Today we have a passel of birds from reader Ed Kroc, whose notes are indented:
Here’s a batch of photos from San Diego taken this past summer. I was along the California coast for about a week in July collecting data on urban-nesting gulls, but of course I always try to make time for a few pictures! Western Gulls (Larus occidentalis) traditionally nest in large colonies on small offshore islands along the American Pacific coast. However, some gulls have moved their nesting sites into urban and semi-urban areas along the coast. This species hybridizes extensively with the resident Vancouver gull, the Glaucous-winged Gull (L. glaucescens), where their ranges overlap in WA and OR. The GW Gull seems to be far more comfortable in an urban environment than the WE Gull, but part of my current research is aimed at trying to better understand these differences.
The first photo shows a fine looking adult male Western Gull. Notice the very dark grey mantle and wings, much darker than the Glaucous-winged Gulls I’ve sent lots of pictures of. You can also see the distinctive bright orange orbital ring. This is the southern subspecies (L. o. wymani) which is a bit smaller and a lot darker than the nominate northern subspecies of WA, OR, and northern CA.
Next is a picture of a chick and parent at their nest site atop a nice hotel complex on San Diego’s harbour. The nest was on the roof of a two-storey flattop, with plenty of foliage around. The chick, who is about four weeks old in the picture, is playing with a bit of dried leaves. The father, as you can see, was alarmed at me as I stood underneath initially, but soon stopped and settled in for a brief nap. I haven’t studied it formally yet, but both this and the GWGull species seem to feel really threatened only when an observer is at or above eye-level with the nest. I was no more than a few feet linearly from the chicks, but I was on the ground below and neither parent minded me. Trying to observe nests 20 or more feet away from a bridge though often leads to dive-bombs and defensive poop-blasts. Data collection can be a messy business!
The final gull picture shows a family atop a small marina building, right on the harbour. These chicks are a bit older than the other ones, probably in their fifth week. You can see the parent on watch craning his/her head around the obstruction to check me out. I didn’t stay long enough to provoke any defensive maneuvers!
After Laridae (Gulls) and Sternidae (Terns), my favourite family of bird is probably Pelecanidae, the Pelicans. They instantly and always put me in mind of their dinosaur ancestors and cousins. We never get pelicans up in BC, so I’m always thrilled to see them when I make it this far south.These shots of Brown Pelicans (Pelecanus occidentalis) were taken at Shelter Island in San Diego. In the first shot, a pelican naps next to a Heermann’s Gull (Larus heermanni), a beautiful gull of the southern North American Pacific coast with a fascinating ecology of its own. I’ll save the facts for another time, but I will mention that these two species seem to get along quite remarkably. They often loaf together in very close proximity. Neither species gets along very well with the resident Western Gulls who tend to be too loud and pushy for their liking.
The final two showcases some of the unique beauty of the pelican. They have a gentle and wise look about them. In flight, I can’t help but think they would have fit right in 100 million years ago.
I love watching seagulls hovering in strong winds; they just seem to be floating in air as the moving air provides all the lift they need without them flapping their wings.
But as much as I like sea gulls, I prefer bay gulls, especially with cream cheese and smoked salmon.
My favourite L. glaucescens story involves one perched on the handrail of the Queen of Surrey, begging for my french fries. As the ferry left the dock, it remained on the rail, first being forced by the airstream to turn its beak to the bow and then finally to spread its 5 foot wingspan and lift smoothly out into the rising wind. It kept close station with very little effort required until finally it gave up on me.
I’d have thought a Western Gull would be wearing a cowboy hat – maybe that’s why I have so much trouble identifying birds.
Gulls get no respect, but I think they’re grand. Living in the middle of middle ‘merica, we don’t get a lot of gulls, but they do pop up on large rivers or on reservoirs like the Lake of the Ozarks. There’s several Ring-Billed Gulls that I see on the lake when I visit my parents. They like to perch on the NO WAKE buoy a few docks down the cove from their house but are so easily startled that I can never get close enough to really view them properly.
and if you like the “wise and gentle” look of pelicans and have access to tw*tter, check out Darren Naish’s (Tetropod Zoology) tw*tter feed for pics of pelicans eating anything and everything they can fit in their mouths, like a very confused pigeon. This also led to a #PelicanFacts which led to some ‘true facts’ such as “pelicans are what REALLY happened to Jimmy Hoffa” and “if the Empire had pelicans they would have defeated the Ewoks at the battle of Endor”
There are pelicans that migrate through the Lake of the Ozarks, but I’ve yet to see them eat a pigeon, or an Ewok for that matter.
Thanks for the recommendation – I will check it out!
Defensive poop blasts! I am not sure I could concentrate on research under that kind of threat.
I wonder if the pelicans and the Heerman’s gulls get along b/c they do not directly compete for food.
To avoid the really nasty stuff, do not look up if the Heron flies directly overhead. At least keep the mouth shut.
I figure it’s only fair for stressing them out. It’s too bad I can’t communicate that I’m not an actual threat though!
I wondered about the red spot on the bird’s bill, then found this, which is quite enlightening for those of us who know nothing about such things http://birdnote.org/show/little-red-spot-gulls-bill; that it’s not a blemish or random occurrence, but is “a crucial visual cue in a chick’s demands to be fed…” Quoting from the article: “In the mid-20th Century, Dutch scientist Niko Tinbergen studied nesting Herring Gulls. He noticed that newly hatched gull chicks were fed by their parents only after they pecked at the adults’ bills [Begging calls of young gulls]. Tinbergen devised experiments that varied the shape and coloration of the adult’s bill. It became clear that the red spot on the adult gull’s bill was a crucial visual cue in a chick’s demands to be fed, and thus its survival. [Begging calls of young gulls].” This research into something so seemingly innocuous as a red spot earned Tinbergen a Nobel.
Also one on the pelican’s bill. How many others have this nutritional bulls-eye on the bill, I wonder. Is it just certain types of sea birds or what?
Yes, I vaguely remember reading about his classical experiments which I think were done with model gull heads to see which cues triggered pecking from a nesting chick. Model heads without the red spot did not trigger as many pecks from nesting chicks.
Interestingly, the presence of a red spot on gull bills is associated closely with body size. The bigger gulls and the ones that hatch chicks that are proportionally much smaller than their parents have the red spots, but other gulls do not. Check out this interesting paper by Ferns and Ross-Smith: http://www.marineornithology.org/PDF/37_1/37_1_85-92.pdf