“It was like the Battle of Britain up there,” he said. “We counted up to 50 pelicans in one formation, and boy did they make a mess of our tent and cars, and on a couple occasions hit myself, my wife and my youngest son.”At the Torrey Pines Gliderport, manager Jeremy Bishop is more focused on the birds’ majesty, calling this year’s winged masses “an amazing influx.”“The consensus out here is it’s got to be the food supply,” he said. “It seems like most of them are heading south, especially in the morning. We’re all guessing some type of abundant food supply.”There doesn’t seem to be more fish in San Diego than in years past, said John Hyde, a biologist at the Southwest Fisheries Science Center in La Jolla. But Laird Henkle, an environmental scientist for the California Department of Fish and Game, said it may be that sardines and anchovies are in short supply in Mexican waters.“The bottom line is the birds go where the food is” — even if that disrupts breeding patterns, Henkle said.Several scientists said the pelicans’ breeding season starts as early as November and runs until June. Many breed in Mexico, then fly north when their young are ready, and one way to guess at whether breeding has a role in any influx is to observe the bird’s bellies and crowns.Young pelicans have brown heads and white bellies, while adults have white heads. A large number of young birds could mean an early successful breeding season, while a large number of adults could mean the opposite.
Snowy plovers have natural predators such as falcons, raccoons, coyotes, and owls. There are also predators that humans have introduced or whose populations they have helped to increase, including crows and ravens, red fox, and domestic dogs. Humans can be thought of as predators too, because people drive vehicles, ride bikes, fly kites and bring their dogs to beaches where the western snowy plover lives and breeds. All of these activities can frighten or harm plovers during their breeding season.
Energy is very important to this small bird. Every time humans, dogs, or other predators cause the birds to take flight or run away, they lose precious energy that is needed to maintain their nests. Often, when a Plover parent is disturbed, it will abandon its nest, which increases the chance of a predator finding the eggs, sand blowing over and covering the nest, or the eggs getting cold. This can decrease the number of chicks that hatch in a�particular year. Did you know that a kite flying overhead looks like a predator to a plover? A kite over a nesting area can�keep an adult off the nest for long periods of time.�
What’s great about this is that, unlike the bird identification books or sites, this tells you how these animals live, how they interact in an ecosystem.
At a Glance Life History (Natural History) of Snowy Plover
- The Snowy Plover frequently raises two broods a year, and sometimes three in places where the breeding season is long. The female deserts her mate and brood about the time the chicks hatch and initiates a new breeding attempt with a different male.
- Young Snowy Plovers leave their nest within three hours of hatching. They flatten themselves on the ground when a parent signals the approach of people or potential predators. They walk, run, and swim well and forage unassisted by parents, but require periodic brooding for many days after hatching.