Thursday, March 30, 2006
This winter featured a moderate invasion of shrikes to Vermont. While reports are dwindling, as birds retreat northward, a single Northern Shrike was observed in Sharon during the past week. Watch for this species, a mockingbird look-alike with white wing and tail patches, atop trees, shrubs, fenceposts and on telephone wires. Lucky observers may hear Northern Shrikes sing their curious song in early spring- a complex sequence of harsh notes, chatter, trills, and whistles.
Lake Champlain continues to be the states birding hot spot, with water birds stealing the show. A Horned Grebe at was seen at Charlotte Town Beach on March 23rd. This excellent spot also hosted an immature male Harlequin Duck (present for 2 weeks), a Ruddy Duck, and a Red-breasted Merganser. Observers in the Lake Champlain Islands found a pair of Tufted Ducks, several Redheads, as many as 5 Barrow's Goldeneyes, 5 White-winged Scoters, and a single Surf Scoter.
The Connecticut River also boasted some good finds during the past week, with a rare White-fronted Goose and a Northern Shoveler at Roundy's Cove north of Bellows Falls on March 21, and a Mute Swan at Brattleboro Retreat Meadows on the 25th.
American Woodcocks are now widespread and beginning their spectacular dusk courtship flights, while the spring's first Wilson's Snipe was reported from Taft Corner in Williston on March 20. A Short-eared Owl was seen at Dead Creek Wildlife Management Area on the 21st, and Northern Saw-whet Owls were reported calling in downtown Montpelier, Shoreham, and Bridport.
The recent steady flow of cold, northern air has kept most migrant songbirds at bay. Tree Swallows are trickling north, with reports during the past week from Florence and Pownal. A Yellow-rumped Warbler, possibly an overwintering bird, was reported from Danby. Fox Sparrows were sighted in Bennington and Danby, while Song Sparrows appeared in five towns. A single Rusty Blackbird, a species in decline, was observed in Danby.
Chris Rimmer, CBD Director
Tuesday, March 28, 2006
The Bicknell's Thrush, known to be declining and believed to number no more than 50,000 individuals globally, nests only in select mountaintop forests of the Northeast and adjacent Canada in spring and summer. These "sky islands" are threatened by global climate change, air pollution, ski area development, telecommunications tower construction, and wind turbine development.
"Bicknell's Thrush faces an uphill battle. It's critical that the nearly 8,000 acres of prime habitat in the Green Mountain National Forest are protected and carefully managed to support these sensitive songbirds," said Chris Rimmer, Director of Conservation Biology at VINS and lead author of the Conservation Strategy. "More can be done to conserve this vulnerable species, and we are pleased that the U.S. Forest Service is receptive to our recommendations."
The Bicknell's Thrush Conservation Strategy provides specific guidelines for important habitat areas within the GMNF that are currently developed for skiing, telecommunications, or wind power facilities. VINS' recommendations include minimizing or mitigating impacts of activities that might alter Bicknell's Thrush habitat, managing vegetation on developed sites to maintain or improve suitable thrush habitat, and conducting small-scale forest manipulations to enhance thrush habitat.
Rob Hoelscher, a GMNF wildlife biologist, believes the Conservation Strategy will be an important planning tool: "Bicknell's Thrush is a high responsibility species on the GMNF, and we�re pleased to have concrete guidelines for helping to ensure its healthy populations."
The biologists also point out that threats to the Bicknell's Thrush extend well beyond U.S. borders. Research by Rimmer and his colleagues during the past decade has shown that at least 90% of the bird's global wintering population resides on Hispaniola (Dominican Republic and Haiti), where the broadleaf forests they inhabit have been severely degraded or destroyed.
In response to this rapid habitat loss, the VINS biologists have called for the creation of an international consortium, to include VINS, GMNF, and other U.S. and Hispaniolan partners, that would bring together the resources needed for on-the-ground protection of winter habitats in the Dominican Republic and Haiti.
"Declining population numbers tell us that time may be running out for Bicknell's Thrush. It's crucial to make progress here in Vermont and North America, but these efforts could be in vain unless we also stem the loss of winter habitat in Hispaniola," said Rimmer.
