Your Handy BAS Guide to the Spring Bird Migration in Cache County

I need a Franklin’s Pollyflobble. But they only migrate through Cache County during a short period. So, what I wanted to know was, when - exactly - is the Pollyflobble expected to arrive? For that matter, when are any of the migratory birds expected to arrive in Cache County? I mean, there’s a lot of birding to do and you gotta target your efforts if you want to make the most of it!

The BAS Birds of Cache County, Checklist & Site Guide 1994 lists 242 species which have been seen regularly in Cache County and another 44 which have been seen at least twice in the last 30 years. (There were lots of changes to the older list, so you want the new 1994 edition, available at the next Audubon meeting, or from A Bookstore on 100 East in Logan.) This Checklist has information on occurrence by season along with preferred habitat for each species, and in the back there are handy descriptions of suggested travel routes to favorite birding sites.

Not all of these birds migrate, of course. And some of them are only seen on the fall migration. So, last year I asked several of the local birders to share their year lists with me, fired up the ol’ PC and entered the dates of first sightings in a database. Needless to say, there’s mega-gobs of data, and I’m not finished entering all of it yet. But, spring is almost sprung, and if anyone is gonna be able to use the results, I decided I’d best get them out there. So, here’s the result.

The list below shows the date each spring migrant can be expected to show up in Cache County, based on the average of a number of first sighting dates. It also shows the earliest date in the database, along with the standard deviation and number of observations. You can use the standard deviation to determine how variable the sightings (and presumably the arrival dates) are. Roughly, you’d expect about 2/3 of all sightings to fall within one standard deviation of the average date. So, if the average arrival date of the Franklin’s Pollyflobble is April 12, with a standard deviation of 7, then 2/3 of the first sightings fall between April 5-19. If you report a Franklin’s Pollyflobble in late February, everyone will be real excited, know whadda I mean? You get the idea.

Mucho thanks to everyone who’s provided me with data so far. They may not know who they are, but they include: Alice Stewart, Al Stokes, E. Hanson, Ed Sparks, Gail Christensen, Ivan Palmblad, John and Terri Barnes, J. Smith, J. Sullivan, Keith and Martha Dixon, Mike Tove, Nancy Warner, Pete Schropp, Bob Atwood, R. Roehlman, S. Silcox, S. Jacoby, Steve van der Wall, and special thanks to Larry Ryel and Keith Archibald.

