The Queens subjects.

The Queens subjects.


The fig tree has for long been considered the Queen of trees. Botanists and biologists confirm that, worldwide, something like 1,200 vertebrate species depend primarily on figs to survive. It is this diversity of life dependant on the fig tree that gives it the distinction of being the Queen of trees.  A study in late 1990’s showed that ten per cent of all birds and six per cent of all mammals depend on figs as part of their diet– (see Who eats figs? Everybody)

Why are fig trees so important to the survival of wildlife? The answer is simple; fig trees have multiple cycles of fruiting with some fig species producing flowers and figs year-round. This means a year-round supply of food for birds and mammals is available. In lean times, a fruiting fig tree can be a godsend for starving animals. (see A job for conservation’s keystone cops).

There are over 750+ species of fig trees in the tropics with most being pollinated by a single species of Fig wasp. The fig trees depend heavily on these wasps to survive. The wasps pollinate the flowers ensuring that the fruits form and the next generation of fig trees can spread their shade over a new patch of the forest. The wasps use the figs as hosts to lay their eggs in. The female wasps enter the fig through a ‘gate’, feed on the figs and make their way down a tubular structure to the flower where they unload their payload of pollen from pollen sacs in the abdomen onto the flower to pollinate it. The wasps use pollen as a bribe to the Queen in exchange for her services as an incubator for her eggs. Fossil evidence showed that wasps used the same method of pollination 65 million years ago with microscopic analysis revealing striking similarities in the pollen sacs of the fossils and their descendants.

Female Fig wasp showing her ovipositor.

The female fig wasps live for about a day and each wasp species can only lay its eggs inside the flowers of its specific fig partner. The winged females have to squeeze through the narrow gate to gain access to the flower and in doing so she rips out her wings and at times even bursts her abdomen. This epitomizes the theory of the ‘struggle for existence’ with the females making the ultimate sacrifice while making their way to their fleshy graves to ensure the survival of the species. Once the female lays her eggs, she dies within the fruit itself. As soon as the eggs hatch, the males break out of their casings and eat into the casing of the females, not to release them, but to mate with them. The males live a short life and after they have mated they begin to die. The drive to perpetuate the species fires up their instinctive response and the males begin to eat at the fruit to help the females break out.

Female fig wasps try to make their way past the ‘gate’.

I had been observing a particular fig tree outside my classroom window in college for quite some time during boring lectures on Hepatitis B. I noticed that the same set of fruits had been on the tree well over a month and a half ago. When I checked the next day, almost all the fruits were unripe, with barely a handful reaching more than 8mm in breadth. Oddly, none of them showed any signs of being pollinated or having fig wasps in them. I had seen this fig tree fruit sometime in February, (roughly 7 months ago), and here it was, with unripe fruits still hanging in clusters on the tree, the characteristic mat of fruits below the tree being nowhere in sight. Surely housekeeping wasn’t so diligent that they wouldn’t let a single fig touch the ground?
(watch: https://youtu.be/8fpKDtLjvaI)

I took a fig early next morning off the tree and with great curiosity split it open. I was surprised to see a number of females fly out from this unripe fig. The fig wasn’t even ripe, it was still hard. Yet the wasps had somehow gotten to it. But if the figs had wasps in them, why weren’t there any ripe fruits on the tree. The White Cheeked Barbets had stopped visiting now, and the squirrels only visited the tree on a bright sunny morning. The cacophony on the fig tree had stopped with the Rosy Starlings, our European migrants being nowhere in sight this time. Last year there were hundreds on the fig tree. 

Fig wasps inside a raw fig.

Why did this happen this time around? I would assume it was due to the fig wasps dying out this season owing to the blistering heat the city faced in March and April with the mercury hitting the roof. When the wasps were exposed to temperatures between 25°C and 38°C and to a various levels of humidity, the lifespan of all four species fell steadily as the temperature rose. By 36°C, the lifespan of three of the species had fallen to just two hours. In the wild this severely reduces the time a wasp has to find a fig of the right species, pollinate it and lay its eggs. In the 1990s, fig-wasps in northern Borneo went locally extinct after a severe drought, and in Florida they disappeared when a hurricane wiped them out. Both species survived thanks to their ability to disperse tens of thousands of kilometers in such short life spans.

