[cobirds] Black-headed or rose-breasted grosbeak Boulder

[wwillem]

This morning I saw what looked like a non-breeding female black-headed or 
rose-breasted grosbeak in our yard. Yellow under-wings, some streaking 
along sides but not on center of breast. Bill rather pale and not clearly 
bi-colored. Any help with more definitive ID would be much appreciated.

Pics on https://ebird.org/view/checklist/S47947208.

Willem van Vliet--
Boulder

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[cobirds] Re: yellow-billed cuckoo

[wwillem]

Maybe best bet is to park in the lot of Scott Carpenter  Park on the w side 
of 30th St., just S of Arapahoe, and then walk along the creek to the 
ponds.  You're bound to see birds along the creek path as well (last week's 
reports included plumbeous vireo, wilson's warbler, summer tanager, western 
tanager, black-headed grosbeak in addition to flickers, blue jays, house 
wrens, chipping sparrows, common grackles, cedar wax wings, and robins).

On Monday, May 14, 2018 at 4:24:31 PM UTC-6, Sharon Kay wrote:
>
> I am curious to know where one can park to view those ponds. I looked on 
> satellite map and don't see parking. Thanks.
>
> On Sunday, May 13, 2018 at 8:54:39 PM UTC-6, wwi...@gmail.com wrote:
>>
>>
>> This afternoon around 2 pm there was a yellow-billed cuckoo at Confluence 
>> Ponds in Boulder, near planked pedestrian bridge. Slender bird with 
>> white spots on long tail.Brown back and crown contrasting with white belly 
>> and chin. Dark eyes. Down-curved bi-colored bill, dark upper mandible, 
>> yellow lower.  https://ebird.org/view/checklist/S45644389.  First 
>> spotted by Ernest Crvich.
>>
>

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[cobirds] yellow-billed cuckoo

[wwillem]

This afternoon around 2 pm there was a yellow-billed cuckoo at Confluence 
Ponds in Boulder, near planked pedestrian bridge. Slender bird with white 
spots on long tail.Brown back and crown contrasting with white belly and 
chin. Dark eyes. Down-curved bi-colored bill, dark upper mandible, yellow 
lower.  https://ebird.org/view/checklist/S45644389.  First spotted by 
Ernest Crvich.

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[cobirds] Re: What CBC data can tell us about House Sparrows in Colorado Springs

[wwillem]

Is it possible to disaggregate the data to see if the variations over time 
occurred across the board or were attributable to some places more than 
others?

Willem van Vliet--
Boulder

On Friday, April 13, 2018 at 12:52:32 PM UTC-6, doug...@gmail.com wrote:
>
> Hi all,
>
> First off, hi! I'm brand new to this list. As dumb luck would have it, the 
> first post I ever received was yesterday from Diana Beatty. She had the 
> wonderful idea to do a linear regression on Christmas Bird Count (CBC) data 
> from Colorado Springs to see if there has been a decline in House Sparrow 
> population size since 1950. Due to my burgeoning interest in House Sparrows 
> as a graduate student, I asked her if she had any more details. In 
> response, she sent the raw data for me to have a look at. A big thanks to 
> her for sending that along!
>
> Diana's analysis was of course correct: that is, that when looking from 
> 1950-2017, there has been no overall trend toward decline. However, my eyes 
> wouldn't stop perceiving little peaks and dips in the cloud of data points. 
> So I split the data up and found that there have been 3 cycles of 
> statistically significant growth and decline since 1950. We're currently in 
> the middle of a decline that began in 2001.
>
> It's no surprise that there have been fluctuations in the 67 years of CBC 
> data that we have. All wild populations fluctuate. The interesting part is 
> telling a story as to why they fluctuate. Often, growth and decline cycles 
> have something to do with climatic patterns, possibly interacting with 
> things like competition and selection. Unfortunately, I'm not sure that I 
> have the expertise to attempt any associations with climate or other 
> factors right now. But it's likely there's something of interest going on, 
> even if we don't know what it is!
>
> I'm attaching a visual representation of the CBC data to this post. I 
> color-coded each of the cycles. The x-axis shows passage of time with the 
> far left side being 1950 and the far right being 2017. On the y-axis is the 
> CBC count data, with lower values on the bottom and higher counts up 
> higher. Note that the red dots, spanning the years 1950-1984, represent the 
> longest and slowest decline. The last 2 declines (the second of which we're 
> currently in right now) occurred on much smaller time scales, from 
> 1985-2000 (black dots) and from 2001-present (blue dots). The lowest ever 
> count in the entire data set was in 2016 with only 177 House Sparrows 
> reported.
>
> While it's likely that a population ecologist could point out several ways 
> I've poorly described these patterns, I think it's cool that Diana began 
> all this with an analysis of publicly-accessible data and shared it on a 
> bird listserv. Thanks a lot to all of you for reading this, and I'd love to 
> continue the conversation if anyone is interested!
>
> Good birding,
> Doug Eddy, Laramie, WY
>
>
> 
>
>
>

