[cobirds] Re: Cohorts

If you were to take down your feeders today, would the birds that have been coming to them starve?  Probably not.  Why?  Birds on average, spend only 20% of their "foraging time" in any one location.  There are feeding hierarchies among individual or family groups of birds and I suspect there may also be feeding hierarchies among groups of birds.  Different groups are allowed to feed in a location when it's their turn?  I too, have noticed that although I have 8-10 of a certain species feeding, that I also see similar size groups with different individuals.  This has been epecially noticeable with the Redpolls.  One group has 3 or 4 orange-variant individuals.  Another group of 8 - 10 does not, however I do not see a group of 20 at any one time.

 

Bob Santangelo

Wheat Ridge

 

On Saturday, January 26, 2013 5:36:23 PM UTC-7, ouzels wrote:

            The ABA blog on redpolls that Ted Floyd cited the other day goes into amazing depths for a casual bird watcher who might sink in the esoteric literature on redpolls, DNA, statistics, etc.

            One minor point, though, that Bill Schmoker mentioned, raises a question I have pondered lately. He said, ". . . Flocks coming to feeders are probably under-counted. For example, if someone counts and reports 75 redpolls at a feeding station, there well may be a pool of 200 or 300 birds coming and going."

            I remember someone saying that if you see 4 Black-capped Chickadees at a feeder at one time, you probably have 16-20 actually patronizing your largess.       

            At our feeders we commonly see 5-10 House Finches at a time. However, when we walk in the field below the house, in a big thicket of wild plums 200-300 yards away, we typically flush 60-120 House Finches.

            Do many species, during non-breeding seasons, move around in small cohorts compared to their local numbers? Do all those House Finches in the field sample our feeders sometime during the day? Or do some scorn our offerings for natural food or a neighbor's feeders?

Hugh Kingery
Franktown, CO

--
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 cobirds+unsubscribe@googlegroups.com.
To post to this group, send email to cobirds@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msg/cobirds/-/zkHwRN0RzN0J.
For more options, visit https://groups.google.com/groups/opt_out.