The USDA Forest Service, which is charged with managing the GMNF, sought VINS' expertise to develop a coordinated Conservation Strategy for this rare species. The end product was a collaborative plan that emphasizes careful management, continued thrush monitoring and research, and public outreach on mountaintop forest ecology and conservation issues.
To view the full GMNF Conservation Strategy, visit http://www.vinsweb.org/assets/pdf/BITHGMNF.pdf
For the fourth consecutive spring, PSU biology chair Dr. Len Reitsma and his colleagues will brave the black flies and mosquitoes in Canaan, N.H., to band, track and study the diminishing Canada warbler, a small black, yellow and slate-colored bird that has been disappearing from the state due to loss of habitat. Reitsma and undergraduate and graduate students from PSU, Louisiana State University and Salve Regina University have collaborated with conservation biologist Dan Lambert, research associate at the Vermont Institute of Natural Science, to produce research they hope will help preserve this species.
As a result of the research, Lambert and Steve Faccio of the Vermont Institute of Natural Science have produced a brochure aimed at promoting and sustaining Canada warbler breeding populations. The publication lists stewardship guidelines for land managers, homeowners and conservationists that focus on the preservation of young forest stands, mixed forest areas and swampy areas where warblers like to nest.
Lambert now works for the American Bird Conservancy as Northeast bird monitoring coordinator and is stationed at VINS as a research associate. He sees a continuing need for research on the Canada warbler, particularly research focused on habitat threats and environmental contaminants such as mercury, which has been shown to alter behavior, reduce breeding success and shorten life spans in northeastern water birds. Because the warbler resides in a variety of habitats, from mixed forest to swamps and timber harvest zones, it is important to study and compare each of these areas in order to determine which conservation practices will best help the species.
�As a conservation biologist, I�m most interested in learning about stewardship practices that help conserve this uncommon and declining species. Understanding differences in the quality of its various habitat types is key to protecting the species,� said Lambert. In order to study the warbler�s habitat preferences and breeding ecology, Reitsma, Lambert and other researchers capture birds and place colored bands on their legs. After releasing the birds, the researchers map their travels using GPS units and characterize their individual territories using standard vegetation measurements. Researchers are able to gain a clear understanding of the habitat preferences of Canada warblers by comparing these vegetation measurements to those of adjacent unoccupied habitat.
One of the more remarkable findings of this study, according to Reitsma, is the fact that about half of the banded birds in the study return each season to the exact same location in New Hampshire. Canada warblers are Neotropical-Nearctic migrants, spending winters in the forested eastern slopes of the Andes Mountains south of Columbia, and traveling over 4,000 miles each year to and from breeding grounds in the northeast.
Mike Hallworth, a PSU graduate student who has participated in the Canada warbler research for the past two years, also finds the bird�s migration patterns remarkable. He is making the warbler�s breeding ecology the focus of his master�s thesis project, and hopes someday to travel to South America to observe the bird in its winter habitat.
�The Canada warbler is an amazing species, and it�s a species that not much work has been done on,� says Hallworth, who is working toward his M.S. in Environmental Science and Policy. �I find it fascinating that a bird that weighs only 10 grams migrates from central New Hampshire to the eastern slope of the Andes twice a year. I also find it fascinating that the males come back to the exact same location, within meters of their previous year�s territory,�
During his field studies, Hallworth has also been looking at the phenomenon of extra pair copulation, which occurs when there is more than one male parent represented in a single nest. Hallworth takes a small sample of blood from parent birds and nestlings to complete this research, which has not previously been undertaken for this species.
Reitsma, Hallworth and other researchers have also been comparing age ratios and breeding successes of male birds in two different habitats, a red maple swamp and a heavily cut, 25-year-old forest, in hopes of making management recommendations for the warbler.
�We can�t wait to get back into the field this spring and face the biting flies to see who has returned again to breed,� said Reitsma.
Monday, March 27, 2006
Friday, March 24, 2006
Until recently, Vermont was the only northeastern state without breeding eagles. Now, with at least two active nests, several territorial pairs, and the successful reintroduction of young eagles at Dead Creek Wildlife Management Area, Vermont Bald Eagles are back, hopefully to stay.
