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Fwd: [cobirds] Regional rarities and the CBRC

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  • Jason Beason
    A very long, but important, email from CoBirds relevant to our side of the state. Very well done Mr. Cooper! For those of you that don t know who Tony
    Message 1 of 1 , Aug 17, 2011
      A very long, but important, email from CoBirds relevant to our side of
      the state. Very well done Mr. Cooper! For those of you that don't
      know who Tony Luekering is; he is one of the most knowledgeable
      ornithologist in the US.

      Thank you,
      Jason Beason
      Paonia - Delta County

      ---------- Forwarded message ----------
      From: <coloradodipper@...>
      Date: Tue, Aug 16, 2011 at 6:12 PM
      Subject: [cobirds] Regional rarities and the CBRC
      To: cobirds@...
      Cc: clw37@..., mji26@..., bls42@...

      Hi all:

      I recently entertained a query from a friend as to why the Colorado
      Bird Records Committee (CBRC) asks for documentation of occurrences of
      certain species that are regular (some are common) in parts of the
      state, but rare or non-existent in other parts of the state (see
      http://www.cfo-link.org/downloads/review_species.pdf).  Since my
      answer might be useful to more than just the querent, I thought that I
      would reply to this venue.  But, first, I will discuss the importance
      of bird-records committees.  For those that think such committees are
      anathema, please don't delete this missive quite yet; please read on.

      Submitting documentation to relevant bird-records committees is
      important to ornithology to enable the layperson to contribute to the
      science.  Without some sort of review of rare-bird occurrence,
      ornithology would be unable to utilize much of the information and
      data generated by the 10s of 1000s of birders, because ornithologists
      would be unable to separate the wheat from the chaff.  Ornithology
      certainly cannot be expected to accept any sighting from any person as
      valid, because all of us make mistakes, whether we care to admit them
      or not.  I can recall visiting the Great Smoky Mountains in my first
      year of birding and, because I didn't put Turkey Vulture on my list of
      expected species there, I noted -- and was certain thereof -- 27 adult
      Golden Eagles in a kettle at one point.  Upon returning home, my
      birding mentor kindly pointed out where I had gone wrong.  This
      experience was the first of many humbling events in my birding career,
      and I will readily admit to still making ID mistakes, though I
      believe/hope that I don't make errors quite as egregious as the Golden
      Eagle mistake.

      With the point of the above paragraph as given, birders in many
      political units have decided to establish committees of skilled
      birders to review occurrences of birds rare to the particular
      political unit, almost always under the auspices of a particular
      respected organization (the CBRC is under the auspices of the Colorado
      Field Ornithologists, the owner of this listserve).  A decision by a
      group of people is almost always more conservative than the most
      liberal opinion of any given member, and conservatism is usually best
      when dealing with aspects that alter the understanding of a particular
      topic (though there are many exceptions).  That is why simple
      submission of data through the eBird review process is not enough for
      reports of review-list species, because that process simply changes
      who the single person responsible for record acceptance from the
      observer to the reviewer.  Yes, for the most part, eBird reviewers are
      highly skilled and responsible individuals, but they are still single
      individuals and one of the reasons that committees are committees is
      to attempt to arrive at a consensus of opinion that might be more
      acceptable than having a single person be the arbiter of all.  A group
      of people also brings differing experience, knowledge, understanding,
      and -- not to be considered inconsequential -- variety of
      acquaintances, which may allow for more thorough discussion and
      treatment of individual reports.

      Though these committees certainly exist in order to come to some group
      decision on the reliability or acceptability of particular reports of
      bird occurrence, one of their other primary reasons for existence is
      as an archive -- some way to store all of the information about bird
      occurrence that has been submitted so that future researchers can
      access it.  Of course, that archival mandate is one that is never
      questioned by birders.  What gets questioned is the rationale behind
      the review of bird reports and why cannot a person's word simply be
      taken as is.  For that, see Golden Eagle report, above.  One important
      thing to keep in mind is that a person's list is a personal thing, one
      can count on it whatever one cares to.  However, science requires some
      form of proof.  For those old enough, one might recall the furor
      created about "cold fusion" in the late 1980s
      (http://en.wikipedia.org/wiki/Cold_fusion).  For science, it matters
      not what any individual states, but what can be proven.  The take-home
      message, if it hasn't already been delivered, is that anyone can make
      a mistake, so any individual report can reasonably be expected to be
      questioned, particularly when that report alters our understanding of
      the world, even if it's just a miniscule portion of that
      understanding, such as the distribution of Red-winged Blackbird.

