Text and photos by Tarun Balpande

Born in Pandhurna (M.P.) and settled in Nagpur, Tarun Balpande works as an Area Manager in the Oncology division of a pharmaceutical company. He was drawn into the excitement of birding five years ago, when he took part in a Great Indian Bustard census. After observing migrating Bar-headed Geese, he now concentrates on migratory birds. He also works on the importance of planting fruit-bearing trees, and on getting a bird-feeder in every home in Nagpur.

In 2008, I came to know through the nagpurbirds e-group, run by Tarique Sani, that several Bar-headed Geese had been collared in Mongolia. In November of that year, Raju Kasambe and I started searching around Nagpur for Bar-headed Geese to check for a collar. At one point, Raju Kasambe spotted “something” yellow on the neck of a goose, but our limited optics didn’t allow us to see it clearly.

But the big day finally came!! On 19 January 2009, my wife Rakhee, son Chaitanya and I, together with Kishor Khandekar were watching a group of Bar-headed Geese, when I suddenly noticed a goose with a yellow collar around its neck. Through my binoculars I could read the letters “NU”, and I was able to click a few images with these letters clearly visible. But what did “NU” mean?

With the help of Raju Kasambe and Tarique Sani, I came to know that black lettering on a yellow collar meant that the goose had been marked in Mongolia. Martin Gilbert informed me that NU was an adult female, captured on 17 July 2008 in the Darkhad Valley, Hovsgol province of Mongolia.

Many Bar-headed Geese had been collared there to understand the migration of this species. These birds were collared by a team led by Martin Gilbert, of the Wildlife Conservation Society, Mongolia. A number of species have been marked using different techniques appropriate for each species. The Bar-headed Geese were marked with a neck collar inscribed with a unique alphanumeric code.

All this happened 4800 km away! The Bar-headed Goose we sighted was at Paradgaon lake, which is situated on the Umred road, around 28 km from Nagpur. The entire season myself and other fellow birders were looking for a collar other than NU, but no one find another collared Goose. At the end of the migration season, we were all looking forward to the next season — NU had left us with wonderful memories.

Next season, on 5 November 2009, Raju Kasambe recorded the first arrival of a flock of 300 Geese at Paradgaon lake. 0n 12 December 2009, I clicked a photo of my old Mongolian girlfriend NU! This affair continued in 2010, when I photographed her again on 26 November. I emailed a message to Martin Gilbert, and he replied: “How good to hear from you again, and thank you so much for sending your sighting! …it is indeed great news that you have been able to relocate NU once again, and I believe this is the first time that we have had any bird resighted in three consecutive years!”. This is the best appreciation for any birdwatcher.

This year, 2011, I started monitoring the lake from 10 November. On 24 November 2011, Rakhee, Chaitanya and I, together with birdwatcher Avinash, saw a flock of 275-300 Bar-headed Geese. I started searching the flock for NU. Euphoria !!! she was there !!! As usual I clicked a few photos.

I am proud to report that NU visits Paradgaon lake for the fourth consecutive year! The exact location of the lake is: 20°92’58.06″N 79°22’24.14″E

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You can see all of Tarun Balpande’s reports on MigrantWatch.

For other reports of marked birds from Mongolia, look at this page on Birds of India. And a copy of a message from Martin Gilbert is here.

For more information about Bar-headed Geese, including some recent information on their migration, take a look at this species profile on the MigrantWatch blog.

By Dr Jayan Thomas

Dr Jayan Thomas is an ophthalmologist by profession; but early in the morning and on Sundays, he is an inquisitive birdwatcher and photographer. Watching a Blue-tailed Bee-eater catch its prey and smash it against a wire before swallowing the bee sparked his curiosity about birds and their behaviour. He lives in Cannanore, Kerala, near the ocean and is President of the Cannanore Ophthalmological Society.

