Friday, June 24, 2011
From Vermont Loon Recovery Project Volunteer, Sue Elliott:
"We arrived at Kent Pond this morning (May 31) around 7:30 to check on the Common Loons. An American White Pelican was sitting on one of the rocks next to loon island, not far from where one of the loons is sitting on the nest. We called for backup, Sue Wetmore (another avid birder), who arrived from Brandon faster than is humanly possible. At about 9:05, one of the loons swam out to the pelican to have a little talk. The pelican then hopped to the next rock, and then into the water. At 9:15 the pelican took flight, circling the pond and then off."
The Kent Pond loon pair hatched their first chick in three years of trying last week. Eric Hanson, VLRP Coordinator
Wednesday, June 22, 2011
VCE's 4th field visit to our long-term Mt. Mansfield ridgeline study site on Monday night and Tuesday morning featured weather that couldn't have been more perfect - clear, calm, and cool. A far cry from our first trip there 3 weeks ago, when we were hampered by howling winds, swirling clouds and temperatures in the mid-30s F. Avian activity was surprisingly slow and quiet, probably because most species are in the midst of incubation, so vocalizing and general movements are lower. We ran 28 mist nets and captured only 20 individuals of our 5 target species, including 6 Bicknell's Thrushes, one of which relinquished the solar geolocator we had attached last June. There are lots of yearling birds on the mountain, a result of last year's productive breeding season thanks to low red squirrel numbers, which is again the case this summer. We have yet to observe a squirrel on Mansfield in 2011.
Notable encounters were a Peregrine Falcon over the ridgeline, a female Yellow-belled Sapsucker in our nets, 2 singing Ruby-crowned Kinglets and a mist-netted female with a full incubation patch, and a singing Black-throated Green Warbler.
We expect activity to pick up again over the next 2 weeks, as young hatch, parents move more widely to forage for them, and males reinvigorate their singing. We're still hopeful of recovering more of the 18 geolocators that we attached to Bicknell's Thrushes a year ago, although we're pleased to have at least 2 back!
Saturday, June 18, 2011
Radio transmitters reveal a surprising predator on wintering grounds
Jason Townsend, a graduate student at the State University of New York, was doing research on Bicknell’s Thrush in the Dominican Republic with VCE when he got a real eye-opener. “When we first started working there, we were shocked in the evening to look up in that blue, dusky light of sunset and see rats climbing all around in the canopy. We suddenly realized that any songbird roosting up there was vulnerable to these guys,” he said.
Rats have long been known to feed on eggs and chicks of ground-nesting species, but to find predation on adult songbirds in the canopy was a surprise. Townsend and colleagues from the Cornell Lab of Ornithology and the Vermont Center for Ecostudies were tracking 53 Bicknell’s Thrushes using radio transmitters. “We didn’t expect to be able to quantify this with radiotelemetry. But then we caught a signal coming from an underground hole. We excavated it and there was the transmitter, some bands, leg bones, a few feathers—all that was left of the bird. We thought it was a fluke, but it happened year after year.”
After the team started trapping rats, they learned that their population was huge. “Our rate of capture as an index of rat presence was extremely high—as high as anything in the literature for a forested area with introduced rats,” Townsend said. “From 25 to 41 percent of our traps caught rats on any given night—that’s a lot of rats. Bicknell’s Thrushes winter in both low elevation rainforest on Hispaniola and also high-elevation cloud forest. In both forests we had rat predation.”
During the study, which was published in 2009 in The Condor, rats killed five Bicknell’s Thrushes bearing transmitters—almost 10 percent. None of the other birds died or were lost during the course of the study. The researchers concluded that rat predation of roosting thrushes is a significant cause of mortality in winter, the season when mortality should be lowest. Townsend said that on Caribbean islands, “You don’t have the natural avian predators—the snakes, small mammals and rodents, and hawks—that you’d have in, say, Costa Rica. In the Caribbean there are a few Sharp-shinned Hawks, but you don’t think of predation as a limiting factor.”
Rats are numerous in Hispaniola’s broadleaf cloud forests where most thrushes live. But on one study area where there was also a stand of Hispaniolan pine, many of the thrushes flew some distance from their daytime habitat to sleep in the pines, where rats are far less numerous. The research team is investigating the possibility that some of the birds are adapting to rats by avoiding their main nocturnal roosting grounds.
