The massive migration of birds brings many through the TCI.

By Simon Busuttil, RSPB Turks & Caicos Operations Manager, Turks & Caicos Islands Iguana Partnership, Biosecurity Advisor

In the Spring 2022 Times of Islands I wrote about some of the discoveries about birds being made and to be made in the Turks & Caicos Islands. Many were about seabirds and shorebirds using the remoter parts of the archipelago, which required expeditions to locate.

However, the joy of birdwatching is that in many cases you can stay still (figuratively and literally), and the birds will come to you. Most birds fly and many migrate. They are often opportunists and can learn.  Those of us who put up a bird table and keep it supplied with food can see how the number of birds and species using it increases over time. And occasionally, a species that you’ve never seen before will turn up in your yard.

At the peak of the last ice age (roughly 20,000 years ago), almost all of Canada and some of the northern US was covered in ice and much of the area south of this was similar to Arctic conditions extant today — taiga down to the Gulf of Mexico, cold steppe grassland on the Great Plains. As the ice retreated, many birds began to move north each season to exploit the increasing area of habitat available. This north to south movement, increasing over thousands of years as the ice retreated, likely formed the origins of the annual avian migration pattern we see today.  

Migration patterns continue to change in response to environmental factors.  Many swans, ducks, and geese are no longer flying as far south and west as in the past to escape cold weather in the east and north. The waterbodies that they use now remain unfrozen for longer periods because of milder winters. They have no need to use up precious energy resources flying further than necessary. This phenomenon has become known as “short-stopping.”

We are yet to notice any short-stopping in TCI (though this is not to say it is not happening). To record such a phenomenon requires years of regular monitoring so that change can be detected. This monitoring has not happened here as it does in the more populous countries where there are hundreds of thousands of birdwatchers who want to put their hobby to good use. As volunteers, their data is collected and analysed.

This year, hundreds of thousands of blackpoll warblers appeared across TCI in October as part of their annual migration.

Around 75% of all the regular species found in North America migrate. These means that over four billion birds migrate in fall across North America. Some move only as far as the southern states and the Gulf coast, others into Central America and the Caribbean, and a few much further down to southern Argentina. Species that migrate vary from the well-known and obvious snow and Canada geese and sandhill cranes, to a host of small birds like warblers, tanagers, orioles, and sparrows — many of which occur here in TCI. These are generally birds of the bush, but many are as likely to occur (and much more likely to be observed) in your garden or yard as they are in an area of bush. They will come to you, their stories are fascinating, and together form one of the natural world’s great events.

One example:  On October 21, 2022, hundreds of thousands of blackpoll warblers appeared across TCI. There was a steady movement east all day and birds appeared everywhere from ground level to the tops of the tallest trees. Over the next few days, numbers grew, with birds using even a single tree in an otherwise urban area. Many were reported dead or injured from collisions with windows, falling prey to cats, or becoming victims of traffic. By early November, numbers had fallen dramatically through mortality and presumably, the birds continuing on their next stage of migration. 

Blackpoll warblers breed in the extensive spruce forests of Alaska and Canada and migrate to spend the winter in northern South America. It is thought that in autumn, the entire world population of this species passes through the Caribbean. For the Alaskan breeders this is an annual round trip of 11,000 miles. Birds leave Canada when the wind is from the northwest, heading southeast out into the Atlantic before picking up the easterly trade winds over the Tropics to arrive on their wintering grounds. It is likely that this year, they encountered unusual weather that forced them west and “grounded” them in TCI in particularly large numbers.

Warblers are the typical small birds of the bush that “seep” and “sip” and disappear into the leaves. They always occur in larger numbers in autumn than in spring.Numbers moving across North America are about half a billion lower in spring after mortality during the winter months and from losses on migration. Also, birds migrate more quickly in spring. There is an understandable urgency to press on quickly to the northern breeding grounds and claim a mate and territory.     

Unlike the blackpoll warblers, most North American birds migrate through Mexico with only outlying individuals coming through the Lucayan archipelago. The peak time to look out for these scarcer migrants — colourful orioles, tanagers, grosbeaks, and warblers — is in October, but migration runs from August through to November and then again in the spring. Most migration takes place at night. Early morning is when these birds are most obvious — hungry after their night’s flight and learning about their new temporary environment. But they will be active all day if you sit tight and wait. Fresh water in a garden can be a great attraction as the day wears on.

Cape May warblers spend the winter in TCI, feeding on fruit, nectar, and invertebrates.

