Date: 7/5/18 10:40 am From: Thomas Kihn <thomaskihn...> Subject: [texbirds] Re: Eurasian collared dove population crash?
I just moved from northern Grimes County on June 1. Now I am in Baytown, so nothing to say about my new location. However, on the ranch were I lived for 5 and a half years until last month I can say that I used to (before this summer) see 4 or 5 of these birds at or around my feeder. But in mid-May this year the numbers jumped to 10 to 12! Maybe just a local fluke. Concerning other doves, this spring is the first time I had Mourning Doves come to the feeder. They were always common on the ranch, but always away from the buildings. Inca Dove completely disappeared about a year ago. One Common Ground-Dove came to the feeder on rare occasions over the time I lived there, none in the last year.This data is based upon casual viewing from my kitchen window but the numbers always indicate total birds seen at one time (no totals over the day of multiple visits by one bird).
Now that I am in Baytown, I hope to visit the Baytown Nature Center regularly.
On Thursday, July 5, 2018 11:14 AM, David Sarkozi <david...> wrote:
I would also caution the use of anecdotal memory as a baseline for comparison, we don't tend to remember negative observations as much as positive in my experience. As an example I was compiling the sighting board checklist for Anahuac NWR. I used the 100 most reported birds from eBird by highest percentage of reports by month, i,e, I used the month with the highest percentage of reports to rank the top 100. American Bittern did not make the cut, it's highest month was only 25%. I had a fellow volunteer differ with my analysis saying her sa the bird almost every visit in season. I asked him to count the number of visits in a row he saw the bird to prove me wrong. After 4 negative visits he conceded the point.
Our memories of how often we see a bird are often very flawed, unless we are counting we don't recall the negatives very well, just the positives.
On Wed, Jul 4, 2018 at 8:59 AM, Joseph Kennedy <josephkennedy36...> wrote:
A couple of years ago I sort of noticed that there were not as many collared doves around the smith point area. Did not see them crossing the bay and places that had large numbers had fewer. Last summer there were fewer but Harvey had something to do with it but did start checking other spots. Numbers on Bolivar were down too as well as around the house.
This summer actually went and censused.
A few years ago I could see 10-15 male doves do their courtship flight over voss and westheimer when I stopped at the red light. This year I see none. The several pairs at the grocery store are gone except for one pair and none have come by the feeder.
Numbers are down maybe 90% on bolivar based on general impressions rather than ticked off numbers.
Had trouble finding more than single pairs at smith point Monday with none at some points that used to have lots
This population drop has occurred over 3 summers in places where I go and sort of count birds every week or at least very often year round. So it is not just a local event.
Has anyone noted similar trends elsewhere. Similar population drops have affected other invasive species after an initial great spurt in numbers as predators and parasites bring the newcomer into control.
The changes at home have not affected the mourning dove and white-winged dove numbers; if anything they are both up. Rock pigeons numbers are up significantly on Bolivar in the same places that I noted collared dove population decreases. And those two species do not compete for nesting sites but perhaps for food.
Joseph C. Kennedy
on Buffalo Bayou in West Houston
(713) 412-4409 twitter ID dsarkozi