Conservation status of New Zealand frogs, 2009

Abstract

A reappraisal of the conservation status of the New Zealand frog fauna is presented using the 2008 version of the New Zealand Threat Classification System. Of New Zealand's four extant endemic species, three are judged to be ‘Threatened’ (Leiopelma hamiltoni being ‘Nationally Critical’, and L. pakeka and L. archeyi being ‘Nationally Vulnerable’) and one ‘At Risk’ (L. hochstetteri ‘Declining’). Three Leiopelma species are listed as extinct—they are known from bone deposits in caves throughout the country until some time in the last 1000 years. Three introduced and naturalised Litoria species are abundant in New Zealand although two (L. aurea and L. raniformis) are threatened in their country of origin (Australia). An additional unidentified frog taxon from northern Great Barrier Island is listed as ‘Data Deficient’.     

The taxonomy of the endemic golden palm civet of Sri Lanka

Two species of palm civet are currently known from Sri Lanka: the widespread common species, Paradoxurus hermaphroditus (Pallas, 1777), and the endemic golden species, Paradoxurus zeylonensis (Pallas, 1778). The latter has two ‘morphs’, one golden and one dark brown, both of which are recorded from all three major biotic zones in Sri Lanka (wet zone, dry zone, and cloud forest). We have examined specimens of both ‘morphs’ from all zones, and conclude that there are actually several species involved: names are available for two of them, we describe a third as a new species, and we draw attention to a probable fourth species, based on two distinctive specimens, the provenance of which are unfortunately unknown. The name zeylonensis probably does not apply to a golden palm civet at all. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 238–251.     

Low levels of hybridization across two contact zones among three species of woodpeckers (Sphyrapicus sapsuckers)

Three species of closely related woodpeckers (sapsuckers; Sphyrapicus) hybridize where they come into contact, presenting a rare ‘λ‐shape’ meeting of hybrid zones. Two of the three arms of this hybrid zone are located on either side of the Interior Plateau of British Columbia, Canada bordering the foothills of the Coast Mountains and the Rocky Mountains. The third arm is located in the eastern foothills of the Rocky Mountains. The zones of hybridization present high variability of phenotypes and alleles in relatively small areas and provide an opportunity to examine levels of reproductive isolation between the taxa involved. We examined phenotypes (morphometric traits and plumage) and genotypes of 175 live birds across the two hybrid zones. We used the Genotyping By Sequencing (GBS) method to identify 180 partially diagnostic single nucleotide polymorphisms (SNPs) to generate a genetic hybrid index (GHI) for each bird. Phenotypically diverged S. ruber and S. nuchalis are genetically closely related, while S. nuchalis and S. varius have similar plumage but are well separated at the genetic markers studied. The width of both hybrid zones is narrower than expected under neutrality, and analyses of both genotypes and phenotypes indicate that hybrids are rare in the hybrid zone. Rarity of hybrids indicates assortative mating and/or some form of fitness reduction in hybrids, which might maintain the species complex despite close genetic distance and introgression. These findings further support the treatment of the three taxa as distinct species.     

The nematode fauna of a temperate Australian mangrove mudflat; its population density,diversity and distribution

The nematode fauna of an estuarine mangrove Avicennia marina mudflat in Southeastern Australia has been intensively studied. About 85% of the nematodes occur in the top cm of soft mud, but 5–7 species inhabit the deeper anoxic mud down to 10 cm, both at low and high tide. One square metre was intensively sampled from four zones with different nematode faunas. At the low tide zone 58% of the nematodes were epistrate feeders, including many diatom-feeders, but in the mangrove zone selective microbial feeders made up over 60% of the population, while between high water neap and high water spring, above the mangrove zone, omnivore/predators and plant root feeding nematodes increased in relative importance. Random replicate cores reliably sampled species occurrence, but gave a high variance in density estimates. Replicate aliquots from homogenised mud gave lower density variance. Nematode densities (maximum 5 × 10⁶ m^-2) were not as high as have been reported from non-mangrove estuaries in other countries, but were within the range found in mangroves elsewhere in Australia. Margalef Species Richness values ranged from 1.7 to 3.89, which is similar to values found in other mangroves mudflats in Australia. Nematode biomass ranged from 888 mg dry weight m² (383 mg C m^-2) at the low tide zone to 19 mg dry weight m^-2 (8 mg C m^-2) at the upper tide level.     

