Indigo Bunting in Briones Regional Park
Sun,
22 Jun 2003 20:44:24 -0700
From: Dennis & Patricia Braddy
EastBayBirders,
The Indigo Bunting at the corral near the intersection of the Old Briones Road and Valley Trails at Briones Regional Park was a bit more cooperative today. During the hour we were there it flew overhead several times and twice it perched in clear view and sang for 5 to 10 minutes straight for an appreciative audience of up to 9 birders.
Dennis and Patricia Braddy
San Ramon
Original Message Next Reply Subject Index
Re: Indigo Bunting in Briones Regional Park
Tue, 24 Jun 2003 17:43:13 -0700
From: Larry Tunstall
This morning I and seven other birders were waiting around the corral near the intersection of Old Briones Road and Valley Trail in Briones Regional Park about 10:30 AM. Emilie Strauss eventually found the Indigo Bunting singing from a snag south of (behind) the corral, at the edge of the thick riparian vegetation.
We all had good looks at the bird for some time. It occasionally flew into the riparian area or out to the corral, but generally seemed to return to the snag.
Instead of being all blue as shown in the field guide illustrations, this bird had white belly and undertail coverts, and a whitish underside to the tail itself. It also had pale wingbars. The color was quite similar to the turquoise blue of a Lazuli Bunting, and the song seemed almost identical to that of a Lazuli Bunting. Photos taken by Mark Wales are at
http://folkbird.net/ebb/archive/pic0306a.htmlThanks to Mark for the photos.
The general consensus of this small group was that the individual probably is a hybrid of Indigo Bunting and Lazuli Bunting.
Good birding, Larry
Larry Tunstall
El Cerrito CA
Original Message Next Reply Subject Index
Re: Indigo Bunting in Briones Regional Park
Tue, 24 Jun 2003 20:37:11 -0700
From: Joseph Morlan
Larry Tunstall wrote:
Thanks to Mark for the photos.And thanks for providing web space where we can view these interesting photos!
The general consensus of this small group was that the individual probably is a hybrid of Indigo Bunting and Lazuli Bunting.
The standard paper on hybridization in these buntings is:
Kroodsma, R.L. 1975. Hybridization in buntings (Passerina) in North Dakota and eastern Montana. Auk 92:66-80.There are plans to get back issues of the Auk online in the near future.
Kroodsma points out that winter adult Indigo Buntings have white bellies and often faint white wing-bars which may remain into spring and summer if the bird delays its pre-alternate molt. This is especially prevalent in first year (2nd calendar year) birds. However, all hybrids do have white bellies.
The photos seem to me to show blue wing-bars, not white, at least on the right wing. One photo shows some white near the bend of the left wing, but could it be a misplaced feather rather than an actual wing-bar?
Hybrid Indigo X Lazuli usually show some rust on the chest and much more white on the underparts than the Briones bird. It's true that the colors of Indigo Bunting are darker than those of Lazuli Bunting, but there is considerable variation. The colors, as I see them on my monitor, look fine for Indigo.
Some overexposed photos of both species and an apparent hybrid are at:
http://www.montereybay.com/creagrus/Bunting-hybrid.htmlA very weird bunting with extensive white underparts is at:
http://members.tripod.com/~tbrc/lazbunt.htmlAnother probable hybrid with extensive white on the belly and fairly crisp unambiguous wing-bars is at:
http://pie.midco.net/dougback/hybrid.htm
I would not place too much weight on the song. Individuals of both species will learn each other's songs. In fact it is known that unsuccessful male Lazuli Buntings will change their song to that of more successful males nearby. It is believed they do this in hopes of fooling the females into thinking they are more fit than they really are (a form of dishonest signaling).
Joseph Morlan, Pacifica, CA
Fall Birding Classes start Sept 3 http://fog.ccsf.org/~jmorlan/
California Bird Records Committee http://www.wfo-cbrc.org/cbrc/
Original Message Next Reply Subject Index
Re: Indigo Bunting in Briones Regional Park
Tue, 24 Jun 2003 21:45:27 -0700
From: Rusty Scalf
If the hybrids are first generation, then one would expect some more or less predictable blend of characters. And if hybrid birds are 'mules,' then all such birds would be F1. But if hybrids are fertile, then their progeny might be a 75 - 25 genetic mix, in which case the characters of one species would be greatly blended down. And if their progeny are fertile....
Anyhow, I wonder if anything is known about fertility rates in passerine hybrids.
Rusty Scalf
Original Message Next Reply Subject Index
Re: Indigo Bunting in Briones Regional Park
Tue, 24 Jun 2003 21:57:24 -0700
From: Joseph Morlan
Rusty Scalf wrote:
Anyhow, I wonder if anything is known about fertility rates in passerine hybrids.
It depends on the species. Fertility is only one measure of fitness. Hybrid buntings appear to be at a selective disadvantage over their parental types, but the cause of that disadvantage is not known.
In meadowlarks, the F1 hybrids are reported to be fertile, but the F2 hybrids are not.
Joseph Morlan, Pacifica, CA
Original Message Next Reply Subject Index
Possible avocet-stilt hybrid in southern Alameda County
Tue, 24 Jun 2003 22:31:36 -0700
From: Jan Hintermeister
Robin Dakin, San Francisco Bay Bird Observatory (SFBBO) biologist, recently discovered a possible American Avocet X Black-necked Stilt. Fortunately for us, wildlife photographer David Cardinal was on hand to document the find. A short report and David's photo are on SFBBO's website:
http://www.sfbbo.org/stavocet.htm
This interesting bird was found in Alameda County on salt pond habitat that is not open to the public. Any further developments on this bird will be posted on our website and in our quarterly newsletter.
Jan Hintermeister
SFBBO Board President
Santa Clara, CA