Tern populations in the Gulf of Maine have declined from approximately 1.5 million pairs in the mid-1800s, to about 82,000 pairs in 2002. This drastic decrease has been mostly attributable to the activities of man. Terns were slaughtered in the late 1800s for their feathers, which were used to adorn ladies hats of the period. When this practice was outlawed, and the Migratory Birds Treaty Act brought into force in 1918, the tern populations began to recover. However, modern fishing technology discarding fish offal and huge, open landfills benefited large species of scavenging gulls. These large gulls drove terns from nesting islands. By the early 1940s, only one nesting island remained for terns in the Grand Manan Archipelago — Machias Seal Island.
Beginning about 1985, a small number of Common Terns broke off from the colony at Machias Seal Island and attempted to nest at Sheep Island, one of a group of three islands, the largest being Kent Island where Bowdoin College has operated a field station since the 1930s. For the most part, the terns were unsuccessful due to the depredations of large gulls. Gulls steal eggs and attack chicks and adults. They will also steal fish from terns when they return to feed their chicks.
There were likely never more than 20 pairs in any given year, and a survey in 2001 by researchers from the GMWSRS (Sarah Wong and Rob Ronconi) revealed only eight pairs. Under active protection in 2002, the Common Tern colony at Sheep Island increased 125% over the previous year, to 18 nesting pairs. Continued and intensified efforts in 2003 led to a further increase to 50 nesting pairs and 60 nesting pairs in 2004. There is every indication that with continued protection and encouragement, the nascent colony will continue to grow each year.
The current success is attributable to a number of factors including a solar powered sound system that plays tern calls continuously. The majority of nests in 2003 and 2004 were located near this speaker system. Similar projects in the Gulf of Maine have seen dramatic increases in the number of nesting terns over a short period of time when these sound systems are used and if the terns can compete with the large gulls. It is almost impossible to eliminate large gulls from Sheep Island but it is hoped that the terns can do this themselves when their numbers grow. Once a large tern colony is firmly established on the island, other seabirds may be attracted to nest, such as puffins and razorbills.
A tern warden is present from usually mid-May until mid-August, observing the terns and scaring off large gulls whenever possible. The field station currently consists of a storage shed, a small travel trailer and an outhouse. We were able to purchase 100 common tern decoys in 2004. We will be erecting a portable observation blind in 2005. Logistical support has been provided by Russell Ingalls (son of one of the owners of Sheep Island) who ferries people and gear to and from the island. We hope to add solar power in the future. All work toward this project is permitted under the Canadian Wildlife Service.
2002, 2003 - Brian Dalzell
Dalzell, a local naturalist, has been the driving force behind the establishment
of a bird observatory on Grand Manan. He began banding migrating land birds
in 1995 from the Grand Manan Archipelago and established the Grand Manan
Bird Observatory to accomplish this goal. The GMWSRS fully agreed with
the principals of the Grand Manan Bird Observatory (GMBO) and had been
acting in an administrative function until it was decided to dissolve the
GMBO and create the Fundy Bird Observatory (FBO) as a project of the GMWSRS.
Although banding migrating land birds still continues it has become primarily
an educational tool. The restoration of a nesting colony of common terns
has become the focus of the FBO.
tern. The adults have a black cap, orange-red beak with black tip,
orange-red feet, grey wings. "Typical" tern similar in size to the
If you can help financially, make a donation using the form provided.
For more information about FBO, contact Brian Dalzell at:
62 Bancroft Point Road, Grand Manan, NB, Canada, E5G 3C9
Checklist of Grand Manan Birds. 2004. written by Brian Dalzell. $5.00 plus shipping
Fabric FBO Crest. $10.00
GMWSRS Scientific Publications
Page revised May 25, 2005
GMWSRS 24 Route 776, Grand Manan, NB, E5G 1A1 email@example.com