Fall movements of Red‐headed Woodpeckers in South Carolina

Fall migration of Red‐headed Woodpeckers (Melanerpes erythrocephalus) can be erratic, with departure rates, directions, and distances varying among populations and individuals. We report fall migration departure dates, rates, and routes, and the size of fall home ranges of 62 radio‐tagged Red‐headed Woodpeckers in western South Carolina. Rates of fall migration differed among years; all radio‐tagged woodpeckers migrated in 2005 (15 of 15), none (0 of 23) migrated in 2006, and 54.2% (13 of 24) migrated in 2007. Of 28 woodpeckers that left their breeding territories, we relocated eight either en route or on their fall home ranges. These woodpeckers migrated short distances (4.3–22.2 km) south along the floodplain forest of a large creek. The variable migration patterns we observed indicate that Red‐headed Woodpeckers may best be described as facultative migrants. We determined the home range sizes of 13 woodpeckers in both seasons, regardless of whether they migrated, and fall home ranges were smaller (mean = 1.12 ha) than summer home ranges (mean = 3.23 ha). Fall‐winter movements of Red‐headed Woodpeckers were concentrated on mast‐producing oak (Quercus spp.) trees, which may have restricted home range sizes. The partial migration we observed in 2007 suggests that factors other than mast crop variability may also influence migration patterns because woodpeckers that year responded to the same annual mast crop in different ways, with some migrating and some remaining on breeding season home ranges during the fall.     

Why do Juvenile Chinese Pit‐Vipers (Gloydius shedaoensis) Select Arboreal Ambush Sites?

Ontogenetic shifts in habitat use are widespread, especially in ectothermic taxa in which juveniles may be an order of magnitude smaller than large adult conspecifics. The factors that generate such habitat shifts are generally obscure, but we studied an unusual system that allowed us to compare consequences of habitat selection between adults and juveniles. Pit‐vipers (Gloydius shedaoensis) on a small island in north‐eastern China feed almost entirely on seasonally migrating birds. During the spring bird‐migration period, individual snakes consistently re‐used either arboreal or terrestrial ambush sites. Snakes in trees were smaller (and more philopatric) than snakes on the ground. This ontogenetic shift in habitat use may reflect the difficulty of capturing birds on the ground, especially by small snakes. In laboratory trials, large (adult) pit‐vipers struck faster, further and more accurately than did small (juvenile) snakes. In experiments with free‐ranging snakes, the proportion of strikes hitting the bird was lower for juveniles than for adults, and lower for terrestrial snakes than for arboreal snakes. Additionally, adult snakes generally seized the bird by the head whereas juveniles frequently struck the body or wings (and thus, obtained a less secure grip). Arboreal ambush sites may facilitate prey capture not only because they give access to smaller birds but also because they render the bird's location more predictable and, hence, enable the snake to position itself optimally prior to the prey's arrival. Because juvenile pit‐vipers are less capable strikers, and are small relative to available prey items, they may benefit from the greater ease of prey capture from branches. Thus, the ontogenetic shift in habitat selection within this species may be because of ontogenetic shifts in the vipers’ ability to capture and ingest large, mobile prey.     

Contemporary pollen flow,mating patterns and effective population size inferred from paternity analysis in a small fragmented population of the Neotropical tree <Emphasis Type="Italic">Copaifera langsdorffii</Emphasis> Desf. (Leguminosae-Caesalpinioideae)

Pollen flow and dispersal patterns were investigated in a small, isolated forest fragment of the Neotropical insect pollinated tree Copaifera langsdorffii, using paternity analysis and eight microsatellite loci. We also investigated the coancestry and effective population size of progeny arrays for conservation and environmental restoration purposes. Open-pollinated seeds were collected from 15 seed trees within the forest fragment, in which all adult trees were mapped, measured and genotyped. Twenty seeds were also collected from the nearest neighbor tree located 1.2 km from the forest fragment. Our results show that levels of genetic diversity were significantly higher in adults than offspring and significant levels of inbreeding were detected in offspring (F = 0.226). From paternity analysis, we observed low levels of selfing (s = 8%) and pollen immigration (m = 8%) in the fragment, but very high levels were detected for the isolated tree (s = 20%; m = 75%), indicating that the population and the tree are not reproductively isolated and are connected by patterns of long distance pollen dispersal (maximum detected 1,420 m). Within the forest fragment, the pattern of pollen dispersal was a near neighbor pattern with 49% of the pollen being dispersed within 50 m. The effective population size of the progeny array was low, indicating the need to collect seeds from a large number of seed trees (at least 76) for conservation purposes. The results show that the spatial isolation of the population and isolated tree due to forest fragmentation has not disrupted genetic connectivity; however, spatial isolation does seem to increase selfing and correlated mating.     