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Re: [cobirds] House Sparrows - Boulder & metro area

[wwillem]

The book:

*The moth snowstorm: nature and joy*.  Michael McCarthy 
. Publ. by John Murray 
(2015).


Willem van Vliet--

Boulder

On Monday, April 9, 2018 at 4:21:36 PM UTC-6, Richard Trinkner wrote:
>
> Some personal House Sparrow data:
>
> Between 1996 and 2015, House Sparrows appear on 30.16% of my Colorado 
> checklists. 
>
> Between 2015 and 2018, they appear on only 13.44% of my Colorado 
> checklists.
>
> They used to be very common bird for my backyard feeders. Between 1996 and 
> 2015, House Sparrows were on 58.21% of my backyard checklists. *So far in 
> 2018, I haven't had a single House Sparrow*.  Not one.  I've completed 26 
> checklists for my yard this year: not a single House Sparrow.
>
> In Boulder, House Sparrows seem to be hanging on in small numbers in very 
> urban areas. I walk to work most mornings in central Boulder. I used to 
> nearly trip on House Sparrows. I still see them often (72% of my morning 
> walk checklists), but now I have to listen carefully for their call and I 
> generally only get a small handful of individuals.
>
> On the center-north Boulder CBC route on which I counted last December, we 
> only found sparrows in only two locations, whereas in past years they were 
> extremely common.
>
> Here's an article about their decline: 
> https://www.sciencedaily.com/releases/2017/10/171003111056.htm.
>
> I've also read that they may be particularly susceptible to cell phone 
> tower radiation, and that their bug food source may be susceptible to such 
> radiation as well.
>
> Cheers,
>
> Richard Trinkner
> Boulder
>
>
>
> On Mon, Apr 9, 2018 at 11:48 AM, 'Hugh Kingery' via Colorado Birds <
> cob...@googlegroups.com > wrote:
>
>> Denver Audubon just received a call from a woman in Lafayette with a 
>> unique subject: where have the House Sparrows gone?
>>
>> She says she used to have as many as 80, but now she sees only a pair or 
>> two, sproadically. They check out her yard and continue on somewhere else. 
>> Have any of you experienced a diminishing numbers of House Sparrows?
>>
>>
>> Hugh Kingery 
>>
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>> .
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>>  
>> 
>> .
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>>
>
>

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Re: [cobirds] House Sparrows - Boulder & metro area

[wwillem]

In *The Moth Snowstorm: Nature and Joy, *Michael McCarthy writes eloquently 
about the near-extinction of house sparrows in London, England. He examines 
several explanations and adds the perspective of possibly more 
geographically restricted habitats for sparrows compared with other urban 
birds affected by the same factors. As a result, these other species would 
be better able to replenish diminished populations by influx from 
elsewhere, whereas sparrows would experience very localized extinction.  If 
true, averages numbers over large areas could obscure significant 
differences from place to place at lower levels of aggregation.