The researchers were tracking just one rare and declining species, but team members have witnessed rat predation on other Caribbean species, including endangered cavity-nesting Hispaniolan Parrots. So the problems with rat predation may be far wider, and deeper, than conservationists realized.
Tuesday, June 14, 2011
The successful candidate will have: (1) a B.S. or higher in conservation biology, ecology, social sciences, or natural resource management; (2) a minimum of 3 years on-the-ground experience in conservation biology or a related field; (3) prior work in Latin America and/or the Caribbean; (4) spoken and written fluency in Spanish and English (working knowledge of French and/or Creole is desirable); (5) excellent oral and written communications skills; (6) demonstrated strong human relations and networking abilities; (7) experience raising funds and a willingness to assist in fundraising efforts targeted at the Caribbean; (8) facility on computers (a working knowledge of GIS is desirable); and (9) a wilingness to travel extensively to and within the Dominican Republic and Haiti, as well as to other Greater Antillean islands, and Vermont. Compensation will be commensurate with education and experience, and the position will be eligible for VCE benefits.
Qualified candidates should submit a curriculum vitae and letter of interest, including names and contact information of 3 references to: Chris Rimmer, Vermont Center for Ecostudies, P.O. Box 420, Norwich, VT 05055 USA, or by e-mail to email@example.com. Deadline for applications is July 15, 2011 and the anticipated starting date is October 15.
Monday, June 13, 2011
Wednesday, June 08, 2011
Last week, loon intern Shannon Maes (from Sterling College) and I rescued a loon tangled up in nylon twine shortly before midnight. Lakeshore residents originally reported the loon in early May when it was moving strongly about the lake. Last Sunday Carol and Colm Radic found it strange to have a loon staying in one place in front of their cottage all day. They observed white line or rope behind the loon, and soon contacted the lake assocation president who then contacted me. The red flags went up as the loon was obviously weaker than a month ago. We approached the loon in daylight but it could still dive 20-30 seconds. That's good news for the loon in that it could still swim pretty well. But it could mean the loon would easily avoid capture. We decided to wait until dark for a nighttime capture attempt. It did not become really dark until almost 10 pm. Shannon, Colm, and I followed the bird until we could not see it anymore, waited another 20 mintues, and then turned on the million power spotlights in search. Of course it had moved from where we last saw it. We searched and searched using binoculars following the beam of the spotlight, a slow and dizzying process. Thinking that it was diving every time the spotlight came near, we headed back up the lake only to find a loon about where the loon had been all day. More often then not, free swimming loons like this dive as the boat approaches. I hooted imitating another adult. The loon turned. I hooted again. The loon hooted back. Wow, it was staying on the surface. Shannon kept the beam right on the bird keeping it somewhat blinded and probably confused. Colm did a great job steering the boat closer. I drove the net into the water in front of the loon now 8 feet away. We had it. We brought the loon to shore, cut the twine free from it's feet and wing, and placed color bands on it's legs. The loon was thin but feisty and I decided to release it since loons do not do well in captivity. Based on it's long dives with the twine around it, I hoped that it would be able to feed itself better now. It's nice to have success after usually not catching loons in these situations. For Shannon, the Radic's, and another neighbor Hud Allen, it was a night to remember holding a loon for a few precious moments.
Loon update: we have confirmed 34 nest attempts and only 2 flooded nests from the late May rains. Many pairs have delayed nesting because of high water, so I expect many pairs to initiate nesting in the nest 2 weeks. *** Eric Hanson
Saturday, June 04, 2011
We ventured up to the Mansfield ridgeline Thurdays night to begin our 19th season studying songbirds in the high elevation forests. It takes a long time to understand demographic changes. We were hoping the diminished winds and clearing skies forecast for the morning would prevail and allow us to get in our first mist-netting session for 2011. We awoke in the pre-dawn to winds howling from the NW and the ridgeline bathed in clouds, temperature hovering at 35F. Not what we hoped, but we managed to find a few sheltered spots and put up 10 nets. Avian activity was low, to say the least. We caught 5 birds total, including 2 Bicknell's Thrushes. One thrush was hatched last year and another was a recapture. We had not seen this bird since 2009 when it was just a year old. It is now in its 4th year.
