Rushton Migration Minutes: An Unexpected Second Wave of Warblers Preceded the Sparrow Surge Last Week… and One of Our Banded Owls Appeared In Quebec!

“Bird Migration is the world’s only true unifying natural phenomenon, stitching the continents together in a way that even the great weather systems fail to do.”
~Scott Weidensaul, Author & Naturalist
red tailed hawk_dalton portella
Red-tailed Hawk by Dalton Portella
Migration is such an exciting time of year because you never know what to expect!  Here at the Rushton Wood Preserve banding station, every day is different and brings new surprises.   As difficult as it is to wake up before the sun rises on banding days, it is much easier when I imagine the endless possibilities of woodland gems we could encounter in one of our 11 webs.
Ruby crowned kinglet in net
Last week (the first week of October) was the first week I really felt the fall chill in the air, but our nets were hot!  On Tuesday (Oct. 4) we banded 60 birds and to our surprise, a bunch of them were warblers.  As I said in my last blog post, we were observing a drastic decline in the volume of warblers and therefore expected that they were almost finished passing through.  Not so!  The second wave of warblers last week must have been the birds who were held back by all the rain of previous weeks.  Whatever the reason for this fallout, we were thankful because we had species that Rushton has never seen before, including a Tennessee warbler.  This dainty warbler of the Canadian boreal forest is becoming increasingly uncommon throughout its range, so having one at Rushton was spectacular.  The Tennessee warbler specializes  in eating the spruce budworm, so its population may be closely tied to budworm fluctuations up north.
TennesseeWarblerLRR
Tennessee Warbler by Robert Royse (taken from Google Images)
Another amazing warbler we banded was the Blackpoll warbler.  Lisa and I had never before seen one, let alone held one in our hand, so we were a bit skeptical at first.  First we thought Pine Warbler, but ruled that out by the black centers in our bird’s feathers.  Next, our guide indicated that in the fall Blackpoll warblers are often confused with Bay-breasted Warblers, but we finally ruled out the Bay-breasted by the bright yellow soles of our bird’s feet! The Bay-breasted has more grayish feet.   Gotta love “confusing fall warblers”.
Blackpoll warbler
Blackpoll warbler in fall plumage at Rushton by Blake Goll
We had 2 Blackpoll warblers that day. One was skinny and the other had lots of fat stored in its wishbone area (or furcular hollow), which is what we love to see on long-distant migratory birds.  It is especially important for Blackpolls to have lots of fuel because they have one of the longest, most strenuous journeys of all our wood warblers.  Their journey begins on their breeding grounds of the northern boreal forest of Canada.  They double their mass and fly all the way to South America, which is impressive in itself.  Even more incredible is that many of the Blackpolls opt for the oceanic flight; they fly from northeastern U.S. out over the western Atlantic  nonstop for 1,864 miles to Puerto Rico or S. America.  The flocks of Blackpolls have shown up as diffuse blobs of glowing green on radar scopes over the West Indies at altitudes of 23,000 ft!  These tiny warblers land in S. America about 88 hours after leaving the New England coast.  Ornithologists have compared this dumbfounding journey to a human running 4 minute miles for 3.5 days, without rest, refueling, or water.  Absolutely mind-boggling!
Other warblers in last week’s catch included Magnolia, Black and White, Common Yellowthroat, and Black-throated Blue.
Female Black throated Blue warbler
Female Black-throated Blue warbler at Rushton Woods Preserve by Blake Goll
Male Black & White warbler
Male Black & White warbler at Rushton by Blake Goll
On Thursday of last week, the sparrows replaced the warblers.  White-throated Sparrows were the catch of the day, and a Lincoln’s Sparrow was the most photographed sparrow of the day.  This very handsome sparrow likes boggy areas and is only seen in our area during migration on his way to the southern U.S. and Central America.
Lincoln's sparrow
Lincoln's sparrow at Rushton by Blake Goll
It is safe to say that last week was an all out fallout for Rushton Woods Preserve.  The migratory birds came in on the cold front overnight and touched down in our enticing habitat by dawn.  Depending on each bird’s individual physical condition, they will stay for a day to several days or even over a week in a stopover habitat such as ours.  Then they will continue their migration, refueled.  We could tell the birds last week had traveled very far overnight because many were showing signs of exhaustion, even those that we “popped” out of the net in seconds.  We quickly processed these tired migrants first and released them immediately, so they could get back to refueling on insects and berries in the rich hedgerows and farm fields.
Rushton Farm
Rushton Farm
I spoke with our farmer, Fred, and he and the other growers who had been working the fields last week noticed the “fallout” of birds as well.  As they were walking through the fields harvesting, they were often startled by birds, including warblers, flying right our from under their feet.  The birds would fly only a short distance away from them and land in the grasses or vegetable plants a few feet away, as if too exhausted to go farther.  Fred suspects the warblers glean insects from the crops; for example, the tomatoes are being left on the vine to rot in preparation for winter because the fermented fruit preserves the seeds for next year.  This rotting fruit attracts a lot of insect activity, which the birds immediately discover.  Fred also notices migrant birds following the farmers as they walk through the fields because the birds know that such human movement kicks up the insects from the undergrowth.  Fascinating stuff!  And to think, many birders never dreamed that farms could be beneficial to birds.  A prize will go to any photographer who helps us document this revelation by getting a picture of a warbler on a tomato plant at Rushton! 🙂
Field sparrow
Field sparrow at Rushton. Blake Goll
This week we have been rained out from banding everyday so far except for Tuesday when we got 81 birds!  The first of the Yellow-rumped Warblers came through; these warblers are the last to migrate because they winter farther north than other warblers, due in large part to their ability to digest berry fruits.  We banded a few other warblers this week including Common Yellowthroat, Black-throated Blue, and Magnolia, but the catch was largely sparrows: Lincoln’s, Swamp, Chipping, Song and Field.  We banded some nice thrushes including Hermit and Wood Thrush in addition to towhees and resident birds like Carolina Chickadee, Tufted Titmouse, and woodpeckers.  The Ruby-crowned Kinglets are moving through in greater numbers now, and there are officially no more Gray Catbirds in Rushton until next spring.
Ruby Crowned Kinglet
Ruby Crowned Kinglet at Rushton. Blake Goll
Perhaps the most exciting birds we caught on Tuesday were a Winter Wren and a Brown Creeper, both very brown but uniquely exquisite.  The Winter Wrens have one of the most elaborate songs of all; their voice echoes the heart of the forest.  The Brown Creepers sing of “Trees, trees, beautiful trees!” in a sweet tinkling