Eagle sightings in Vermont this winter confirm that the species is returning to its historic glory. Eagles were found in good numbers last week on Lake Champlain, and several pairs were observed sitting on their large stick nests along both sides of the Connecticut River. Check out Vermont eBird to see where all the Bald Eagle sightings have been in 2006.
Other raptor reports included a northern harrier in Thetford, numerous sightings of sharp-shinned hawk, Cooper�s hawk, and northern goshawk, a red-shouldered hawk in Castleton, the first reports of broad-winged hawks arriving back from South America in Leicester and Brattleboro, numerous red-tailed hawks with a high count of eight in West Rutland Marsh, American kestrels returning to nest boxes throughout the state, and a peregrine falcon over Mt. Horrid.
Proof that winter isn�t quite over, flocks of over 100 bohemian waxwings were observed in Essex, Rutland, South Burlington and Woodstock, with smaller flocks in Addison, Ferrisburg and Charlotte. They are often found feeding in crab apple trees and can be easily mistaken for the more common cedar waxwing, but look for the distinctive rusty feathers under their tails. Large flocks of common redpolls continue to be reported at feeders.
Five gray jays were sighted at Victory Bog on March 14th. This boreal species is one of Vermont�s earliest breeders and may be nesting now. Horned larks were present at Dead Creek WMA on March 18, while tree swallows and an eastern meadowlark were observed at Herrick's Cove on March 16. Migrant fox sparrows appeared in Manchester Center, Bennington, Stowe and Dummerston last week.
VINS Conservation Biologist
Monday, March 20, 2006
Location: Loma La Canela, Dominican Republic
Weather: 2 days of rain, 3 of sun and 5 of orange mud!
We spent 5 days in La Canela, March 13-17,2006. Loma La Canela is a part of the Reserva Científica Loma Quita Espuela in the northeastern mountains of the Dominican Republic. This range, the Cordillera Septentrional, is heavily developed for agriculture, and the reserve represents one of only two protected areas within the range. It is one of the best watered parts of the DR, receiving almost year-round precipitation from the trade winds. We experienced 2 days of steady rain, 3 of sun, and 5 of Canela's famous orange mud.
In spite of it's protected status, agricultural activity is evident throughout the reserve. A local "campesino" (rural farmer) was slashing and burning just 500m from our campsite and had already "sembrado" (seeded) another "conuco" (small farm field) 1km from our campsite. He has no fear of reprisal, and talks freely of his claim to the land via ownership by his great-great-grandfather. Park guards know him, and also freely talk of the 5 other families currently tending conucos within the park, all of whom have similar old family claims to reserve land. The guards feel that they do not have the authority to deal with these old entrenched families, and instead focus their efforts on preventing new incursions.
Three Dominican field biologists accompanied me. We set out to survey and mist-net all the Bicknell's Thrush that we could along an established trail (approx. 4KM). Surveys along this trail in 2002, 2004, and 2005 showed a substantial population of Bicknell's Thrushes, with 32 detected in 2004 and 33 detected in 2005. This year, however, we were only able to detect 15. These 15 proved extremely difficult to capture in mist nets. We know from radio telemetry studies that birds in other parts of their Dominican range are territorial and respond aggressively to any territorial intrusion. The reaction of birds at Loma La Canela this year was not aggressive to play back. Many of the 12 birds we attempted to net in fact moved away from the sound of playback, or only approached from above and with minimal aggression. Birds did not swoop low in the direction of the amplifier, nor did they vocalize in response to playback. We were only able to capture 4 birds for measurements, blood samples and release.
One potential explanation for the apparently low populations and potentially non-territorial behavior of birds at Canela this winter was the obvious lack of available fruit. In other years there has been an abundance of small berries throughout the forest, especially of the slender understory tree locally called cafetan. All previously collected fecal samples have been composed entirely or mostly of fruit pulp and seeds. This year, however, there was almost no fruit on the trees and a preliminary analysis of collected fecal samples shows a mostly insect composition. It will be interesting in future years to quantify both fruit and insect abundance at Canela. We know that in the Sierra de Bahoruco, territorial birds wintering in high elevation cloud forest have an almost exclusively insectivorous diet. We have also measured the abundance of insects available in the Bahorucos. Future studies of Canela's insect abundance will be helpful in shedding light on the differences between these two sites.
