Tuesday, April 8, 2008

Bulletin #33 - Monterey CA gulls and Monarch Butterfly hibernation

David McDonald Photography
Friendswood Texas
April 8, 2008

Bulletin #33 – Monterey California #5 – gulls and Monarch Butterfly

Hello friends,

Gulls were a major target for me on this trip as the Austin Texas Audubon society was putting on a gull identification workshop and they needed some additional photos.

My guide, Rick Fournier, is an expert on all birds. He pointed out the confusing species to me as well as helped with other gulls pictures I took after my day with him.

The Glaucous-winged Gull (Larus glaucescens) is a large 26” pale mantled gull of the Pacific coast from Seattle to Alaska. They winter all down the coast to Baja California. I managed to get only a single photo of a bird from a rather long distance, but the pale mantle and primary wing tips being the same or lighter color are the things to look for.


In Bulletin #32, I showed the photos of a hybrid Hermit x Townsend’s warbler. Well, gulls also hybridize extensively, especially the large gulls. In Sibley’s field guide, the gull section starts with 4 hybrids. The Glaucous-winged x Herring Gull and Glaucous-winged x Western Gull, he states are relatively common.

Fortunately my guide, Rick Fournier, was able to identify these confusing birds for me. These hybrids just add to the confusion for birders trying to sort out the complex plumage variations of gulls.

Here is a Glaucous-winged x Herring Gull hybrid. The difference between this bird and the pure Glaucous-winged Gull above is subtle, but pertains to color of primary wing-tips being darker in the hybrid. I certainly would not know the difference in the field, but can see it in the photos.


The other hybrid is Glaucous-winged x Western Gull. I was actually able to get several detailed photos of a bird on Carmel River beach. In this bird, the wingtips are darker still and it also some black spots show on the wings indication the Western Gull parentage. Byron Stone of Austin pointed out the detailed differences of this bird and I’ll put his emailed analysis after the 4 photos.

http://www.pbase.com/image/95354433 click ‘next’ 3 times

Hi David,

This bird is also a hybrid. It is a Glaucous-winged X Western Gull hybrid, which I believe is sometimes called an "Olympic Gull" because they are so common on the Olympic Peninsula in Washington, making up half or more of Glaucous-winged-type gulls there.

Note on the spread-wing shot the dark trailing edge of the underwing. This in NOT a pure Glaucous-wing character. Note also how the dorsal surface of the wingtips are as dark as the rest of the upperwing. In pure GW Gull, the wingtips should be paler than the rest of the upperwing. Also notice several dark spots throughout the dorsal wing surface, evidence of Western Gull lineage.

Note also how large the bill is, with a very pronounced gonydeal angle. This also suggests Western Gull influence.

Finally, note how the head and nape of this gull has a lot of dark smudges. I believe that pure Western Gull winter adults tend to have an immaculate white head.
Very interesting bird, and one which we rarely have a chance to study here in Texas.

Byron Stone

With all these hybrids, it sometimes makes the definition of what is a separate species confusing. One definition of a ‘species’ is a distinct population that cannot interbreed without causing sterile offspring such as a horse mating with a donkey to produce a mule. Mules are sterile. These hybrid gulls can breed and produce offspring, so are these really separate species? I leave that to the experts. The rest of us just keep our lists.

For a change of pace, I will show you a couple of photos of Monarch Butterflies (Danaus plexippus). As most of you know, the Monarchs east of the Rocky Mountains migrate to Mexico in the winter. I’m sure you have all seen pictures of thousands of butterflies on trees in the mountains there.

However, what is not so well known is that the Monarchs west of the Rockies just migrate to the California coast in select locations from Marin County south. On the Monterey peninsula, there are 2 spots in the town of Pacific Grove, that are readily accessible to view this spectacular gathering of butterflies. In fact, Pacific Grove advertises itself as ‘Butterfly Town USA’

When we went there in February, it was a warm sunny day and the butterflies were starting to open their wings and flutter about.

The first photo shows several large clumps of butterflies on Spanish Moss hanging in a tree.


The second is a cropped version of the above.


Scientists are able to track the migration of these wonderful insects by attaching paper tags with adhesive to their wings.

Here is a close-up showing a butterfly with a red tag in the center of the picture.


If you go back to the first 2 photos and look closely, you can see white tags on several of the butterflies.

This remarkable gathering of butterflies is truly one of the wonders of nature. If you ever are in the Monterey area in the winter months, I encourage a visit Pacific Grove to see the ‘butterfly trees’.

For more information on the Monarch Butterflies in Monterey County, California, please visit the web site of the Ventana Wilderness Society.


Happy birding and photography,

David McDonald

photos copyright 2006 - 2008 David McDonald

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