The Orange County Breeding Bird Atlas, a joint project of the local Sea and Sage Audubon Society and the National Audubon Society, is a five-year project to map the nesting areas of the more than 100 bird species that breed in the county.
The project, now in its third year, divides the county into 111 blocks, each 5 kilometers square. During breeding season, from February through September, volunteers survey their assigned blocks on a regular basis. When breeding activity is discovered, the block is listed as “confirmed” for that species.
The list below shows bird species that have been found to breed in Orange County, followed by the number of blocks in which the species has been confirmed through the 1988 breeding season. Some species--including the most widespread local breeder, the European starling--are not native to the county, and may in fact be harming native species by competing for limited food resources and nesting sites.
Each week, Clipboard will profile one of Orange County’s breeding birds, including an illustration of the bird, a map showing where it has been discovered to breed, and notes on its natural history.
For information on the atlas and on how to participate in its final year, call the Sea and Sage Audubon Society chapter office, (714) 543-7393.
Confirmed Species Blocks European starling 76 House finch 74 Northern mockingbird 65 Anna’s hummingbird 60 Bushtit 58 House sparrow 57 Black phoebe 52 Red-tailed hawk 51 Mourning dove 51 Cliff swallow 50 American crow 48 Brown towhee 46 Red-shouldered hawk 40 Scrub jay 37 Common raven 36 Hooded oriole 36 Killdeer 35 Mallard 35 Northern oriole 35 Brewer’s blackbird 34 Lesser goldfinch 34 Song sparrow 34 American kestrel 33 Great-horned owl 32 Northern rough-winged swallow 30 California quail 29 Rock dove 29 Cassin’s kingbird 27 Red-winged blackbird 27 House wren 25 Loggerhead shrike 24 Rufous-sided towhee 23 Spotted dove 23 Cooper’s hawk 22 Bewick’s wren 20 Cactus wren 19 American coot 18 Ash-throated flycatcher 18 American robin 17 Common barn owl 17 Western kingbird 17 Acorn woodpecker 16 Black-headed grosbeak 15 Brown-headed cowbird 15 Phainopepla 15 Plain titmouse 15 Black-shouldered kite 14 Blue grosbeak 14 California thrasher 14 Nutall’s woodpecker 14 Wrentit 14 Black-chinned hummingbird 13 Common yellowthroat 12 Greater roadrunner 12 Pied-billed grebe 12 Western bluebird 12 Northern flicker 11 Hutton’s vireo 10 Ruddy duck 9 Western meadowlark 9 White-throated swift 9 Common ground dove 8 Green-backed heron 8 Lark sparrow 8 Rufous-crowned sparrow 8 Barn swallow 7 Black-necked stilt 7 Burrowing owl 7 American goldfinch 6 Black-crowned night heron 6 Black-tailed gnatcatcher 6 Costa’s hummingbird 6 Great blue heron 6 Say’s pheobe 6 Western wood-pewee 6 American avocet 5 Belted kingfisher 5 Violet-green swallow 5 Western screech owl 5 Common moorhen 4 Grasshopper sparrow 4 Least tern 4 Long-eared owl 4 Orange-crowned warbler 4 Western flycatcher 4 Allen’s hummingbird 3 Band-tailed pigeon 3 Black skimmer 3 Blue-gray gnatcatcher 3 Canyon wren 3 Cinnamon teal 3 Lazuli bunting 3 Marsh wren 3 Purple finch 3 Spotted sandpiper 3 Tri-colored blackbird 3 Black-chinned sparrow 2 Clapper rail 2 Dark-eyed junco 2 Golden eagle 2 Lawrence’s goldfinch 2 Savannah sparrow 2 Sora 2 White-breasted nuthatch 2 Caspian tern 1 Cattle egret 1 Chipping sparrow 1 Common poorwill 1 Double-crested cormorant 1 Elegant tern 1 Forster’s tern 1 Hairy woodpecker 1 Lesser nighthawk 1 Mountain quail 1 Parrot 1 Rock wren 1 Royal tern 1 Snowy plover 1 Tree swallow 1 Turkey vulture 1 Warbling vireo 1 Yellow warbler 1
Nest with young seen or heard.
Nest with eggs.
Adults attending young: adult carrying fecal sac or food for young, or feeding fledged young.
Occupied nest: adults entering or leaving nest site in circumstances indicating occupied nest (includes high nests or nest holes, the contents of which cannot be seen) or adults incubating or brooding.
Recently fledged young incapable of sustained flight, or downy young restricted to the natal area by dependence on adults or limited mobility.
Used nest or eggshells found.
Distraction display or injury feigning.
Nest building, by all but wrens and woodpeckers.
Nest building by wrens or excavation of holes by woodpeckers.
Agitated behavior or anxiety calls from adult.
Visiting probable nest site.
Courtship behavior or copulation.
Permanent territory presumed through defense (e.g. chasing of other birds, or song at the same location on at least two occasions a week or more apart).
Pair observed in suitable nesting habitat during its breeding season.
Singing male present in suitable nesting habitat during its breeding season.
Species observed in suitable nesting habitat during its breeding season.
Species observed in block during breeding season, but believed not breeding.
Source: Sea and Sage chapter, National Audubon Society.