Ah - I see Bill Schmoker already commented! What I can say is that we were astounded that day that BOWAs outnumbered geese on the CBC!
On Monday, January 30, 2023 at 2:59:23 PM UTC-7 Scott Severs wrote: > All CBC historical data by species (or circle) can be queried here: > > > https://netapp.audubon.org/CBCObservation/Historical/ResultsBySpecies.aspx?1 > > On Monday, January 30, 2023 at 2:55:44 PM UTC-7 Scott Severs wrote: > >> The Boulder CBC once held the annual Christmas Bird Count’s all time >> highest record for bohemian waxwings in the continental United States, >> *11,284 >> individuals seen in one day in 1987! Yes that's 11 thousand! * >> >> >> >> On Monday, January 30, 2023 at 6:51:39 AM UTC-7 [email protected] >> wrote: >> >>> I downloaded and compiled all the eBird accepted Bohemian Waxwing >>> checklists for the Denver Metro area (Denver, Adams, Arapahoe, Douglas, >>> Jefferson, Broomfield). Hugh Kingery suggested a definition of an irruption >>> to be greater than 4 birds on a checklist and to cover at least a period of >>> 2 weeks. I sorted it into date order for these combined 6 counties. After >>> dropping all checklists with less than 5 birds or an X in the count, I was >>> left with 215 checklists with BOWAs in the Metro area over a 75 year >>> period. Hugh had BOWAs back in 1948 close to the zoo. >>> >>> eBird was started by Cornell in 2002. Not many birders used it at that >>> time but it is now widely used. Many birders have entered their historical >>> records which is such valuable information. Many thanks to all the >>> reviewers that really make this a trusted source of data. And thanks to all >>> the birders that are now submitting checklists, we really have a great >>> resource of birding data. >>> >>> David Suddjian was the first to see our current amazing irruption on >>> 12/23/2022 in Ken Caryl. He confirmed the 20 flyovers by the "tight >>> formation, size and calls". And it is possible we will continue to see this >>> current irruption even into April. >>> >>> We have to go back *14 years* to get to the closest previous >>> irruption for the metro area. It was in the winter of 2007-2008. It began >>> on 12/14/2007 at Chatfield State Park and the last sighting that winter was >>> at Columbine West on 4/13/2008. The high count that winter was 200 BOWA in >>> Douglas county on 1/15/2008. >>> >>> Going back *2 more years* to the winter of 2004-2005 was a large >>> irruption year as well. It began on 11/24/2004 in Broomfield and finished >>> on 3/21/2005 in Douglas county. The high count for this period was 2000 (a >>> conservative count they said) and was recorded in Adams county at "Federal >>> & 120th by Norm, Ted, Dave and Marilyn" on 11/30/2004. >>> >>> You have to go back another *13 years* to the winter of 1990-1991 to >>> get another irruption for the Denver Metro area. Beginning on 12/12/1990 at >>> Chatfield and continuing to 4/5/1991 at Joe Roller's Yates home in Denver. >>> He had 22 BOWA and commented on their "mean looking facies". There are 5 >>> records for this irruption winter and the average count was around 40 BOWAs. >>> >>> The 1980's had 5 winters with BOWA irruptions. 79-80, 81-82, 84-85, >>> 86-87 and 87-88. The largest count on a checklist for the 1980's was 1000 >>> BOWA on 1/12/1988 in Greenwood Village by Hugh Kingery. He made this >>> comment "Heritage Village, Littleton (6465 S. Niagara).No details. This >>> month saw a lot of BOWAs in metro Denver.". >>> >>> There is only one year in the 1970's and one year in the 1960's that >>> shows irruptions in the eBird historical data in the Metro area. 1976-1977 >>> had a checklist with a high count of 1000 BOWA at Cherry Creek SP on >>> 3/12/1977. And finally in the winter of 1968-1969 there was a report of >>> 2000 BOWA at Bow-Mar on 12/20/1968 reported by Van Remsen with this comment >>> "invasion year; careful estimate". >>> >>> As more historical data is entered and as more birders use eBird, the >>> data will get better. I did download all of the Colorado BOWA data and it >>> contained right at 1000 records. All of Colorado averages an irruption >>> every 3 years. But the Denver Metro area, from 1948-2023, has had 11 >>> irruptions in this 75 year span. So, we average an irruption about every 7 >>> years. Enjoy this one while it lasts. Sure has been fun. >>> >>> Gregg Goodrich >>> Highlands Ranch >>> >> -- -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/cobirds?hl=en?hl=en * All posts should be signed with the poster's full name and city. 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