Captain’s Log: What Makes Seabirds Swarm?
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By Capt. David Bacon, Noozhawk Columnist
Feeding opportunities often trigger their aerial acrobatics
The sky over the water can be clear of bird life one minute, and then 60 seconds later a swirling, diving swarm of birds gathers thick enough to make me think Alfred Hitchcock was right about The Birds. Where do they come from so fast? Sometimes we joke that they come right up out of the sea.
The truth is, many seabirds — including gulls, pelicans, shearwaters, cormorants and others — have terrific visual acuity that enables them to spot potential feeding opportunities a great distance away. Match those eyes with fast wings and an “always hungry” attitude, and you have swarms of birds in a heartbeat.
What do the birds see that makes them beat wings so fast and furious? Well, much to the frustration of boat fishers — who quickly reel in their lines, fire up their engines and race to where the birds are — it’s not always a case of predator fish chasing small fish to the surface to feed. That scenario is what boat anglers hope for and indeed often enjoy (resulting in catches of bonito, barracuda and yellowtail), but more often it is something else.
I am blessed to be able to spend a great deal of time on the water, so I frequently get to see birds swarm up and go wild. Some of the triggering activities include: 1) Dolphins working a baitball (anchovies or sardines, most typically) to the surface to feed. Dolphins are the absolute best at herding and eating schools of small fish. 2) Sea lions playing with food on the surface. Sometimes they are just playing, and at other times they are ripping apart sections or pieces of captured fish so they can swallow it. They often do this by savagely thrashing and slapping fish on the surface. 3) Schools of baitfish coming to the surface for their own reasons, such as the availability of food.
In all of these cases — as well as in the case of predator fish driving small fish to the surface — the result is the same: namely, a feeding opportunity for birds that are at the right place at the right time. That is why a bird has to be fast and always watchful — both near and far — for the next feeding opportunity.
Know what really amazes me? It is how a hundred birds can squawk, wheel, swerve, dive, feed and soar — all within an area 20 yards wide without more crashes.
I doff my well-worn hat to the flight skills and aerial acrobatic capabilities of our magnificent seabirds.
— Capt. David Bacon operates WaveWalker Charters and is president of SOFTIN Inc., a nonprofit organization providing seafaring opportunities for those in need. Visit softininc.blogspot.com to learn more about the organization and how you can help.
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