Soaring Singers of Skies
By Shanuka Kadupitiyage
Migratory birds are one of the many wonders of nature that are an integral part of the ecosystems of not only Sri Lanka, but also the entire world. They contribute much to the environment and have much cultural significance to the people and nations they visit. Birdwatchers gather to observe them, making migratory birds a valuable asset to the tourism industry as well. Each year, these birds fly across continents following ancient routes that generations of these bird species have travelled in order to avoid harsh climate conditions as the seasons change, visiting tropical habitats during the harsh winters of their homelands, only to return once the ice starts to thaw and spring is in the air.
Scientists continue to study the various migratory bird species in hopes of unlocking new scientific discoveries, to learn what impact they have in the countries and habitats they visit, and how we can better live alongside these avian migrations. That’s because these birds currently face a huge threat to their survival, and as always, we are the main culprits. Reports have shown numbers of these species dwindling, which can cause severe ripple effects to habitats across countries, climates, and oceans.
This is why every 8 May, people across the globe celebrate World Migratory Bird Day with the purpose of raising awareness about migratory birds, their importance, and the modern-day threats towards their survival as a species. Sri Lanka is one of the many tropical destinations of these migratory birds, coming from various destinations throughout Asia and Europe, and houses thousands of birds belonging to many different species during the cold winter months of the north.
Because of the ideal geographical location, our tiny island is a critical factor for the survival of many migratory bird species across the globe. Ceylon Today reached out to Senior Lecturer at the Department of Zoology – Environmental Sciences of the University of Colombo Dr. Sampath Seneviratne – a leading research scientist in molecular ecology, evolution and ornithology as well as a senior lecturer in zoology – for more information about Sri Lanka’s many avian visitors and how we can be better hosts to these international guests.
Mistaken from the start
Dr. Seneviratne explained that migratory birds travel across vast distances through various flight paths that are called ‘flyways’. Scientists study and map these routes because they are critical to getting a better understanding about avian migration. As important as they are, we learnt that, “The general consensus about migratory routes are based on anecdotal observations.” He went further on and explained that there is a majority acceptance of three main routes which migratory birds follow to reach Sri Lanka – a concept introduced by the colonial settlers of the country who followed these birds. “In some books, you’ll see maps of how these birds travel in the country.
However, the irony is that these are all fictitious routes, with no scientific studies proving their accuracy.” We learnt from Dr. Seneviratne that for the past few centuries, colonial naturalists who travelled across the country reported these routes according to their observations, drawing up various conclusions. He agreed that it’s acceptable that when there isn’t enough information, assumptions are made. Unfortunately, these assumptions have become established to the point that in the minds of the people, fiction has literally become fact. “These were just ideas put forward by colonial birders (birdwatchers). In reality, we have no clue as to where they come from,” he said.
So, how do scientists find the paths these migrators follow? “There is a programme which we call the ‘National Bird Ringing Programme’,” he continued. “It’s a collaboration between the University of Colombo and the Department of Wildlife Conservation (DWC) of Sri Lanka.” Dr. Seneviratne explained that through the programme, special rings are attached to each bird’s leg as a marker. If the bird is ever captured in a research project again, then researchers would have gained a glimpse on that bird’s flying patterns. “If you ever see that ring again, you would know where the bird has come from, wherever you may be in the world,” he said.
For many years, using a systemised coding method, researchers from all over the world collaborate, placing bands on birds and recovering them in order to track the flying patterns of migratory birds. “We’ve had band recoveries from Iran, India even from Australia.” While this method can show where migratory birds travel, it cannot show the flight path of these birds. “That was the case until last May,” Dr. Seneviratne said. “Last May, we started a relatively ambitious project to place satellite transmitters on to some of these key migrant birds.” With the use of satellite tracking and GPS, local scientists can now track the route of these migratory birds in real time.
That way we can finally uncover the truth behind the flight paths of these birds. Unfortunately, this project comes with a hefty price tag, with one satellite tracker costing as much as US$ 2,000. However, the money invested in these units are well worth it since the data they deliver to researchers is essential for their studies. “It emits a signal every half-hour to show their exact real-time location, as well as transmit other measurements such as their body temperature and environmental conditions.”
We learnt from Dr. Seneviratne that the flight paths speculated those many years ago were in fact, wrong. He added that, “They depend on geography, geology, wind, weather patterns, global climate, star constellations, and the earth’s magnetic field,” to plot out their actual flight path according to their benefit. Dr. Seneviratne explained that there are many flyways for every region of the world, each with their own challenges and threats to these migratory birds. Thanks to our geographical positioning, we are at the southernmost point of the central Asian flyway, which starts from Russia and Europe going all the way to Southern India and Sri Lanka. “Billions of birds fly along these routes each year, flying south during October and November during the fall season to avoid the winters of the north and back to their homes where they will breed.”
