Thursday, 29 June 2017

Re: [cobirds] Re: Dickcissel plant associations

Very nice information, John.  While Dickcissels seem to occur in many different plant communities, as you point out, they are NOT everywhere.  I am struggling to see the keys to their occupation of a particular site or region.  Is it structure or food or both?  My botanist friend Dave Steingraeber from CSU told me tonight that he heard from a colleague that drought in the northern prairie states (Dakotas, etc.) is perhaps forcing birds from normal strongholds into other places.  The result is birds in novel areas or birds at abnormally high numbers in areas where they occur with regularity in low numbers.  Lush vegetation seems to be a key to where they settle for the summer but I suspect the prey base that lush vegetation supports is the real answer.  Whatever the answer(s), it is interesting. 


Again, thanks to you and everybody who has chimed in on this issue.


Dave Leatherman

Fort Collins




From: cobirds@googlegroups.com <cobirds@googlegroups.com> on behalf of mvjohnski@gmail.com <mvjohnski@gmail.com>
Sent: Thursday, June 29, 2017 7:36 PM
To: Colorado Birds
Subject: [cobirds] Re: Dickcissel plant associations
 
Dave: We have been carefully observing the plant cover types where we are seeing the dickcissels. Myself and a range conservationist discussed this very topic yesterday on our trip to see Dickcissels south of Alamosa. Here is the San Luis Valley perspective....list:

Tall Brome Grasses: Usually of nonnative grasses like smooth brome, timothy
Tall Grasses-Alfalfa complex: Birds are in a mix of these two plant cover types.
Barley: Today I heard one singing in a barley field. These are all cover types. Habitat types or plant associations usually refer to native plant potentials. A cover type is just the combo of plants that are currently on an ecological site.
Most of these types are currently being cut for hay. In which case, birds have moved to fencelines or uncut corners and edges. We will be looking at this population to see if we can see breeding evidence, aka Atlas procedures.

I have not seen or heard any Dickcissels in the San Luis Valley that are on native habitat types/plant associations. Not surprising since we lack true tall grass prairie ecosystems in our high desert shrubland communities. 

John Rawinski
Retired Soil Scientist USDA


On Monday, June 26, 2017 at 12:08:12 PM UTC-6, Dave Leatherman wrote:

I would be interested in hearing from COBIRDS folks about their observations of the dominant plant(s) in the areas where Dickcissels seem to be territorial (lots of singing on multiple days).  Of course, alfalfa has always been a crop that seems to attract Dickcissels, presumably because of the sulphur and white butterfly caterpillars found in these fields, and probably a lot of other insects like grasshoppers.


During this year when the Colorado prairie and foothills are lush with plant life due to much needed moisture over the last couple years, Dickcissels can exist in our midst and they seem to have choices.  Which choices are they making?  In addition to alfalfa fields, I have also seen them in salt-cedar/tamarisk (of all things, in this case near Nee Noshe Res south of Eads (Kiowa)) and in wild licorice (Glycyrrhiza lepidota) north of Nunn (Weld).


What other plants are you seeing Dickcissels favor?


Thanks,

Dave Leatherman

Fort Collins

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