The Importance of Ficus (Moraceae) Trees for Tropical Forest Restoration

Forest restoration is an increasingly important tool to offset and indeed reverse global deforestation rates. One low cost strategy to accelerate forest recovery is conserving scattered native trees that persist across disturbed landscapes and which may act as seedling recruitment foci. Ficus trees, which are considered to be critically important components of tropical ecosystems, may be particularly attractive to seed dispersers in that they produce large and nutritionally rewarding fruit crops. Here, we evaluate the effectiveness of remnant Ficus trees in inducing forest recovery compared to other common trees. We studied the sapling communities growing under 207 scattered trees, and collected data on seed rain for 55 trees in a modified landscape in Assam, India. We found that Ficus trees have more sapling species around them (species richness = 140.1 ± 9.9) than non‐Ficus trees (79.5 ± 12.9), and significantly more saplings of shrub and large tree species. Sapling densities were twice as high under Ficus trees (median = 0.06/m²) compared to non‐Ficus (0.03/m²), and seed rain densities of non‐parent trees were significantly higher under Ficus trees (mean = 12.73 ± 3/m²/wk) than other fruit or non‐zoochorous trees (2.19 ± 0.97/m²/wk). However, our regression model found that canopy area, used as a proxy for tree size, was the primary predictor of sapling density, followed by remnant tree type. These results suggest that large trees, and in particular large Ficus trees, may be more effective forest restoration agents than other remnant trees in disturbed landscapes, and therefore the conservation of these trees should be prioritized.     

Global meta-analysis of tree decline impacts on fauna

Significant portions of the world's forests have been impacted by severe and large-scale tree declines characterised by gradual but widespread loss of vigour and subsequent death of either single or several tree species. Tree deaths represent a threat for fauna that are dependent on forest habitats for their survival. Although tree declines have received considerable scientific attention, surprisingly, little is known about their impacts on fauna. In total, we calculated 631 effect sizes across 59 studies that quantified the impact of tree declines on animal abundance. Data representing 186 bird species indicated an overall increase in bird abundance in response to tree declines (meta-analysis mean ± estimation g = 0.172 ± 0.053 [CI 0.069 to 0.275], P = 0.001); however, there was substantial variability in responses (significant heterogeneity P < 0.001) with a strong influence of diet as well as nesting guild on bird responses. Granivores (especially ground-foraging species, e.g. Passerellidae species), bark-foraging insectivores (e.g. woodpeckers), as well as ground- and cavity-nesting species apparently benefitted from tree declines, while nectarivorous birds [and, although not significant, aerially foraging insectivores (e.g. flycatchers) and leaf-gleaning insectivores (canopy-feeding)] were less common in the presence of tree declines. Data representing 33 mammal species indicate a tendency for detrimental effects of tree declines on mammals that use trees as refuges, while aerial foragers (i.e. bats) may benefit from opening up the canopy. Overall the average effect for mammals was neutral (meta-analysis mean estimation g = −0.150 ± 0.145 [−0.433 to 0.134], P = 0.302). Data representing 20 reptile species showed an insufficient range of responses to determine any diet or foraging effect on their responses. Data for 28 arthropod taxa should be considered with caution, as we could not adequately separate taxa according to their specialisations and reliance on key habitat. The data broadly suggest a detrimental effect of tree declines (meta-analysis mean estimation g = −0.171 ± 0.072 [−0.311 to −0.031], P = 0.017) with ground-foraging arthropods (e.g. detritivores and predators such as spiders and centipedes) more likely to be detrimentally impacted by tree declines. The range of responses to tree declines signifies substantially altered animal communities. In many instances, altered ecosystem function due to loss of key animal services will represent a significant threat to forest health.     

