirs and muriquis for: (1) the dung beetle community associated with their feces; (2) the seed burial probability and burial depth by dung beetles; and (3) the seed mortality due to predators or other causes according to burial depth. We determine how seed burial affects seed dispersal effectiveness (SDE) and compare the dispersal quality of four plant species dispersed by these frugivores. Muriqui feces attract 16‐fold more dung beetles per gram of fecal matter and seeds experience 10.5‐fold more burial than seeds in tapir feces. In both feces types, seed mortality due to predation decreases with burial depth but seed mortality due to other causes increases. Total seed mortality differ within plant species according to the primary disperser. Therefore, the effect of seed burial on SDE varies according to the plant species, burial depth, and primary disperser. As tapirs and muriquis differently affect the seed fate, they are not functionally redundant. Since the effect of the primary disperser persists into the post‐dispersal events, we should consider the cascading effects of these processes when assessing functional redundancy.     

Intra‐community coalitionary lethal attack of an adult male southern muriqui (Brachyteles arachnoides)

We report on the first evidence of intra‐community coalitionary lethal aggression in muriquis (Brachyteles). The event occurred in southern muriquis (Brachyteles arachnoides) during a long‐term study (>15 years) of two social groups inhabiting mostly pristine Atlantic forest habitat in the Parque Estadual Carlos Botelho, southern São Paulo State, Brazil. The attack took place deep in the core area of the Group Caetê home range. Tense agonistic behaviors and vocalizations preceded the lethal coalitionary attack, and the tension increased over a 36–48 hr period. One adult female and two unidentified individuals also took part in a coalition led by six adult males. The members of the coalition collectively approached, embraced, immobilized and repeatedly bit the entire body of an adult male, resulting in severe bleeding injuries and the victim's death in less than 1 hr after the attack commenced. Combined ecological, behavioral and spatial data related to the event indicate that this was an intra‐community attack and suggest social tensions related to mating competition as the proximate trigger of the coalitionary killing. The attack resembled those reported for chimpanzees, with clear numeric superiority and a low risk of injury to aggressors, resulting in the death of a lone conspecific victim. This observation (n=1) is suggestive of a capacity for escalated aggression in muriquis and reinforces arguments for the potential adaptive significance of intra‐community aggression in male philopatric societies, as reported for spider monkeys and chimpanzees. These characteristics challenge the view of the muriquis as a peaceful primate and support the general hypothesis that imbalances of power contribute to intra‐specific killing in primates, such as chimpanzees and humans. Am. J. Primatol. 71:860–867, 2009. © 2009 Wiley‐Liss, Inc.     

Population Variation in Patch and Party Size in Muriquis (Brachyteles arachnoides)

We examined the relationship between food patch size and feeding party size with comparative data from two populations of muriquis (Brachyteles arachnoides) in the 37,797-ha forest at the Parque Estadual de Carlos Botelho (PECB), São Paulo, and the 800-ha forest at the Estação Biológica de Caratinga (EBC), Minas Gerais. Precipitation was more abundant and less seasonal at PECB than EBC, and the density of large trees (>25.0 cm) was higher at PECB (206 ha ^–1 ) than at EBC (132 ha ^–1 ). At both sites, the size of feeding parties is positively related to the size of food patches. As predicted, food patches at PECB are significantly larger than those at EBC for both fruit and leaf sources. Contrary to expectations, feeding parties were larger at EBC than PECB. The higher population density of muriquis and sympatric primates at EBC may make large associations more advantageous to these muriquis than to muriquis living at lower population densities in PECB.     

Density of Primates in Four Semi-deciduous Forest Fragments of São Paulo,Brazil

Populational parameters of primates in the remaining southeastern Brazilian Atlantic Forest have been estimated, but investigations are biased to coastal evergreen sites. In this study density of three primate species was assessed through line-transect surveys in four semi-deciduous forest fragments (240 to 1450 ha) in Fazenda Barreiro Rico, eastern range of central Plateau of São Paulo state, Brazil. A total of 274 km was surveyed from January to October 2000. I estimated densities via DISTANCE software. Two of the largest fragments contained five primate species while two of the smallest ones harboured, respectively, four and two species. Densities of Cebus apella (15.34–47.92 ind./km²), Alouatta guariba (8.32–34.61), and Brachyteles arachnoides (19.92–35.11) were considerable. Differently from C. apella and A. guariba, B. arachnoides presented a density higher than previously estimated for the largest patch. The hypothetical minimum total population of B. arachnoides (601) may be the largest in semi-deciduous sites. This reinforces the value of the area in terms of its relative contribution for conservation of this endangered species. The narrow spatial scale distribution of forest fragments at Barreiro Rico and its proximity to academic institutions make the site suitable for programs of forest connectivity, studies on conservation biology, and wildlife management endeavours.     

