First genetic tests done on Bermuda longtails

Cherished as the first harbinger of spring, Bermuda’s longtail has always held a special place in the hearts of islanders. 

And while we know that the white-tailed tropicbirds, as they are also known, make their return to the island in the sunnier months, there are many unanswered questions about the enigmatic bird. 

One important question currently being asked in the conservation world is whether our longtail is unique to the island or whether, when they migrate, they interbreed with other sub-species. 

For the first time genetic tests are being done on the birds to help determine this, while providing a wealth of other information to scientists studying them.

The Bermuda Government is doing collaborative research with James Reynolds, a British professor at the University if Birmingham in the UK. 

If it is determined that they are indeed unique, it could be grounds to offer the Bermuda longtail even more protection than they are currently granted.

Senior Conservation Officer for the Department of Conservation Services, Jeremy Madeiros, told the Bermuda Sun during a longtail blood sampling trip to Nonsuch Island: “Ours is the most northerly breeding population of that seabird so it is possible that they have been isolated long enough to become a distinct sub-species. 

“If ours are different that gives us a lot more impetus to protect them as they are more unique.

“But the Bahamian birds seem to come up around our area, geolocator studies have proven that, so it is quite possible that you might have Bermudian birds interbreeding.”

White-tailed tropicbirds exist in the Indian Ocean, in the Mozambique Channel between Madagascar and east Africa, on Ascension Island and in the Caribbean. They are also found in the western
Pacific.

Curator at the Bermuda Aquarium and Zoo Patrick Talbot is working with Mr Madeiros, the Bermuda Zoological Society’s manager of animal care and quarantine, Roma Hayward and BZS intern Calum Morrison, to carry out the blood sampling on Nonsuch.

Internationally important

Mr Talbot, of BZS, told us: “Bermuda’s population has at least 3,000 pairs — but the population for the entire Caribbean basin, from The Bahamas to Trinidad, was estimated, only at about 2,000 pairs. 

“Ours is internationally important. If they are interbreeding, then anything that happens to our population is going to affect the whole population so we need to get as much information as we can.”

If it turns out they are related to other colonies, Bermuda could provide the missing link in the story of the historic migration of the longtails. This is the area of the collaboration that professor James Reynolds, is particularly interested in. He is studying a colony of longtails on the Ascension Islands in the Southern Atlantic and is working with Bermuda to try to “piece together the missing pieces in the genetic jigsaw”.

He said: “They are definitely one of the most enigmatic species that we work with on Ascension and the Bermudan sub-species is biologically important as it is the most northerly breeding of all populations in the world. Our aim is to examine how closely related genetically it is to Ascension birds and to those in the Indian Ocean so we can start to understand how the species spread so much through tropical waters. We are in the process of trying to obtain more blood samples from Caribbean populations but your (Bermuda’s) birds could be the largest piece of the puzzle that requires our research focus… 

“If Bermudan birds are closely related it provides us with finer details of the evolutionary path and mechanisms that resulted in the present day distribution of the species.

“It would be very exciting because it would suggest a relatively ‘recent’ movement of birds between
Bermuda in the north
Atlantic and Ascension in the south Atlantic.

“It may be that analysis of the samples from Bermuda really does reveal that your island is the ‘missing link’ in the story. 

“I do hope so.”