Rockjumper Tours

aba events

Sibley’s field identifiable subspecies

David Sibley’s ground-breaking Guide to Birds, 11 years old this year and still the standard by which North American field guides are judged, was notable for his treatment of identifiable subspecies as regional forms rather than the seemingly more exact latin named subspecies.  This was done largely to discourage birders from jumping the gun and making ill-informed identifications to specific subspecies (which can be really tough even when they’re easy), but also to encourage observers to be more aware of the incredible variation within species so as not to overwhelmed by an aberrant individual.   Sibley’s explanation, in his own words, is here.

But subspecific identification is a siren song, and the lure is strong, and David Sibley himself has offered a list of subspecies that he considers to identifiable in the field.  His rationale for what he includes, and doesn’t include, is as follows:

In trying to establish consistent and simple (even if subjective) criteria for naming subspecific variations, I have approached this list narrowly from a birder’s field identification perspective. For each species I asked the question “If I were on an island in the middle of the ocean, and one [species x] showed up, would I be able to tell which regional population it came from?” If the answer is a confident “yes”, it gets a name. I’ve also included names for a lot of “maybe” subspecies, and for these I describe my concerns in the comments.

This is not a list of “identifiable forms”. I have limited this list to subspecies, which have a discrete geographic range. Color morphs, age and sex variations, hybrids, and more can be fascinating and there is often scientific value in recording those details, but I have excluded them from this list.

Birders may quibble with what Sibley includes – and what he doesn’t include – but a full accounting of the identifiable subspecies and, in fact, the determination of what it even really means to be a subspecies, is ongoing.

It’s fascinating stuff, and if the prevalence of “more study needed” in this list is any indication, these questions are going to keep interested field birders busy for some time to come.

Facebooktwitter
The following two tabs change content below.
Nate Swick

Nate Swick

Editor, Social Media Manager at American Birding Association
Nate Swick is the editor of the American Birding Association Blog, social media manager for the ABA, and the host of the American Birding Podcast. He lives in Greensboro, North Carolina, with his wife, Danielle, and two young children. He is the author of Birding for the Curious and The ABA Field Guide to Birds of the Carolinas.
American Birding Podcast
Birders know well that the healthiest, most dynamic choruses contain many different voices. The birding community encompasses a wide variety of interests, talents, and convictions. All are welcome.
If you like birding, we want to hear from you.
Read More »

Categories

Authors

Archives

ABA's FREE Birder's Guide

via email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

  • Open Mic: How to talk about climate change as a young birder June 4, 2018 11:37
    One of the challenges in talking about climate change is the disconnect that people feel when hearing about things like sea level rise and their daily lives. Birders, young and old, can play a major role in bridging this gap. […]
  • Meet Teodelina Martelli, 2018 ABA Young Birder of the Year May 26, 2018 2:27
    Meet Teodelina Martelli, a 17-year-old homeschooled birder living in Thousand Oaks, California and one of the 2018 ABA Young Birders of the Year. […]
  • Meet Adam Dhalla, 2018 ABA Young Birder of the Year March 27, 2018 5:42
    Meet 12-year-old Adam Dhalla from Coquitlam, British Columbia, one of the 2018 Young Birders of the Year! Want to learn more about how you could be the next Young Birder of the Year? Registration is open for the 2019 contest now! ——– Q: Were you a birder before you started the ABA Young […]

Follow ABA on Twitter