Hi,

In 2001 I participated in a breeding bird survey of the natural areas of
the Holden Arboretum conducted by Carol Skinner:

https://kb.osu.edu/dspace/bitstream/handle/1811/23979/V103N4_098.pdf;jsessionid=352A4364F679C6670B2332DBAC855275?sequence=1


In that study we found Ovenbirds in good numbers on all wooded properties.

Since 2007 I have been conducting ongoing breeding bird surveys or the same
areas. The protocol we use is different.  We use the OBBA2 upgrade protocol
and no set transects, instead tracking our variable routes via GPS.
 Additionally we only survey on weekends where as the Skinner study was
conducted every day of the week, and because of the weekday runs, we would
start far earlier than we do now, usually at 0500 or 0530 as opposed to
0600 or 0630 now.

We do not find Ovenbirds in the numbers we did in 2001.  In 26 runs during
May, June and July of 2011 we found Ovenbird only 3 times, compared to 15
times during the same time frame in 2001. I wonder how much of this
difference is due to less coverage and later starts and how much is due to
actual declines in Ovenbird populations on these properties?

European earthworms have devastated the leaf litter and herbacious layers
in some areas of Holden's forests but most areas are very healthy.
 Holden's forests tend to be large and unfragmented ranging from a few
hundred acres to over 1000 acres in 2 areas.

I have sort of noticed this lack of Ovenbirds but did not realize how
dramatic it was until was prompted to look at my field notes by David
Brinkman's comments. This now has me wondering if there is cause for
concern and if we should be looking for Ovenbirds more carefully.  Because
the OBBA2 data is qualitative and not quantitative It does not help to
answer this question, and because of the changes in protocol from the first
OBBA it is difficult to draw conclusions over the 2 decades between the
studies.

Haans Petruschke
Kirtland

______________________________________________________________________

Ohio-birds mailing list, a service of the Ohio Ornithological Society.
Our thanks to Miami University for hosting this mailing list.
Additional discussions can be found in our forums, at www.ohiobirds.org/forum/.

You can join or leave the list, or change your options, at:
http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS
Send questions or comments about the list to: [log in to unmask]