Toucans (Ramphastos ambiguus) facilitate resilience against seed dispersal limitation to a large‐seeded tree (Virola surinamensis) in a human‐modified landscape

Large‐seeded plants may suffer seed dispersal limitation in human‐modified landscapes if seed dispersers are absent or unable to disperse their seeds. We investigated dispersal limitation for the large‐seeded tree Virola surinamensis in a human‐modified landscape in southern Costa Rica. During two fruiting seasons, we monitored crop size, seed removal rates, the number of fruiting conspecifics within 100 m, and feeding visitation rates by frugivores at trees located in high and low forest disturbance conditions. Seed removal rates and the total number of seeds removed were high regardless of the disturbance level, but these parameters increased with tree crop size and decreased with the number of fruiting V. surinamensis trees within a 100 m radius. Trees at low disturbance levels were more likely to be visited by seed dispersers. Black mandibled toucans (Ramphastos ambiguus) and spider monkeys (Ateles geoffroyi) were the most important seed dispersers, based on visitation patterns and seed removal rates. Spider monkey feeding visits were more frequent at high disturbance levels, but the monkeys preferentially visited isolated trees with large yields and surrounded by a low number of fruiting Virola trees within 100 m. Toucan visitation patterns were not constrained by any of the predictors and they visited trees equally across the landscape. We suggest that isolated and highly fecund Virola trees are an important food resource for spider monkeys in human‐modified landscapes and that toucans can provide resilience against seed dispersal limitations for large‐seeded plants in human‐modified landscapes in the absence of hunting.     

Characterization of polymorphic microsatellite loci in the terrestrial isopod Porcellionides pruinosus

We developed a set of six polymorphic microsatellite loci for the woodlouse, Porcellionides pruinosus. We screened 43 individuals from three French populations and found that locus‐specific allelic diversity ranges from 3 to 17 alleles (mean = 9.8) and observed heterozygosity ranges from 0.51 to 0.89 (mean = 0.77). These are the first microsatellites loci reported from the woodlouse.     

The Effect of Spatial Structure of Pasture Tree Cover on Avian Frugivores in Eastern Amazonia

The movement of frugivores between remnant forests and successional areas is vital for tropical forest tree species to colonize successional habitats. The response of these species to the spatial structure of pasture tree cover is largely unknown. We studied avian frugivores that were found in primary forest edges and large pastures in eastern Amazonia, Brazil. We determined how the small‐scale spatial structure of pasture trees at forest edges affects five response variables: bird presence, visitation rate, duration of visit, species richness, and an index accounting for species’ level of frugivory and abundance in forests. We used hierarchical linear models to estimate the effect of four predictor variables on response variables: (1) clustering of pasture trees; (2) percent canopy cover of pasture trees; (3) distance of pasture tree to forest edge; and (4) tree crown area. The study species, many of which are widely distributed in the Neotropics, were generally insensitive to percent cover and clustering of trees. Frugivore visitation to individual trees remained constant as cover increased. Visitation was positively correlated with focal tree distance to forest edge and crown area. The positive relationship between distance and visitation rates may be due to the increased abundance of some resource further from forests. If pastures were abandoned the distance from forest edges would not likely limit frugivore visitation and seed deposition under large pasture trees in our study (i.e., up to 200 m distant).     