It was Sunday the 30th of October 2011, and myself and Mr. PC Rajeevan had decided to go to a place called Ezhome about 23 Km from Cannanore (Kannur), on the coast of northern Kerala. I woke up at 5 AM and started my journey to Ezhome by 5.30 AM. Rajeevan was at Ezhome waiting for me and after a cup of hot roadside café tea we were on to a slow birding walk, with binos, camera and an umbrella, as it was drizzling. The first bird to be seen was a Purple Heron, then a Blue-tailed Bee-eater and so on. After 2 hours of birding we counted about 40 species and were about to call it a day, when we decided instead to first go to Madaipara, since it is close to Ezhome. We reached Madaipara just before noon, and so bird activity was very low. Suddenly Mr. Rajeevan spotted a group of birds across the road and we went to check them out. There were about 200 Lesser Sand Plovers feeding on a burned patch of grass, and some bathing in rock pools. Among these Lesser Sand Plovers was a smaller and slimmer bird with yellow legs and pearly edged wings. What could this be? We were intrigued.

With caution we approached the bird and found to our surprise that it was quite unusual. Since the bird was feeding and walking around we had ample time to take some decent photos. During flight the upper parts appeared uniform, with no prominent wing pattern. Driving back home we discussed the possibilities of a new species being sighted in Kerala.

We whittled down our “differential diagnosis” of the bird to three species:
1. Buff-breasted Sandpiper.
2. Long-toed Stint
3. Reeve (Female Ruff)

Long-toed Stint is almost similar to this new bird, but the stint has prominent facial markings. Reeve was a possibility, but this new bird did not have a post-ocular stripe. A post-ocular stripe is essential for the bird to have been a Reeve. Moreover this bird was substantially smaller in size than a Reeve. (For a visual estimate of size see the photos below, which have this bird together with Lesser Sand Plovers.)

Now the only other possibility was the Buff-breasted Sandpiper, a New World bird. Yes, this bird looked like the Buff-breasted Sandpiper in size and all other features. This bird was about 19 cm with a plain face, an eye-ring , streaked crown and yellow legs. The picture of the bird was sent all around the world by MigrantWatch and others. We are thankful to Praveen J., Sashikumar, Aasheesh Pittie, Bill Harvey, Rex De-Silva and Krys Kazmierczak for having identified the bird as the Buff-breasted Sandpiper.

Buff-breasted Sandpiper (Tryngites subruficollis) breeds in the Arctic tundra of North America and is a long distance migrant to South America, mainly Argentina. The Canadian wildlife service estimates that there are only about 15,000 birds in the world and hence it is classified as Near Threatened by the IUCN Red List. This bird which came to Madaipara could have been lost: instead of going to Argentina, this bird might have been wind-blown from the Great Plains Flyway of North America and landed up in India. Our sighting appears to be only the third of this species from South Asia.

Madaipara is a laterite flat hillock near the Ezhimala Naval Academy. On one side of Madaipara is the Arabian sea and the other side a mountain range of seven small hills (Ezhimala in Malayalam means seven hills). Sandwiched between the sea and the seven hills is a long meandering river. Madaipara is basically a flat land with few trees and shrubs and a lot of weeds. The vegetation is sometimes set on fire, and these spots are ideal for birds which come in search of insects. There are occasional rock puddles too on the hillock up to Spring. The Buff-breasted Sandpiper was seen here for 4 days. Of these, I sighted it on two different days and my birding pal Rajeevan sighted it on all 4 days.

Finding a rare bird like this is one of the dreams of the serious birder. Locating and identifying a species that is least expected is a great challenge and great thrill. You have to be ruthlessly honest with yourself for this. Reporting a rare bird carries a lot of responsibility. It becomes part of science. If you believe that you have seen a rare bird, study it carefully, take photos, video if possible and note the circumstances of the sighting. Then as soon as possible alert other birders.

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You can see Dr Jayan Thomas’s MigrantWatch sightings and photos here.

More about the Buff-breasted Sandpiper from Wikipedia and from the Cornell Lab of Ornithology.

In the Pied Cuckoo campaign, MigrantWatchers have contributed 363 sightings of this wonderful species so far (until 15 July 2011). A summary of these sightings from places to where the Pied Cuckoo migrates shows that it does, by-and-large, arrive in advance of the monsoon, but the exact dates are variable.

To illustrate the general pattern of migration of this species, we have put together this animated map, which shows the progression of Pied Cuckoo migration across the country in advance of the monsoon.

