We’ve been treated over the last year with some splendid photos of peregrine falcons taken by reader Bruce Lyon by the California coast (see here and here for previous installments). This is the latest batch, the result of what Bruce called “one of his top natural history encounters, ever.” His notes are indented:
Here is another installment of photos of the nesting pair of peregrine falcons (Falco peregrinus) I have been following for the past couple of years on the California coast between Santa Cruz and San Francisco. This batch of photos is from a single evening in May 2015 when the peregrine family had some squabbles over food. It was one of the most enjoyable and memorable natural history encounters I have ever had. The lighting was nice too!
When I arrived at the nest cliffs, both parents were out hunting and the three chicks were perched at various spots along the cliff top. Eventually the adult female came cruising up the coast from the south with a freshly killed band-tailed pigeon in her talons. She flew around a corner out of sight towards one of her favorite plucking stations. By the time I got into position to be able see what was going on at the plucking site, there was already a fledgling getting to work on the pigeon and the adult had flown to the nearby cliffs to perch. Although the parents were shy about letting me approach when they had prey, the fledgling was completely unconcerned. I was able to sit on the top of the cliff not too far way and watch it eat. It spent the next hour eating the pigeon.
Below: The fledgling with its pigeon carcass. The peregrines eat four species of dove/pigeons but the yellow feet of the band-tailed pigeon are diagnostic—the other species all have pink feet.
The adult female was perched nearby and several times she approached the plucking station and seemed interested in landing—if I had to guess, she did not want the prey item to be entirely consumed by this one piggy little chick. However, the fledgling had other ideas—each time the adult approach to land the fledgling mantled the prey aggressively and the adult circled away. (Mantling is where a bird of prey hunches over and drops its wings around the prey, apparently to hide the prey from another predator that might steal it. It also seems like an aggressive signal of ownership.)
Below: mom does a flyby but does not land.
Eventually a second chick landed at the plucking station, grabbed the prey from its sibling and then turned and mantled the prey. After about a minute the original chick left—its crop was bulging and I expect it was pretty satiated.
Below: The newcomer mantles the prey. Note the bulging throat area (crop) on the chick in behind; it is stuffed with pigeon.
The second chick was left in peace for only a few minutes because the mom finally could not stand it any longer and came in and landed on the plucking station. She really wanted that pigeon and this lead to an amusing parent-offspring tug-of-war. For over ten minutes she tried every trick in the book to snatch the pigeon away from the chick; the chick countered by mantling the prey, keeping its body between the prey item and its mom, and whining nonstop. The adult tried to get around the chick’s blockade by walking around the other side, but the chick invariably pirouetted to block her. The adult even poked her head several times under the chick and tried to pry the carcass free with a powerful yank, but all without success.
Below: This time mom means business.
Below: the next four images show the parent-offspring tug-of-war.
The battle lasted for a dozen minutes but the chick was triumphant in the end and flew off with the carcass to another favored dining spot. Another chick soon joined it—since it did not have a full crop I assume that this was the third chick. As the photos below show, these two chicks seemed to share the food—there was no prey mantling and no signs of aggression.