While all of this sounds like the species can recover easily… with sustained rises in global temperature; the life span of these wasps is expected to take a hit with a marked change in fruiting patterns that may also affect other creatures over time. The failure of the figs ripening this year seems to be a clear indication of this. And the number of figs that show the presence of the wasps also suggests a decrease in populations of the figs. Only time can tell if the figs will ripen or if they will fall to the ground unripe like they have been doing so for the past few weeks and if the Queens subjects live to pollinate another set of flowers.

Do check out this amazing video to get a better understanding of what exactly happens during the course of a wasp’s life. (PS: 52:00 mins long, so watch it if you are really keen on knowing what a wasp does--- 

References:

·         Jevanandam, N., Goh, A.G.R. & Corlett, R. 2013. Climate warming and the potential extinction of fig wasps, the obligate pollinators of figs. Biology Letters 9: X-X.  Published online March 20, 2013 doi: 10.1098/rsbl.2013.0041

·         http://www.sanctuaryasia.com/magazines/features/10208-no-climate-for-fig-wasps.html

·         The Influence of Temperature on the Reproductive Success of a Fig Wasp and Its Host Plant Areej Alkhalaf, Rupert J. Quinnell, and Stephen G. Compton

Walking the Ghats.

Walking the Ghats:

It has always been a dream to visit a sky island and climb all the way to the top of the Ghats to look down and marvel at the sheer beauty of such an untouched pristine eco-system. I have had multiple opportunities to observe birds at lower altitudes in the Ghats at multiple locations among which Ooty, Mudumalai, and Agumbe were my most memorable experiences.
But all of these sites were to the north of the Shencottah Gap. The second largest geographical barrier in the Western Ghats eco-system.  Recent research by a team of scientists has shown that such deep and wide valleys can cause nested phylogeographic variations in bird populations. Which, simply put  is the effect of such large geographical gaps serving as barriers for dispersal of populations leading to populations on either side evolving into a separate species over time. 

The Shola forests gradually make way for Montane grasslands at altitudes of 1100mtrs.  It is this fragmentation of habitats across the peaks and on the hills themselves that causes populations to be isolated from others.

I had never observed birds across a gap, so when the opportunity presented itself I hurriedly packed my bags, picked up my gear and set off by train to my destination- Tirunelvelli. Making my way up the mountain terrain, I noticed that while the birds looked similar to their relatives on the other side, their song pattern was different when compared to the ones I had previously heard. Research has shown that birdsong is genetically determined and variations in the song do exist across populations that have been isolated and exist completely independent of each other. Most seasoned birdwatchers will not be able to tell the difference between some of these birds if both specimens are placed together. However, molecular evidence provides strong proof for the existence of genetic variations amongst populations sampled from both sides of the Ghats.


A yellow browed bulbul whose song differed markedly from its relative to the north of the Shencottah Gap.

When I had my first sighting of the birds that were restricted to the south of the Shencottah gap, I found that I was unfamiliar calls. But the birds making them were all too familiar. It is mind boggling to see how the existence of these gaps can influence speciation in such a massive manner. Once you make your way to the top of the peak, only then will you understand the scale at which these gaps may influence dispersals and distributions. At that moment, you are suddenly reminded of the great scientist, Charles Darwin aboard the H.M.S Beagle and you start to wonder if there are really multiple species hiding in plain sight, and you’ve just brushed them off because they didn’t look all too different to you.

It may be hard to understand the scale of isolation being spoken about here, but if you stood on one of the larger peaks to the south of the Shencottah, you wouldn’t be able to find another mountain peak for the next 40kms. Which mind you, is a very long distance for specialist birds to fly across. The main constraint being that these birds require specific microclimates and microhabitats to survive without the existence of which, dispersal is impossible for these feathered beauties.


Even among the mountain peaks of the same range, the gap is quite noticeable.

These are two neighboring peaks and while the bird populations on both sides was to a great deal similar, there was not much variation between them. But imagine this on a larger scale.
As part of my Masters thesis I will be studying populations at multiple locations and mapping the exact location of endemics In the Western Ghats. Only time can tell what surprises these hills hold. 

A Russel's Kukri from the Hills of the Western Ghats


A Nyctibatrachus (Night Frog) photographed in a waterfall from the hills.


A Malabar Torrent Dart Damselfly from a freshwater stream in the Ghats


A Kalakad Dancing frog- Another Endemic of the Western Ghats.