Response of timber rattlesnakes to commercial logging operations

Forest management practices in the eastern United States directly impact large parcels of land that serve as habitat for timber rattlesnakes (Crotalus horridus). We assessed the behavioral response of timber rattlesnakes to commercial logging activities and the impact of such activities on a timber rattlesnake population in northcentral Pennsylvania. We radiotelemetrically monitored 67 individual snakes over periods of up to 4 years, marked and recaptured 306 snakes, and conducted search and survey efforts before, during, and after commercial logging operations on 3 timber sale parcels (totaling 154.2 ha). Location and timing of timber sales created the maximum opportunity for interaction of snakes with logging operations and with altered habitat. Observed logging-related mortality of snakes was low (<2% of the population/yr), but potential mortality could have reached 7%. Logging activity and resulting habitat changes did not alter behavior or movement patterns of telemetrically monitored snakes. Snakes with established activity ranges in timber sale areas continued to use these areas both during and after logging operations. Similarly, snakes with activity patterns that did not include timber sale areas did not alter their movement patterns to include such sites in the short-term. Timbering increased structural diversity of the habitat and, concurrently, diversity of habitat used by timber rattlesnakes increased. Our results suggest that the opportunity exists to develop forest management practices that provide timber products while limiting impacts on behavior and habitat use of timber rattlesnakes. To further reduce impacts to timber rattlesnake populations we recommend that management agencies require commercial logging contractors, sub-contractors, and field employees to adhere strictly to a policy that prohibits the intentional killing of rattlesnakes encountered during logging activities. © 2010 The Wildlife Society.     

When seasnake meets seabird: Ecosystem engineering,facilitation and competition

Ecosystem engineers such as burrowing seabirds can increase habitat availability for sympatric taxa – but only if the burrow's owner allows other species to use the newly created shelter site. Our studies on a small Pacific island suggest that an avian burrower (the wedge‐tailed shearwater Puffinus pacificus) is both a facilitator and a competitor for amphibious seasnakes. Video camera inspection of 102 burrows revealed frequent usage of these burrows as retreat sites by the snakes, with Laticauda laticaudata restricted to burrows <4 m from the water's edge, whereas Laticauda saintgironsi often used burrows further inland. Snakes never occupied burrows that contained adult shearwaters, suggesting active burrow defence by the birds. Model snakes that we inserted into burrows were attacked, especially on the head and upper body, and we found one snake pecked to death outside a burrow. Wedge‐tailed shearwaters act as facilitators, creating a thermally favourable microhabitat and substantially enhancing habitat suitability for snakes; but they are also competitors, aggressively competing with snakes for occupancy of the resource that has been created.     

Estimation of epiphytic biomass and nutrient pools in the subtropical montane cloud forest in the Ailao Mountains,south-western China

Canopy organic matter (COM) composed of epiphyte community exists as a complex subsystem in the montane cloud forest (MCF). We estimated the biomass and nutrient pools of COM in a subtropical MCF in the Ailao Mountain National Nature Reserve (NNR). The diameter at breast height (DBH) of host trees was the best parameter in the estimation of epiphytic biomass, compared to the height (H) of host trees and the combination of both parameters. The effect of host tree species was negligible in the estimation. Therefore, it was concluded that the DBH data of all trees of a forest regardless of species was a suitable index for the non-destructive estimation of epiphytic biomass in field surveys, especially for investigations of larger study areas. According to species-specific equations, the total COM biomass was estimated to be 2,261 ± 537 (SD) kg ha⁻¹, which was dominated by bryophytes (73.6%) and canopy humus (13.9%). The greatest proportion of COM was located on the inner branches (52.2%), followed by outer branches, trunks, the understory, and branch junctions. The nutrient pools (mean ± SD, kg ha⁻¹) of the COM were: N = 37.9 ± 9.0, P = 1.97 ± 0.47, K = 9.6 ± 2.3, Ca = 9.6 ± 2.3, Mg = 2.64 ± 0.63 and Na = 0.25 ± 0.06. Assessments of epiphytic biomass and nutrient capital supported the idea that the canopy subsystem holds a substantial pool of nutrients, especially when compared to the labile components of the forest ecosystem.     

