The Common Tern is Bermuda’s rarest breeding seabird, with just five pairs breeding in 2017. Only three of these succeeded in producing clutches of eggs; the other two were female/female pairs. While Common Terns are not a species of conservation concern worldwide, their decline in Bermuda is worrying conservationists. Miguel Mejías, who has been studying the species for his doctorate, notes that there is genetic evidence to suggest that Common Terns in Bermuda are unique to the island. That is possible
grounds for subspecies status. “Given these facts, it is highly recommended that the status of Bermuda’s Common Terns be elevated to Critically Endangered”, he says.
Mejías is the author of the recently published Common Tern Recovery Plan. He says that the birds are more solitary than Common Terns on the mainland, nesting on small islets or floating, artificial structures in bays and harbours. The birds are facing a variety of threats, including powerful hurricanes, which overlap with the Common Tern breeding season – surface-nesting terns are completely exposed. Their only defense is
to take flight, in an attempt to ride out the storm, whilst remaining close to their breeding sites.
The other main threat is predation from rats, which can easily swim to the islets. Nsets are also trampled by humans, there is predation of chicks by land crabs and Common Tern breeding sites are also threatened by fast growing, invasive plants,
especially the salt-tolerant Australia pine (Casuarina equstifolia; hereafter ‘Casuarina’).
The new action plan intends to improve conditions for the terns by:
1. Continued population monitoring.
2. Sign posting of all nesting islets.
3. Modification of artificial tern nesting structures.
4. Removal of invasive vegetation from nesting islets.
5. Control rats on nesting islets.
6. Amend fisheries regulations to better manage Bermuda’s baitfish stocks.
7. Identify the non-breeding range of Bermuda’s Common Terns.
8. Promote island wide awareness of Common Terns on Bermuda.
Find out more here.
Photo: By Tony Hisgett – Flickr: Common Tern 7, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=18403719