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Dakin, Robin, Jennifer Parkin and Tom Ryan. 1997. Tern of the Season: Forster's Terns in South San Francisco Bay. Tideline. Vol 17 No. 3 1-3.
by Robin Dakin,
Jennifer Parkin and Approaching a Forster’s tern (Sterna forsteri) breeding colony, you can hear the calls of the adults and see them regularly flying to and from the island, delivering fish to their young and exchanging parental duties with their mates. As you get closer to the colony, a few curious adults may fly over you, making their distinctive buzzing call, investigating you to determine whether you pose a threat to their eggs and young. Scanning the island colony with your binoculars, you can see the black caps and bright orange beaks of sitting adults peeking above the vegetation. If you view the greater surroundings, you may spot distant terns hovering, and then diving into ponds and sloughs as they forage to feed their growing chicks. And if you stay longer to watch, you will begin to understand the day-to-day lives of these fish-eating specialists. As the adult terns stand to trade incubation duties or to tend the nest, you may be able to see two or three small olive-brown eggs, splotched with black markings, but their camouflage is nearly perfect against the dun- colored island dirt. Newly hatched chicks are identically colored, covered with a sandy-brown down with black markings. As you watch, an adult may fly in with a newly-caught, still struggling fish. It may appear too large for the chick to eat, but eventually the chick swallows the fish and sits down to digest. Other larger, |
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Tern of the Season: Forster's Terns in Last updated:
May 27, 2008
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