Sampath S. Seneviratne

University of Colombo · Department of Zoology and Environment Sciences

Mechanosensory use is a seldom-mentioned function for feather ornaments, yet recent experimental evidence showed that the elaborate facial plumes of crevice-dwelling whiskered auklets, Aethia pygmaea, have just such a sensory role. Here we explored the evolutionary patterns of mechanosensory function of similar facial feather ornaments in related s...

Hybridization has challenged taxonomy, since hybridizing forms could be stable evolutionary entities or ephemeral forms that are blending together. The island of Sri Lanka has 2 subspecies of the flameback woodpecker D. benghalense: D. b. jaffnense in the north and D. b. psarodes in the south. Red plumage separates the endemic phenotype D. b. psaro...

Question: Are phylogenetic relationships the major determinant of vocal relationships in non-oscine birds (birds that do not have a learning component in the vocalization)? Background: Both environmental variables and phylogenetic affinities can affect vocalizations. Unlearned vocalizations are characteristics of most non-oscine bird families, whic...

The evolutionary history of a phylogenetically distinct group of organisms (a clade) can be traced by using a phylogenetic tree. Such phylogenetic trees can also be used to measure the amount of evolutionary history captured by each member species (node) in the tree. Evolutionary Distinctness (ED) and Evolutionary Distinct and Globally Endangered S...

Co-occurrence of closely related taxa on islands could be attributed to sympatric speciation or multiple colonization. Sympatric speciation is considered to be rare in small islands, however multiple colonizations are known to be common in both oceanic and continental islands. In this study we investigated the phylogenetic relatedness and means of...

Citizen science is a growing branch of public participation in scientific research, where individuals contribute to data collection and monitoring, thereby enhancing scientific knowledge at local and global scales. With nearly a million contributors and 1.6 billion bird observations, eBird (www.ebird.org) is the largest global citizen science platf...

A group of mammals consisting of populations of individuals with direct and indirect interactions is called a mammalian community. Elevational gradients profoundly affect such mammalian communities, shaping diverse patterns across altitudinal ranges. To investigate these elevation-associated effects on non-volant mammalian communities and to under...

Most ground-nesting birds do not build a well-insulated nest. Therefore, they exhibit specific incubation behaviour to maintain optimal egg temperatures (~37 0 C) despite fluctuating environmental conditions (temperature could vary between 20 0 C-50 0 C). To study these patterns of incubation behaviour, we studied the variation of the ground, air a...

Breeding Phenology, Pairing Patterns and Parental Behaviour of Dinopium Flamebacks in Sri Lanka

The global decline in Biodiversity has made it crucial to understand the ecology and distribution of endangered species for effective conservation through management. Here we present a study of a Critically Endangered (CR) species of bat, Pouched Tomb-bat (Saccolaimus saccolaimus), found in a private forest, protected under the Preservation of Land...

This is a feature article on Biogiographical influence on Avian Distribution using the available online research details.

Nestling development in Dinopium Flamebacks of Sri Lanka: A study using endoscope nest cameras

The yellow wagtail complex, previously considered a single species (Motacilla flava), has recently been divided into two: the Western Yellow Wagtail (Motacilla flava) and the Eastern Yellow Wagtail (Motacilla tschutschensis). Previous studies conducted elsewhere have shown noticeable differences in hind claw length and the first flight call between...

Climatic conditions play a major role in changing the species’ distribution. Climatic conditions could also change along an elevational gradient. Here, we investigated the bird community variation in response to the climatic conditions along an elevational gradient of one kilometre in the submontane zone of Sri Lanka. The bird community was studied...

The characterization of the behavior of wild buffaloes in Sri Lanka would help to understand the wild traits of these animals. Wild buffaloes can be seen at the high-elevation plateaus (altitudes ranging 1200 – 1400m) of the Issengard Biosphere Reserve, Belihuloya. Using trap cameras with video mode, their behaviors were studied for four months fro...

The characterization of the behavior of wild buffaloes in Sri Lanka would help to understand the wild traits of these animals. Wild buffaloes can be seen at the high-elevation plateaus (altitudes ranging 1200 – 1400m) of the Issengard Biosphere Reserve, Belihuloya. Using trap cameras with video mode, their behaviors were studied for four months fro...

The causes of population divergence in vagile groups remain a paradox in evolutionary biology: dispersive species should be able to colonize new areas, a prerequisite for allopatric speciation, but dispersal also facilitates gene flow, which erodes population differentiation. Strong dispersal ability has been suggested to enhance divergence in patc...

Endemic species mostly are habitat specialists. Therefore, the survival of endemic species is limited by the availability of their preferred habitat. Along an elevational gradient, the distribution of endemics may vary depending on the geology, availability of resources, energy, and space. This study was carried out in order to investigate the dist...

