Three Rivers Birding Club Southwestern Pennsylvania

The Peregrine Vol 23, No 5, September/October 2024
Full-length Article
Blue Grosbeaks in SW PA

Blue Grosbeaks have recently attracted attention in Western Pennsylvania. Somewhat similar to Indigo Buntings, they are slightly larger and have cinnamon wing bars and a much more massive beak. In recent years they have successfully nested in western Allegheny County, and birds were spotted in two locations in Butler County. Hopefully they will be confirmed during Pennsylvania Bird Atlas 3.

The American Bird Conservancy says, "Originally a nester in the southern and central United States, Mexico and western Central America, the Blue Grosbeak has been expanding its breeding range northward." Its range map shows Blue Grosbeaks in New Jersey and southeastern Pennsylvania, but not in the rest of the Commonwealth.(ABC - Blue Grosbeak). According to National Audubon Society (Audubon - Blue Grosbeak), it prefers "Brush, roadsides, streamside thickets. Breeds in dense low growth in semi-open country, including woodland edges, brushy fields, young second-growth woods, hedgerows."

Blue Grosbeaks are interesting because of some recent evidence that they are attracted to recently disturbed areas or at least perhaps the recovering edges of disturbed areas. The fact that they suddenly appeared near an active surface mining area in Butler County in 2022, at which an artificial wetland is being constructed, supports the idea that perhaps they are a "pioneer" bird species, like ruderal plants that are the first to move into disturbed areas, which they exploit until the habitat returns to a more mature, state.

The probable first western Pennsylvania record for this species came from Todd Sanctuary in Butler County (Table 1). Father Roch Raible, a Capuchin Franciscan friar who was a high school biology teacher, found the bird. Fr. Roch banded birds at Herman, Summit Twp. Butler County by sponsoring a bird banding club and engaging students in many outdoors activities. This 2018 eBird entry by Geoff Malosh (Geoff Malosh Checklist) included these local details: Blue Grosbeak is a former breeder in the Imperial Grasslands area, and was present in each of the summers from 1994-1997, but they did not return in 1998 or thereafter. There is also a single record of one bird at the grasslands on 29 Jul 2006, but no breeding evidence was noted that year, and the bird was not seen thereafter, or in any year since, until 2018. Ironically, the ongoing development (destruction) of the grasslands along King Road may well be what attracted the species to attempt to breed here again this year, as the trees and secondary Blue Grosbeak last bred in this area. The clearing of the area has, in a way, put the area back to something like the way it looked in the early 1990s (though thoroughly degraded, comparatively), and thus apparently has (temporarily) made this spot attractive to BLGR once again. It's the same story with Yellow-breasted Chat, which is also more common in this section of the grasslands this year than they have been in over a decade or more.

The 2nd Pennsylvania Breeding Bird Atlas (2004-2009) map showed breeding records in Mercer, Westmoreland and Greene Counties (see map on p.8 of The Peregrine Sept/Oct 2024). Twenty years later, at the start of the 3rd Pennsylvania Bird Atlas (2024-2029), the species remains very scarce and localized in the western half of the state. Nevertheless, with populations just over the border with West Virginia and Ohio, PA birders should continue to watch and listen for this charismatic avian newcomer to western Pennsylvania.

Blue Grosbeak

(Photo by Tom Moeller)