Crossing the (Wallace) line: local abundance and distribution of mammals across biogeographic barriers

Past and ongoing vertebrate introductions threaten to rearrange ecological communities in the Indo‐Malay Archipelago, one of Earth's most biodiverse regions. But the consequences of these translocations are difficult to predict. We compared local abundance and distributions in four tropical mammal lineages that have crossed from Asia to Wallacea or New Guinea. The local abundance of macaques (Macaca spp.), which naturally crossed Wallace's Line, was higher in Sulawesi (east of the line; mean = 3.7 individuals per camera station, 95% CI = 2.2: 5.1) than in Borneo (west of the line; mean = 1.1, CI = 0.8: 1.4), but the local abundance of Malay civets (Viverra tangalunga), Rusa deer, and Sus pigs was similar in their native ranges and where they had been introduced by humans east of Wallace's Line. Proximity to rivers increased Malay Civet local abundance and decreased the local abundance of pigs in parts of their introduced ranges (Maluku and New Guinea, respectively), while having no effect on local abundance in their native ranges (Borneo) or other areas where they have been introduced (Sulawesi). That local abundance was higher east of Wallace's Line in just one of four mammal lineages is consistent with findings from plant invasions, where most species have similar abundance in their native and introduced ranges. However, species’ ecology may change as they enter new communities, for example, their patterns of abundance at local scales. This could make it difficult to predict community structure in the face of ongoing species introductions.     

Replicated throughfall exclusion experiment in an Indonesian perhumid rainforest: wood production,litter fall and fine root growth under simulated drought

Climate change scenarios predict increases in the frequency and duration of ENSO‐related droughts for parts of South‐East Asia until the end of this century exposing the remaining rainforests to increasing drought risk. A pan‐tropical review of recorded drought‐related tree mortalities in more than 100 monitoring plots before, during and after drought events suggested a higher drought‐vulnerability of trees in South‐East Asian than in Amazonian forests. Here, we present the results of a replicated (n = 3 plots) throughfall exclusion experiment in a perhumid tropical rainforest in Sulawesi, Indonesia. In this first large‐scale roof experiment outside semihumid eastern Amazonia, 60% of the throughfall was displaced during the first 8 months and 80% during the subsequent 17 months, exposing the forest to severe soil desiccation for about 17 months. In the experiment's second year, wood production decreased on average by 40% with largely different responses of the tree families (ranging from −100 to +100% change). Most sensitive were trees with high radial growth rates under moist conditions. In contrast, tree height was only a secondary factor and wood specific gravity had no influence on growth sensitivity. Fine root biomass was reduced by 35% after 25 months of soil desiccation while fine root necromass increased by 250% indicating elevated fine root mortality. Cumulative aboveground litter production was not significantly reduced in this period. The trees from this Indonesian perhumid rainforest revealed similar responses of wood and litter production and root dynamics as those in two semihumid Amazonian forests subjected to experimental drought. We conclude that trees from paleo‐ or neotropical forests growing in semihumid or perhumid climates may not differ systematically in their growth sensitivity and vitality under sublethal drought stress. Drought vulnerability may depend more on stem cambial activity in moist periods than on tree height or wood specific gravity.     

Elevational distribution of restricted range forest tree taxa in eastern Tanzania

The forests of eastern Tanzania are a globally important biodiversity hotspot. In this study 361 eastern Tanzanian restricted range forest tree taxa were assessed. Of these taxa, 223 occurred in the Eastern Arc, 150 in Coastal forests, 17 in Northern forests and 21 in the Lake Nyasa forests. The majority of the taxa had restricted elevational ranges with 76.3% occurring in no more than two 200 m elevational bands out of a total potential elevation range of 3000 m. The majority of the taxa occupied a small area in the eastern Tanzanian forests, with 201 taxa being only found at a few sites. In determining priority areas for conservation, selection of taxon definitions can have important effects. For example, tree size varies with elevation, so if only large trees are used then site selection will be biased towards particular areas.     