Capture techniques and morphometrics for the woolly spider monkey,or muriqui (Brachyteles arachnoides,E. Geoffroy 1806)

A total of 12 free-ranging muriquis (Brachyteles arachnoides) were captured with Telazol® at Fazenda Esmeralda, Minas Gerais, Brazil, and at Fazenda Barreiro Rico, São Paulo, Brazil. All animals were measured, marked, weighed, and released. Previously reported data suggested that Brachyteles is a sexually dimorphic species with female-male body weights of 12–15 kg, respectively. We found no statistically significant difference in body weight between females (mean = 8.4 kg, range = 6.9–9.3 kg, n = 4), and males (mean =9.6 kg, range = 9.3–10.2 kg, n = 4). Our results are at variance with previously published body weights in the literature. Larger sample size may reveal a significant sexual difference, particularly in body weight. © 1993 Wiley-Liss, Inc.     

Sexual dimorphism in canine length of woolly spider monkeys (Brachyteles arachnoides,E. Geoffroy 1806)

We measured canine teeth from 28 woolly spider monkeys (Brachyteles arachnoides) to assess sexual dimorphism and population differences. The specimens are from the Brazilian states of Bahia, Minas Gerais, Espírito Santo, Rio de Janeiro, and São Paulo. We found strong sexual dimorphism in canine length for individuals belonging to populations south of 22°00 latitude but no sexual dimorphism in canine length from individuals of populations north of 21°00 latitude. Canine length did not vary among females of northern and southern populations. However, southern males had significantly longer canines than northern males. This geographical difference in canine morphology, together with the presence or absence of thumbs and published accounts of differences in genetics and social structure between northern and southern populations, suggests thatBrachyteles arachnoides may be composed of at least two subspecies, which appear to be separated by the rivers Grande and Paraiba do Sul and the Serra da Mantiqueira.     

Population density of primates in a large fragment of the Brazilian Atlantic rainforest

We performed a line transect survey (352.4 km) of primates in the Serra de Paranapiacaba, at one of the largest relatively undisturbed fragments of the Atlantic rainforest of Southeastern Brazil (ca. 1400 km²), in August 1998. The brown capuchin, Cebus apella nigritus, was the most common species found in the area (20 groups, density estimate: 5.31 ± 2.05 individuals per km², mean ± SE). Nine groups of the brown howler monkey, Alouatta guariba clamitans, and eight of the woolly spider monkey, Brachyteles arachnoides arachnoides, were also recorded, with preliminary density estimates of 0.79 ± 0.40 and 2.33 ± 1.37 individuals per km², respectively. Density estimates for these species in other fragments of Atlantic rainforest are reviewed, showing that densities in Paranapiacaba are among the lowest reported. It is suggested that the higher densities reported for isolated populations in small forest patches (<50 km²) is related to the absence of main primate predators, the density compensation phenomenon and the ecological plasticity of some primate species. In contrast, local extinction in many small patches is probably related to hunting pressure. Given the important primate populations found in the Paranapiacaba fragment, conservation strategies for the studied species should give priority to effective protection of the largest remnant fragments from illegal hunting and deforestation, rather than translocation of individuals or captive breeding programs to introduce monkeys in small forest fragments vulnerable to hunting and of uncertain future.     

Ground use by northern muriquis (Brachyteles hypoxanthus)

Many arboreal primates descend to the ground, a custom that may occur more frequently in disturbed habitats, and in the presence of researchers to whom the primates are habituated. In this paper, we describe opportunistic observations of ground use in two groups of northern muriquis (Brachyteles hypoxanthus) at the RPPN Feliciano Miguel Abdala, Minas Gerais, Brazil. Members of both groups were observed drinking, resting, feeding, playing, and traveling on the ground to different degrees, and variation in the levels of habituation of the two groups may be responsible for the differences in the distribution of their terrestrial activities. The potential increase in vulnerability to predation or disease owing to ground use has implications for the conservation of this critically endangered species.     

