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

by Bryan Dixon ([email protected])
Published in the March 1995 issue of the Stilt.
Bridgerland Audubon Society, P.O. Box 3501, Logan, UT 84323-3501


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.

Have a great migration! - Bryan Dixon

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

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