Page 17 - Black Range Naturalist Oct 2020

On August 13, 2015, Chapline collected the specimen shown above on the east slope of the Black Range. It was described at that time as Echinochloa crus-galli which is an introduced species with a world-wide distribution. In 1967, Ali & Gould (at the Tracy Herbarium) identified the specimen as Echinochloa muricata, a native species with wide distribution.
I am far from competent enough to venture an opinion about which is correct. But I would like to note that it was found in wet loam in a meadow which was mostly (60%) covered with sedges and rushes - perhaps one of the long gone ciénegas of the Black Range.
Speciation: American Crow/ Northern Oriole/Mexican Duck
On the issue of species boxes and our strong belief in clinal differences comes news that the Northwestern Crow and the American Crow are to be lumped into one species. Of interest here is that this is not due to a new analysis of DNA and a decision to draw the line somewhere else - nope, the range of the American Crow has been spreading into the range of the Northwestern Crow for decades and the two hybridize. Whereas their species traits spread apart in the past because of geographic separation, they are now
experiencing a reconciliation, having moved back into the same neighborhood. “Corvus caurinus is recognized as representing a geographical trend, rather than a species or subspecies, and thus is treated as a junior synonym
of Corvus brachyrhynchos.” It is the process, rather than the particular, of this decision which is of interest to us in the Black Range.
Lest you think that this is a simple process with a predictable outcome, consider the Northern Oriole. During my birding life the speciation determination of Baltimore and Bullock’s Oriole has bounced back and forth. It has been known for quite some time that the hybridization zone between these (sub)species has been drifting westward. In “Genomic and plumage variation across the controversial Baltimore and Bullock’s Oriole Hybrid Zone”, Walsh et al., The Auk, August 1, 2020, note that the hybridization zone between the two subspecies has narrowed and that the two subspecies do not appear to be blending into a single species (Northern Oriole).
Taking the leap in the other direction is the decision to recognize the Mexican Duck (Anas diazi) as a full species, separate from Mallard (reversing the decision made in 1973 to ‘lump’ the two). This ‘new species’ can be found in the Black Range.
In part, the decision to split Mexican Duck from Mallard was based on work by Dr. John P. Hubbard, yes, the same John Hubbard who regularly contributes to this publication. See The Biological and Taxonomic Status of Mexican Duck.
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