Changes in growth,porosity, and radial oxygen loss from adventitious roots of selected mono‐ and dicotyledonous wetland species with contrasting types of aerenchyma

Growth in stagnant, oxygen‐deficient nutrient solution increased porosity in adventitious roots of two monocotyledonous (Carex acuta and Juncus effusus) and three dicotyledonous species (Caltha palustris, Ranunculus sceleratus and Rumex palustris) wetland species from 10 to 30% under aerated conditions to 20–45%. The spatial patterns of radial oxygen loss (ROL), determined with root‐sleeving oxygen electrodes, indicated a strong constitutive ‘barrier’ to ROL in the basal root zones of the two monocotyledonous species. In contrast, roots of the dicotyledonous species showed no significant ‘barrier’ to ROL when grown in aerated solution, and only a partial ‘barrier’ when grown in stagnant conditions. This partial ‘barrier’ was strongest in C. palustris, so that ROL from basal zones of roots of R. sceleratus and R. palustris was substantial when compared to the monocotyledonous species. ROL from the basal zones would decrease longitudinal diffusion of oxygen to the root apex, and therefore limit the maximum penetration depth of these roots into anaerobic soil. Further studies of a larger number of dicotyledonous wetland species from a range of substrates are required to elucidate the ecophysiological consequences of developing a partial, rather than a strong, ‘barrier’ to ROL.     

Phytoperiphyton of the Samarga River basin (Primorskii Krai)

In the periphyton of the Samarga River basin, 313 species of algae (337, including infraspecific taxa) from eight divisions have been found. The groups of algae from the river main flow, creeks, streams, and the mouth are described. Data on the density and biomass of periphyton algae are presented. A decrease in these parameters after a flood is shown. In algal flora composition, benthic oligohalobic species of algae, preferring a slightly alkaline environment, dominate. At the river mouth a significant amount of mesohalobic species has been observed. A sanitary and biological evaluation of water quality has shown that the mass development of xenoand oligosaprobic algae defines the excellent quality of the river water. All parts of the main flow correspond to the oligosaprobic purification zone, class II of water purity (saprobic index of 0.95–1.48). The good quality of the Samarga River water is ensured by the absence of pollution sources and the satisfactory condition of its catchment area forests.     

The good,the bad,and the ugly: which Australian terrestrial mammal species attract most research?

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Species distribution models contribute to determine the effect of climate and interspecific interactions in moving hybrid zones

Climate is a major factor delimiting species’ distributions. However, biotic interactions may also be prominent in shaping geographical ranges, especially for parapatric species forming hybrid zones. Determining the relative effect of each factor and their interaction of the contact zone location has been difficult due to the lack of broad scale environmental data. Recent developments in species distribution modelling (SDM) now allow disentangling the relative contributions of climate and species’ interactions in hybrid zones and their responses to future climate change. We investigated the moving hybrid zone between the breeding ranges of two parapatric passerines in Europe. We conducted SDMs representing the climatic conditions during the breeding season. Our results show a large mismatch between the realized and potential distributions of the two species, suggesting that interspecific interactions, not climate, account for the present location of the contact zone. The SDM scenarios show that the southerly distributed species, Hippolais polyglotta, might lose large parts of its southern distribution under climate change, but a similar gain of novel habitat along the hybrid zone seems unlikely, because interactions with the other species (H. icterina) constrain its range expansion. Thus, whenever biotic interactions limit range expansion, species may become ‘trapped’ if range loss due to climate change is faster than the movement of the contact zone. An increasing number of moving hybrid zones are being reported, but the proximate causes of movement often remain unclear. In a global context of climate change, we call for more interest in their interactions with climate change.     

