Restoring the Common Tern in the Islands

The peep- peep –peep call of the Common Tern is a ubiquitous part of the sound of the 1000 Islands.

Once a very plentiful part of our waterbird population in the St Lawrence River Valley, the Common Tern has dropped to significantly low levels, due to a loss of nesting habitat and the expansion of Ring-billed Gulls. As a result of this dramatic decline in numbers, the Common Tern was listed as a threatened species in New York State. Save The River (STR) and Thousand Islands Land Trust (TILT) have formed a cooperative effort, in conjunction with Dr. Lee Harper, of Riveredge Associates, to monitor Common Tern nesting areas on the River. Residents from the Chippewa Bay area have also been very involved in helping to monitor and restore Tern habitat.

Dr Harper estimates “the number of Common Terns breeding on Lake Ontario and the St. Lawrence River has declined dramatically over the last sixty years from as many as 20,000 breeding pairs to only a few thousand nesting pairs.”

STR first became involved in 1997, with TILT volunteering the use of their Eagle Wing Shoals and Tidd Island soon thereafter. TILT maintains some of the last natural nesting shoals, still utilized by Common Terns, on the Upper St. Lawrence River.

Working with then STR Executive Director Stephanie Weiss, Dr. Harper laid out an ambitious site monitoring plan ranging from Clayton to Chippewa Bay of historical tern nesting sites, as well as the St. Lawrence Seaway’s navigation cells (navcells). The cooperation of the Seaway, in making these navcells more tern friendly, has been very important in the restoration of the Common Terns in this area. Stephanie could be seen zipping around the River from May through July counting nests, hoping for chicks to be hatched, and then helping Lee and his crew band the young chicks before they fledged and flew from the nests.

By the year 2001, the 1000 Islands portion of the monitoring project had become too large for one person to handle, and Stephanie recruited our daughter Sara (who needed a six week senior thesis project) to take on the responsibility of monitoring the sites from Clayton down to Chippewa Bay – including several Canadian sites.

Starting in late April, the sites were inspected and necessary repairs were made to the sites. As the terns were forced off many of their historic nesting sites, due to construction on small islands and development on other bird friendly habitat, terns adapted to using many of the Seaway’s navigation markers as places to lay their eggs. The navigation markers had flat concrete decks, which were not nest friendly for the tern eggs. Heavy spring winds and thunderstorms would blow the eggs around the surface, breaking them open and further reducing the nesting success of this species.

In order to improve nesting conditions for the birds, pea gravel was brought into the nesting sites to create a more suitable nesting substrate that terns could create nests on. This allowed eggs to stay in place resting on the gravel, which also doubled to keep the eggs and chicks up off the ground and slightly insulated from rains and spraying water. One of our challenges was to haul 5 gallon buckets of pea gravel, donated by local contractors out to the navcells and several flat topped granite islands to try to make the sites more hospitable. While we made a dent in the problem, it was not until Dr. Harper, after receiving approval from the Seaway, delivered tons of gravel to the navcells that the sites became truly productive.

Monitoring these many sites in early spring is not easy work and can be dangerous if the weather rapidly deteriorates. One of the first sites Sara and I visited on our own in 2001 was a small –shoal sized- granite island with steep sides. Sara stepped-off the bow of our 16’whaler type Mariner, and promptly disappeared from view as she slipped between the rock and the bow of the boat into the frigid water. After quickly retrieving her and wrapping her in an old boat cover, we determined she was not injured. To my amazement (and fatherly pride) she insisted on completing our two-hour monitoring voyage – still soaking wet.

All of the data collected by STR and TILT’s volunteers is gathered on standardized reporting format and reported at the end of the season to Dr Harper. This critically important information helps Dr. Harper plan for habitat restoration efforts. Most of the navcells have now been encircled by plastic netting, which helps to keep young chicks from jumping off the high cells into the River before they can fly. A necessary tool at chick banding time is a small fish net to retrieve “jumpers” who jump into the water. The Eagle Wings shoals located just off Clayton, has been covered with a polypropylene line grid, installed each spring and broken down late summer by TILT and STR volunteers. Holes are drilled into the granite and steel bars are stuck into the holes to anchor the grid. It is an intense and fun day long effort. TILT transports the crew out to the islands in their fantastic work boat, and lunch is provided for all volunteers. And more volunteers are always welcome!

Predation on the nesting sites is a naturally occurring challenge to the restoration of the Common Tern population. Weather can also wreak havoc on the nests. We have seen eggs rolled off shoals and smashed as a result of spring and early summer thunderstorms.

Herring gulls have been a significant historical predator of the Common Tern, sharing nesting sites on the shoals and small islands. With the use of night vision cameras provided by Dr Harper, photos of owls and mink stalking the eggs and chicks have been recorded. Geese and crows are also known to eat the eggs, and osprey can move in and disperse an entire nesting tern colony from a navcell site. As the osprey recover in the 1000 Islands region, competition for nesting sites for the tern is very active.

In spite of all the challenges thrown up by Mother Nature and population encroachment, the Common Tern is making an amazing comeback in the St Lawrence River region. This is due in a large part to the efforts of our STR and TILT volunteers, coordinated by TILT and STR Staff, and guided by Dr Lee Harper. Many of our volunteers have been heading out on the River in inclement weather for years, tolerating little pecks on the head by anxious Tern parents as they tally the nests and chicks on a weekly basis. These little Common Terns that are hatched here range all over the continent. Dr Harper just reported that a chick he banded on the St Lawrence in 2008 was spotted nesting as an adult at a colony in Wisconsin in 2013 and 2014. Terns born on the St. Lawrence River also nest on Lake Ontario, Oneida Lake, and Lake Champlain.

Volunteers to help monitor the sites and work on the grids are always needed. While it can be cold and windy work, the reward of seeing a new group of chicks hatched and fledged is extremely rewarding. Save The River, the Upper St. Lawrence Riverkeeper, has as its mission protecting the St. Lawrence River through Advocacy, Education, and Research. The Thousand Islands Land Trust works to conserve the natural beauty, diverse wildlife habitats, water quality and the outdoor recreational opportunities of the Thousand Islands region. Call STR or TILT if you are interested in volunteering to help restore the Common Tern on the St. Lawrence.

By John Peach

John Peach has been working with STR, TILT, Dr. Lee Harper and many other volunteers since 2001 on the tern restoration project. He is quick to say, “It takes a committed team of these organizations and their volunteers to make the project a success.”  But certainly his leadership and enthusiasm over the years has helped in building its momentum. 

John and his wife, Pat, live on Huckleberry Island near Ivy Lea from May through October. The rest of the year they reside in Princeton, NJ, although John continues to make frequent return visits to the Islands throughout the winter. John retired several years ago from his career in international business. His family has owned a place in the Thousand Islands for over 50 years. John is a past president of Save The River, and is still active on the Save The River board.

Click here to see John’s other articles for TI Life.