Two new genera of songbirds represent endemic radiations from the Shola Sky Islands of the Western Ghats, India

A new species of silverline butterfly, Cigaritis Donzel, 1847 (Lepidoptera: Lycaenidae), from the Western Ghats biodiversity hotspot, India

A new species, Cigaritis conjuncta sp. nov. (Lepidoptera: Lycaenidae), is described based on five male and four female specimens from Honey Valley, Kodagu District, Karnataka, which is part of the Western Ghats biodiversity hotspot, India. Cigaritis conjuncta sp. nov. is distinguished from all other congeners in India and Sri Lanka based on the following combination of diagnostic characters in the male: (a) dorsal forewing outer half, costal margin and nearly upper half of the cell black without orange markings, the remaining wing shining deep blue, (b) dorsal hindwing tornus pale orange-red with two black spots, (c) ventral forewing bands at end of discal cell conjoined, and (e) ventral hindwing subbasal and discal bands composed of spots that are not separated but conjoined to form broad bands that have irregular outlines, leaving only a narrow background colour in between. Female is similar on the ventral side, but entirely dark brown above. Male and female genitalia are dissected and figured for two paratypes of each sex, and natural history notes on the species are provided.

Endemicity and radiation in waterfalls of the Western Ghats: The genus Cremnoconchus (Gastropoda: Littorinidae)

Snails of the genus Cremnoconchus - the only freshwater members of the gastropod family Littorinidae - are endemic to the spray zones of numerous waterfalls in the Western Ghats of India. Cremnoconchus consists of nine described and possibly numerous undescribed species as many of these appear to be restricted to specific waterfalls. This is the first attempt at resolving the relationships between the various species in this genus and establishing its monophyly in the family. Further, we also undertake species delimitation analysis to characterize cryptic diversity in this group. Phylogenetic analyses based on nuclear and mitochondrial genes support the monophyly of Cremnoconchus within the family. A fossil-calibrated Bayesian time tree suggests that this freshwater lineage diverged from its marine counterparts around 90.40 million years ago. The separation of Cremnoconchus from its marine ancestors might have been facilitated by the break-up of Gondwana or fluctuating sea levels during this period. Species delimitation analysis retrieved 12 potentially undescribed species in this group. These species formed two distinct clades in the phylogeny, one largely confined to the northern Western Ghats and the other to the central Western Ghats. Species belonging to the northern and central Western Ghats seem to have separated around 56.11 mya, i.e. after the northern Western Ghats were formed. Additionally, spatial isolation due to the patchiness of suitable habitats (waterfalls) and low mobility might have facilitated their diversification.

The latitudinal taxonomy gradient

Emerging large-scale datasets coupled with statistical advances have provided new insights into the processes that generate the latitudinal diversity gradient (LDG). But many of these studies run into an old, if often underappreciated, problem: The interpretation of the data critically depends on the consistent application of criteria to define what constitutes a species. This is particularly pernicious for the LDG because good species have been easier to recognize in temperate than in tropical regions. We provide evidence that this latitudinal taxonomy gradient exists, discuss how this potentially impacts inferences about latitudinal variation in ecoevolutionary processes such as population differentiation and speciation, and provide a roadmap for how to mitigate taxonomic biases in the study of biodiversity patterns.

A multi-species occupancy modeling approach to access the impacts of land use and land cover on terrestrial vertebrates in the Mumbai Metropolitan Region (MMR), Western Ghats, India

Urbanization is one of the main drivers in the conversion of natural habitats into different land use and land cover types (LULC) which threaten the local as well as global biodiversity. This impact is particularly alarming in tropical countries like India, where ~18% of the world's population live, and its ever-growing economy (i.e., industrial development) expanded urban areas by several folds. We undertook this study to examine the impacts of urbanization (i.e., LULC) on terrestrial vertebrates (mammals, birds, reptiles, and amphibians) in the Mumbai Metropolitan Region (MMR), Western Ghats, India. We sampled different habitats ranged from highly disturbed urban areas to less disturbed forested areas. Multiple sampling methods such as quadrat sampling, line transect, point count, and camera trapping were used to quantify the target taxa. We used multi-species occupancy modeling in the Bayesian framework to estimate detection probability and occupancy and to assess the effect of various LULC on different species. All four groups showed a significant negative impact of increasing anthropogenic habitat cover on occupancy. Out of 213 species detected in this study, 96% of mammals, 85% of birds, 93.75% of amphibians, and 69.43% of reptiles showed a negative effect of anthropogenic habitat cover. Evidence suggests that historical and recent human disturbances could have played an important role in transforming this area from semi-evergreen and moist deciduous forest to open, scrubby, dry deciduous, and fire-prone landscape. This might be the reason for the high occupancy of open and degraded forest habitat preferring species in our study area. We recommend species-rich areas in the MMR, e.g., Karnala Bird Sanctuary (KBS) and Prabalgad-Matheran-Malanggad Hill Range (PMMHR), must be conserved through habitat restoration, ecotourism, public awareness, and policymaking.