Spatial zonation of macrobenthic fauna in Zhanjiang Mangrove Nature Reserve, Guangdong, China

The spatial zonation of macrobenthic fauna in the core region of Zhanjiang Mangrove Nature Reserve was studied with two transects vertical to the shoreline. The first transect was near Deyao Village where three faunal zones of the mangrove swamp could be divided into the following types from the high tide part to the low tide part: the Assiminea lutea-Uca arcuata-Paracleistostoma crassipilum zone, the Cleistostoma dilatatum-Macrophthalmus erato-Littoraria melanostoma zone, and the Paracleistostoma depressum-Cerithidae cingulata zone. Mollusck and crustacean exhibited the highest individual density in this transect. Mollusck mainly influenced the dynamics of community biomass as well as the species diversity index. In the second transect near Hongzhai Village, the following four faunal zones could be determined: the Littoraria melanostoma-Pseudoringicula sinensis-Ceratonereis burmensis zone, the Assiminea lutea-Cleistostoma dilatatum zone with a dominant species belonging to the Ellobiidae, Upogebia sp.-Paracleistostoma depressum zone, and the Metaplax sheni-Cerithidae cingulata zone. The crustacean showed the highest individual density in this transect. Similar to the Deyao transect, dynamics of community biomass and the species diversity index of the Hongzhai transect were mainly influenced by mollusck. By hierarchical clustering and nonmetric multidimensional scaling, the macrobenthic fauna communities could be divided into three and four groups in the Deyao and Hongzhai transects, respectively. These groups corresponded to different types of vegetation of the mangrove swamp. Taken together, our observations indicated that the spatial zonation of the macrobenthic fauna was mainly affected by the characteristics of the mangrove community, sediment characteristics and the tidal line.     

Mediterranean v. continental small mammal communities and the environmental degradation of the Dinaric Alps

In order to test for the existence of distinct, regionally-based small mammal faunas, distributional patterns were examined in thirty one species of small mammals (insectivores and rodents) inhabiting the Dinaric Alps (western Balkans). The small mammal fauna was found to consist of three groups: a group of ‘generalist’ species that occurred throughout the study area, plus distinct coastal and continental small mammal assemblages. The continental small mammal assemblage is considerably more species-rich, whilst that of the coastal zone is largely restricted to generalists and species with geophilic or fossorial life-styles (many of which are also commensal with humans). The two assemblages appear to be associated with different vegetation types, and the transition between them lies on the coastal slopes of the Dinaric Alps at c. 700–900 m of altitude. We discuss possible determinants of assemblage composition and species richness, and particularly the possible role of prehistoric environmental degradation in the context of the reduced species-richness of the coastal zone.     

Drosophilidae (Diptera) of Australia's Northern Territory: ecology and biogeography

Abstract   The drosophilid fauna is well documented in eastern Australia but is poorly known in other parts of the continent. This paper summarises what is known of this fauna in the Northern Territory (NT), and includes results from banana trapping in the humid and arid zones. The 42 recorded species include species that breed in fruit, fungi and/or flowers, and a larval predator of scale insects. Drosophilids occur in all three major climate zones (humid, semiarid and arid) but predominate in the humid zone. Banana-attracted species in the humid zone (wet-dry tropics) were common in all sampled habitats: urban, rainforest and open woodland. They included predominantly urban and/or rainforest species. Of the species collected in open woodland, some are likely to be breeding there, whereas others may have been intercepted during movement across the area. The semiarid fauna is a depauperate version of that found in the humid region. Only three species have been recorded in the arid region: an endemic arid specialist, and two cosmopolitan species ( D. simulans and D. melanogaster ) in urban Alice Springs. Overall, the NT drosophilid fauna represents a depauperate version of that found in eastern Australia, probably because of climatic factors and natural barriers to range expansion. There is little evidence of regional endemism, with probably only one (and at most three) species endemic to the NT, and no evidence of independent, natural dispersion from nearby Indonesia.     