On Monday, April 9, 2018 at 4:21:36 PM UTC-6, Richard Trinkner wrote:
>
> Some personal House Sparrow data:
>
> Between 1996 and 2015, House Sparrows appear on 30.16% of my Colorado 
> checklists. 
>
> Between 2015 and 2018, they appear on only 13.44% of my Colorado 
> checklists.
>
> They used to be very common bird for my backyard feeders. Between 1996 and 
> 2015, House Sparrows were on 58.21% of my backyard checklists. *So far in 
> 2018, I haven't had a single House Sparrow*.  Not one.  I've completed 26 
> checklists for my yard this year: not a single House Sparrow.
>
> In Boulder, House Sparrows seem to be hanging on in small numbers in very 
> urban areas. I walk to work most mornings in central Boulder. I used to 
> nearly trip on House Sparrows. I still see them often (72% of my morning 
> walk checklists), but now I have to listen carefully for their call and I 
> generally only get a small handful of individuals.
>
> On the center-north Boulder CBC route on which I counted last December, we 
> only found sparrows in only two locations, whereas in past years they were 
> extremely common.
>
> Here's an article about their decline: 
> https://www.sciencedaily.com/releases/2017/10/171003111056.htm.
>
> I've also read that they may be particularly susceptible to cell phone 
> tower radiation, and that their bug food source may be susceptible to such 
> radiation as well.
>
> Cheers,
>
> Richard Trinkner
> Boulder
>
>
>
> On Mon, Apr 9, 2018 at 11:48 AM, 'Hugh Kingery' via Colorado Birds <
> cob...@googlegroups.com > wrote:
>
>> Denver Audubon just received a call from a woman in Lafayette with a 
>> unique subject: where have the House Sparrows gone?
>>
>> She says she used to have as many as 80, but now she sees only a pair or 
>> two, sproadically. They check out her yard and continue on somewhere else. 
>> Have any of you experienced a diminishing numbers of House Sparrows?
>>
>>
>> Hugh Kingery 
>>
>> -- 
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>> "Colorado Birds" group.
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>> email to cobirds+u...@googlegroups.com .
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>> .
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>> https://groups.google.com/d/msgid/cobirds/162ab861dc0-179e-141ed%40webjas-vab073.srv.aolmail.net
>>  
>> 
>> .
>> For more options, visit https://groups.google.com/d/optout.
>>
>
>

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[cobirds] Cinnamon teal, Boulder County

[wwillem]

Yesterday afternoon, there were two cinnamon teal at Pella Crossing in the 
northern pond, east of 75th, mixed with redheads, common mergansers and 
ring-neckeds.  Also present were common goldeneyes, two canvasbacks, a 
hooded merganser, two green-wingeds, a few mallards and gadwalls, and lots 
of coots.

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[cobirds] suggestions for books on migration

[wwillem]

I would welcome suggestions for books on bird migration, including maps, 
not necessarily but preferably with information specific to Colorado.

willem van vliet--
Boulder

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[cobirds] Re: stray birds

[wwillem]

Thank you!  Looks like a terrific resource.  

I'm also interested in further work that has examined or is examining 
changes observed in Atlas II in relation to factors such as urban 
development, natural resource exploitation, road building, pollution and 
other aspects of habitat destruction.  Is there systematic or even 
anecdotal evidence, locally or systematical across the state?

Willem van Vliet--
Boulder, CO

On Friday, November 17, 2017 at 12:37:28 PM UTC-7, wwi...@gmail.com wrote:
>
>
> The recent sightings of the varied thrush and black-throated blue warbler 
> behind the Base-Mar Center in Boulder raised a few questions for me. I am 
> new to this list so my apologies if these questions are not appropriate for 
> this forum. 
>
>  
>
> I am curious about research that has examined spatial patterns of stray 
> birds and their characteristics (e.g., relative to their numbers, life 
> stage, sex, species, habitat) and as well as possible changes in historical 
> patterns owing to human-caused factors. I’ll be grateful for references to 
> pertinent studies.
>
>  
>
> Willem van Vliet—
>
> Boulder, CO
>

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[cobirds] stray birds

[wwillem]

The recent sightings of the varied thrush and black-throated blue warbler 
behind the Base-Mar Center in Boulder raised a few questions for me. I am 
new to this list so my apologies if these questions are not appropriate for 
this forum. 

 

I am curious about research that has examined spatial patterns of stray 
birds and their characteristics (e.g., relative to their numbers, life 
stage, sex, species, habitat) and as well as possible changes in historical 
patterns owing to human-caused factors. I’ll be grateful for references to 
pertinent studies.

 

Willem van Vliet—

Boulder, CO

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