Altitudinal gradients offer an ideal research setting to investigate the patterns of distribution of parasites, vectors, hosts, and host immune responses across different environmental conditions. However, very few studies had been done on the parasite profile in birds along the altitudinal gradient in Asia. The study was conducted at the Issengard...

Abstract – Biogeography comprises the study of patterns of the geographic distribution of organisms and the factors which govern those patterns. An interacting group of different species in a particular location is called a community. Here we studied the avian community responses along the elevation gradient in a sub-montane forest and the drivers...

Nest Site Selection, Cavity Characteristics, and Cavity Use of Dinopium Flamebacks in Sri Lanka

Yellow wagtail complex was long considered a single species (Motacilla flava). Recent phylogenetic studies however, split this species into two; the Western Yellow Wagtail (Motacilla flava) and the Eastern Yellow Wagtail (Motacilla tschutschensis). Until 2020, there were no records of the Eastern Yellow Wagtail in Sri Lanka. Nonetheless, using seve...

Hybridization or introgression enables species to mix traits, allowing horizontal gene flow and varying parental alleles and phenotypes. Belihuloya, located in the intermediate zone is a transitioning point between dry and wet zones, where two sister species, the Sri Lanka Drongo (Dicrurus lophorinus), limited to the wet zone, and the Greater Racke...

Hybridization or introgression enables species to mix traits, allowing horizontal gene flow and varying parental alleles and phenotypes. Belihuloya, located in the intermediate zone is a transitioning point between dry and wet zones, where two sister species, the Sri Lanka Drongo (Dicrurus lophorinus), limited to the wet zone, and the Greater Racke...

Parasites thrive by consuming host resources, causing a decline in host fitness. This burden drives host evolution, exerting selective pressure on both. The main objective of the study was to investigate parasitic profile and host immune responses in avian hosts along altitudinal gradients in Sri Lanka. This research took place in the Issengard Bio...

The model of allopatric speciation in an island biogeographic framework suggests that the division of ancestral mainland populations lead to two or more allopatric island species through natural or sexual selection, or through genetic drift. Climatic conditions can influence the process of speciation by creating physical barriers that prevent gene...

The aptly named microcormorants (currently placed in the genus Microcarbo) form a morphologically diminutive and distinct clade sister to all other living cormorants and shags. However, the relationships within Microcarbo are largely speculative. Sequence data resolve these relationships unam-biguously, with our phylogeny suggesting that the microc...

The Kentish Plover Charadrius alexandrinus Linnaeus 1758 is a common shorebird in Eurasia and North Africa that breeds in a variety of habitats, exhibits different extents of migratory behaviour, and is an emerging model species of breeding system evolution. Here we focus on the resident population found across the southern tip of India and Sri Lan...

Elaborate avian feather ornaments have proven to be enigmatic because their function is often unclear, even though they are used in courtship and social displays. Male and female Whiskered Auklets Aethia pygmaea display on their faces four elaborate feather ornaments that serve both courtship and mechanosensory functions: three bilateral pairs of w...

We reviewed the systematics of Lycodon striatus (Shaw, 1802), including all available name‐bearing types of its synonyms after evaluating phylogeographic (genetics), morphological (morphometry, meristic, and hemipenes), osteological and distribution evidence. Lycodon striatus sensu lato is widely distributed throughout South and Central Asia and mi...

Nesting within the arthropod nests is rare but can be found in several lineages of birds. In Asia, only the Rufous Woodpecker (Micropternus brachyurus) (RUWP) shows this peculiar nesting behavior where it breeds inside the nest of the Crematogaster ant. This study focused on the symbiotic relationship between RUWP in Sri Lanka (M. b. jerdonii) and...

Urbanization-related environmental and landscape changes often negatively impact biodiversity, primarily due to habitat loss and fragmentation, forcing wildlife to migrate to new habitats. Nevertheless, urban exploiters and urban adapters seem to thrive in urban environments. Behavioral plasticity might play a role in their successful urban adaptat...

The variation in climatic conditions over space and time is considered a major driving force in speciation. Gloger's rule is one such rule that broadly explains the variation in the colouration of endotherms (birds and mammals) with the effects of climatic parameters. This predicts that endothermic animals tend to have darker colouration in warm an...

Hybrid zones reveal the strength of reproductive isolation between populations undergoing speciation and are a key tool in evolutionary biology research. Multiple replicate transects across the same hybrid zone offer insight into the dynamics of hybridization in different environments, clarifying the role of extrinsic forces on the speciation proce...

This is the latest update of the National Red List assessment of the Birds of Sri Lanka. The book provides the latest Red List status of 244 birds that have breeding populations in Sri Lanka. The book also provides an overview of the taxonomy, evolutionary trends, biogeography, habitats and their status, threats to the birds and analysis of the glo...