Molecular phylogeny and biogeography of African diploid barbs, ‘Barbus’, and allies in Africa and Asia (Teleostei: Cypriniformes)

African diploid barbs (‘Barbus’, Clypeobarbus, Barboides, etc.) are a group of small cyprinids with a body size less than 20 cm and widely distributed in drainages across Africa. These species constitute a significant component of African freshwater fish fauna. This study is the first to focus on the molecular systematics and biogeography of African diploid barbs ‘Barbus’ and its African and Asian allies using both mitochondrial and nuclear genes. We test for monophyly of groups, determine interspecific relationships and estimate the time of divergence of 52 species of ‘Barbus’ and allies using two mitochondrial and four nuclear genes. Resulting trees demonstrate that ‘Barbus’ and allies (Systomus, Barboides, Clypeobarbus and African tetraploid barbs) form a strongly supported clade; however, ‘Barbus’ is not resolved as monophyletic. Divergence time analyses identify the separation between Systomus and ‘Barbus’ plus African allies may have occurred around 26 MYA. In addition to the phylogenetic results, these findings highlight the need for more thorough taxonomic and systematic studies on ‘Barbus’ and allies using morphological and additional molecular data and greater taxon sampling, including the type species of the genus Enteromius, ‘Barbus’ potamogalis.     

Spatial Distribution of the Nematode Fauna and Production of Three Nematodes (Tobrilus gracilis,Monhystera stagnalis,Ethmolaimus pratensis) in the Profundal of Piburger See (Austria, 913 m a.s.l)

The species composition and the spatial distribution of the nematode fauna of Piburger See is discussed briefly. The study then concentrates on the three species (Tobrilus gracilis, Monhystera stagnalis, Ethmolaimus pratensis) which form the lake's profundal nematode fauna between depths of roughly 8 and 13 meters. This profundal fauna is separated by a distinct metalimnetic abundance minimum from the very diverse littoral community. In addition to taxonomic and ecological considerations, the zonation of the three species within their main habitat is described, and life cycles cohort production as well as annual production are evaluated from the field data. Total annual nematode production within the profundal habitat (8–13 m) in Piburger See amounts to 11.6 kg per hectare. 65 % of which are contributed by T. gracilis, 22 % by M. stagnalis and 13 % by E. pratensis. For the whole area under observation (6 to 13.5 m, including the scarcely populated border zones) mean annual nematode production is 7 kg per hectare.     

THE VERTEBRATE FAUNA OF THE PRIMAEVA BEDS OF THE FRæNKELRYGGEN FORMATION OF VESTSPITSBERGEN AND ITS BIOSTRATI-GRAPHIC SIGNIFICANCE

New occurrences of Traquairaspis sp., Oniscolepis? sp., Turinia sp., Cephalaspis (Zenaspis) cf. excellens Wängsjö, Nostolepis sp. and Ischna-canthidae gen. et sp. indet. are recorded from the primaeva Beds. Taken as a whole, the vertebrate fauna of these beds shows a general resemblance to those of the upper part of the symondsi zone and the lowermost part of the leathensis zone in the Welsh Borderland. For this and other reasons it is suggested that the Frænkelryggen Formation should be correlated approximately with the symondsi and leathensis zones of the British ‘Psammosteus’ Limestones Group and that the equivalent of the boundary between these zones should be placed either in, or just above, the primaeva Beds.     

Monitoring microbial aeroflora using vegetable waste media: an ecological aspect

For isolation of aeromicroflora in ecologically different zones, a liquid vegetable waste, deproteinised leaf juice (DLJ) was used instead of usual media. DLJ samples from three different plants, cowpea (Vigna sinensis), turnip (Brassica campestris) and radish (Raphanus sativus), were used in order to determine their efficiency as potential growth media for different types of microbes. Four different ecological zones of West Bengal, India were selected to study the aeromicroflora. The zones were as follows: (i) densely populated and industrially polluted Calcutta (CAL); (ii) plateau region of western part of the state (WEST); (iii) Terai region of Northern Bengal (TER); (iv) sandy coastal zone of Midnapore district of Southern Bengal (SB). Each zone was subdivided into three subzones. The variation in population of fungi, bacteria and actinomycetes among these zones was studied. The relative abundance and species diversities of microbes were noted. The study indicates that pollution and ecological diversity both play important roles in controlling the above two factors.     

