Peregrine Falcon raiding the tern colony

While I was at Great Gull Island, New York, July 3-5, two different Peregrine Falcons were passing through the tern colony. I never saw one catch a tern, but they were definitely hunting as they rocketed over the island low and fast with about a hundred screaming terns right behind, then turned and made another pass. After a few passes over different parts of the island the falcon would leave and fly out across the water, returning a few hours later to try again.

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One tern right on its back, the Peregrine Falcon flinches.
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This is how the Peregrine Falcon was escorted by a large group of terns as it coursed back and forth over the island, but the photo does not give a sense of the speed they were all traveling.
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Two Common Terns keeping pace with the Peregrine Falcon, and staying on its back. The falcon was traveling very fast, but maintaining that speed easily. The terns were keeping up but sprinting.

I managed a few photos of one of these hunting excursions. In looking at my photos I confirmed something I thought I had noticed – there were no Roseate Terns among the group harassing the falcon, only Common Terns. This is true to their nature, Roseates have a reputation for being less aggressive than the Common Terns, but I had never considered how that might extend to predators. When a Great Black-backed Gull flies by the island the terns sound the alarm and escort it away from the colony, but I had never paused to think that it might be only Common Terns that do this.

And if that’s true, it brings up the question of whether a Roseate Tern nesting colony can be successful in this region without Common Terns for protection.

2 thoughts on “Peregrine Falcon raiding the tern colony”

  1. Pingback: Blog Birding #234 « ABA Blog

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