Postrelease movement and habitat selection of translocated pine martens Martes martes

Monitoring postrelease establishment and movement of animals is important in evaluating conservation translocations. We translocated 39 wild pine martens Martes martes (19 females, 20 males) from Scotland to Wales. We released them into forested areas with no conspecifics in 2015, followed by a second release in 2016, alongside the previously released animals. We used radio‐tracking to describe postrelease movement and habitat selection. Six martens (15%) were not re‐encountered during the tracking period, of which four undertook long‐distance dispersal. For the remaining individuals, we characterized two phases of movement, “exploration” followed by “settlement,” that differed between releases. In the first release, martens remained in exploration phase for a mean of 14.5 days (SE = 3.9 days) and settled at a mean distance of 8.7 km (SE = 1.8 km) from release sites, whereas martens released in year two, alongside resident conspecifics, traveled away from release sites at a faster rate, settling sooner, at a mean of 6.6 days (SE = 1.8 days), but further, at a mean distance of 14.0 km (SE = 1.7 km) from release sites. Animals released in year one did not exhibit habitat preferences overall but within forests they favored recently felled areas, whereas animals released in year two showed strong selection for forested habitat but did not discriminate between forest types. The presence of conspecifics appeared influential for settlement and site fidelity of translocated martens and was associated with more rapid but more distant dispersal of the later cohort. Releases of animals in close proximity appeared to promote site fidelity and rapid establishment of ranges in the recipient environment.     

Up-scaling to stand transpiration of an Asian temperate mixed-deciduous forest from single tree sapflow measurements

Species diversity in mixed forest stands is one of the factors that complicate up-scaling of transpiration from individual trees to stand level, since tree species are architecturally and functionally different. In this study, thermal dissipation probes were used to measure sap flow in five different tree species in a mixed-deciduous mountain forest in South Korea. Easily measurable tree characteristics that could serve to define individual tree water use among the different species were employed to scale up transpiration from single trees to stand level. Tree water use (TWU) was derived from sap flux density (SFD) and sapwood area (SA). Canopy transpiration E was scaled from TWU while canopy conductance (g _c) was computed from E and VPD. SFD, TWU and g _c were correlated with tree diameter at breast height (DBH) for all the five measured species (SFD: R ² = 0.21, P = 0.036; TWU: R ² = 0.83, P < 0.001; g _c: R ² = 0.63, P < 0.001). Maximum stand transpiration (E) during June, before the onset of the Asian monsoon rains, was estimated at 0.97 ± 0.12 mm per day. There was a good (R ² = 0.94, P < 0.0001) agreement between measured and estimated E using the relationship between TWU and DBH. Our study shows that using functional models that employ converging traits among species could help in estimating water use in mixed forest stands. Compared to SA, DBH is a better scalar for water use of mixed forest stands since it is non-destructive and easily obtainable.     

Movements and Habitat Use of an Endangered Snake,Hoplocephalus bungaroides (Elapidae): Implications for Conservation

A detailed understanding of how extensively animals move through the landscape, and the habitat features upon which they rely, can identify conservation priorities and thus inform management planning. For many endangered species, information on habitat use either is sparse, or is based upon studies from a small part of the species’ range. The broad-headed snake (Hoplocephalus bungaroides) is restricted to a specialized habitat (sandstone outcrops and nearby forests) within a small geographic range in south-eastern Australia. Previous research on this endangered taxon was done at a single site in the extreme south of the species’ geographic range. We captured and radio-tracked 9 adult broad-headed snakes at sites in the northern part of the species’ distribution, to evaluate the generality of results from prior studies, and to identify critical habitat components for this northern population. Snakes spent most of winter beneath sun-warmed rocks then shifted to tree hollows in summer. Thermal regimes within retreat-sites support the hypothesis that this shift is thermally driven. Intervals between successive displacements were longer than in the southern snakes but dispersal distances per move and home ranges were similar. Our snakes showed non-random preferences both in terms of macrohabitat (e.g., avoidance of some vegetation types) and microhabitat (e.g., frequent use of hollow-bearing trees). Despite many consistencies, the ecology of this species differs enough between southern and northern extremes of its range that managers need to incorporate information on local features to most effectively conserve this threatened reptile.     