Distribution of water bugs (Heteroptera: Nepomorpha, Gerromorpha) over latitudinal zones in the northeast of European Russia

Data on the taxonomic composition of water bugs (Heteroptera: Nepomorpha, Gerromorpha) in the northeast of European Russia are given. A total of 34 water-bug species, which belong to 16 genera and 8 families, are recorded. The species diversity of Nepomorpha and Gerromorpha changes northwards: 33 occur in the taiga zone and only 8 species occur in the tundra zone. The bulk of the fauna consists of Eurosiberian (29%) and trans-Eurasian (26%) species; in latitude-related terms, the temperate group is most richly represented (64%). The species composition of the aquatic and semiaquatic heteropteran fauna of the region is especially similar to that of the tundra and taiga zones of Western Siberia.     

The canopy beetle faunas of Gondwanan element trees in Chilean temperate rain forests

Aim To describe the coleopteran fauna occurring in canopies of temperate Gondwanan tree species in terms of their diversity and guild and taxonomic structures, and to test the proposition that this structuring reflects the Gondwanan origins of this fauna. Location The Andes and the coastal cordillera of temperate Chile. Methods Canopy fogging was used to sample beetles from 29 trees. The samples were statistically described using S_chao and the Simpson diversity index D. Cluster analyses and multi‐dimensional scaling (MDS) were performed. The taxonomic and guild structures of the Chilean coleopteran fauna were compared quantitatively with those found in other parts of the world using homogeneity chi‐square and t‐tests. Results A collection of 25,497 beetle specimens was obtained primarily from Nothofagus dombeyi, Nothofagus obliqua and Araucaria araucana. The specimens collected were distributed between 485 morphospecies and included 107 putative, new generic‐level taxa and 223 apparently undescribed species. Estimates of the size of the canopy beetle fauna showed that 600+ species were likely to be present. The communities found on a tree species differed markedly between years. MDS plots showed less community divergence between tree species for predators than for phytophages and xylophages. The guild structure was similar to that found on Australian ‘Gondwanan’ trees but differed significantly from the community structures found on ‘Laurasian’ tropical and temperate trees in supporting fewer phytophages and saprophages, but more xylophages. The predator guild showed a different pattern, with tropical faunas differing from those of more temperate regions, irrespective of hemisphere, as did the distribution of superfamilies. Main conclusions The beetle fauna found in the canopies of N. dombeyi, N. obliqua and A. araucana was large (600+ species), with about half of the species undescribed. S_chao was found to vary with sample size and to give lower estimates of S than species attenuation curves, raising the possibility that the two methods are estimating the sizes of different statistical communities. It is possible that the attenuation curve is estimating the number of species to be found on a particular tree species, while S_chao is estimating the ‘carrying capacity’ for beetle species of individual trees, and this varies from tree to tree. Care also needs to be taken in experimental design when monitoring temporal changes in forest insect communities given the difference in communities found between years in this study. The proportions of phytophages, saprophages and xylophages resemble those of a ‘Gondwanan’ rain forest from Australia and differ significantly from those of tropical and temperate ‘Laurasian’ forests.     

A quantitative description of the forest vegetation on an altitudinal gradient in the Mount Field National Park,Tasmania, and a discussion of its history and dynamics

The aim of this study was to describe the forest vegetation along an altitudinal transect running from 158 m to 1220 m (treeline) in the Mount Field National Park, Tasmania. Eighteen 1 ha plots were sampled along this transect, using a modified point-centred quarter method for species composition and density. Size frequency distributions were used to calculate basal areas. Estimates of relative density, frequency and basal area for each species were combined in to an importance value. The altitudinal ranges of all woody species were determined. The altitudinal temperature lapse rate was measured, and data on soil pH obtained. The initial ‘direct gradient’ analysis revealed relatively well marked discontinuities in the vegetation which were further examined by ordination and classification techniques. The latter provided a simple threefold classification into altitudinal zones. The lower zone reaches from the Park entrance (158 m) to between 600 and 670 m, and comprises tall open forest dominated by Eucalyptus regnans and/or E. obliqua and with a ‘wet sclerophyll’ understorey characterized by Olearia argophylla. The middle zone stretches from c. 670 to 940 m and comprises closed rainforest or ‘mixed’ forest (i.e. with senescent emergent eucalypts) dominated by Nothofagus cunning hamii and Atherosperma moschatum. This zone is characterized by the absence of O. argophylla and the presence of Phyllocladus aspleniifolius. The upper part of this zone constitutes an interdigitating transition to the subalpine forests, usually dominated by E. coccifera and occurring on suitable sites between c. 880 m and the timberline. The transition to subalpine forests is associated with a marked decline in basal area. Species richness (of woody plants) increases with altitude to reach a peak in the sub-alpine zone. This trend is the reverse of that normally encountered elsewhere in the world, and is mainly due to relatively high α and β diversities in the shrub stratum of this zone. The significance of fires, aspect and substrate is discussed in relation to the variations in composition within each zone. The low diversity of Nothofagus-dominated rainforest is thought to be due, in part, to the intense competitive thinning in the eucalypt re-growth phase following burning, and the subsequent ‘capture’ of the Eucalyptus niche by Nothofagus. It is speculated that, in Tasmania, the downhill migrations during the cooling phases of the Pleistocene were associated with extinctions of lowland forest taxa, while uphill migrations during warming phases were associated with speciation on the plateaux of the present subalpine zone. This hypothesis implies that the relative proportions of land area available at different altitudes, now and in the past, have determined the relative rates of speciation and extinction, and hence the altitudinal gradients of species richness.     