Phylogeography and phylogeny of the epineritic cosmopolitan bonitos of the genus Sarda (Cuvier): inferred patterns of intra‐ and inter‐oceanic connectivity derived from nuclear and mitochondrial DNA data

Aim To reconstruct the phylogenetic relationships of the four species of the genus Sarda (Sarda sarda, Sarda orientalis, Sarda australis and Sarda chilensis) and their phylogeographic history in the context of historical and ecological biogeography. Also, to reconstruct within‐species phylogenetic relationships to test whether the North Atlantic and Mediterranean populations of Atlantic bonito (S. sarda) warrant subspecies status, and the validity of the allopatric northern and southern populations of eastern Pacific bonito (S. chiliensis), recognized as S. chiliensis lineolata and S. chiliensis chiliensis. Location Representative samples of all four Sarda species collected world‐wide were analysed. Methods Phylogenetic inference was carried out with neighbour‐joining, maximum parsimony and maximum likelihood, employing nucleotide sequences of the mitochondrial DNA (mtDNA) control region I (CR‐I) and of the single‐copy nuclear DNA (nDNA) Tmo‐4c4 gene. Analysis of molecular variance was used on the mtDNA data to estimate the extent of geographic population structuring. Results Gene trees derived from mtDNA and nDNA data yielded concordant phylogenies that support the monophyly of the genus Sarda. The following sibling pairs received strong statistical support: striped bonito (S. orientalis) with Australian bonito (S. australis), and Atlantic bonito (S. sarda) with eastern Pacific bonito (S. chiliensis). Furthermore, the origin of S. sarda mtDNA is paraphyletic with respect to S. chiliensis, and these results are indicative of introgression. The analysis of Tmo‐4c4 sequences corroborates the ancestral hybridization between these allopatric species. Comparisons of north‐west Atlantic and Mediterranean populations of S. sarda using mtDNA CR‐I data revealed substantial genetic differentiation. By contrast, no differences between the putative northern and southern allopatric subspecies of S. chiliensis were detected. Main conclusions The monophyly of the genus Sarda as indicated by morphology is corroborated using both molecular markers. However, molecular phylogenies depicted a paraphyletic relationship between S. sarda and S. chiliensis. This phylogeographical relationship is better explained by an ancestral introgression facilitated by trans‐Arctic contact during the Pleistocene. The pronounced genetic differentiation between S. sarda samples from the north‐west Atlantic and the Mediterranean is consistent with the differentiation of these two regions, but not with the amphi‐Atlantic speciation hypothesis. Finally, the S. chiliensis lineolata and S. chiliensis chiliensis subspecies status is not supported by the molecular data.     

Phylogeography of an Italian endemic salamander (genus Salamandrina): glacial refugia,postglacial expansions,and secondary contact

The Italian endemic genus Salamandrina has been historically regarded as monotypic but, recently, studies based on both mitochondrial and nuclear markers have indicated the existence of two distinct species of spectacled salamanders: Salamandrina perspicillata, in central and northern Italy, and Salamandrina terdigitata, in southern Italy. We analyzed nucleotide variation at mitochondrial and nuclear genes [cytochrome b, 12S and 16S rRNA, recombination activating gene (RAG 1)] in 223 individuals from 56 locations, aiming to investigate their genetic structure and recent evolutionary histories. Phylogenetic and phylogeographical analyses revealed the existence of three and two genetically distinct groups of populations in northern and southern salamander, respectively. Historical demographic analyses led to the inference of range expansion for both species in the late Pleistocene. During the last glacial stage, each salamander survived in a single refugium, namely the southern in Calabria and the northern in central Italy. At the end of this period, both lineages expanded northward and established secondary contact. Spatial distribution of RAG 1 haplotype variation revealed two differentiated population groups corresponding to the major mitochondrial (mt)DNA clades. Nuclear pattern of introgressive hybridization was more extensive than the highly limited introgression of mtDNA markers. From a conservation standpoint, southern Latium and Calabria proved to be the major genetic diversity reservoirs, thus deserving particular conservation efforts. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 903–922.