The invisible migrants: Why Bangladesh must protect its smallest winter visitors
Bangladesh must choose to be a safe home - not a killing ground - for migrants and all wildlife
Every winter, Bangladesh transforms into a living aviary as migratory birds arrive in breathtaking numbers. From the icy heights of the Tibetan Plateau, Bar-headed Geese, known locally as Dhushar Rajhansh, sweep down to the country's wetlands. Greylag and White-fronted Geese (Koiri and Sadakopal Rajhansh) gather in dense flocks, while Common and Ruddy Shelducks (Chokha-Chokhi and Shachokha), Pintails (Lenja), Mallards (Neelshir), Red-crested Pochards (Laalshir), Wigeons, Gadwalls (Piong Hansh), Teals (Patari Hansh), and Whistling Ducks (Sharali) bring constant movement to the haors, beels, rivers, and coastal mudflats.
Along the tidal edges, Curlews (Gulinda) and Whimbrels (Chhoto Gulinda) probe the soft earth for food, joined by plovers (Batan), sandpipers (Chapakhi), snipes (Kadakhocha), knots, redshanks (Lal-pa Piu), greenshanks (Sabuj-pa Piu), stilts (Lal-pa Dhenga), and phalaropes. Overhead and along the water's edge, gulls (Jolkobutor), terns (Gangchil), cormorants (Pankowri), herons and egrets (Bok), ibises (Kasteychora), storks (Sarash or Manikjor), spoonbills (Khuntey Bok), moorhens (Jol Murgi), swamphens (Kalim Pakhi), and rails (Kora or Hulti) complete the seasonal spectacle – turning Bangladesh's winter landscape into a vibrant crossroads of global birdlife.
These are all mega fauna wintering or passaging through Bangladesh in Autumn, Spring and winter
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These birds are large, conspicuous, and often colourful. Because they come in flocks and occupy open wetlands, people notice them. Unfortunately, they are also the birds most frequently shot, trapped, poisoned, netted, sold, and consumed. For many hunters and traders, winter means open season.
But this highly visible migration has created a dangerous misconception: that migratory birds in Bangladesh are mostly large waterbirds and that they are merely "guest birds" or seasonal visitors with little ecological value. This belief is widespread—not only among rural communities and hunters, but also among educated urban populations, media professionals, engineers, and even individuals responsible for law enforcement.
The truth is very different.
Bangladesh is not just a winter refuge for large waterfowl. It is, more importantly, a critical wintering, stopover, and passage habitat for hundreds of species of small migratory birds, most of which pass unnoticed, uncelebrated, and unprotected. These birds are the invisible migrants—tiny, drab-coloured passerines and some small non-passerines that quietly arrive in autumn for a brief stay, largest numbers arrive in winter, and many pass through the country in spring.
They do not form spectacular flocks. They do not sit in open water. They hide in bushes, grasslands, reedbeds, croplands, orchards, roadside trees, city parks, islands, chars, tea gardens, and even tiny urban gardens. And yet, they form the backbone of ecosystem services that sustain agriculture, horticulture, forestry, and human health.
This article focuses on these overlooked migrants, their numbers, roles, habitats, and the urgent need for strong government action to make Bangladesh a truly safe home for all migratory birds.
How many migratory birds do we really have?
Bangladesh hosts approximately 720 species of birds. Traditional narratives often suggest that "about half" of these are migratory. While technically correct, this framing hides a crucial fact:
- Only around 90–110 species of migrants are large, easily visible waterbirds and waders.
- Over 250–300 migratory species are small birds, mostly passerines (songbirds), with a few small non-passerines mixed in.
In other words, the overwhelming majority of migratory bird species in Bangladesh are small, terrestrial or semi-terrestrial birds.
These include:
- Warblers (leaf warblers, reed warblers, bush warblers)- Patafutki
- Flycatchers/Chotok or Kitvook
- Chats and robins/ Fidda
- Pipits and wagtails/Tulika & Khonjon
- Larks- Bhorot Pakhi
- Buntings/Bagheri
- Shrikes/Koshai Pakhi
- Thrushes/ Dama
- Small cuckoos/Kokil/Shorgom/Papiya
- Minivets/ Satsohheli
- Orioles/Holdey Pakhi
- Drongos (several species)/Fingey)
- Swallows and martins/ Ababil & Nakkati
- Swifts/ Ghor Ababil
- Small rails and crakes/Hulti
- Some kingfishers and bee-eaters/ Machhranga & Shuichora
Most of these birds breed in Central Asia, Siberia, the Himalayas, Mongolia, China, and Eastern Europe, and travel thousands of kilometres to escape harsh winters. Bangladesh is not a random stop—it is a life-saving destination.
Migratory birds visiting Bangladesh primarily follow two major international flyways: the East Asian-Australasian Flyway (EAAFP) and the Central Asian Flyway (CAF), utilising Bangladesh's extensive wetlands, river systems (Ganges-Brahmaputra-Meghna basin), and coastal areas as crucial stopover sites for rest and refuelling during their long journeys from northern breeding grounds to southern non-breeding areas. Bangladesh is a partner in the EAAFP and has designated several Flyway Network Sites like Tanguar Haor, Hakaluki Haor, and Nijhum Dwip (https://eaaflyway.net/migratory-birds-of-bangladesh-and-eaafp-sites) .
