Wednesday, June 13, 2018

Flying dolphins!

We had a blast watching dolphins last Sunday!

The pelagic trip offshore 30 miles from San Diego on June 10 was primarily for bird watching. However, we came across numerous pods of dolphins chasing schools of fish to the surface. The Common Dolphins--both the long-beaked and short-beaked varieties--herded the fish together in a final splashing assault.

So many fish at the surface attracted Elegant Terns and Sooty and Pink-footed Shearwaters. These birds were diving into the water from flight. While the terns flew high into the air again for impressive high-dives, the shearwaters would often remain in the water. They'd stick their head under to look for fish, then run a few feet on the water with wings open and plunge into the water again.

Sooty Shearwater puts on the brakes to avoid flying into leaping Common Dolphin
Sooty Shearwater puts on the brakes to avoid flying into leaping Common Dolphin
Every once in a while a dolphin would decide to jump out of the water. Photographing such a random jump is pretty impossible. However, occasionally one dolphin would jump several times in a row. Thus I was able to photograph this dolphin's near mid-air-collision. I keep imagining I can see a goofy grin on the dolphin's face and hear the angry cussing of the shearwater.

Common Dolphin rockets to space
"We have liftoff." SpaceX has nothing on this little rocketman.
Common Dolphin riding the bow wave
Common Dolphin riding the bow wave.
As usual, several dolphins peeled off from the feeding group to come and play in the bow wake of our boat. It must be nice to so easily find and capture your food that you can take a play break right in the middle of dinner!

You don't realize how poorly these close-up animals photograph, though. The water distorts their appearance. When they break the surface for a quick breath, the splash nearly completely hides them. These close animals are best shown in video, where our slow eyes can combine all the frames of distorted outlines and splashes into an exciting spectacle.

Friday, June 1, 2018

Cackling Goose

The Cackling Goose is rather rare in the San Diego region. There are many forms, but the expected form is the Aleutian Cackling Goose (Branta hutchensii leucopareia). A few are sometimes mixed in with flocks of the much larger Canada Goose, from which these smaller birds were split as a separate species in 2004. The Ramona Grassland Preserve or, rather, the nearby cattle pastures are a good place to look.

The Aleutian Cackling Goose below was found grazing with coots in a small park on the edge of the San Diego Bay, in Chula Vista, on February 18, 2018.

Aleutian Cackling Goose
Aleutian Cackling Goose
Another form that may be found in winter is the Ridgway's Cackling Goose. It has a dark purplish-brown breast.

The Ridgway's Cackling Goose (B.h. minima) is 25 inches long, bill to tail, the size of a tame Mallard. The Aleutian Cackling Goose is an inch or two longer. The Canada Goose flocks here are Western Canada Goose (B. canadensis moffitti) with a length of 45 inches--quite the difference!

For a primer on separating Cackling and Canada Goose see this blog post.

Wednesday, May 30, 2018

Black-bellied Plover

Black-bellied Plovers winter commonly along San Diego's beaches. "Winter" is a relative term. For many shorebirds "winter" could mean all but 6 weeks in "summer,"--May 15 to June 15--when adults rush to the Arctic tundra to breed, then rush back. And some non-breeding birds remain locally all summer.

Black-bellied Plover

Black-bellied Plovers habitualize themselves to people on beaches. Thus it is relatively easy to get good, close photos of these birds. One of the highest concentrations where approach is easy, is at Crown Point Park on Mission Bay. Several hundred plovers hang out on the sand beaches, often with other shorebirds including Red Knots, Short-billed Dowitchers, Dunlins, Sanderlings, Ruddy Turnstones, Marbled Godwits, and Willets. Other birds winter birds flocking together on the beach there includes Royal Terns and Black Skimmers.

These photos, however, came from the mouth of the Tijuana River estuary, on February 18, 2018.

Black-bellied Plover

The striking black underparts of adults is attained in April and May and remains to September. I don't see this breeding plumage often in southern California--even in late spring. I'm just guessing, but it may be that primarily only first-year birds winter this far south? Such first-year birds (certainly top photo) remain in the plumages shown here all summer, similar to gray winter adults, but with some black feathers showing on the wing coverts (lower photo). Adults should complete molt into breeding plumage (a considerable energy budget) before migrating north (also a considerable energy budget). They won't molt and migrate at the same time--it takes too much energy. Or, maybe I just haven't been on the beach at the right time in spring.