This animation has been made by selecting March-to-July sightings from all Pied Cuckoo reports in the MigrantWatch database between 1 July 2007 and 15 July 2011. To compare these sightings with the onset of the monsoon, we have also added in lines depicting the normal onset of the monsoon (digitised from a map available from IMD Pune).

In March and April, almost all sightings are from southern India, where the species is known to be resident year-round. This remains so until the middle of May. In the third week of May, the first migrant sightings appear, in the West and the North-east. As the monsoon hits the Andamans, the first birds in northern India are seen. More and more birds are subsequently seen across the West, North and East. By the time the monsoon reaches Kerala (in the first week of June), Pied Cuckoos are everywhere, except perhaps the extreme West and North-West.

Where are the gaps in information? Do you see patterns that would be interesting to follow up? Do leave a comment below.

Thanks, of course, to all MigrantWatchers who have contributed their Pied Cuckoo sightings!

Every year, thousands of Bar-headed Geese make an epic journey, twice crossing the mighty Himalayas over some of the highest peaks in the world. In doing so, they fly higher than any other bird in the world and faster than most others. It’s an inspirational story of tenacity and physical endurance, which even inspires poetry (of a sort!) in some people. Read on to learn more about this fascinating species.

Size: 71-76 cm; Weight: 2-3 Kg. Unmistakable; sexes alike; juvenile has pale grey head and neck with brown stripe running though eyes, across crown and backward down the neck. Forages mostly on land by grazing; feeds on grasses, roots, stems, sea-weeds on coasts, etc. Breeds on mountain lakes generally at 4,000-5,000m in the Palaearctic region and winters in the lowland swamps and lakes in India and some neighbouring countries.¹

The Bar-headed Goose is among our most good-looking and charismatic migrants; but there is more to this beauty than meets the eye. Every year the species embarks on one of the most incredible high altitude migrations known from the avian world.

The Bar-headed Goose breeds near wetlands across the vast trans-Himalayan highland, and further north in Central Asia. During winter, a large number of these birds migrate to the Indian subcontinent, crossing the towering Greater Himalayan range before panning out across the region, all the way to Kanyakumari. Incredibly, some populations are known to over-fly the very highest peaks, 8km above sea-level, where the air is extremely thin (Oxygen pressure only a third of that at sea level) and incredibly cold (sometimes below -50 degrees C) ². A recent study that tracked the migration of Bar-headed geese using satellite telemetry states that “The bar-headed geese… actually crossed mountain areas regardless of their height and did not avoid even very high summits… (One of the individuals) had to overcome the Tien Shan Mountains and the Alai Range, with summits up to 7km above sea level.³”

This migration is remarkable not only because of the altitude at which the birds fly but also the speed at which it happens. Using jet streams these birds can achieve speeds of over 150km per hour, and cover distances of 700-1,000km in a single day ². In other words, an individual that takes off from a wetland in north India, reaches altitudes over 7km in a few hours, crosses the Himalayas, and lands in Tibet, all in the same day!

Bar-headed Geese have physiological adaptations that help it achieve this feat of a migration that few other animals can possibly survive². It has a large heart which beats extraordinarily fast and haemoglobin with a remarkably high affinity to oxygen making it possible for the bird to take on high-altitude flight without any time to acclimatise². Also, their wings are rather large and they are powerful flappers⁴.

So this is clearly a star migrant that is built to fly high. But why it chooses to fly over the highest peaks instead of using lower passes is a question yet to be answered.

The current global population of the species is estimated at around 52,000-60,000 mature individuals and a range (breeding and winter) of 2,370,000 sq km ⁵. But it is possible that the distribution of the species might be dramatically altered in the future because of global warming, change in agricultural patterns, the creation of wildlife reserves in Tibet, and loss of wetland habitat in the wintering grounds⁶.

Global Distribution Map © WWF Wild Finder

 

In India, we have a population of the Bar-headed Goose that breeds in the wetlands of Ladakh, but for the rest of the country, this species is a winter migrant⁷. Its distribution in winter stretches across the northern plains and southwards to the southern most tip of the country⁸.

 

 

 

 

 

 

 

 

 

 

MAPS – (a) Sightings on MigrantWatch and BirdSpot⁹ (b) First sightings (2008 to 12 Dec 2010) in the MigrantWatch database

The birds arrive in India in November and migrate back to their breeding areas around mid March⁶. According to MigrantWatch data, the species is usually first sighted across the northern pains in Nov-Dec and in south India in Dec-Jan.

