Ian's note about red-winged blackbird arrival dates is a good chance
for me to plug (yes, once again) the use of eBird. Arrival dates over
many years and a broad geographic range can be great for us to track
potential climatic effects on migration.
For example, from 1960 to 2002 Kathleen Anderson (one of the founders
of Manomet Bird Observatory) recorded the first date each spring that
migrating birds were seen on her property. Researchers at Boston
University wanted to find out if a naturalist's diary could be
valuable for detecting potential changes in phonological events like
spring migration. Their work was recently published in the Wilson
Bulletin, a professional ornithological journal (see below for citation).
For over 50 years Anderson has lived on a 100 acre farm just south of
Boston and not far from the ocean. Everyday she was on her farm she
recorded the birds, flowing plants, butterflies and amphibian
choruses she encountered. Her observations were not systematic, but
gathered as she enjoyed a walk or simply from the back porch. She
was also occasionally away from her farm for several days at a time.
The four BU biologists were able to extract her sightings from her
journals, put them into a computer database and statistically analyze
them. A nearby weather station showed that mean annual temperatures
in the region raised 3.6F. Could her records show species responding
to the warming with earlier spring phenology?
There was enough data to look at 16 bird species, 3 plants, 3
amphibians and 2 butterflies. Five bird species showed significantly
earlier arrival dates including, Wood Duck, Ruby-throated
Hummingbird, House Wren, Ovenbird, and Chipping Sparrow. The
strongest trend was for Wood Ducks which arrived on average 32 days
earlier than they did when Anderson first began recording her
sightings and Hummingbirds arrived 18 days earlier. Overall, 22 of
the 24 species they examined showed trends toward earlier spring
activity, an overall average of 8 days earlier.
Kathleen Anderson had no idea that her records might be a piece in
the climate change puzzle when she started to record her observations
over 30 years ago. Just as we now have no way of knowing what all
the records we put on Vermont eBird might shed light on
someday. Right now over a dozen volunteers are slowly entering
nearly 30 years of Records of Vermont Birds data from boxes in the
closet into Vermont eBird. Will these historic records shed any
light on the past or are they too scattered in effort and
geography? We won't know until they are all entered.
Recently, John Simpson stopped by VINS and dropped off nearly 40
years of daily bird records that his late mother, Nancy Simpson,
dutifully kept each day at her house in southern Vermont. Slowly we
will enter these records into Vermont eBird and examine them for any
clues they may offer. Thanks to Vermont eBird, in 40 more years
someone, maybe one of us, will have thousands of records in which to
look back upon for clues to the ever changing bird world.
I took a look at the Red-winged Blackbird arrival dates from 1966 to
2004 for this data set. From 1966 to 1990 there is a trend toward
earlier arrival dates at her house. From 1990 - 2004 the trend
changes to a later arrival time. Anderson's data for Redwings showed
a trend toward an earlier date of arrival, but it was not
Hundreds of bird watchers are contributing their bird sightings to
the Vermont eBird database, providing a valuable inventory of
Vermont's birds. As we have learned from Kathleen Anderson's
naturalist notes, one of the most significant contributions that you
can provide to further the understanding of the timing and
distribution of birds is to repeatedly record bird sightings at a
single location. To take Vermont eBird to the next level the Cornell
Lab of Ornithology and VINS have created the
Survey , a standardized way you can contribute your sightings to Vermont eBird.
To read the original article in the Wilson Bulletin, visit your local
college or university library to find:
Ledneva, A., A.J. Miller-Rushing, R.B. Primack and C. Imbres. 2004.
Climate change as reflected in a naturalist's diary, Middleborough,
Massachusetts. Wilson Bulletin 116(3): 224-231.
Thanks for reading this long email!
Conservation Biology Department
Vermont Institute of Natural Science
27023 Church Hill Rd.
Woodstock, VT 05091
Visit the CBD Blog: http://www.vinsweb.org/cbd/news.html
>>Subject: Red-winged consistency
>>From: "Ian A. Worley" <Ian.Worley AT UVM.EDU>
>>Date: Wed, 15 Mar 2006 07:03:50 -0500
>>At daybreak this morning, being the 15th of March, I was delighted, but not
>>surprised to have our first Red-winged Blackbirds of the spring in a mass
>>flock singing away from the tops of a cluster of pines by the house. Over
>>the last 30 years at our house on the southern end of Snake Mtn. in
>>Cornwall, most every year (about every 4 out of 5 years) a flock of 30-50
>>Red-winged Blackbird males makes its first appearance on the 15th. They
>>were, of course, greeted with appreciation ..... and a blanket of new snow!