I recently acquired a 600mm lens which I plan to use with 1.4x teleconverter often, probably for birds much of the time I suspect, and have been out practicing with it. The combination is too long for pelicans and sea lions, so I have been seeking smaller subjects. This time of year the Coast Walk in La Jolla is a great place for hummingbirds, and lately I have seen a few warblers there as well. These small birds are damn hard to photograph as they move around erratically, so its good practice. Here are a few favorites I shot recently, most with teleconverter (effective 840/5.6). Cheers, and thanks for looking!

Whimbrel Foraging Amidst Spring Wildflowers on Coast Walk, La Jolla.
Image ID: 40256
Species: Whimbrel, Numenius phaeopus
Location: La Jolla, California

Orange-Crowned Warbler Amid Spring Flowers, Coast Trail, La Jolla.
Image ID: 40243
Species: Orange-Crowned Warbler, Leiothlypis celata
Location: La Jolla, California

Orange-Crowned Warbler Amid Spring Flowers, Coast Trail, La Jolla.
Image ID: 40249
Species: Orange-Crowned Warbler, Leiothlypis celata
Location: La Jolla, California

A perfect Brown Pelican Head Throw with Distant Ocean in Background, bending backwards, stretching its neck and gular pouch, winter adult breeding plumage coloration.
Image ID: 40252
Species: Brown Pelican, Pelecanus occidentalis, Pelecanus occidentalis californicus
Location: La Jolla, California

Rufous Hummingbird Brilliant Gorget Display While Perched, Coast Walk, La Jolla.
Image ID: 40260
Species: Rufous Hummingbird, Selasphorus rufus
Location: La Jolla, California

Orange-Crowned Warbler Amid Spring Flowers, Coast Trail, La Jolla.
Image ID: 40250
Species: Orange-Crowned Warbler, Leiothlypis celata
Location: La Jolla, California

Audobon's Yellow-Rumped Warbler in Flowering Aloe, Coast Walk, La Jolla.
Image ID: 40255
Species: Audobons Yellow-Rumped Warbler, Setophaga audoboni
Location: La Jolla, California

Whimbrel Foraging Amidst Spring Wildflowers on Coast Walk, La Jolla.
Image ID: 40258
Species: Whimbrel, Numenius phaeopus
Location: La Jolla, California

Rufous Hummingbird with Open Beak Perched on Branch, Coast Walk, La Jolla.
Image ID: 40266
Species: Rufous Hummingbird, Selasphorus rufus
Location: La Jolla, California

Rufous Hummingbird Brilliant Gorget Display While Perched, Coast Walk, La Jolla.
Image ID: 40263
Species: Rufous Hummingbird, Selasphorus rufus
Location: La Jolla, California