Conservation

The Bar-headed Goose is currently categorized as ‘Least Concern’ under the IUCN Red List, which means that it is not considered to be under threat. However, there are reports that the population has been affected adversely in recent decades due to hunting by humans, unsustainable levels of egg collecting and habitat destruction^1,3. In addition to persecution by humans, this species is also known to face serious threats from disease. High mortality of these birds was recorded from lakes in China in 2005 during an outbreak of the H5N1 strain of avian influenza ². The species may also be sensitive to climate change if migration patterns become mistimed with periods of peak food availability during the breeding season⁶.

Satellite tracking

In recent years some research on the migration of this goose has been taken up using satellite telemetry. One such study found that the individuals that were captured in the wintering grounds of India-Nepal migrated distances of 500-800 km and climbed more than 4.5 km to reach their breeding grounds on the Tibetan plateau. Geese captured in China were found to be breeding and wintering in relatively higher elevations – wintering at 4,000 m and breeding at 3,200 m, but migrating 400-800 km farther than the geese from India-Nepal. Finally, geese captured in Mongolia demonstrated a leapfrog migration – i.e. they were flying over the other sub-population from their wintering grounds in the Indian subcontinent to their breeding grounds in Mongolia ⁶.

MAP – Locations (circles), migration pathways (lines), and capture areas for 60 Bar-headed Geese marked with satellite transmitters in China (red), India (yellow), Mongolia (green), and Nepal (blue). The red-dotted line between China and Mongolia represents a goose marked pre-breeding (April) at Qinghai Lake, China which migrated to Mongolia for breeding; all other red lines represent birds marked post-breeding at Qinghai Lake.⁶

Another study that followed migratory geese in Kyrgyzstan fond that the four individuals marked in Kyrgyzstan followed three completely different migration routes leading to their wintering areas in Pakistan, India and Uzbekistan via southern Tajikistan and in western Tibet ³. The study also recorded flight speeds of up to 680 km per actual migration day, even during crossings of very high summits ³.

 

The Bar-headed Goose is a remarkable bird in many ways. It is amazing think that these birds can simply wake up one morning, take a test flight to check the winds, and decide to simply fly over the highest mountain range on the planet. How lucky we are to be on the other side of this flight to see these geese land noisily on our waterfront!

 

 

The Anser – by Uttara Mediratta & M. O. Anand

How many peaks must a goose fly above
before it can earn its stripes?
Now, how many days must a goose fly strong
before it reaches its home?

Yes, how many blizzards must it face
before it can see the sun?
The Anser my friend is blowin’ in the wind
The Anser is blowin’ in the wind …

(with partial credit to Bob Dylan)

Illustration – Sartaj Ghuman

References

1. del Hoyo, J., Elliott, A. & Sargatal. 1992. J. Handbook of the Birds of the World: Vol 1 : Ostrich to ducks.  Lynx Edicions.

2. Newton, I. 2008. The Migration Ecology of Birds.  Elsevier Academic Press.

3. Köppen, U., Yakovlev, A.P., Barth, R., Kaatz, M. & Berthold, P. 2010. Seasonal migrations of four individual bar-headed geese Anser indicus from Kyrgyzstan followed by satellite telemetry. Journal of Ornithology 151, 703-712.

4. Whiteman, Lily. 2000. The High Life. Audubon Magazine. Downloaded from <http://audubonmagazine.org/birds/birds0011.html>

5. BirdLife International. (2010) Species factsheet: Anser indicus. Downloaded from <http://www.birdlife.org/datazone/speciesfactsheet.php?id=379>

6. Takekawa, J.Y. et al. 2009. Geographic variation in bar-headed geese Anser indicus: connectivity of wintering areas and breeding grounds across a broad front. Wild Fowl 59, 102-125.

