More than a dozen volunteers from San Diego Audubon and other local groups headed out to a small island in Mission Bay known as FAA Island, yesterday. The volunteers were there to pull weeds and other plants in order to prepare the area for possible use by the California least tern for nesting next year. The small, man-made island with an FAA transmitter is off-limits to the general public and is often used by roosting gulls and other birds. Because of the disturbed soil, non-native plants often grow and obliterate nest sites that would otherwise be used by birds like the least tern.
San Diego Audubon also recruited volunteers to the island last year, clearing brush and making the area friendlier for ground nesting birds such as the least tern. In that year, the terns made 156 nests among 80 pairs of birds. Seven of those nests produced fledged young. The terns have been using the island every year since 1989 to raise young. The island is one of seven official nesting sites managed around Mission Bay. Invasive plants like the Russian thistle and tall growing plants like the telegraph weed grow back each year and needed to be managed.
Plants that stay bright green are also a problem and often need to be reduced and controlled. According to Rebecca Schwartz, Conservation Program Manager for San Diego Audubon, least tern eggs are designed to blend into a shoreline environment that is mostly gray or brown. Having a bright green carpet of plants makes those eggs more visible to predators. Other plans are to make the island less desirable and give less advantage to the least tern’s chief predators.
Yesterday’s volunteers worked for several hours and piled massive amounts of plants onto tarps and in trash bags to be carried off the island. At least two more trips to the island to maintain and prepare the site for nesting and study are planned before nesting season begins on April 15th. Volunteers are needed, but space is limited, so they must RSVP by contacting Rebecca Schwartz at Schwartz@sandiegoaudubon.org or by calling 858-273-7800 ext. 101.