The out-of-India hypothesis: evidence from an ancient centipede genus, Rhysida (Chilopoda: Scolopendromorpha) from the Oriental Region, and systematics of Indian species

The Oriental Region has been a focus of biogeographical research for more than two centuries. We examined systematics and biogeography of the centipede genus Rhysida in this region. A robust species hypothesis for the Indian subcontinental and Southeast Asian Rhysida clade uses molecular, morphological and distribution data. Twelve species are recognized in two monophyletic species complexes, eight belonging to the Rhysida immarginata and four to the Rhysida longipes species complex. They include Rhysida aspinosa, Rhysida crassispina, R. immarginata, R. longipes and seven new species, five of which are formally named in this paper: Rhysida ikhalama, Rhysida konda, Rhysida lewisi, Rhysida pazhuthara and Rhysida sada The nine Rhysida species are documented taxonomically and their morphological variation is reviewed. An integrative systematic approach reveals that diversity of Rhysida in the Indian subcontinent has been underestimated. Both species complexes started to diversify in the Early to Late Cretaceous in the Indian subcontinent. The out-of-India hypothesis is supported in both clades, because Southeast Asian species are nested in Indian subcontinental clades. Historical biogeographical analyses suggest two independent post-collision dispersal events, one in the immarginata clade and another where R. longipes expanded its range into Southeast Asia.

Coalescent Theory of Migration Network Motifs

Natural populations display a variety of spatial arrangements, each potentially with a distinctive impact on genetic diversity and genetic differentiation among subpopulations. Although the spatial arrangement of populations can lead to intricate migration networks, theoretical developments have focused mainly on a small subset of such networks, emphasizing the island-migration and stepping-stone models. In this study, we investigate all small network motifs: the set of all possible migration networks among populations subdivided into at most four subpopulations. For each motif, we use coalescent theory to derive expectations for three quantities that describe genetic variation: nucleotide diversity, F_ST, and half-time to equilibrium diversity. We describe the impact of network properties on these quantities, finding that motifs with a high mean node degree have the largest nucleotide diversity and the longest time to equilibrium, whereas motifs with low density have the largest F_ST. In addition, we show that the motifs whose pattern of variation is most strongly influenced by loss of a connection or a subpopulation are those that can be split easily into disconnected components. We illustrate our results using two example data sets—sky island birds of genus Sholicola and Indian tigers—identifying disturbance scenarios that produce the greatest reduction in genetic diversity; for tigers, we also compare the benefits of two assisted gene flow scenarios. Our results have consequences for understanding the effect of geography on genetic diversity, and they can assist in designing strategies to alter population migration networks toward maximizing genetic variation in the context of conservation of endangered species.

Discovery of a deeply divergent new lineage of vine snake (Colubridae: Ahaetuliinae: Proahaetulla gen. nov.) from the southern Western Ghats of Peninsular India with a revised key for Ahaetuliinae

The Western Ghats are well known as a biodiversity hotspot, but the full extent of its snake diversity is yet to be uncovered. Here, we describe a new genus and species of vine snake Proahaetulla antiqua gen. et sp. nov., from the Agasthyamalai hills in the southern Western Ghats. It was found to be a member of the Ahaetuliinae clade, which currently comprises the arboreal snake genera Ahaetulla, Dryophiops, Dendrelaphis and Chrysopelea, distributed in South and Southeast Asia. Proahaetulla shows a sister relationship with all currently known taxa belonging to the genus Ahaetulla, and shares ancestry with Dryophiops. In addition to its phylogenetic position and significant genetic divergence, this new taxon is also different in morphology from members of Ahaetuliinae in a combination of characters, having 12-13 partially serrated keels on the dorsal scale rows, 20 maxillary teeth and 3 postocular scales. Divergence dating reveals that the new genus is ancient, dating back to the Mid-Oligocene, and is one of the oldest persisting monotypic lineages of snakes in the Western Ghats. This discovery adds to the growing list of ancient lineages endemic to the Agasthyamalai hills and underscores the biogeographic significance of this isolated massif in the southern Western Ghats.