The Rufous Woodpecker (Micropternus brachyurus jerdonii) is arguably the rarest woodpecker and probably one of the rarest birds in Sri Lanka. Its population seems to be declining in the recent past. Its density, distribution, and population status were evaluated using various techniques. Variable line transects with a fixed 20 m distance for either...

The Ashy-headed Laughingthrush, an endemic bird to Sri Lanka, has been historically considered a laughingthrush in the genus Garulax. However, recent phylogenetic studies have suggested a new classification for the species under the genus Argya (true babblers). However, as the name suggests, the Ashy-headed laughingthrush shows remarkable morpholog...

Isolating barriers that drive speciation are commonly studied in the context of two‐species hybrid zones. There is however evidence that more complex introgressive relationships are common in nature. Here, we use field observations and genomic analysis, including the sequencing and assembly of a novel reference genome, to study an emergent hybrid z...

Hybrid zones reveal the strength of reproductive isolation between populations undergoing speciation and are thus a key tool used in evolutionary biology research. Multiple replicate transects across the same hybrid zone offer further insight into the dynamics of hybridization in different environments, clarifying the role of extrinsic forces on th...

Isolating barriers that drive speciation are commonly studied in the context of two-species hybrid zones. There is however evidence that more complex introgressive relationships are common in nature. Here, we use field observations and genomic analysis, including the sequencing and assembly of a novel reference genome, to study an emergent hybrid z...

Zoogeographical affinities of the Sri Lankan avifauna: a preliminary chorological analysis on the on the distribution of the ecologically, geographically and taxonomically closest (or presumed to be closest, when phylogenies are not available) relative in each lineage of all 34 Sri Lankan endemic bird species, based on the Phylogenetic Super Tree o...

Sexual dimorphism may appear in various forms such as anatomical, plumage, or vocal features. Production of such variation can be costly. However, sexual dimorphism may provide long-term fitness benefits. The Sri Lanka Bush Warbler (Elaphrornis palliseri) is a sexually monomorphic and monotypic passerine endemic to the montane cloud forests of the...

Both sexes of Whiskered Auklets (Aethia pygmaea) display the most elaborate feather ornaments of any seabird: a slender black forehead crest, and 3 bilaterally symmetrical pairs of white facial plumes (superorbital, suborbital, and auricular). We studied patterns of ornament variation in 796 banded individuals (147 of known sex, 254 of known age fr...

Summary.—Yellow wagtails Motacilla sp. observed in Sri Lanka in November 2019 had the ‘rasping’ voice characteristic of Eastern Yellow Wagtail M. tschutschensis. DNA confirmed two individuals as M. t. tschutschensis / plexa, whilst plumage characters suggested one was M. t. plexa and the other M. t. tschutschensis, the first records of the species...

We examined the phylogenetic relationships of South Asian bulbuls with focus on endemic species to understand the historical biogeography of the region. Molecular phylogenetic analysis, divergence date estimation and ancestral area reconstruction were performed to understand the role of paleoclimate on extant bulbul diversity and their distribution...

Vocal divergence can be driven by genetic relatedness, environment or both. Vocalization plays a key role in evolution of birds, therefore the evolutionary significance of vocalization can be understood by studying how vocal traits drive phenotypic and genotypic divergence in them. Sri Lanka has seven species of babblers (members of the families Ti...

The Issengard Biosphere Reserve is located at Imbulpe, Belihuloya, in Ratnapura District of the Sabaragamuwa Province of Sri Lanka. It is a privately owned conservation forest, located at the catchment of Samanalawewa Reservoir. This 16-acre forest is a disturbed, sub-montane forest. This article covers the study carried out to determine the Tempor...

Being endemic to Southernmost India and Sri Lanka, the Grizzled Giant Squirrel (Ratufa macroura) is the most range-restricted species of all giant squirrels. The melanic form of Sri Lankan Grizzled Giant squirrel (R. m. melanochora) is phenotypically unique and lives in the wettest regions of the island. Here we tried to clarify the evolutionary af...

The species; Ratufa macroura exists in three different coat colorations. R.m.melanochora in Sri Lankan wet forests has morphologically diverged from the R.m.macroura in the intermediate zone and R.m.dandolena shared between Sri Lankan Dry zone and Mainland India. This study investigated 1) the correlation of geo-climatic parameters with the morphom...

Many passerines possess extravagant vocalizations which often provide evolutionary advantages. Birds have evolved many variations in vocalization in order to withstand the associated costs. The current study focused on investigating intraspecific vocal variations in Sri Lanka Bush Warbler (Elaphrornis palliseri) which is a range restricted montane...

Hill swallows (Hirundo domicola) are aerial insectivores that reside in both undisturbed natural environments and in human residential areas. Adapting to human altered landscapes are challenging as resource distribution is altered; natural nesting sites may be removed and novel disturbances are introduced. In order to survive anthropogenic change b...