7. Rasmussen, P.C. & Anderton, J.C. 2005. Birds of South Asia: The Ripley Guide. Volumes 1 & 2.  Lynx Edicions.

8. Krishnan, M. Occurrence of the Bar-headed Goose (Anser indicus) in south India. Journal of the Bombay Natural History Society 84, 204

9. Shyamal, L. BirdSpot. Accessible from <http://sites.google.com/site/birdspot/home>

 

Relevant Links –

Videos and other information on BBC Wildlife Finder

Bar-headed Goose Bibliography on AVIS-IBIS (An Avian Information System – Indian BioDiversity Information System)

BirdLife International’s summary sheets on Bar-Headed Goose

Bar-headed Goose on MigrantWatch: Sighting data || Species Identification Guide

 

(Update on 8 June)

New research (by the BNHS and others) on Bar-headed Geese based on satellite-tracking shows that the geese display amazing feats while crossing the Himalayas on migration. They can climb many thousand metres in altitude in only a few hours; and do so without the assistance of tailwinds. Wonderful studies like this add greatly our understanding of Bar-headed Goose migration!

Press coverage:
Wise geese chase sinks a myth – Telegraph (Kolkata)
High-flying geese don’t need winds – The Hindu
The Most Extreme Migration on Earth? – Science Now

The original research article:
The trans-Himalayan flights of Bar-headed Geese.

Even if you’re not on Twitter, you can follow the exciting adventures of Dinara. This female Sociable Lapwing (Vanellus gregarius) is one among nine birds that have been fitted with state-of-the-art satellite tags by scientists at the Sociable Lapwing Project, a collaborative effort by BirdLife International, Swarovski and The Royal Society for the Protection of Birds. Thanks to ‘The Amazing Journey’ – the popular face of this project – internet users can follow, real time, the migratory movements of these birds. The tags have revealed that these nine Sociable Lapwings, which breed in Kazakhstan, overwinter in places as far apart as Saudi Arabia and India. Dinara herself was at the Little Rann of Kutch over the new year. Learn more about the life of one of the planet’s rarest birds at The Amazing Journey. And if you live close to Ahmedabad, keep an eye out for Dinara.

Check out Sociable Lapwing data on MigrantWatch, and add your sightings!

 

 

 

 

By Nimesh Ved
Nimesh Ved works in conservation education across different segments of society in south Mizoram. While doing so, he finds himself lucky to expand his awareness and appreciation of wildlife in north-eastern India.

Saiha, at the southern tip of Mizoram, has offered me many sightings of avian migrants during my three years of working here as the head of the Samrakshan Trust’s conservation education efforts. A sighting of the Common Kestrel Falco tinnunculus was one of my first contributions to the MigrantWatch database last year; and this year too they came back to Saiha to fill my winter months with some memorable sights.

My first sighting of kestrels in the current season was when we saw two of them take small dives in mid-air, turning (almost!) on their sides and catching insects; this spectacle went on for 15 min. It was fun to see small insects disappear amidst this ‘dance’ of the kestrels; as I write I recall Kipling’s eloquent narrative of the ‘Dance of Elephants’ in his ‘Toomai of the Elephants’. We just sat there at our base-camp and soaked in this sight.

On later occasions, we have heard their high-pitched calls at about 6 in the morning, as if chastising us for not making an early start to the day.

One evening at about 4 pm we saw about 20 to 25 Kestrels flying in circles about 30 feet above the ground. There was a fire in the valley and they were presumably enjoying feeding on the insects that fled the fire. It was mesmerising to see the kestrels moving around in joy like children coming out of school. This also led me to look up literature on the Lesser Kestrel Falco naumanni that I thought was a part of that day’s excitement.

Confusions on raptors has often led me to Rishad Naoroji’s book Birds of Prey of the Indian Sub-continent and here I found some of the day’s observations to be in consonance with his notes on the Lesser Kestrel - “Essentially insectivorous, highly social and flocking species”; “Taking prey (mostly insects) more often on the wing than the Common Kestrel, otherwise hunts similarly but mostly in small groups or large loose flocks, 10 m to 15 m above the ground”; “In Africa catches insects disturbed by grass fires in the air”. Next I checked up the web to confirm calls of the Common Kestrel and Lesser Kestrel. While most of the calls I had noticed belong to the Common Kestrel, the call I had heard today (15 Nov 2010, 1:45pm) was that of the Lesser Kestrel, which has a lower-pitched and harsher voice.