A typical stream in the hills

With such a diverse landscape holding hundreds of enigmatic creatures, this habitat is filled with surprises. The Bio-diversity of this region is evident in the bird population that calls these hills home. Some of these birds are found nowhere else in the Sub-continent, let alone in the world.

I will be leaving in November to the Ghats for 3 months to map and document the endemic birds of the Ghats. More surprises then.

Watch this video to get a glimpse of "The jewel of South India".

Why is endemism important ?

Endemism as Wikipedia puts it can be defined as an ecological state of a species being unique to a defined geographic location, i.e. an island, nation, country, range, zone or a particular habitat type. The Western Ghats of India is a hotspot for endemic birds with close to twelve species being found only here and nowhere else in the world. The Ghats un along the western edge of the Deccan plateau in Peninsular India starting just north of Bombay and ending in the south at the tip of the peninsula. Most of the endemics can be found distributed in highly restricted localities in the states of Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu, although a few of these restricted-range species have also recorded from disjunct localities in the hills to the east, in northern Tamil Nadu and southern Andhra Pradesh. The levels of endemism among these restricted range species varies to a great deal with seven out of the sixteen endemics being found from sea level to c. 1500 mtrs across the Ghat ranges. While some species like the White-Bellied Shortwing can be found mainly above elevations of 1500 mtrs and in select patches in these hills. Another bird that is hard to come across and can be found only in select locations is the Black and Orange Flycatcher.

                                 

The Nilgiri Flowerpecker, endemic to the Western Ghats, but found distributed across a wide area.  (©Joiston Pereira)

https://www.facebook.com/Pixelsfromthewild/- More Images

The question then arises as to why endemics are so important to an ecosystem. Endemic birds are extremely selective in their habitat preferences and minor changes in their habitats will have cascading effects on the distribution and population of these birds. For example birds that are restricted to selected patches and colonize the moist understory, prefering a particular micro-climate will be most susceptible to the effects of climate change when compared to other endemics that are widespread across the Ghats. In the case of restricted endemics such as the Shortwing or the Black and Orange Flycatcher, the slightest alteration in habitats as a result of anthropogenic activities or global climate change will lead to severe declines in populations. Therefore these birds can help serve as indicators for the health of an ecosystem.

Black and Orange Flycatcher

Ultramarine Flycatcher- another endemic from the Ghats.


Certain birds such as the Shortwing and the Broad tailed Grassbird can be found only in certain locations in the Ghats such as Grasshils in Ooty, the Avalanche hills, Peppara hills, and a handfull of other sites. With such varying levels of endemism, it is possible to determine the effect of habitat fragmentation, climate change as well as indirect effects of human presence in these previously untouched areas of the Ghats. The level of endemism exhibited by a species also helps to understand the specialist nature of its habitat preference as well as to create a map of the endemic birds and their exact distributional ranges in the Ghats. Current efforts are on to create a map of the various populations of endemics which would provide an exact picture of the level of endemism being exhibited by various species as well the size and distribution of specific populations.

Among the endemic birds, some such as the Malabar Grey Hornbill, Malabar Parakeet, Heart Spotted Woodpecker, etc can be found distributed across a wide area in the Ghats with populations from Tirunelvelli in the south to Bhigwan in the north, successfully being able to colonize the landscapes across the three major geographical gaps (see Mind The Gap). While some species have been unsuccessful in dispersing across these gaps owing to the specialist nature of their habitat preferences. 

Heart SPotted Woodpecker (L) and Malabar Grey Hornbill(R)
https://www.facebook.com/Pixelsfromthewild/

Endemism therefore it would seem is important to determine the effects of habitat modifications, adaptations, distributional patterns, etc that may be influenced due to anthropogenic pressures or due to climate change events. It is after all a criteria for evolution, and if 'survival of the fittest' doesn't go in favor of these birds, we can very well say goodbye to some spectacular winged jewels of the hills.

Endemic birds from the Western Ghats

                                 Isolated but not alone?

The "Sahayadris" as they are locally known are the largest range of mountains in Southern India. The Ghats run through seven states in the southern peninsula- Gujarat, Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu and finally ending at Kanyakumari, the southernmost tip of India (Vijayan, V.S, 2007). These hills run for over 160,000 sq kms before and are responsible for the south west monsoons. The mountains block the rain clouds that come across from the Arabian Sea and it is this yearly phenomenon that is responsible for the formation of seasonal streams.


