After a long absence for work-related stuff, ecologist/evolutionist Bruce Lyon of UCSC has submitted photos, and says he has a lot more that he’ll send when things settle down. His notes are indented, and you can enlarge the photos by clicking on them.
Brandt’s cormorants (Urile penicillatus) have started a nesting colony right beside the road at the entrance to Natural Bridges State Beach close to my office and there is constant activity and interesting behaviors to watch. A few are laying, many are building nests and flying in with beaks full of seaweed, and some are still looking for a mate and doing silly displays that show off their gorgeous blue throat pouches (which match their blue eyes). I got a new camera and lens and this was an ideal situation to test out the new camera.
Unmated males display their blue throats to attract a mate, and also waggle their wings up and down in a charming (silly-looking) display:
Desperately seeking. . . .
This one’s strutting paid off:
The birds are nicely spaced out:
This is how the birds become nicely spaced out—come too close and a fight will break out:
Look at those blue eyes—Frank Sinatra had nothing on these birds with his eyes, but his voice was nicer than their frog-like croaks [JAC: you can hear the calls here):
Birds were constantly flying into the colony with their beaks full of algae for building their nests.
It also seems that seaweed may be used in courtship—new pairs certainly get excited when one of the pair returns with nesting material:
Lovely! Among the diving birds, cormorants and anhingas are my favorites. I love watching them swim underwater.
Further south, on beaches from Santa Barbara to Malibu, we’ve been finding sick and dying cormorants and pelicans. Especially the pelicans. It’s very sad and for awhile wildlife rescuers were overwhelmed. It’s a red tide that is now, thankfully, largely dissipated. I think the birds now coming up from the south will be spared.
Thanks for the really excellent photos of obviously healthy and beautiful birds.
Those are very interesting. I wonder if the blue is a structural color, rather than a pigment.
Hi Mark
I have assumed it is structural but I don’t know for sure.
I’ve wondered about this, too. A quick search via Google resulted in the following interesting report. Apparently bird skin color can occasionally be both structural and pigmentary, though the cormorant skin looks structural to my uneducated eye. (The cormorant’s eye is a really interesting blue, as well.)
https://journals.biologists.com/jeb/article/206/14/2409/13691/Structural-colouration-of-avian-skin-convergent
From the report:
“Based on what is known about avian phylogeny, there is not a single unambiguous instance of homology of structurally coloured skin between any two avian families (Table 1). The structural colours of the anhingas (Anhingidae) and the cormorants (Phalacrocoracidae) come closest, but it is unlikely that the structurally coloured species within these families are basal.”
And:
“Pre-existing melanin deposition in the skin may enhance the likelihood of subsequent evolution of structural colouration within a lineage by making the optical effects of chance variation in superficial collagen nanostructure immediately more visible. Many bird genera with structurally coloured skin have close relatives with melanin-pigmented facial skin: e.g. cormorants (Phalacrocoracidae), ducks (Anatidae), avocets (Recurvirostridae) and honeyeaters (Meliphagidae). Likewise, plesiomorphic bare skin may also foster the evolution of structurally coloured skin, since variations in integumentary nanostructure would be immediately observable and potentially subject to selection. The featherless eye ring is a good example of a broadly distributed bare skin, and, not surprisingly, the most common position for structural colours is around the eyes (Figs 2, 3).”
Wow, learn somethin’ new everyday about things you thought were plain as can be – the blue feature – wow!
Wonderful documentation in photos! That is a gorgeous blue.
Thank you for the information.
The many ferry docks in Puget Sound are nesting sites for cormorants. They are abundant and they make a massive mess with their nests, nest remnants, and droppings. One interesting thing I’ve noticed is that they strongly prefer to fly close to the water. If a cormorant “wants” to go from the top of one set of posts to another, the bird almost always flies from its perch (about 50 feet above the water) down to about a foot above the water. It then flies just above the water until it approaches the destination posts, at which point it flies almost vertically up to its new perch. The birds almost never fly straight from one set of elevated posts to the other without dipping almost into the water first, even thought it would save a fair amount of distance and (seemingly) expenditure of energy. It’s interesting!
Lovely photos. Enjoyed the captions.
Wow, what a treat. Beautiful photos of beautiful birds, and your camera looks like it made a fine trial run. Thanks for this wonderful set.