How exciting to confirm that the rare Lesser Kestrel visits Saiha! It would be wonderful to know where they come from and how long they spend here.

Some notes on Kestrels from the literature
About Indian Birds by Salim Ali and Laeeq Futehally ~ ‘There is only one bird which can really remain quite stationary, in the air, even when its wings do not move, and that is the kestrel.’
A Pocket Guide to the Birds of Mizoram by Anwaruddin Choudhury ~ Common Kestrel is a common winter visitor to Mizoram.

Relevant Links
BirdLife International’s summary sheets on Common Kestrel and Lesser Kestrel
Calls of Common Kestrel and Lesser Kestrel
MigrantWatch data on Common Kestrel and Lesser Kestrel.

Nimesh Ved blogs here. He can be contacted at nimesh.ved [at] gmail.com.

First arrival of the Pied Cuckoo in 2010 in relation to the onset of the Southwest Monsoon

by Mousumi Dutta

Mousumi Dutta is a frequent contributor to the MigrantWatch database. She is an avid birder, and spends her spare time on bird and wildlife conservation. She works with the Indian Meteorological Department, and so has a particular interest in bird migration. Mousumi’s MigrantWatch sightings page is here.

India’s climate is dominated by monsoons. Most of its annual rainfall (86%) occurs during the Southwest monsoon months. The monsoon is a key influence on agricultural output as well as the overall economic growth of India. From ancient times it has been believed that the onset of the monsoon is associated with the appearance of the Pied Cuckoo Clamator jacobinus.

The Southwest monsoon normally sets in over Southeast Bay of Bengal on 20 May and then over Kerala on 1 June. An analysis of the first sighting dates of the Pied Cuckoo and the onset of the Southwest monsoon for the year 2010 (see figure below) shows a fairly systematic pattern. In general, the first sighting of this species in a State is 20-25 days in advance of the onset of the monsoon in that State. This appears to be earlier, relative to the monsoon, than reported for last year.

These patterns indicate an interesting relation between the onset of the monsoon and the arrival of Pied Cuckoos. Long term studies are needed to clarify the details of the relationship between the monsoon winds and Pied Cuckoo migration.

Methods
First sighting dates (after January 2010) for Pied Cuckoos for each State were taken from the MigrantWatch database. (Maharashtra and the four southern States were excluded.) Dates of the onset of the monsoon for each State are taken from the Indian Meteorological Department’s monsoon pages (click on “Northern Limits of Monsoon”). The data used to generate the figure are given below. The links under “Reported by” point to the sighting page on MigrantWatch.

State	First Sighting	Onset of Monsoon	Reported by
Orissa	16 May	13 June	Aditya Panda
West Bengal	17 May	14 June	Supriyo Ghatak
Gujarat	30 May	16 June	Nandita Amin
Madhya Pradesh	10 June	4 July	Anand Kumar Bhatt
Uttarakhand	27 May	5 July	Sharad Khanna
Chandigarh	6 June	5 July	Vikram Jit Singh
Delhi, including NOIDA	31 May	5 July	KB Singh, email to MigrantWatch
Haryana	22 June	5 July	Vikram Jit Singh
Himachal Pradesh	29 June	5 July	Devinder Singh Dhadwal
Rajasthan	24 May	6 July	Saandip Nandagudi

 

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If you would like to make your own visualisation and analysis of Pied Cuckoo sightings, you can download all 300+ records here. Please share your findings with everyone at MigrantWatch – send us (mw@migrantwatch.in) a small blog post and we will put it up.

By T. R. Shankar Raman

Originally published in ‘The Hindu’ on 1 November 2009

Every year, as the south-west monsoon fades across our land, a sense of restlessness and upheaval brews in the high Himalayas. The grey skies of August transform into the clear blues of September and a developing chill marks the air. The landscape and trees are gathering the colours of autumn; winter is not far. Then, in the high mountains, in ravines with willow and rhododendron, in lichen-encrusted forests of fir and birch, millions of little birds prepare themselves for a great journey.