The Western Ghats of India, a biodiversity hotspot and a UNESCO world heritage site.

This area is one of the world's ten "Hottest biodiversity hotspots" containing over 7,402 species of flowering plants, 139 species of mammals, 508 bird species, 1,814 species of non-flowering plants, 179 amphibian species, 6,000 insects species and 290 freshwater fish species. It is estimated that over 325 threatened species call these Ghat ranges home. There is also a high possibility that species may still lie undiscovered and some may even be hiding in plain sight. There are 16 species of birds that are considered extremely endemic to this mountain range and can be found nowhere else in the world. They are, the Nilgiri Woodpigeon, Malabar Parakeet, Malabar Grey Hornbill, White-bellied Treepie, Grey-headed Bulbul, Broad-tailed Grassbird, Rufous Babbler, Wynaad Laughingthrush, White faced Laughingthrush, Grey Faced Laughingthrush, White bellied Shortwing, Black-and-rufous Flycatcher, Nilgiri Flycatcher, White-bellied Blue-flycatcher, Crimson-backed Sunbird and the Nilgiri Pipit.


White-Bellied-Blue-Flycatcher


Malabar Trogon male, another endemic of the Western Ghats.

With specific habitat preferences being exhibited, these birds are extremely selective in the types of habitats that they choose to utilize. It is this specialization that behaves as a driver to induce genetic variations among populations. The Western Ghats are non-contiguous with three prominent gaps occurring along the length of the mountain range, the Palaghat Gap, the Shencottah and the Chaliyar valley. These gaps, coupled with the various other geographical, climatic, physical, altitudinal barriers, etc lead to species remaining isolated from larger populations over time. Such populations are deemed “Allopatric Populations” which are separated from a larger population of related individuals by a geographical barrier.

Research has shown that isolation and genetic drift is responsible for variations in song patterns of endemic songbirds (Robin. 2010), this proves that genetic drift is seen to occur across populations, including those that aren’t isolated.

Observations amongst birds of the Ghats from either side of these prominent gaps show that there is a variation in the song as well as pitch of the calls. Individuals from both sides also exhibit subtle plumage variations in a small number of cases. On a molecular level however, using what geneticists refer to as Ultraconserved elements Or UCE (Gil Bejerano et al. (2004), which are sequences in the genome that are highly conserved amongst evolutionary distant taxa. Utilizing specific sequence capture probes, one can sequence the genome of these fragments and post alignment based on homology; obtain a clearer picture of the entire genome sequence of the organism. Since these UCE’s are extremely conserved in their positions at specific loci on the genome, subtle variations between sequences of individuals of the same species will provide researchers with evidence for allopatric speciation amongst specialist endemics. However, till date researchers have made use of microsatellite DNA variations as well as variations among nuclear genes as evidence to point towards phylogenetic splits. URE’s have yet to find their footing in molecular biology studies.


What would be interesting though would be to study the variations in the genomes of endemic birds across gaps as well as non-endemics and check if a pattern emerges, with a particular threshold distance to qualify as geographical genetic barriers. Endemics, owing to their specialist nature do not disperse as readily as generalists, this pattern should be evident in the genomes with allopatric endemic individuals exhibiting larger variations among the URE’s across the gaps and generalists exhibiting fewer variations among the URE’s. Theoretically, even among endemic individuals that are found throughout the Ghats as opposed to those found only in certain localities, variations should be seen in the genomes. This opens up a Pandora’s Box of questions for taxonomists and biologists alike. Have we missed reading the fine print? Are there species hiding in plain sight? Do widespread endemics also experience the effects of allopatric speciation to the same extent as their specialist compatriots?



References:



1. Nayar, T.S.; Rasiya Beegam, A; Sibi, M. (2014). Flowering Plants of the Western Ghats, India (2 Volumes). Thiruvananthapuram, India: Jawaharlal Nehru Tropical Botanic Garden and Research Institute. p.1700.



2. Myers, N.; Mittermeier, R.A.; Mittermeier, C.G.; Fonseca, G.A.B.Da; Kent, J. (2000). "Biodiversity Hotspots for Conservation Priorities". Nature. 403: 853–858.doi:10.1038/35002501. PMID 10706275.