Expected Date of 1st Bird Sightings

Common Name	Avg Date	Earliest Date	StDev Days	No. Obs
Ring-billed Gull	03/06/95	02/18/95	8	15
Snow Goose	03/11/95	02/25/95	14	5
California Gull	03/11/95	02/23/95	11	16
Cinnamon Teal	03/12/95	02/19/95	14	16
Sandhill Crane	03/14/95	03/03/95	7	16
Sage Sparrow	03/14/95	03/04/95	12	4
Say's Phoebe	03/18/95	03/05/95	17	4
American Avocet	03/28/95	03/16/95	6	20
Eared Grebe	03/31/95	03/10/95	11	19
Franklin's Gull	03/31/95	03/07/95	11	19
Greater Yellowlegs	04/01/95	02/18/95	14	18
American White Pelican	04/02/95	03/22/95	8	4
Long-billed Curlew	04/03/95	03/27/95	5	19
Tree Swallow	04/04/95	03/15/95	15	17
Black-necked Stilt	04/05/95	03/23/95	6	19
Red-breasted Merganser	04/05/95	03/19/95	14	16
Swainson's Hawk	04/05/95	02/22/95	18	16
Mountain Bluebird	04/05/95	02/28/95	32	15
Savannah Sparrow	04/06/95	03/15/95	11	15
Western Grebe	04/07/95	03/16/95	15	19
Lesser Golden Plover	04/08/95	04/08/95		1
Dble-crested Cormorant	04/09/95	03/13/95	19	17
Common Loon	04/10/95	03/28/95	8	18
Willet	04/10/95	03/30/95	7	18
Mourning Dove	04/11/95	02/20/95	23	15
White-faced Ibis	04/13/95	03/30/95	6	18
Snowy Egret	04/13/95	03/29/95	13	14
Vesper Sparrow	04/14/95	03/16/95	13	10
Clark's Grebe	04/14/95	03/25/95	19	9
Snowy Plover	04/14/95	03/22/95	11	14
Horned Grebe	04/14/95	03/24/95	17	9
Blk-crowned Night-Heron	04/14/95	03/11/95	12	18
Barn Swallow	04/15/95	03/31/95	7	17
Lesser Yellowlegs	04/15/95	03/25/95	11	15
Turkey Vulture	04/16/95	03/29/95	17	16
Baird's Sandpiper	04/16/95	03/27/95	10	12
Cattle Egret	04/20/95	03/27/95	14	14
Long-billed Dowitcher	04/20/95	03/29/95	13	15
Osprey	04/20/95	04/06/95	15	10
Blue-winged Teal	04/22/95	04/03/95	14	12
Bonaparte's Gull	04/23/95	04/10/95	15	5
Cliff Swallow	04/25/95	04/16/95	7	13
Violet-green Swallow	04/25/95	04/03/95	18	14
Solitary Sandpiper	04/26/95	04/11/95	11	4
Marbled Godwit	04/28/95	04/21/95	6	10
Caspian Tern	04/28/95	04/07/95	17	16
Western Sandpiper	04/28/95	04/17/95	13	13
Black-bellied Plover	04/28/95	04/16/95	7	8
Least Sandpiper	04/28/95	04/13/95	10	11
Semipalmated Plover	04/29/95	04/17/95	9	11
Bank Swallow	04/29/95	03/31/95	14	13
Sanderling	05/01/95	04/17/95	11	6
Green-tailed Towhee	05/01/95	04/24/95	5	7
Dunlin	05/01/95	04/07/95	12	8
Wilson's Phalarope	05/01/95	04/20/95	11	14
North Rough-winged Swal	05/01/95	04/13/95	13	13
Forster's Tern	05/02/95	04/10/95	12	15
Semipalmated Sandpiper	05/02/95	04/22/95	9	10
Yellow-rumped Warbler	05/02/95	02/16/95	26	13
Fox Sparrow	05/02/95	03/29/95	33	11
Lazuli Bunting	05/04/95	04/18/95	12	15
Rock Wren	05/05/95	04/24/95	10	4
House Wren	05/07/95	04/21/95	10	15
Yellow Warbler	05/07/95	04/27/95	7	13
Orange-crowned Warbler	05/07/95	04/21/95	9	17
Western Kingbird	05/08/95	04/16/95	11	17
Red-naped Sapsucker	05/08/95	03/31/95	22	12
Northern Oriole	05/08/95	04/18/95	9	15
Nashville Warbler	05/09/95	05/02/95	6	5
Broad-tailed Hummingbird	05/09/95	04/24/95	10	14
Great Egret	05/09/95	04/27/95	10	6
Chipping Sparrow	05/10/95	04/21/95	10	14
Red-necked Phalarope	05/10/95	05/02/95	8	10
Spotted Sandpiper	05/10/95	04/08/95	16	15
Black-headed Grosbeak	05/10/95	05/02/95	5	15
White-throated Swift	05/12/95	04/18/95	18	15
Western Tanager	05/14/95	05/02/95	6	12
American Bittern	05/14/95	04/19/95	17	11
Virgina's Warbler	05/14/95	04/25/95	13	14
Calliope Hummingbird	05/15/95	04/14/95	20	15
Common Yellowthroat	05/16/95	05/05/95	8	12
Wilson's Warbler	05/17/95	05/06/95	7	10
Black-throated Gray Warbler	05/17/95	05/01/95	13	11
Warbling Vireo	05/17/95	05/06/95	10	14
Dusky Flycatcher	05/17/95	05/07/95	11	11
Blue-gray Gnatcatcher	05/18/95	05/12/95	6	7
Black-chinned Hummingbird	05/18/95	05/04/95	9	11
Black Tern	05/19/95	04/26/95	11	10
MacGillivray's Warbler	05/19/95	05/01/95	14	15
Brewer's Sparrow	05/19/95	04/21/95	19	8
Lark Sparrow	05/19/95	05/08/95	11	11
Stilt Sandpiper	05/20/95	05/14/95	7	3
Solitary Vireo	05/21/95	05/11/95	16	11
Grasshopper Sparrow	05/22/95	04/20/95	27	7
Eastern Kingbird	05/23/95	04/28/95	12	10
Common Poorwill	05/24/95	05/06/95	18	8
Flammulated Owl	05/25/95	04/18/95	22	8
Western Wood-Pewee	05/25/95	05/07/95	16	13
Bobolink	05/26/95	03/28/95	21	12
Lincoln's Sparrow	05/27/95	05/05/95	16	8
Yellow-breasted Chat	05/28/95	05/17/95	12	10
Willow Flycatcher	05/30/95	05/09/95	13	12
Gray Catbird	05/31/95	04/28/95	17	11
Sage Thrasher	06/01/95	04/14/95	38	5
Swainson's Thrush	06/01/95	05/10/95	18	12
Hammond's Flycatcher	06/03/95	05/17/95	16	7
Common Nighthawk	06/03/95	05/17/95	11	13
Olive-sided Flycatcher	06/03/95	05/20/95	11	10
Purple Martin	06/05/95	05/17/95	13	8
Burrowing Owl	06/08/95	04/11/95	39	4
Cordilleran Flycatcher	06/08/95	05/12/95	16	8
Williamson's Sapsucker	06/10/95	05/18/95	17	7
Blue Grosbeak	06/20/95	06/02/95	21	4
Rufous Hummingbird	07/19/95	07/02/95	10	6