Why we do not notice the tiny migrants
1. Size and Colour
Most small migrants are:
- Less than 15–20 cm long, 10 to 20 g in weight
- Brown, grey, olive, or dull green
- Designed by evolution to blend into vegetation
They are not gaudy like ducks or storks. Their survival depends on invisibility. They need to merge with background.
2. Habitat Choice
Unlike large waterbirds that gather in open wetlands and often in large numbers, small migrants prefer:
- Bushes and shrubs
- Tall grasses
- Reedbeds
- Crop fields
- Tea gardens
- Roadside vegetation
- Urban parks and gardens
- Village groves and
- Kitchen gardens
A single bush in a city park can host 10–20 species of migratory birds at once—yet passersby may not notice a single one.
3. Behaviour
Small migrants:
- Forage quietly
- Move constantly
- Rarely form large flocks
- Spend most of their time hidden inside foliage
Their migration is a silent migration.
The enormous ecological role of tiny migrants
1. Natural pest control: The invisible army
Most small migratory birds are insectivores.
A single warbler, flycatcher, or wagtail:
- Eats 20–50 insects per hour
- Feeds for 8–10 hours a day
That means:
- 200–500 insects per bird per day
Now imagine:
- Thousands of birds
- From over 250 species
- Spread across farms, forests, villages, and cities
This translates into millions of insects removed daily, including:
- Crop pests
- Mosquitoes
- Caterpillars
- Leafhoppers
- Beetles
- Grasshoppers
- Flies
Without these birds, farmers would face:
- Increased pesticide dependence
- Higher production costs
- Soil and water contamination
- Health risks to humans
These birds are free, efficient, and environmentally safe pest managers. Also, their stool or droppings are manure for the soil that in turn support the crop cultivation.
2. Protection of Agriculture and Horticulture
- Small migrants protect:
- Rice fields
- Wheat and maize crops
- Vegetable farms
- Fruit orchards
- Tea gardens
- Home gardens
They reduce pest outbreaks before they reach damaging levels. In tea gardens, for example, migratory flycatchers and warblers are among the most effective controllers of leaf-eating insects.
The economic value of this service, if calculated, would amount to billions of taka annually.
3. Pollination and Seed Dispersal
While insects dominate pollination, birds also play a role:
- Some migrants feed on nectar
- Others consume fruits and berries
By doing so, they:
- Pollinate flowers
- Disperse seeds across landscapes
- Aid forest regeneration
- Maintain plant diversity
In degraded landscapes, migratory birds often become agents of ecological recovery.
4. Maintaining ecosystem balance
- Small migrants are:
- Prey for raptors
- Predators of insects
- Competitors that regulate resident bird populations
They keep ecosystems dynamic and resilient. Their disappearance would trigger cascading ecological effects.
Habitats used by small migrants
Unlike large waterbirds, small migrants occupy a wide range of habitats:
1. Terrestrial habitats
- Forest edges
- Scrublands
- Village groves
- Orchards
- Roadside trees
- Urban parks
2. Agricultural landscapes
- Paddy fields
- Mustard fields
- Vegetable plots
- Fallow lands
3. Wetland-associated vegetation
- Reedbeds
- Grass beds
- Marsh edges
- Floating vegetation
These habitats are often ignored in conservation planning, yet they are critical for migrants.
The dark reality: Hunting and illegal trade
Large migrants under fire
Large migratory birds face:
- Shooting by licensed and unlicensed gun owners
- Mass trapping with nets
- Poisoning using banned chemicals
- Sale in illegal markets
- Consumption as "delicacies"
Entire flocks can be wiped out in a single night.
Small migrants are not safe either
Although less targeted, small migrants suffer from:
- Indiscriminate netting
- Habitat destruction
- Pesticide poisoning
- Light pollution
- Urban expansion
Many die without anyone noticing.
The myth of 'guest birds'
Calling migratory birds "guest birds" is misleading and harmful.
These birds are part of our ecosystems to
- Provide direct benefits to our economy
- Depend on Bangladesh for survival
They are not guests.
They are seasonal citizens of our landscapes.
What the government must do: Concrete actions
1. Strict enforcement of wildlife laws
- Zero tolerance for hunting of migratory birds
- Confiscation of guns used illegally
- Heavy fines and imprisonment for offenders
- Special winter enforcement drives
2. National awareness campaign
- Media campaigns explaining the role of small migrants
- School curriculum inclusion
- Training for journalists and law enforcers
- National TV stations and print media should broadcast messages of small bird protection and conservation
3. Habitat protection beyond wetlands
- Protect bushes, reedbeds, grasslands
- Urban green space conservation
- Migratory bird-friendly farming practices
4. Ban on bird poisoning
- Strict control on toxic chemicals
- Monitoring of wetlands and fields
5. National migratory bird monitoring programme
- Citizen science initiatives
- University involvement
- Long-term data collection
6. Regional and International Cooperation
- Flyway-based conservation
- Collaboration with range countries
- Compliance with international treaties e.g. Ramsar, CMS, etc.
Conclusion: Making Bangladesh a safe home
Bangladesh lies at the heart of major migratory flyways. Every winter, millions of birds trust our land, water, and vegetation with their lives. Some arrive in noisy flocks, others silently slip into bushes and fields.
Protecting migratory birds is not charity. It is self-preservation.
If Bangladesh becomes unsafe, these birds will disappear - and with them will vanish natural pest control, ecological balance, and a living connection to the wider world.
A country that protects its smallest, quietest visitors proves its maturity as a steward of nature.
Bangladesh must choose to be a safe home - not a killing ground - for migrants and all wildlife.
