Lumps and Splits – Wowza!

First, a little background on lumping and splitting, when talking about bird species: lumping is when two once distinct species are put into one; splitting is when one species becomes two. This happens quite frequently and there has been recent talk with crossbills. Cackling Goose was split from the Canada Goose a while back. This article comes from the Wisconsin Birding Listserv (thanks to birder William Mueller for posting this):

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News from the Birding Community E-Bulletin for April of ’07

“BARCODE SPLITS AND LUMPS:

It was announced in February that genetic testing among North American birds may have revealed as many as 15 potential new species. Revealing the Canadian-led results were scientists from the University of Guelph (the Biodiversity Institute of Ontario) and Rockefeller University, along with colleagues at the Smithsonian Institution, the Canadian Wildlife Service, and the Royal Ontario Museum. The researchers discovered the 15 potential new species among 643 types of birds studied between Arctic Canada and Florida.

No less surprising, the study revealed that a number of birds currently classified as separate species are so genetically similar that they could actually represent varieties of the same species. The study revealed 14 pairs of birds with separate identities that were almost genetic “twins,” a trio of birds representing a DNA “triplet,” and eight gull taxa that were practically identical. The study determined that many of these species are actually indistinguishable to the human eye and ear.

Look-alike taxa representing 15 potential “splits” include Northern Fulmar, Solitary Sandpiper, Western Screech-Owl, Warbling Vireo, Mexican Jay, Western Scrub-Jay, Common Raven, Mountain Chickadee, Bushtit, Winter Wren, Marsh Wren, Bewick’s Wren, Hermit Thrush, Curve-billed Thrasher, and Eastern Meadowlark.

The Birdfreak Team says: Three wrens split yet not the House; the one with an endless amount of sub-species. Would there become a “Midwestern Meadowlark”? It’s surprising that Song Sparrow isn’t on the list. Any others?

The “lumps” of “virtually identical” taxa potentially include: Snow Goose and Ross’s Goose; Black, Mallard and Mottled Duck; Blue-winged and Cinnamon Teal; King and Common Eider; Western and Clark’s Grebe; Laughing and Franklin’s Gull; California, Herring, Thayer’s, Iceland, Lesser Black-backed, Western, Glaucous-winged and Glaucous Gull; Red-naped and Red-breasted Sapsucker; Black-billed and Yellow-billed Magpie; American and Northwestern Crow; Townsend’s and Hermit Warbler; Golden-crowned and White-crowned Sparrow; Dark-eyed and Yellow-eyed Junco; Snow and McKay’s Bunting; Great-tailed and Boat-tailed Grackle; and Common and Hoary Redpoll.

The Birdfreak Team says: The lumps is where we find the oddest findings: EIGHT gull species put into ONE! Blue-winged and Cinnamon Teals? They might hybridize but seem pretty distinct in the field. White- and Golden-crowned Sparrows certainly seem distinct.

DNA barcode sequences are very short, and they can apparently be obtained relatively quickly and inexpensively in the laboratory. These tests reveal what amounts to a genetic “barcode” for each bird that is similar to the black-and-white parallel lines found on food packages at supermarkets. Paul D.N. Hebert from the University of Guelph, maintains that this genetic process may prove to be a “master key for identifying species, one whose power will rise with increased taxon coverage and with faster, cheaper sequencing.”

Current controversy surrounding the DNA bar-coding system derives not so much from the method itself, but from assertions that the process would supersede existing and long-standing taxonomic theories. The technique does suggest that DNA bar-coding in the future should stand alongside other traditional taxonomic tools to combine morphological, behavioral, and genetic investigations in order to more accurately determine exactly what constitutes a species. DNA bar coding will provide an additional tool for more traditional and integrative taxonomy.

Work among the researchers is continuing in an attempt to collect DNA information on the remaining 47 North American bird species, as well as several more species that are considered extinct. The goal is to finish an all-bird DNA inventory by 2011.

Curiously, next month will mark the 300th anniversary of the birth of Linnaeus (i.e., Carl von Linne), the Swedish naturalist who established the conventions for naming living organisms as well as the system of scientific classification that, with a few modifications, is still in use today. How appropriate that a 21st-century DNA bar-coding approach for birds is being discussed at this very time!”

The Birdfreak Team says: All this DNA stuff is great but will it make field identification even harder? Will it render all field guides obsolete? Will sub-species get proper recognition when it comes to conservation issues? When will Yellow-rumped Warblers be split again? This is exciting information but a bit overwhelming. Thoughts, comments? We’d love to hear from you!