Hi all,
Some of you may be familiar with the “problem” of Red Crossbill call types in North America, where named subspecies are generally unidentifiable (and are likely to not even constitute valid populations). In contrast, the call type system developed by Jeff Groth accurately categorizes crossbills into identifiable and mostly reproductively isolated populations, but is not a formalized taxonomic system and thus does not appear on the Clements Checklist. Prior discussion on this forum has asked the question about what iNat’s approach to this system should be, in terms of observation fields or adding the call type system as a component of the taxonomy, but I’d like to ask a slightly different question. Many of the named subspecies appear to line up relatively well with call types: for example, Loxia curvirostra sitkensis and Type 10 (Sitka Spruce) both occur in the Pacific Northwest, are small-billed, and even include references to Sitka Spruce in the name. However, these populations were described almost a century apart from one another, and there is no formal research linking the two. The few RG observations of sitkensis are identifiably Type 10, and it appears that community consensus has linked these taxa together (similarly to what’s happened with benti and Type 2, for example). So in cases like this, where an unidentifiable named subspecies and an identifiable “informal” form appear to likely correspond, should a subspecies-level identification be used? Or should we stick to the existing observation field for types and ignore subspecies in cases where there is not a definitive link? (A few subspecies and types, like for example percna and Type 8, or mesamericana and Type 11, are pretty clearly identical and there shouldn’t be problems there). Apologies if a similar topic has already been discussed, and thanks in advance for any thoughts!