Geographical and host species barriers differentially affect generalist and specialist parasite community structure in a tropical sky-island archipelago

Understanding why some parasites emerge in novel host communities while others do not has broad implications for human and wildlife health. In the case of haemosporidian blood parasites, epidemic wild bird mortalities on oceanic islands have been linked to Plasmodium spp., but not genera like Haemoproteus. Indeed, Haemoproteus is absent from many oceanic islands. By contrast, birds on continental islands share long coevolutionary histories with both Plasmodium and Haemoproteus, and are thus ideal model systems to elucidate eco-evolutionary endpoints associated with these parasites in oceanic islands. Here, we examine eco-evolutionary dynamics of avian haemosporidian in the Shola sky-island archipelago of the Western Ghats, India. Our analyses reveal that compared to Plasmodium, Haemoproteus lineages were highly host-specific and diversified via co-speciation with their hosts. We show that community structure of host-generalist Plasmodium was primarily driven by geographical factors (e.g. biogeographic barriers), while that of host-specialist Haemoproteus was driven by host species barriers (e.g. phylogenetic distance). Consequently, a few host species can harbour a high diversity of Plasmodium lineages which, in turn, are capable of infecting multiple host species. These two mechanisms can act in concert to increase the risk of introduction, establishment, and emergence of novel Plasmodium lineages in island systems.

The critically endangered forest owlet Heteroglaux blewitti is nested within the currently recognized Athene clade: A century-old debate addressed

Range-restricted species generally have specific niche requirements and may often have unique evolutionary histories. Unfortunately, many of these species severely lack basic research, resulting in poor conservation strategies. The phylogenetic relationship of the Critically Endangered Forest Owlet Heteroglaux blewitti has been the subject of a century-old debate. The current classifications based on non-phylogenetic comparisons of morphology place the small owls of Asia into three genera, namely, Athene, Glaucidium, and Heteroglaux. Based on morphological and anatomical data, H. blewitti has been alternatively hypothesized to belong within Athene, Glaucidium, or its own monotypic genus Heteroglaux. To test these competing hypotheses, we sequenced six loci (~4300 bp data) and performed phylogenetic analyses of owlets. Mitochondrial and nuclear trees were not congruent in their placement of H. blewitti. However, both mitochondrial and nuclear combined datasets showed strong statistical support with high maximum likelihood bootstrap (>/ = 90) and Bayesian posterior probability values (>/ = 0.98) for H. blewitti being nested in the currently recognized Athene group, but not sister to Indian A. brama. The divergence of H. blewitti from its sister taxa was between 4.3 and 5.7 Ma coinciding with a period of drastic climatic changes in the Indian subcontinent. This study presented the first genetic analysis of H. blewitti, a Critically Endangered species, and addressed the long debate on the relationships of the Athene-Heteroglaux-Glaucidium complex. We recommend further studies with more data and complete taxon sampling to understand the biogeography of Indian Athene species.

Molecular phylogeny and systematics of the centipede genus Ethmostigmus Pocock (Chilopoda : Scolopendromorpha) from peninsular India

Integrative taxonomy assesses the congruence between different lines of evidence for delimiting species, such as morphological, molecular or ecological data. Herein molecular phylogenetics is used to test monophyly and determine the phylogenetic position of the Old World tropical centipede genus Ethmostigmus Pocock, 1898, and to define species boundaries for Ethmostigmus in peninsular India. A phylogeny of the family Scolopendridae based on DNA sequence data for three markers from 427 specimens sampling in all major lineages (144 individuals generated in this study) recovers Ethmostigmus as a monophyletic group, but relationships among the genera in its subfamily Otostigminae are poorly supported. Two species delimitation methods for DNA sequence data and phylogeny are integrated with morphology and geographic data to propose a well-supported species hypothesis for Ethmostigmus on the peninsular Indian plate. Five species of Ethmostigmus are recognised in peninsular India, of which E. coonooranus Chamberlin, 1920 and three new species, namely, E. agasthyamalaiensis, sp. nov., E. sahyadrensis, sp. nov. and E. praveeni, sp. nov., occur in the Western Ghats, a biodiversity hotspot. The lesser-known Eastern Ghats harbour one species, E. tristis (Meinert, 1886), which has been nearly unreported for 130 years. This study highlights the value of an integrative approach to systematics, especially in underexplored, high biodiversity regions and where morphological variation is limited among closely related species.