Bird migration widens the distribution of a species through their wintering and breeding grounds while allowing a single species to geographically separate into reproductively isolated populations. The absence of gene flow among these regional populations results in the formation of subspecies, which may eventually become separate species, a key pr...

Personality can be partly determined by genes hence variation in personality associated with genes give rise to variation in personality among individuals within a population. DRD4 gene has been associated with a number of personality traits, such as, novelty seeking, early exploratory behaviour, boldness and weariness. Having these traits may be n...

Sexual dimorphism driven by exaggerated phenotypes is widespread among birds. Besides their evolutionary function, there are many associating costs. Hence some species of birds have evolved optimized signaling mechanisms enabling them to overcome the cost of conspicuousness. Iris dichromatism plays a key role in making one sex is distinguishable fr...

An endemic species is one that restricted to a defined geographical location. Islands provide a strong degree of geographical isolation to form new species and thus lead to endemism. This study is focused on resolving evolutionary history of Hill Swallows among closely related taxa in the Pacific Hirundines (Swallows of the genus Hirundo). There ar...

Ratufa is giant arboreal squirrels restricted into South and South East Asia. They are diverged into four phenotypically different taxa; Ratufa macroura, R.indica, R.bicolor and R.affinis. Sri Lanka’s Grizzled Giant squirrel; R.macroura is the most range-restricted species of the genus being endemic to Southernmost India and Sri Lanka. The phylogen...

Examination of the Dendrelaphis bifrenalis populations on Sri Lanka showed that there are two populations that are morphologically different from each other. One population is distributed only in the wet zone forests (hereafter treated as wet zone population), while the other population occurs widely in the dry zone and intermediate zones (hereafte...

A review of J. Drew Lanham's Home Place

Sri Lanka’s location, historic and geologic isolation from the continental landmass, topography and climate act to shape its biogeography and biodiversity, including conferring a remarkably high level of endemism, given its close proximity to the mainland. The island hosts several ‘point endemic1 species and even monotypic endemic genera. However t...

The typical model of allopatric speciation in island biogeographic framework suggests that the division of ancestral mainland populations leads to two or more allopatric island species through natural or sexual selection or through genetic drift. Here we studied the phylogenetic status and phenotypic variation of Dicrurus paradiseus allospecies com...

Although the avian family Anhingidae is unequivocally monophyletic, the number and relationships of the component species within the single genus (Anhinga) have long remained unclear. Here, we use extensive mitochondrial and nuclear DNA sequence data (8,878 bp) to show that four species should be recognized. Our fully resolved and well‐supported tr...

Forces of selection and drift are intense when birds spread across continents and nearby islands, which lead to divergence and eventual reproductive isolation. Here we studied the patterns of divergence in multiple levels in a group of woodpeckers found across tropical Asia known as Dinopium flamebacks in the light of how isolation, mate choice and...

Sri Lanka's geological history, varied cllmate and topography have shaped its rich speciesdiversity (Abeyrama &Seneviratne, 2017: Weerakoon et al., 2012). lts climate is driven mainly by the monsoonal rains and topography; where there is a south-central mountainous region, which rises to an elevation of 2, 500 m, surrounded by broad lowland plains...

Key components of biodiversity cannot be treated equally due to the limitations of resources available for conservation. Therefore biodiversity should be prioritized in effective conservation and site based conservation is one such model to achieve that. However parameters related to ecology, sociology and economics (aka. tourism) are primarily use...

The Indian Cormorant (Phalacrocorax fuscicollis) is a common avian piscivore that occurs throughout the Indian subcontinent and east to southern Vietnam. Its evolutionary relationships, however, have remained obscure, largely because of a lack of material available for either osteological or genetic analysis. Here we show using DNA-sequence data fr...

Shorebirds in the Order Charadriiformes are primarily ground nesters and most of them do not make an insulated nest. As a result each shorebird family utilizes a unique breeding habitat in the wetland ecosystem. Pratincoles (Family Glariolidae) are a group of desert-adapted shorebirds that breed in arid landscapes. The Oriental Pratincole (Glareola...

Different components of biodiversity cannot be treated equally due to the limitations of knowledge and resources, and the heterogeneity in the distribution of biodiversity in the landscape. Therefore, biodiversity should be prioritized in effective site-based conservation. Parameters related to ecology, sociology and economics are primarily used fo...

Co-occurrence of closely related taxa on islands could be attributed to sympatric speciation or multiple colonization. Sympatric speciation is considered to be rare in small islands however multiple colonizations could be common in both oceanic and continental islands. Sri Lanka is a continental island in the Indian continental shelf of the Norther...

Phenotypic and genetic affinities of a sessile South Asian endemic bird: Dark Fronted Babbler.