We found the following birds on our ridgeline study area:
Common Raven 1
Winter Wren 3
Ruby-crowned Kinglet 1
Bicknell's Thrush 7
American Robin 2
Yellow-rumped Warbler (Myrtle) 5
Blackpoll Warbler 8
White-throated Sparrow 6
No red squirrels up there, but that won't be the case a year from now, as a banner crop of fir cones is on the way. Bicknell's Thrushes and others better crank out the young this summer, because 2012 will be a challenging year, with red squirrels.
Photo: Male and female flowers on a Balsam Fir tree on Mt. Mansfield. Wind pollinated, the cones will mature later this year. Photo by KP McFarland.
Friday, June 03, 2011
In birds as in humans, female fertility declines with age.
But some female birds can slow the ticking of their biological clocks by choosing the right mates, according to results of a study published online last week in the journal Oikos.
Female birds become progressively less fertile as age takes its toll, says biologist Josh Auld of the National Evolutionary Synthesis Center in Durham, North Carolina, and co-author of the Oikos paper.
Older females lay fewer eggs, and they lay them later in the season--at a time when less food is available for their chicks.
But despite abundant evidence of fading fertility in females, scientists knew little about the role played by their mates. "The thought was that males didn't matter," Auld says.
But they do...
Click here to for entire article
Thursday, June 02, 2011
May 2011 is now in the record books. It was a month to remember, for me and all Windsor County birders. Back on May 1st, there were still redpolls at my home on Bragg Hill, but that wasn’t the only notable species in Norwich that day. I arrived home (from a morning of birding) to find a Golden-crowned Sparrow! Although a one-day-wonder, it was seen well and photographed by several others. Not to be outdone by this vagrant, a Northern Goshawk and an Eastern Towhee also made an appearance at our house that afternoon. After this phenomenal start to May, things never really slowed down -- I could never have imagined that this second state record wouldn’t be the best bird of the month!
As of today (June 1), 171 species and nearly 750 checklists have submitted to eBird for my home county of Windsor. For comparison, last May we had 144 species and 440 checklists. This may have been the single “birdiest” month in the documented history of Windsor County – a month of quality as well as quantity. Highlights included: Common Eider (the first in 30 years), second-ever for the county White-winged Scoter (at least 3 groups; none last year), Lesser Scaup (none in 2010), Semipalmated Plover (more than a dozen; none last year), Bicknell's Thrush (singing on Mt. Okemo), Black Terns, Golden-winged Warblers, Long-tailed Ducks, Black-billed Cuckoos, Whip-poor-will, and nesting Red-bellied Woodpeckers and Blue-gray Gnatcatchers.
Last but not least, Vermont got a new species just yesterday – 2 Marbled Godwits beside the Connecticut River, near Pompy Farms. My Dad and I found them feeding on the mudflats with geese and Mallards. They were gone within a half hour, flying off to the south. As much as we hated to see them leave, viewing them in flight erased any doubt about their identification. The entire time we watched, the birds seemed restless. They preened and stretched, allowing brief views of their underwing coverts. Additional features that helped us confirm the ID included the orange upper half of the bill and their overall buff color.
Explaining why any and all these rarities turned up in May is difficult. The 12 shorebird species found may in part have resulted from low water levels on the Connecticut River. These were very low on and off during the month, providing shorebirds a place to land (and birders ample excuses to bird). Another explanation would be the County Birding Quest. As many of us have experienced first hand, the Quest has revamped birdwatching in Vermont. While it may be reducing our productivity at work and in school, it has certainly had an enormous impact on the county bird list!
A more typical explanation for the bounty of rarities might involve the weather. It has been a weird month weatherwise. The heavy rains and super-hot days seem a little extreme. I can only guess, but it is possible the godwits were blown here by the same weather system that brought the White Pelican to Kent Pond in Killington. Whatever the reason(s), May has been a birding month many of us will remember.
Marbled Godwit photo courtesy of Bryan Pfeiffer