A Northern Mockingbird came to the oriole feeder this morning. It fed on grape jelly briefly, then stayed around as Baltimores came by. Finally, after quite a few photos, it flew into the yard.
I've been curious to know if there are any studies that show changes in the population centers of our breeding birds. These would parallel the analyses by National Audubon, using 40 or so years of winter bird count data. The winter data show sometimes marked shifts in winter populations, often to the north (about two thirds of the 300 plus species) or in other directions (about one third). The movements generally conform to what one would expect from climate change. The presence of the mockingbird has me wondering about this species, "specifically." As a youth, I knew it to expand its range a little north during winter, into southern Iowa. Occasional mockers would show up on winter counts, often near large red cedars with a good berry crop. Those birds returned to Missouri in the summer. Other birds with known northward expansion include Great-Tailed Grackles, and it's my impression each spring that a wider array of southern and western species get blown off course into Iowa, on the way elsewhere. Recall that a Mountain Bluebird, a Lazuli Bunting, Bewick's Wrens, and several others have been seen just this year and reported here. Anyhow, if there are studies on breeding bird populations, or if any BBS participants have stories or conclusions to share, I'm curious. Thanks, Lee Searles Des Moines --- Please contribute your sightings to our list; it is only as good as members make it! --- Birding channel recommendation for FRS/GMRS radio use: Primary selection; channel 5/0 , alternate selection; channel 6/0 --- This mailing list is sponsored by the Iowa Ornithologists' Union. Membership available on-line at http://www.iowabirds.org/iou/PayDues.aspx. ----- You are currently subscribed to ia-bird as: [email protected]
