Wednesday, April 13, 2022

Flightless Cormorant

There are about 40 species of cormorant and the largest and only flightless one among them is the flightless cormorant, also known as the Galapagos cormorant, which is endemic to the Galapagos Islands. It has wings that are about one-third of the size necessary for a bird of its proportions and size to fly and the keel on the breastbone where flight muscles are attached is significantly smaller than on other cormorants. 
This is the first flightless cormorant I recall seeing, at Moreno Point on Isabela Island. Note the very small wings and turquoise eye. 
It feeds on fish, small octopi and other small marine animals and dives to feed near the sea floor, no more than about 218 yards offshore. Males and females look similar, but males are about 35% heavier. Juveniles are glossy black and have dark eyes instead of turquoise colored eyes. 
These three birds (this and the two below) were three among many at Vicente Roca Point on Isabela Island. I thought this one might be a different species, with its white throat, but iNaturalist confirms they are all of the same species and I think they are all juveniles. 

Even in the Galapagos Islands it has a restricted range: they are only found on Fernandina Island and the northern and western coasts of Isabella. Those were areas we visited and we saw lots of them. They are in the area of Equatorial Undercurrent which provides cold nutrient rich water. In 1983 an El Nino event reduced the population by 50%, to about 400 of them. By 1999 the population was back up to about 900 birds. 
This is the only photo I have of a flightless cormorant on Fernandina Island, at Espinoza Point. 
They are found on rocky shores and forage in the coastal waters. Because they are so sedentary and stay along the same coast, often limited by hundreds of yards, there is large genetic differentiation between different colonies and between the two islands. It is one of the world's rarest birds, a description (rare) that seems to apply to many of the endemic species that inhabit the Galapagos. 
These are on a rocky spot outside Elizabeth Bay on Isabela Island 
I did not take as many photos as I could have. After getting a few, I just quit taking photos of them for the most part. If I'd known they were only limited to two islands (and only some areas of the one) and had great genetic differences, even on the same island, I would have taken more when I had the opportunity. 

1 comment:

  1. They are like a child's drawing--everything out of proportion. Strange birds.