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. Include bird species and location in the subject line when appropriate * Join Colorado Field Ornithologists https://cobirds.org/CFO/Membership/ --- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/cobirds/7866c0a1-40c6-41e7-b547-6e5aba6a6537n%40googlegroups.com.