”Globally, the populations of migratory birds have been decimated in a very short period of time,” Dr. Seneviratne explained. “Some species have lost up to 90 per cent of their population over the past 100 years.” As for why, Dr. Seneviratne explained common issues throughout the world and also region-specific challenges. “One of the biggest problems is habitat loss, both forests and wetlands.” He explained that with loss of habitats, the birds are not only losing places to live, but also becoming more vulnerable to predators, even domestic animals such as cats and dogs.
“If you cut down Sinharaja, all the birds there that have been calling Sinharaja home for millions of years won’t leave, searching for other homes, they will try to live in whatever conditions there are and simply die off.” He noted that harm and encroachment on breeding grounds and locations where they spend the winter months happen due to farming, development, and other human activity. When breeding grounds get poisoned due to pesticides and other pollutants, their reproductive success is devastated. Many also die off because of being exposed to these pollutants as they spend their winter months.
The same is true for stopover locations where these birds that travel thousands of kilometres, stop for rest and recuperation along their journey. Any impact on those locations could mean death for these birds, even before they reach their destinations. He also noted that hunting has been a major threat to the migratory bird populations of the world, with thousands, even hundreds of thousands of birds being hunted for sport and for trophy collectors. He spoke of netting being a major issue as well where people throwing large nets to capture massive flocks of birds to consume for meat.
While there are laws in place to protect migratory birds from such practices, hunting continues to be practiced throughout the world, causing a major dent in these bird populations that are already being decimated due to habitat loss and pollution as they traverse the continents, making each migratory journey a one filled with danger and death. Dr. Seneviratne continued, pointing out that climate change is another massive problem for migratory birds and their populations. “These birds depend on weather patterns being reliable. As an example, there are birds that breed in the Arctic Circle, far north, while spending winters in tropical climates. These birds have to fly back to their breeding grounds just as the ice melts.
If they arrive earlier, these birds would die because of the cold, and if they arrive too late, they might not have enough time to lay eggs and successfully raise chicks. There’s a narrow window of three to four months that these birds have to time perfectly.” Because seasons and weather patterns are never set dates and are constantly in flux, birds rely on specific changes in the weather which they detect in order to leave for their breeding grounds. If weather patterns do not follow these predictable patterns and adverse weather conditions continue to increase, Dr. Seneviratne said it will be another massive challenge for the future of migratory birds around the world.
The Sri Lankan context
Dr. Seneviratne pointed out that because of Sri Lankan culture and societal norms, hunting has never been a major issue for migratory bird populations that do spend their winter months here, even if they are being hunted down at a massive scale throughout their journey to and from their winter and breeding habitats. “People don’t haphazardly kill animals, which is a great help in protecting these species.
While illegal hunting and shooting is a major issue in other parts of the world, it does not happen in a grand scale within the country.” However, habitat destruction is a major issue in Sri Lanka today, which can drastically impact the survival of these migratory birds. This is why the RAMSAR convention and other protective laws enacted in the country have been essential in protecting migratory bird species. “That’s why we’ve been worried. If you dilute that protection in place for other reasons, migratory birds will suffer. Whatever protection given by the Forest Department and DWC will directly benefit these species.”
A global effort for a global crisis
This year, we celebrate the special day with the theme, “Sing, Fly, Soar – Like a Bird!” Migratory birds travel vast distances and are key players in habitats across continents. Any harm to their biodiversity and success as a species has a direct impact, not only on one ecosystem, but also on habitats throughout the world. This is why protecting these avian travellers is crucial in minimising human impact on environments. Protecting these birds cannot be done by one country alone, but through multiple countries working together, across borders, connecting the whole world.
You can help
Even you can play a part in protecting these species and helping the scientific community better understand migratory birds. “eBird is a global platform for citizen science. Anyone who sees a bird can report their location.” Using their downloadable mobile app, you can contribute to help better understand the flight habits of birds throughout the world. The information you provide is used by hundreds of conservation movements, and thousands of researches and studies conducted by scientists around the world. Because Sri Lanka is a key destination for many migratory birds from Scandinavian Europe to Russia, you can play a massive part in protecting these birds, even if you live in the heart of Colombo. “Colombo city is one of the 18 RAMSAR cities in the wold,” Dr. Seneviratne explained. “It is also the only RAMSAR city in South Asia.
Being a capital city, this makes Colombo a very unique and globally important wetland for migratory birds.” “Have a nature-friendly garden. Have a fruit tree. The value of trees is not just timber or exotic flowers. It may not give direct benefit for us, but it helps the planet in many ways. All types of animals will come and use that tree, even migratory birds may visit to take rest and recover.” He explained that whether you are in the city, living in a small apartment or have an estate, just having extra plants can make a huge difference.
“If you encounter a stressed bird, just give it some personal space, keep it in a box or someplace safe from cats and other predators to allow it to recover and fly away. During migration, they can get exhausted. Colombo sees a lot of such instances. There are close to a million people living in Colombo, and even small actions can make a substantial difference.”
(Pix courtesy Dr. Sampath Seneviratne)