How to Spot the Rare Least Tern
A week after my first least tern exploration at Crab Cove, (“Terns to Stay Busy for Summer,” June 23) I received another opportunity to learn more about the birds and their neighbors at Alameda Point with Leora Feeney, co-chair of Friends of Alameda Wildlife Reserve. On a calm and sunny Saturday morning, equipped with binoculars and a spotting scope, we observed the terns and other birds fly and forage over Seaplane Lagoon at Alameda Point.
As we approached the lagoon, my first surprise was seeing the amount of animal diversity in the area. We saw numerous terns and a myriad of other birds, including gulls, ospreys, pelicans and herons.
When looking at least terns, I notice that they are the smallest birds among those in Alameda. According to Feeney, least terns were once called “sea swallows” due to their “least” size. However, Feeney pointed out that birdwatchers also pay close attention to the tern’s beak shape and color, its pointed wings and its deep wingbeat (amount of vertical wing movement) to distinguish a least tern from other birds.
Compared to a Caspian tern, for instance, least terns are smaller, caw less coarsely and feature a yellow beak while Caspian terns’ beaks are red. On the other hand, the tiny Forsters are slightly more difficult to discern, although they too have red beaks and white tails while least terns have grey tails. The least terns’ small size and unique physical attributes give them greater agility compared to its predators, said Feeney.
In addition to the least terns, Alameda Point is also home to many birds that are inherently different from the tern. Larger birds like gulls and ospreys often roam above the lagoon, foraging and aggressively establishing nests nearby. Feeney said that several gulls once contested the ospreys’ nest, which is enclosed in a metallic structure and located across the lagoon from the USS Hornet and ready reserve fleet. Even though the gulls attacked them repeatedly and ferociously, the ospreys ultimately retained control over their territory,” Feeney said.
On the other hand, pelicans seem to experience a relatively tranquil lifestyle. Although slightly smaller than gulls and ospreys, pelicans live together on the periphery of the lagoon. This provides protection from predators and easy access to fisheries. Feeney additionally noted that pelicans are different from most other birds since they breed in the winter and were foraging when we visited.
Likewise, Great Blue Herons are among the largest and most prominent bird at the Point. However, unlike their larger counterparts, herons prefer to live in isolated areas with slightly higher elevations, such as tall trees where they create nests and can defend their habitat against potential predators.
As we neared the end of our exploration, we briefly stopped at a haul-out near the Hornet and a breakwater on Ballena Bay. According to Feeney, the haul-out is a resting place for harbor seals, mammals that regularly visit Alameda’s shores. (See related story on front page news.)
The breakwater on Ballena Bay was originally built to prevent strong winds from damaging the harbor. Birds like Forster’s terns and gulls, however, prefer to use it as a resting place.
“Nature rules and sustains us. It is important for us to feel connected.” Feeney said. “To exclude nature from our lives is to distance ourselves from the most important lessons of our life.”