Why Do Laughing Gulls Come to the Virgin Islands for the Summer?

An adult laughing gull has a black hood during breeding season. 

There are no gulls in the Virgin Islands during the winter, but then the laughing gulls suddenly arrive right around the first of April. And like other spring visitors, they tend to come in groups and enjoy loud, amorous beach parties.  

Laughing gull couples use buoys for offshore trysts. 

However the laughing gulls are known to be monogamous. Before long the couples will work together to make nests and raise their chicks out on the smaller, uninhabited cays. They usually stay together in large groups through the nesting season, for safety in numbers.    

I recently began to wonder where these laughing gulls actually come from, and why they are only around in the summer.  

 

Most migratory birds in the Virgin Islands arrive when it is winter in the northeast and food is scarce. Then they leave in the spring to go up north for their breeding season. In the fall, when it gets cold again in the northern parts of the U.S., those birds fly back down. 

 

These laughing gulls are on an opposite schedule – coming to the Virgin Islands to nest, and then leaving in the fall. 

 

One possible explanation could be that the Virgin Islands laughing gulls come to escape the winter in South America, where the seasons are reversed. However, the non-breeding range for these birds is mostly along the northern coasts of South America, and the Caribbean. The  seasonal temperature difference between these areas and the Virgin Islands would be fairly low. Meanwhile, they are considered to be year-round residents within some of the coastal areas of the Greater Antilles. 

 

So I am now thinking that the laughing gulls arriving yearly in the Virgin Islands have not actually traveled very far. And that they probably come for the relative safety provided by the smaller, uninhabited islands here, rather than for the warm summer weather. They may even be returning to the places where they were born and raised. 

 

The laughing gull nests are usually simple grassy structures set into low vegetation on the ground, so being isolated offshore could provide important protection from possible predators.   

 

In the summer, there are often large bunches of baby fish available around the Virgin Islands to feed hungry gulls, and their chicks. And these days, there are rafts of sargassum to pick over too. 

Groups of laughing gulls gather to dive for newly hatched fish.

Besides diving for fish (or trying to steal them from the pelicans), the laughing gulls will also walk along beaches and shorelines looking for shellfish, crabs and large insects. On popular beaches, they may also be attracted to trash left by humans. 

 

Beach walks sometimes reveal tasty crustaceans.

 

Interestingly, for the last couple of years there have been some laughing gulls staying in the Virgin Islands later in the fall than usual, including a few sightings recorded in the annual December bird counts on St. John. 

 

However, they look quite different when they are not in their breeding plumage. The black hoods become just blurry gray patches on their heads. 

 

Laughing Gulls lose their black hoods after breeding season is over. 

It takes about three years for the young ones to get their adult feathers. At first their back feathers are brown with white edges. Over time the feathers on top start turning gray.  

 

Immature laughing gulls have a mottled brown and gray look.

   

Unfortunately, large numbers of laughing gulls and other birds on islands or coastal areas near airports can sometimes be dangerous to air traffic, so air traffic controllers are not happy to see them around. In fact, just recently, a bird strike caused injuries to passengers on a small plane coming into St. Thomas. 

 

In the Virgin Islands, the U.S. Department of Agriculture’s Wildlife Services program is responsible for keeping birds from getting in the way of arriving or departing planes. Their researchers have found that patches of water collecting on the runways can attract thirsty gulls, so good drainage is important. Controlling insects so they don’t hatch in large groups on grassy areas near runways will also keep the gulls from congregating near the airport, which helps both visiting birds and people in planes stay safe.  

 

However, most of the laughing gulls aren’t all that interested in hanging around the airport. Like other visitors, I think they come to the Virgin Islands to enjoy the beautiful beaches.  

Local Kestrels Are Adapting to the New Composite Utility Poles

The replacement poles, made out of fiberglass and resin, are designed to be lighter, stronger, and more wind-resistant than the old wooden utility poles. Their installation was largely funded by the Federal Emergency Management Agency, and the Housing and Urban Development program, as part of a larger effort to strengthen the Virgin Islands grid infrastructure following the extensive damage caused by Hurricanes Irma and Maria.  

 

The wooden poles have now mostly been replaced, and already some concerns have been raised about the relative strength of the new poles. Especially when cars run into them. 

 

However, I wonder if much thought was given to how these new poles affect the birds living in the Virgin Islands. 

 

American Kestrels are small falcons (about 9-10 inches in length), with sharp wings, longish rust-colored tails, and prominent dark streaks under their eyes. They live year-round across much of the United States and the Greater Antilles, and are common nesting residents in the Virgin Islands. They can often be seen sitting on high perches scanning for the lizards they like to eat, along with occasional mice or large insects. They swoop down quickly to nab their prey, and then often return to the perch to eat.   

 

The flat tops on the old wooden poles provided platforms for important kestrel activities, including hunting, eating, courting and mating. 

 

                              

 

But the new poles have pointed tops, specifically designed to prevent birds from perching on them. So the kestrels have had to adapt. 

 

                           

 

The points on the poles may actually be intended to keep other types of birds from building nests up there. That is not a concern for kestrels because they make their nests in cavities, like holes in trees. They are more interested in platforms for hunting and mating. 

 

The arms supporting the wires on the new poles have now become important bird spaces, and the wires themselves are being more heavily used. The kestrels were quite noticeable this spring as they carried on their loud courtship activities. Near our house, their frequent loud meetups were hard to miss - and were conducted almost entirely on the wires.   

 

I usually saw the female land on the wire first. I knew it was a female because her back and wings were both brown, while the males have blue wings and brown backs. 

 

She might preen for a few minutes, or stretch out her tail. Then she’d start making loud, sharp “kee-kee-kee” cries, which is what usually caught my attention. But her calling out was not meant for me. Soon she would look around and lift her tail to beckon her mate.

 

                          

 

He would fly over, possibly sit nearby for a few minutes, and then suddenly press tightly against her as one or both of them yelled noisily. Soon afterwards, they would fly off.

 

                          

 

By contrast, they are quite secretive about their nests. Fortunately for me, one of my neighbors has a suitable tree hole for kestrel nesting right in front of his house, which is why there are usually some kestrels in our area. 

 

A couple of years ago I was able to hide under my neighbor’s deck and observe the babies peeking out, waiting impatiently for the parents to come feed them.  

                          

 

Then later I watched the nestlings emerge from hiding and first test their wings. It took them a while to learn how to catch their own lizards, so for quite a long time they would stand on the utility pole equipment and screech for the parents to bring them something to eat.  

 

                          

 

Overall, I don’t think the kestrels are as happy with the design of the composite poles. Still, they do seem to have figured out how to use the new equipment, and the wires themselves, to support their own purposes. So that’s good.