I thought I had missed them. As I was parking, I saw a big flock of Brown Pelicans in the air, over my head, flying away from the North Basin southwesterly. My punishment for getting to the park late, I thought. But then on the water I saw more of them. Many more. Three years ago I counted more than one hundred Brown Pelicans on the North Basin, and I thought that had to be an all time record. Today there were twice as many or more, not including the hundreds who had left as I arrived. In some places the pelicans were as thick as Scaup. Obviously the attraction was food. The tide lay at inches above zero, not a record by any means, but so low that some of the birds at the shallower south end of the cove hit bottom with their feet. None of the pelicans was bomb diving, the way they can and do when the herring are running in deeper water. They were all scooping the water with their giant bills inches below the surface, getting little things. There must have been a lot of little things to keep all those big birds active for well over an hour.
The birds worked elbow to elbow, as it were, but I saw no collisions, and no bird snapped or pecked at another. They must have a code of ethics about that. What really mystifies me about a gathering like this, as I’ve noted on previous occasions, is how they communicate. I don’t believe that all these hundreds of birds happened to roost on the same pier somewhere, and when a leader gave a signal, they all went. These birds almost certainly came from different places. On the water they formed three, sometimes four clusters, and as I mentioned, large numbers of them took off early while others remained. There has to be some way to spread the word between different colonies so that they all show up together in this spot. Unfortunately, as far as I was able to determine from the literature available online, little is known about how and why pelicans move, either long distances in migration, or short distances for foraging. Source. The sole scholarly article that mentions “communication” dates from 1977 and is not available for free online reading; not even the abstract is public. So screw the independent researcher [but see Update below!]. Besides the wide area communication that brings the flocks together at the same time, there’s obviously short range communication both on the water and in the air, as the birds sometimes appear to move chaotically but shortly thereafter move in a more organized pattern, without any .obvious vocalization.
Fortunately, I can lay aside my frustration at the paltry state of human knowledge and allow my brain cells to be washed over with a sense of wonder, admiration, and beauty. These birds, among the more obvious descendants of dinosaurs, have been active on land, water and in the air long before we featherless bipeds strutted our poor stuff upon the earth. Our profit-driven petroleum industry extirpated some populations of pelicans in the Gulf of Mexico, but conservationists managed decades later to re-establish them. Locally at least, if today’s big gathering is fair evidence, the Brown Pelican population is doing OK.
Updated 6/23: Thanks to a reader who led me to the Open Science website sci-hub, I now have the 1977 paper by Prof. Ralph Schreiber that mentions pelican communications. Unless and until someone claiming copyright orders me to cease and desist, I’m making it available to readers here. Prof. Schreiber’s very interesting paper, based on thousands of hours of fieldwork in Florida, observes that these pelicans rarely fight one another, and that they do not communicate with vocalizations, as I would confirm from what I saw here. He identifies a number of typical body movements that the birds use to communicate with each other in the course of nest building, mating, brooding, and preening. Almost all of these interactions occur one on one, or one on two, with the birds on the ground. He has no remarks about the organization of flocks in the air, and does not raise the question whether these birds can communicate information about good feeding sites. Thus we have good knowledge how honeybees share feeding site locations, but no clue how these birds do it.