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Dive Dry with Dr. Bill

#626: Birds That Swim, Fish That Fly

The absence of giant kelp in the dive park the last 6 months has altered the behavior of a number of species. One such critter is the garibaldi's damsel cousin, the blacksmith. Actually about half of them are damsels (or dames) and the rest must be dudes... at least if they want to propagate the species! Blacksmith no longer have the shelter of the giant kelp and its canopy to hide from airborne predators like cormorants and pelicans.

In response, they have been forming pretty massive schools that tend to congregate along the reefs and wrecks. The lack of kelp canopy has made it much easier for the cormorants to see this prey species and dive directly down to it rather than having to detour around the kelp. Of course the large schools of blacksmith, often tightly bunched, make selecting an individual fish to munch more difficult for the cormorant.

On a dive in early February, I floated midwater at a depth of about 30-35 ft filming cormorants as they dove to capture their lunch. No Big Mac for these birds... they wanted a fish sandwich. Healthy? Maybe not. Based on the blacksmith I've filmed that survived attacks by kelp bass, morays and the like; their flesh is red meat too! The cormorants were joined by three yellowtail that have been patrolling the dive park for the past few months.

Those of you who have worked for or taken one of the SCICo Discovery Tours have probably heard the line "We have fish that fly and birds that swim." Cormorants do their locomotion (with apologies to Little Eva for my more "mature" readers) with their feet. The wings are held close to the body to streamline the bird and the webbed feet drive the bird forward in its search for nourishment.

They are incredibly efficient and hard to follow with my video camera as they dart past me. Years ago I had one swim up past me at 65 ft. and I waited for it to take a gulp of air and drop back down, filming it as it descended and then poked its head under rocks looking for sheltering fish or invertebrates including shrimp and crab. It stayed down for about 90 seconds, but that was actually a shallow dive. Cormorants have been found in fish traps and nets at depths of 150+ ft., while other species are known to dive to as much as 200 ft. and there are a few reports of them reaching depths of over 300 ft.

Some species of cormorants have been used by fishermen in Japan to catch fish in rivers. A snare is placed over their throat to prevent them from swallowing the larger fish they capture. When the bird returns from depth, the fisherman retrieves the fish and sends the cormorant back down. This practice, known as ukai, has been employed continuously for over 1,300 years. Historically, cormorant fishing was also used in China, Greece and Peru where it may have started in the 5th century AD.

Even though our local cormorants are largely marine and spend time under the ocean, I am certainly no bird expert! Back when I was working on Lindblad Expedition/National Geographic eco-cruise ships in the Sea of Cortez, Belize and Honduras; I told our passengers to throw away their binoculars since they were worthless underwater. I quickly found out that some avid birders do not have well-developed senses of humor! Given that, I cannot readily tell one species of cormorant from another underwater (even if I had binocs), so I'm offering the following information about a common local species, the Brandt's cormorant (Phalacrocorax penicillatus).

This species is black in color and has a dark bill with a hook at the tip. They reach almost three feet in length and may have wingspans of up to four feet. They are found only on the West Coast of North America from Alaska to Mexico. Occasionally one sees large "rafts" of these birds floating near shore and diving for food. I wondered if these large groups might be congregating to migrate, but my research suggests that they do not and are permanent residents of a region. They may, however, move from one location to another within their normal geographic range to follow food sources.

The Brandt's cormorant's primary breeding range is from California to Alaska. Many of these birds nest in colonies on the ground out on San Miguel Island near Pt. Conception. During breeding season they exhibit beautiful turquoise eyes (if you get close enough to see them!), a bright blue pouch and white plumes of feathers on either side of the head. The gallant male establishes the nest site, gathers nesting material such as terrestrial weeds, grasses, twigs and seaweed which is all glued together with poop (how delightful). His lady friend lays three to six blue eggs in it and both parents care for the chicks.

This recent dive reminded me of an earlier one when I was attacked by a crazy cormorant! It would swim above me, sticking its head in the water to locate me and then plunge down and attack my camera housing. I wasn't sure if it was demanding a fee from me for filming its life story or just wacked out on tainted fish. Apparently it also attacked two other groups of divers with cameras the same day. Strange... but true! No fish story this.

© 2015 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. You can also watch these episodes in iPod format on YouTube through my channel there (drbillbushing). 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 reading warning sign at dive park and crazy cormorant attacking my camera;
cormorant swimming underwater after blacksmith

This document maintained by Dr. Bill Bushing.
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