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Dive Dry with Dr. Bill

#451: Hey... Bird Brain!

Conducting the monitoring for the Sea Trek operation this summer has resulted in my spending more time navigating a boat than I have since my days at Toyon when I owned the "banana boat" and captained the John Adams and K.V. during my biology classes and on dives with my students. Like divers, anglers and boaters in general, I love being out on the water. Maybe it is the ions in the air that result from close proximity with the sea. Maybe it is just the sense of freedom one gets in a vessel that doesn't have to follow the direction of a freeway (assuming traffic is moving at all), and can alter course at a moment's notice to explore something that pops up on the horizon... like a pod of dolphins or a whale. Thanks to Tim Mitchell's skiff and the Coastal Commission, I've enjoyed that freedom quite a bit. Since the boat is tied up to one of our dinghy docks, it also means I'm spending a fair bit of time out on the Pleasure Pier.

One thing I've noticed this year that escaped my attention during previous summers, was an example of unusual "learning" on the part of some of our local marine birds. As I motored out in the skiff, I observed brown pelicans and cormorants waiting at the base of the Pleasure Pier's pilings. They were keeping watchful eyes on the anglers fishing above from the end of the pier. When one hooked a small kelp bass, senorita or other undersized fine finned friend, the fine feathered friend would rush out to steal it from the line... fish, hook, line and sinker. Or they'd wait until the angler had extricated the hook and try to catch it when it was thrown back into the water. Based on what I saw, I wouldn't sign any of them up as outfielders for the Chicago Cubs!

Now looking at this behavior from one perspective, it was apparent these birds had learned something... they could obtain a much easier meal by stealing from humans. Maybe the seagulls who grab our french fries taught them this trick... or the dastardly thief who stole my dive computers (may he find both his arms broken so others won't become victims). Like some humans today, these birds had found a way to avoid hard work and still get fed. Why spend your days as a cormorant diving under water and swimming hard to catch an elusive fish or two when you can get something that falls like manna from "heaven" above? Why should a poor pelican suffer a head injury from diving into the water in pursuit of a sardine or anchovy when it can grab a juicy calico while sitting practically still. At this rate, these birds may become obese like the youth of today (and yours truly) who spend too much time in front of a computer! At least I'm creating educational videos for you, rather than playing games all day.

Of course "easy pickings" are an advantage in many cases. The senorita, sheephead and kelp bass that pick the copepod parasites off our giant sea bass are examples of species which have found ways to not only gain an easy meal, but also help others by ridding them of parasites. Of course there are dangers associated with this too... few "parasite pickers" will feed on a sea bass' head where the copepods tend to be thickest since the mouth may suck them inside as an appetizer. Another good example of not exerting too much energy to grab a morsel are the filter feeders which attacj to top the bottom and let plankton and other organic nutrients come to them with the currents.

But is this apparently learned behavior really "smart?" Are the pelicans and cormorants proving instead that they are real "bird brains" in doing this? From my perspective, yes. The individuals I observed all had monofilament fishing line extending out from their bills, suggesting they had swallowed a hook. In fact, one of the pelicans apparently got "hooked" five times that day according to one of the anglers, although it apparently shook most of them. I witnessed one incident where the pelican grabbed the calico in its bill while the fish was still hooked. It fought the angler hard for about 15 seconds before releasing the fish. Perhaps from the birds' perspectives, they feel "no pain, no gain." They'll have to speak for themselves.

A few weeks ago I was filming marine birds for an episode of my "Munching and Mating in the Macrocystis" cable TV show. I witnessed and filmed one brown pelican that had been hooked in the throat. The truly sad thing was that this bird couldn't fly. The monofilament line had entangled in its wings, torn off a few feathers out and caused it to stumble when it tried escaping from the beach into the water to swim away (its only option). I couldn't get to it in time to try to extricate the hook and remove the line, and looked for it over the course of a week hoping to do so. I never saw it again so hopefully it got loose.

Although one angler was obviously angry at the birds' presence, most were concerned about hurting them. It certainly wasn't the fault of the fishers that these birds decided to take the easy way out by freeloading. Although I've been an educator most of my life, I have no secrets I could engage to undo the "learning" these feather brains have acquired. Just how many sharp hooks will it take before they weigh the cost vs the benefit and decide to return to the "old fashioned way" of procuring their dinner? Will they try to "educate" others of their species to take advantage of this nearly free lunch, or will they keep their little secret all to themselves? How will they fare under natural selection? Increased food supply with less enmergy expended is a plus, but a "well placed" hook could render them non-reproductive (as in dead). I guess I'll just have to keep observing to see what happens over time.

© 2011 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 29, 10:00 AM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. Please help me climb out of self-imposed poverty... buy my DVD's (see this link). Yes, take Dr. Bill home with you... we'll both be glad you did!

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Cormorant looking up to heaven for its daily manna and capturing a calico for its effort; brown pelican "wrestling"
with angler for a bass, and the one that tripped and stumbled on the beach due to fishing line entanglement.

This document maintained by Dr. Bill Bushing.
Material and images © 2011 Star Thrower Educational Multimedia