brown creeper
Brown Creeper (from Google Images)

voice, and their secretive habit makes them very exciting to spot creeping along a tree trunk.  They sing of trees, crawl up and down trees, place their nests behind flaps of loose bark on trees, and even look like they are cut from the same cloth of tree bark.  Their long , gnarly toes even remind be of tiny tree branches, and their marvelously curved bill is perfectly suited to “tickling the tree trunks” for insects.  What a wonderful little bird.

Winter wren
Winter wren. Blake Goll
Speaking of wonderful little birds, the Northern Saw-whet Owls are on their way to Rushton!  Please read the following notification from the Rushton Banding crew:
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Northern Saw-whet Owl
Northern Saw-whet Owl. Blake Goll

2011 NSWO Update!

You’re invited to the Rushton Woods Banding Station this fall for a rendez vous under the stars to observe first-hand the techniques and uses of bird banding and to learn about the biology of Northern Saw-whet Owls.  We will open to the public from October 20 until November 23 with Thursday, Friday and Saturday evenings available, but we can accept visitors on a RESERVATION BASIS ONLY.  Many people wish to visit our station with the hope of seeing these owls up-close, but our space is extremely limited.

The monitoring of Northern Saw-whet Owls (NSWO) is a nocturnal activity whereby this small owl species is caught using a system of loudspeakers (playing their calls) surrounded by mist nets in which the owls become entangled. The information collected from this process gives scientists information about the cyclical nature of the migratory cycles of these species and their reproductive success.

Please reserve an evening by e-mailing Lisa Kiziuk at lkr@wctrust.org as soon as possible and note that banding is weather dependent as rain or high winds will cause the station to close.

The station is located in the farm shed at Rushton Woods and Farm Preserve and the GPS address to use is 1050 Delchester Road, Malvern, PA 19355.  Please note that parking is at a premium and you may be asked to park in the field lot. DRESS WARMLY.

Important NSWO Update!

Yesterday we received news that one of our “Rushton NSWOs” was caught at the Observatoire d’Oseaux de Tadoussac in Quebec.  Here is the link to the observatory where she was caught on October 3 2011:  http://www.explos-nature.qc.ca/oot/.  NSWO number 0494-81906, or “Frenchy” as we call her, was caught at the Rushton Woods Banding Station last year on November 6 and weighed in at 99.3g.  She was a “hatch year” owl, which means she was born in the summer of the year we caught her.  This year on October 3, she weighed in at 103.3g, a sizable increase, possibly in preparation for migration, and she is now aged as a “second year” owl.  We hope to see her again at Rushton this Fall!

New This Year:

In order to help support our long-term monitoring of the population dynamics of Northern Saw-whet Owls, and to improve our understanding of these mysterious night visitors, the Rushton Banding Crew is seeking donations to the program through our newly created “Owl Donation Box.”  Your contributions will help financially sustain our continued collection of valuable information about these nocturnal birds, which are discreet and difficult to monitor.  Your contributions also help fund our songbird banding efforts.

See you under the stars!

The Rushton Woods Banding Crew

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Ok Folks, that’s all for now.  Phew! I had a lot to tell you! There is just so much happening in the natural world this time of year, and birds make these seasonal transitions so much more evident and exciting.  Remember, you are welcome to share in the excitement Tuesday and Thursday mornings at the Rushton Woods Preserve banding station through the first week or so of November.
Make sure you go see “The Big Year” this weekend…I can’t wait!
~Blake