Whilst many of these birds, including the blackpoll warblers, move on by late November, several species spend the winter with us, departing north in spring. Cape May warblers feed on fruit, nectar, and invertebrates during their winter in TCI. They can be found in both native bush and landscaped grounds. Numbers vary enormously each year as the population is controlled by the number of spruce budworms available to feed their young in the forests of northern North America. In good years the population booms. (This winter 2022/23 is a poor one compared to last year.)

Alongside Cape May warblers there are delicate grey and yellow parula warblers, and both black-throated blue warblers and yellow-throated warblers whose names describe them perfectly. The former two are more common in native scrub but the yellow-throated has a penchant for tall palm trees planted around resorts and grounds. All can be seen relatively easily around resorts and residential areas, especially those adjacent to remaining areas of native bush.  

There are many other inconspicuous birds that have only been recorded a few times but are likely much commoner than the number of records so far suggests. Examples include:  Rose-breasted grosbeaks travelling to winter on the steep slopes of the northern Andes; eastern wood pewees en route to the upper reaches of the Amazon basin; and delicate Tennessee warblers that share a similar boom and bust population cycle as the Cape May warbler. They are rarely recorded in TCI, taking a much more westerly migration route.  

One of the exciting things about migratory birds is that they can appear anywhere. There was an eastern wood pewee in buttonwoods by the side of the road as I took my kids to school one morning in November. The TCI Football Association’s soccer fields at the Graceway Sports Centre on Providenciales proved a mecca for migrating birds after Hurricane Fiona this year. There are few areas of freshwater marsh on TCI and after heavy rain, the pitch was sodden and mimicking the freshwater marshes needed by some species of wading bird. Over 40 pectoral sandpipers spent several weeks using the field regularly, probing in the newly soft earth for invertebrates to fuel their incredible journey. We know that these small wading birds were on their way to the pampas grasslands of southern Argentina. For the individuals breeding in the furthest north, this is an incredible annual round trip of over 18,000 miles.

Away from the bush, any walk or visit has the potential to make a bird discovery. The North West Point area and the National Trust’s Heritage Trail at Bird Rock Point at opposite ends of Providenciales are good places to see migrating birds. Wheeland ponds and the Blue Hills pier are easily accessible sites where you do not even have to leave the car to observe the birds. This can make taking photographs relatively easy, as birds are not as spooked by cars as they are by people. Being close to the sea, both areas attract seabirds, especially after storms.   

This Forster’s tern was documented in December 2016 at Blue Hills pier. It is a tricky species to identify and rarely recorded in TCI.

Photographs can be great sources of information about rare birds. Terns are generally white with a dark cap and apart from size are very similar looking, often occurring in mixed flocks of different species. Several types of tern are in TCI between March and September and the largest, the royal tern with its huge orange bill, spends all year with us. Other species occur during migration or winter. Looking through bird photos with a friend recently, we found that he had photographed a Forster’s tern at Blue Hills pier back in 2016. A tricky species to identify, it had only been recorded a few times in TCI and never previously been fully documented.

This American white pelican photographed at the Providenciales Golf Course in January 2019 was a first-ever record for TCI.

An encounter with another keen photographer of birds led to her sending me a series of photographs taken during COVID lockdown walks. Scrolling through images of “Herons, Egrets, and Flamingos,” I saw a couple called “Pelicans.” Opening the files expecting to see our resident brown pelican, I was delighted to find photographic evidence of the first-ever record of an American white pelican in TCI taken at Provo Golf Course in January 2019. 

The migration of four billion birds into and out of the North American continent is one of the earth’s great natural rhythms. We see fragments of it here in TCI — a small warbler resident in the trees around our yard for a couple of days, a party of blue-winged teals on a pool that were not there the day before. To get a broader view, North America now has a sophisticated real-time monitoring program that is publicly accessible (https://birdcast.info/about/). Networks of radar combined with data and algorithms create real-time forecasts and detailed maps of the numbers of birds migrating on any particular night during the migration season for the contiguous American states. It does not cover the Caribbean but gives some idea of what might be coming our way on any night and thus what might be waiting to be found when we go birdwatching the following day.

The scale of bird migration is astonishing. That such an annual event takes place all around us — almost without us knowing — is equally amazing. Observing it and having even the slightest understanding of what is taking place can create a strong sense of seasonality and a spiritual link to the natural world. Increasingly we know that these are important factors in robust mental health.

Simon Busuttil now lives and works in TCI. He has been birdwatching for 40 years and led birdwatching tours across the world. He would be delighted to advise on birds and birdwatching in TCI and look at any bird photographs. He is currently writing a book on TCI’s birds and would welcome any records that people have. He can be contacted on simonb.tcint@gmail.com.