3. "The Peninsula". Asia-Pacific Mountain Network. 2007.


4.Vijayan, V.S. "Research needs for the Western Ghats" Ashoka Trust for Research in Ecology and the Environment (ATREE). Retrieved 21 June 2007.

Mind The Gap!

                             MIND THE GAP!

The Western Ghats in southern India is a chain of mountains running along the western coast of the Indian peninsula for about 1,600 kms. The Ghats have for long been considered as a global biodiversity hotspot (Myers et al. 2000), and also features in the list of UNESCO world heritage sites. The Ghats are non-contiguous and have a varying elevation owing to which there are numerous wide and deep valleys that form along the length of mountain range. This fragmentation is responsible for the formation of continental islands (sky islands) that can be defined as a, ‘continental or inland terrain made up of a sequence of valleys and mountains,’ (Warshall 1994). The Western Ghats Mountains in southern India harbor one such tropical sky island system (Warshall 1994) that consist a mosaic of high elevation montane temperate, evergreen forests ( OR ‘Sholas’ as they are locally called) and montane grasslands. The Shola forests have been known to host a great deal of endemic birdlife and are considered as models to study the evolution of species from an ancestral distributional range. 

The hills of Kalakad Mundunthurai Tiger reserve (Western Ghats), south of the Shencottah gap.


Mosaic of Shola forests and grasslands in the sky islands. 

The white-bellied shortwing, considered to be a rare species until recently, is a globally threatened (Vulnerable B1+2a,b,c,d,e; BirdLife International 2001), passerine, understory bird endemic to the Western Ghats of India (Collar et al. 2001). There are five species of shortwing found in the Indian Subcontinent of which three are found in the North East and two are endemic to the Ghats. The White bellied shortwing is  found uniquely in the Shola forests at elevations of 1500 msl and above on the sky island systems of  the Western Ghats (Robin & Sukumar 2002; Robin et al. 2006). These birds are specialists in terms of their habitat preferences and slight changes in their habitat can affect their populations. Once reported to be fairly common (Ali and Ripley 1987), there have been only a few records lately.

 
 Rufous bellied shortwing (©Clement Francis)

White bellied Shortwing (©Bopanna Pattada)

 The most likely causes of the decline in population can be attributed to loss of its montane evergreen habitat, continuing habitat fragmentation and degradation (Birdlife International 2001). It is estimated that the Western Ghats has lost about 25.6% of the forest cover in the last two decades (Jha C. 2010)

 Fragmentation in these mountain ranges occurs on three levels, firstly on a larger, geographical level with wide and deep valleys serving as biological barriers that prevent dispersal of individuals. Second, the mosaic of montane grasslands and high elevation shola forests and lastly, fragmentation as a result of anthropogenic effects have all contributed to the formation of allopatric populations that are genetically isolated on these ‘sky islands’.

Palaeoendemics such as Shortwings; which prefer a specialist paleoclimate and geography are affected by the deep valleys of the Palghat and Shencottah gaps (Robin et al. 2010). The Western Ghats are an ancient mountain system with the largest geographical gap, the

c. 40 km wide Palghat Gap serving as the major biological barrier, and the smaller Shencottah Gap, further south acting as a barrier on a smaller magnitude. The topography of the Western Ghats is relatively very old, having taken shape about 65 million years ago (Ma) (Gunnell et al. 2003). This indicates that the geographical conditions and paleoclimate was conducive for colonization of the mountains by passerine birds much before they actually arrived on the evolutionary scene 50-60 million years ago. The White-bellied Shortwing exhibits high population genetic divergence across islands, with populations on a single island being genetically similar, although ecologically isolated (Robin et al. 2010). Populations that inhabited islands across larger valleys such as the Palaghat Gap were found to exhibit far greater genetic divergence when compared to individuals across the smaller valleys. The evidence points to a pattern of colonization by these birds with two probable strategies of colonization. Ancestral individuals could have first arrived at the foothills and gradually moved up the mountains as paleoclimate varied as a result of which sightings have been mainly restricted to above 1500 mts. Another theory postulates that ancestral individuals initially colonized the first island in the sky island system and gradually hopped across islands to colonize them, as a result of which, hypothetically the oldest ancestors should be on the first island in the system. 