The birds are so small that they can nestle snugly in the palm of your hand, or even fit into a loosely closed fist. They are most unassuming and drab, dressed in pale greens and humble olives, or in dull browns with scarcely a dash of yellow or orange, sometimes dabbed with pale wing-bars and stripes. They merge so well with the leaves that were they not so active and restless—flitting their wings and calling regularly to announce their presence—it would be hard to even spot them. And yet these wispy little birds, weighing around ten grams, can stake claim to great achievement. Every year, millions of them migrate hundreds to thousands of kilometres—in a matter of days even—flying south from the high Himalaya, the Caucasus and mountains of Central Asia to winter in the foothills, plains, plateaus, and hill ranges across India. And here, after a lull of many months, when the trees and shrubs are a-flutter with lively chirps and twittering song, we know that the leaf warblers are back.

Burning fat
The leaf warblers, as one may guess, have a close association with the foliage of shrubs and trees where they restlessly search for their insect prey. Their restlessness is heightened in the days that precede migration. The birds feed in the foliage, as if in a frenzy, to load up for their journey a crucial stock of fuel: a few grams of fat. That hundreds to thousands of kilometres can be efficiently travelled on a few grams of fat is one of the primal wonders of bird migration. Burning fat is more efficient than burning sugars or proteins, producing as a by-product water, another key need for those long hours on the wing.

Although many birds, including small ones like warblers, fly non-stop between their breeding and wintering grounds, the leaf warblers may make brief stop-overs en route. Thus warblers heading to the southern tip of India may be recorded on passage at sites in northern India or the Deccan in August-September and then again in April-May during the return journey.

Changing lifestyles
In southern India, the most ubiquitous of the leaf warblers is the Greenish Warbler. This species has three forms that differ slightly in plumage and call, which ornithologists sometimes separate into three species. It is found in a range of habitats from urban gardens and plantations to tropical forests, preferring the canopy of trees.

When these warblers leave the sub-tropical and temperate forests of the Himalaya or the mountains beyond for the tropical deciduous and evergreen forests of the south, it is not just the tree species and the habitat they use that changes. They make a fundamental change in their lifestyle. Up north, these warblers live and breed in pairs during the summer, each pair defending its territory from other pairs for its valuable trove of insect food.

Yet, when they come south for the winter, the males and females separate—each individual maintains its own territory. A female sings and defends a territory from other members of its species, just as a male does. Following the monsoon rains, insect prey are rich enough in the foliage to attract the warblers, but scarce enough to warrant staking out a territory to defend it from the warbler multitude.

The territories the birds defend are not large. A single hectare of tropical forest may pack two to four birds holding territories. By marking individuals with numbered and coloured rings on their feet, ornithologists have shown how the same individuals return to the very same quarter hectare of forest after their long journey every year—a feat of fidelity and orientation that one cannot help appreciating in so small a bird.

When the warblers arrive in our forests and gardens in September and October, they arrive singing. These are territorial songs staking claim to their all-important grove of trees or little segment of forest. During the first few weeks, the trees are busy with songs and territorial skirmishes as some warblers settle down in their winter turf and others are chased out of it. The songs then give way to simpler, short call notes serving to merely announce their presence (a boon to birdwatchers to detect and identify each species). Then, over a relatively quiet period, the warblers moult into a new set of feathers, as if to greet the new year.

Linking worlds apart
As April arrives carrying the promise of Himalayan spring, the relentless forces of nature and instinct turn the birds northward. Once more, the birds feed briskly to load up on fat. There is a flurry of song, as if in preparation for the territorial battles to be waged shortly on their breeding grounds. And then, one day, the tree where you have watched the warbler for several months is silent, and the bird is gone again.

And yet, when the warbler departs, it leaves behind a new awareness. An awareness, stirring deep wonder and strangely uplifting, that a tree in one’s garden may be linked to a specific, even if unknown, corner of the Himalaya by one individual bird. A renewed sensibility that the garden and that Himalayan corner, and a range of stop-over sites along the warbler’s route are all needed to keep alive this tiny linker of worlds. The warbler’s journey then seems a brave voyage of survival and connectedness, surmounting artificial boundaries and national differences in a way that transcends our best-intentioned bilateral efforts at cooperation. Softly and unobtrusively, as it has done for millenia, the little warbler continues to tie us to other lands and peoples and nations far away.

T. R. Shankar Raman is with the Nature Conservation Foundation.