Scale dependence in the species‐discharge relationship for fishes of the southeastern U.S.A.

1. Species‐discharge relationships (SDR) are aquatic analogues of species‐area relationships, and are increasingly used in both basic research and conservation planning. SDR studies are often limited, however, by two shortcomings. First, they do not determine whether reported SDRs, which normally use complete drainage basins as sampling units, are scale dependent. Second, they do not account for the effects of habitat diversity within or among samples. 2. We addressed both problems by using discrete fish zones as sampling units in a SDR analysis. To do so, we first tested for longitudinal zonation in three rivers in the southeastern U.S.A. In each river, we detected successive ‘lower’, ‘middle’, and ‘upper’ fish zones, which were characterized by distinct fish assemblages with predictable habitat requirements. Because our analyses combined fish data from multiple sources, we also used rarefaction and Monte Carlo simulation to ensure that our zonation results were robust to spurious sampling effects. 3. Next, we estimated the average discharge within each zone, and plotted these estimates against the respective species richness within each zone (log₁₀ data). This revealed a significant, linear SDR (r² = 0.83; P < 0.01). Notably, this zonal SDR fit the empirical data better than a comparable SDR that did not discriminate among longitudinal zones. We therefore conclude that the southeastern fish SDR is scale dependent, and that accounting for within‐basin habitat diversity is an important step in explaining the high diversity of southeastern fishes. 4. We then discuss how our zonal SDR can be used to improve conservation planning. Specifically, we show how the slope of the SDR can be used to forecast potential extinction rates, and how the zonal data can be used to identify species of greatest concern.     

Biological invasion on an oceanic island mountain: Do alien plant species have wider ecological ranges than native species?

Abstract. Spatial distribution patterns of alien plant species were compared with those of native species on a windward slope of Mt. Haleakala (3055 m). Oceanic islands are considered susceptible to biological invasion, and this study numerically tested this circumstantial evidence with the following questions: Are all habitats equally susceptible; and, do successful invaders have wider realized niches than natives? The mountain slope consists of three distinct altitudinal bioclimatic zones (hot moist lowland, wet montane cloud, and cool arid high-altitude zones). Ordination indicated that alien species' ranges and population expansions were clustered in the lowland and high-altitude zones. The lowland zone had been subjected to natural canopy dieback, and the high-altitude zone to grazing by domestic and feral ungulates. By contrast, the montane cloud forest was relatively intact in terms of number and cover of native species. Thus, susceptibility to alien invasion clearly differed among zones, and the primary causes seemed to be the obvious disturbance factors. The mean ecological range along the altitude-rainfall gradient was significantly (P < 0.05) greater for native than for alien species in most life-form groups. The reasons for the greater number of climate generalists among the natives vs. the range-restricted aliens appear to be related to: (1) the pre-alien condition with a depauperate flora which allowed for ‘ecological release’ of successful native colonizers, and (2) the climatic pre-adaptation of alien invaders which restricts them from penetrating over a broader spectrum of climatic zones in a floristic matrix subjected to increasing interspecific competition.