Map showing the location of the Palaghat Gap and the Shencottah Gap (Source: V.V. Robin) 

On examining the effects of genetic differentiation across populations of the white-bellied shortwing, (Brachypteryx major), on different islands of this sky island system it was observed that individuals separated by the larger, 500-million-year-old geographical genetic gap- the Palaghat Gap, were found to be genetically different from those on islands separated by smaller valleys. Genetic analysis showed significant variations in combined mitochondrial DNA genes (cytochrome b, cytochrome oxidase 1 and control region).  However populations from Grasshills and Kodaikanal showed little genetic differentiation using the same molecular markers. (Robin et al. 2010). ). It was also observed that although all three populations have similar habitat structure characterized by stunted montane evergreen Shola forests (described in Meher-Homji 1984; Shanker & Sukumar 1999), geographical isolation had lead to phylogenetic divergence over time. As a result of this divergence, two newly discovered subspecies, B. m. major and B. m. albiventris, separated by a geographical gap in the Western Ghats (Palaghat gap), with the former and latter distributed to the north and south of the gap respectively (Robin et al. 2013) were identified. Using molecular methods of sequence analysis the White-belied Shortwing was split into two subspecies, the White-bellied Shortwing, and the Rufous-bellied Shortwing. Ongoing research has provided evidence for the existence of a nest basket effect wherein deep and wide valleys serve as drivers for phylogeographic divergence, with the oldest divergences exhibited by the Palaghat Gap, while the younger divergences were seen in the Shencottah Gap and the Chaliyar valley.

However certain species failed to exhibit a pattern of divergence for which four probable patterns have been suggested. (i). Ability of species to actively disperse across these barriers, (ii). Extinction and recolonization responses to paleoclimatic changes, (iii).  Incomplete lineage sorting owing to recent divergence, (iv). recolonization during inter-glacial periods where conditions at lower altitudes were warmer compared to cooler climates at high elevations. (Robin, Vishnudas Ck, Pooja Gupta. 2015). Various inter-related factors therefore have been found to influence divergence amongst endemic birds of the sky islands. Topographical variations of the valleys, deep and wide valleys and paleoclimatic conditions have been found to serve as drivers for divergence. Further research is required to assess which of these factors impact individual species, either singly or in combination to help serve as drivers for divergence. There is a need to assess if this pattern of divergence is restricted to highly endemic specialists, or if patterns of divergence and the nest basket effect hold true for species exhibiting a broader distributional range. The outcome of such a study would be a complete phylogenetic map to the endemic birds of the Western Ghats, if not one for all the birds of the Western Ghats. This would enable detection of variations amongst inhabitants on either side of the Gaps and assess whether sub-species have been hiding in plain sight. Use of advanced molecular methods of sequencing can provide evidence for the existence of any such divergences that may not have previously been looked into. Assessment of the age of the phylogenetic divergence can serve to establish whether allopatric populations alone exhibit divergences over time or if species that have successfully colonized these sky islands before the arrival of the shortwing also exhibit divergences as a result of these geographical, genetic barriers which are ancient in their origin.

References:

i. A view from the past: shortwings and sky islands

of the Western Ghats – Robin V V, A. Sinha & U. Ramakrishnan, Indian Birds Vol. 7 No. 2 30 (Publ. 15 October 2011)

ii. Ancient Geographical Gaps and Paleo-Climate Shape the Phylogeography of an Endemic Bird in the Sky Islands of Southern India- V V Robin, A Sinha, U Ramakrishnan- PLOS One · 2013 October

iii. Deep and wide valleys drive nested phylogeographic patterns across a montane bird community, Proceedings of the Royal Society B: Biological Sciences · July 2015

iv. Determining the sex of a monomorphic threatened, endemic passerine in the sky islands of southern India using molecular and morphometric methods, V. V. Robin , Anindya Sinha,

Uma Ramakrishnan- Current Science · September 2011

v. Islands within islands: two montane palaeo-endemic birds impacted by recent anthropogenic fragmentation -ROBIN. V. V , Gupta. P et al - Molecular Ecology ∙ July 2015

vi. Singing in the sky: song variation in an endemic bird on the sky islands of southern India

V. V. Robin, Madhusudan Katti et al,  January 2013, Rare Animals of India

vii. Status and distribution of the Whitebellied Shortwing (Brachypteryx major) in the Western Ghats of Karnataka and Goa, India- Bird Conservation International · December 2006

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