      Let us consider a hypothetical sighting of a single Red-winged
      Blackbird in Campo, Baca County, Colorado, on 22 April.  If the
      reporter had actually mis-identified something else as the reported
      Red-winged Blackbird, it doesn't really alter our understanding of
      Red-winged Blackbird distribution, because the species is, at worst,
      uncommon to, at most, abundant in the area around Campo at all times
      of year.  However, if the bird mis-identified as a Red-winged
      Blackbird were actually a Cassin's Finch, that would change our
      understanding of that species' distribution, at least a little.  And,
      if that mis-identified bird were actually a Tawny-shouldered
      Blackbird, that would change our understanding of that species'
      distribution quite a lot.  The more radically a particular observation
      would change current understanding, the more detail about that
      observation will be required to be accepted by science.  This bit is
      of particular importance when dealing with the subject of regional

      Colorado sits astride an incredible juxtaposition of differing
      biogeographical regions and that fact is the reason that the state
      list is nearing 500 species (when that milestone is reached, CO would
      be the only non-coastal, non-Mexico-border state with that
      distinction).  However, because of that habitat variety and a host of
      other biogeographical reasons, particularly the differences between
      eastern and western Colorado, there are quite a lot of species that
      are common (even abundant) on one side but unknown or virtually
      unknown on the other.  Good examples of this include Grasshopper
      Sparrow (common to abundant breeder on the eastern plains; but only 1
      or 2 good records west of the eastern foothill edge) and Purple Martin
      (uncommon but local breeder in western Colorado, but with only ~10 or
      so good records in eastern Colorado).  Additionally for Purple Martin,
      there is some concern that the "eastern" subspecies and the "western"
      group of subspecies might be separate species, though I suspect that
      this will be shown not to be true.  However, if a split were more
      likely, one can easily see how the CBRC might want documentation for
      such a rare "species."  I find that it helps if one imagines a state
      boundary running along the west side of Larimer, Boulder, Jefferson,
      Douglas, El Paso,Fremont, Huerfano, and Las Animas counties and then
      considering what the Records Committee for the state of "Western
      Colorado" would like to see as far as documentation of bird
      occurrence.  Or what the ECBRC would like to see.  Even on the eastern
      plains of Colorado, there is a small suite of species, exemplified by
      Field Sparrow, that are of uncommon to common occurrence in the
      easternmost tier of counties, but which rarely stray west of there.
      Or, at least, rarely get found and identified correctly west of there
      (I've seen multiple birders identify immature White-crowned Sparrows
      as Field Sparrows).

      For my final example of the importance of documenting regional
      rarities, I refer you to the occurrence this past winter of a
      Curve-billed Thrasher in Eagle County.  That species (as currently
      constituted) is a widespread and uncommon to common breeder in
      southeastern Colorado, but rare north of the Palmer Divide and
      virtually unknown west of the eastern foothill edge, despite the
      species' predilection for vagrancy.  As such, this out-of-range
      occurrence received little play on the listserves in Colorado.
      However, Jacob Cooper, interested in bagging a pretty darned "good"
      county bird, went up to ogle the thing.  Though I don't know, I
      imagine that he was pretty surprised when he saw the bird and noted
      that it appeared to be referable to the western form of Curve-billed
      Thrasher typically found in the U.S. only in Utah, Nevada, Arizona,
      and California and which looks and sounds different from the eastern
      form that so many of us have seen in the semi-desert areas of
      southeastern Colorado.  Since he took pictures and submitted a
      complete report to the CBRC, upon acceptance by that body, science
      will have gained a bit more understanding about Curve-billed Thrasher
      distribution.  However, there is strong published evidence (genetic
      and otherwise) that the eastern and western forms of the species are
      actually separate species and if that is so, science will have gained
      a much larger chunk of understanding, as the occurrence would be the
      first for Colorado.

      To bring us back to the archival aspect of any bird-records
      committee's duties, let us imagine that Jacob did not submit
      documentation to the committee.  Then, when his computer crashed or
      his house burned down, all physical records of that bird's occurrence
      will have been lost.  Future researchers would have no recourse but to
      discount the occurrence, as there would be not a scintilla of proof of
      such an important record.  However, since he did submit a record,
      those bits of physical proof -- the pictures and the written
      documentation -- will be archived at the Denver Museum of Nature and
      Science, as are all reports submitted to the CBRC (with duplicates of
      all records held by the current Chair) -- even the ones that are found
      lacking in some respect and were not accepted by the CBRC.  All of
      those records will always remain available to future researchers.
      That cannot be said of individual personal websites, photo
      collections, etc.

      In summation, birding is a very individual hobby and I feel that one
      of the primary reasons that it is so popular, is that it is so
      flexible.  A given enthusiast can take the hobby as far as s/he cares
      to, whether just enjoying watching birds at a backyard feeder or
      researching and writing scholarly publications on bird distribution.
      Or anywhere in between or sideways.  However, all of us that do more
      than just ogle birds at feeders without caring to put names to them
      can join the uncountable thousands of people that contribute to the
      science of ornithology by dutifully reporting -- and defending -- ones
      sightings.  To extend our understanding of what is the best-known
      group of organisms on the planet -- and most of that knowledge gained
      by amateurs!  I strongly encourage submission of checklists to eBird
      (www.ebird.org) and also submission of reports of Colorado review-list
      species (http://www.cfo-link.org/downloads/review_species.pdf) to the
      CBRC (http://cfo-link.org/CBRC/login.php5).

      I thank you for your time.


      Tony Leukering
      Villas, NJ

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      Jason Beason
      Special Monitoring Projects Coordinator
      Rocky Mountain Bird Observatory
      Phone: 970-310-5117

      Paonia Satellite Office:
      39405 Lund Road
      Paonia, Colorado 81428

      “Conserving birds and their habitats”
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