By Nate Swick and George Armistead
Occasionally fascinating discussions break out on the ABA’s Facebook forums that deserve some wider attention. This post intends to pull that discussion away from the relative obscurity of Facebook and open the conversation to a larger audience.
On March 13-14, a Black-billed Magpie was reported and photographed by Jacquie and Brian Penney in their yard on Harbor Island, Beaufort County, South Carolina. The identification to genus is not in question (more on that below). And according to the observers, the bird was very shy and would not allow close approach. It showed no bands, no outward signs of feather wear, and did not vocalize. But where the heck did it come from?
Is it a natural vagrant? It is an escapee? If a natural vagrant, is it a Black-billed from western North America (Pica hudsonica) or a Eurasian Magpie (Pica pica)?
Common consensus seems to settle around it likely being an escapee. But, if accepted, this would not be a first occurrence of this genus in South Carolina. An additional record of Black-billed Magpie is noted inThe Auk from May-June, 1934 (.pdf, see bottom of page 1) perhaps not coincidentally following an abnormally brutal, cold winter. The author of the 1934 record notes two other “recent” records, one from Florida (deemed an escapee), and another in New Jersey.
The 1934 record wasadded to the hypothetical list (.pdf) by the South Carolina BRC in 2004. You all don’t need to be reminded, but “brutally cold” were adjectives tossed around quite a bit over the last couple months with regard to the weather.
Consider too that other states in the east also have records of Black-billed Magpie, but few since the late 70s. It would be interesting to know if magpies are now less commonly kept in captivity today then compared to earlier decades.
Other notable sightings (some not accepted), from nearby states are as follows.
- New Jersey:7 total. Species is on the “Uncertain Provenance” list for the state.
- Maryland:8 total. Between 1931-1963, not all accepted by BRC.
- Virginia: 5 total. Between 1940-1978, 1, from Chincoteague, in March 1957 was one of multiple reports in the East (e.g., New Jersey, New York, Pennsylvania, and Delaware) that year, suggesting that this individual was associated with a larger influx and thus potentially naturally occurring.
- North Carolina: 1, Chapel Hill, 23 March 1960. Not accepted by BRC
The genus Pica is home to at least three species: Eurasian, Black-billed and Yellow-billed Magpie. The ABA Area’s Black-billed, despite looking much more similar to Eurasian is most closely related to the California endemic,Yellow-billed Magpie (the two diverged relatively recently after colonization from Asia via the Bering landbridge (Lee et al. 2003)). In Eurasia there is considerable geographic variation and 10+ subspecies of Eurasian Magpie, while our Black-billed is monotypic (one form). Generally magpies are birds of open country that are also quite vocal with an impressive repertoire of sounds. Preferring cooler arid areas they have avoided the humid, warm Midwest and Southeastern U.S. At the southern and eastern reaches of their range they gravitate towards areas of higher elevation (Trost 1999).
From the Midwest, where vagrancy from the interior west is more expected, there are a number of extralimital records. It is an open question whether eastern magpie records like this South Carolina bird are associated with exceptionally cold winters, but it’s an idea worth exploring. Records outside the winter months are perhaps more questionable and could mask a pattern of vagrancy in the colder months.
The idea of a Eurasian Magpie straying to the eastern ABA Area is interesting to consider. It seems unlikely, but not impossible. While certain corvids (crows, ravens, jays, ets.) are strong fliers and capable of significant dispersal, this seems less true of magpies, at least for long distances. One might sooner expect one in western Alaska, but South Carolina is kind of a tough sell. One originating from Scandinavia and coming through Canada is not out of the question though. Eurasian Jackdaw might provide a good model by which to examine the vagrancy of Eurasian Magpies to eastern North America.
As with ABA Area reports and records of jackdaw, ship-assisted birds may be tough to rule out. Corvids are clever ship-riders, and the East Coast has no shortage of ports that receive ships from Europe. If a Eurasian, the bird could well have moved southward in response to the cold winter, ending up in SC, or could have come in with a ship from Europe to a major port like Charleston, South Carolina. It is not uncommon for mariners to feed such birds during Atlantic crossings.
Such records are not simple speculation. A magpie in Nova Scotia in 2008 was probably Eurasian, though photos were deemed inconclusive, and was determined to be most likely ship-assisted (McLaren, 2012).
According to the BNA Account (Trost 1999), compared to Eurasian magpies, Black-billed averages smaller, longer-tailed, longer-winged, and the bill is slightly longer and more slender. (Given the variation in Eurasian forms, however, probably this needs more study). Wing pattern seems as though it could be useful too, and at least in a cursory examination of internet images, some Eurasian Magpies have narrower trailing dark borders to the inner primaries compared to Black-billed Magpie (for what it’s worth, the flight shot of the SC bird shows a bird with a fairly broad black border).
The South Carolina records committee will have its hands full attempting to determine the provenance of a magpie. Comparing the photos with those of Eurasian Magpies may help settle the species involved, but it may never resolve the bird’s origin, as an escapee is tough to rule out. Short of a band around its leg or a claim of a lost bird, provenance is unknowable.
The decision ultimately lies in the capable hands of the SC BRC. This talk of vagrancy always spurs interesting discussion in birder circles. Have a look at the discussion on the ABA Rare Bird Alert page, and let’s open it up to the larger community. Please feel free to speculate in the comments.
Love these sorts of discussions? Then you’d surely love North American Birds, the ABA’s journal of ornithological record. ABA members are entitled to a discounted subscription rate. More information is available at the NAB site.
Thanks to Ned Brinkley for his comments on an earlier draft of this post.
Thanks to Rick Wright, Brooke McDonald, Andy Wilson, James W. Beck, Laura Erickson, Dave McClain, Kent Fiala, Wendy Ealding, Bill Hubick, Glenn Coady, Michael Retter, Jesse Ellis, “Bottomland Mud” and Ryan Brady, for their comments on the original thread, from which much of this information was gleaned.
Lee, S., C.. S. Parr, Y. Hwang, D. P. Mindell, and J. C. Choe. 2003. Phylogeny of magpies (genus Pica) inferred from mtDNA data. Molecular Phylogenetics and Evolution 29(2):250-257.
McLaren, I. A. 2012. All the Birds of Nova Scotia. Gaspereau Press: Kentville, NS.
Trost, Charles H. 1999. Black-billed Magpie (Pica hudsonia), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/389
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