Landscape‐level tree cover predicts species richness of large‐bodied frugivorous birds in forest fragments

Large‐bodied frugivorous birds play an important role in dispersing large‐sized seeds in Neotropical rain forests, thereby maintaining tree species richness and diversity. Conversion of contiguous forest land to forest fragments is thought to be driving population declines in large‐bodied frugivores, but the mechanistic drivers of this decline remain poorly understood. To assess the importance of fragment‐level versus local landscape attributes in influencing the species richness of large‐bodied (>100 g) frugivorous birds, we surveyed 15 focal species in 22 forest fragments (2.7 to 33.6 ha, avg. = 16.0 ha) in northwest Ecuador in 2014. Fragment habitat variables included density of large trees, canopy openness and height, and fragment size; landscape variables included elevation and the proportion of tree cover within a 1 km radius of each fragment. At both the individual species level, and across the community of 12 species of avian frugivore we detected, there was higher richness and probability of presence in fragments with more tree cover on surrounding land. This tendency was particularly pronounced among some endangered species. These findings corroborate the idea that partially forested land surrounding fragments may effectively increase the suitable habitat for forest‐dwelling frugivorous birds in fragmented landscapes. These results can help guide conservation priorities within fragmented landscapes, with particular reference to retaining trees and reforesting to attain high levels of tree cover in areas between forest patches.     

Integrative taxonomy provides evidence for the species status of the Ibero‐Maghrebian grass snake Natrix astreptophora

The grass snake (Natrix natrix) is Europe's most widely distributed and, in many regions, most common snake species, with many morphologically defined subspecies. Yet, the taxonomy of grass snakes is relatively little studied and recent work has shown major conflicts between morphologically defined subspecies and phylogeographical differentiation. Using external morphology, osteological characters, and information from 13 microsatellite loci and two mitochondrial markers, we examine differentiation of the subspecies N. n. astreptophora from the North African Maghreb region, the Iberian Peninsula and neighbouring France. According to previous studies, N. n. astreptophora corresponds to a deeply divergent mitochondrial clade and constitutes the sister taxon of all remaining grass snakes. In the French Pyrenees region, there is a contact zone of N. n. astreptophora with another subspecies, N. n. helvetica. Our analyses of microsatellites and mitochondrial DNA reveal that the distribution ranges of the two taxa abut there, but both hybridize only exceptionally. Even though many morphological characters are highly variable and homoplastic in grass snakes, N. n. astreptophora differs consistently from all other grass snakes by its reddish iris coloration and in having significantly fewer ventral scales and another skull morphology. Considering further the virtual absence of gene flow between N. n. astreptophora and N. n. helvetica, and acknowledging the morphological distinctiveness of N. n. astreptophora and its sister group relationship to all remaining subspecies of grass snakes, we conclude that Natrix astreptophora (Seoane, 1884) should be recognized as a distinct species. Further research is needed to explore whether N. astreptophora is polytypic because a single sample of N. astreptophora from Tunisia turned out to be genetically highly distinct from its European conspecifics.     

The trade‐off between fecundity and egg size in a polymorphic population of Arctic charr (Salvelinus alpinus (L.)) in Skogsfjordvatn,subarctic Norway

Reproductive traits differ between intralacustrine Arctic charr morphs. Here, we examine three sympatric lacustrine Arctic charr morphs with respect to fecundity, egg size and spawning time/site to assess reproductive investments and trade‐offs, and possible fitness consequences. The littoral omnivore morph (LO‐morph) utilizes the upper water for feeding and reproduction and spawn early in October. The large profundal piscivore morph (PP‐morph) and the small profundal benthivore morph (PB‐morph) utilize the profundal habitat for feeding and reproduction and spawn in December and November, respectively. Females from all morphs were sampled for fecundity and egg‐size analysis. There were large differences between the morphs. The PB‐morph had the lowest fecundity (mean = 45, SD = 13) and smallest egg size (mean = 3.2 mm, SD = 0.32 mm). In contrast, the PP‐morph had the highest fecundity (mean = 859.5, SD = 462) and the largest egg size (mean = 4.5 mm, SD = 0.46 mm), whereas the LO‐morph had intermediate fecundity (mean = 580, SD = 225) and egg size (mean = 4.3, SD = 0.24 mm). Fecundity increased with increasing body size within each morph. This was not the case for egg size, which was independent of body sizes within morph. Different adaptations to feeding and habitat utilization have apparently led to a difference in the trade‐off between fecundity and egg size among the three different morphs.