Friday, March 17, 2006
Last weekends sighting of a male Harlequin Duck off Charlotte Town Beach provided an exceptional treat for Vermont birders. This boldly-plumaged diving duck is among eastern North Americans most rare and sought-after waterfowl species. The Charlotte bird, first observed on March 11 in the company of 20 Common Goldeneyes, provided only Vermonts 11th confirmed record. The birds appearance may have been fleeting, as it has not been reported since Sunday, but birders should continue scanning this excellent location, which has produced many exciting Lake Champlain rarities over the years.
Harlequin Ducks occupy a unique ecological niche among North American waterfowl. Breeding on fast-flowing rivers of Québec, Labrador, Newfoundland, and New Brunswick, the species
winters along rocky coastlines from Nova Scotia to as far south as Virginia. In both habitats,
birds show an unmatched ability to negotiate turbulent waters, as they dive for invertebrate
prey. The East Coast population of Harlequin Duck numbers fewer than 2,000 individuals and has decreased in recent decades. The causes of this decline are not entirely clear, but this rare
species ranks as a high conservation priority.
Other waterfowl provided many of the past weeks birding highlights. These included an early-returning Pied-billed Grebe and 100 Snow Geese on Shelburne Bay, more than 2,000 Canada Geese at Dead Creek in Addison, and Wood Ducks at several locations statewide (including an unusually large flock of 75 at Vernon). Notable diving ducks reported from the Colchester railroad causeway off South Hero included 2 Tufted Ducks among large flocks of Greater Scaup, two pairs of Barrows Goldeneyes, and 2 White-winged Scoters.
Among raptors, a Northern Harrier in Hartford on March 12 provided an unusual sighting for eastern Vermont. American Kestrels made their first appearances in 3 towns, while a gray-phase Gyrfalcon in South Hero on March 7 was a rare find. The East Warren Snowy Owl, a reliable presence since mid-February, continued to delight birders as of March 10.
Other new spring arrivals included the seasons first Killdeers and a report of very hardy Tree
Swallows near Killington. American Robins, Red-winged Blackbirds, and Common Grackles are
now widespread in Vermont. Soon the Eastern Phoebes and Hermit Thrushes will be singing!
Chris Rimmer, Director Conservation Biology
Wednesday, March 15, 2006
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 statistically significant.
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 eBird Site 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.
Thursday, March 09, 2006
Location: Dept. Santa Cruz, Bolivia
Weather: You guessed it: really hot and humid
We wrapped up our field work two days ago, and headed back to the city of Santa Cruz. We counted Bobolinks at the two night roosts once more before leaving. One roost had approximately 80,000 birds, and we counted another 50,000 at the other nearby roost....for a grand total of 130,000 Bobolinks! Perhaps numbers are building as Bobolinks begin their migration north, and birds from other areas are coming into these roosts.
Most males are now in their full breeding plumage, the females are almost finished molting. I have found that the female molt is generally about a week behind the male molt, which is interesting given that females tend to arrive on the breeding grounds about a week later than the males. The feathers are fresh and bright and the birds look quite handsome. The males are singing complete songs now. If it were not for the heat and the squaking of the parrots, I could close my eyes and imagine I was in a Vermont hayfield.
Today I am flying to Asuncion, Paraguay, where I will be meeting with an ecotour group, most of whom are VINS volunteers. We will be visiting the Pantanal and Iguazu Falls for birding and all-around naturalizing and adventuring. Although I adore Bobolinks, it will be a nice change to be checking out other species!
Tuesday, March 07, 2006
Weather: 28.9 F (-1.7 C) and clear
Spring is in the air despite the temperatures. Birders are reporting that some owls are now nesting and ravens have been seen carrying sticks to nest sites.
For example, a Great Horned Owl has again nested on the west side of the North Springfield Dam Reservoir. You can see it with a spotting scope from the overlook at Eleanor Ellis/Springweather Nature Area.
If you find a nesting bird, consider reporting it to the Vermont Breeding Bird Atlas and Vermont eBird.
VINS Conservation Biologist
Friday, March 03, 2006
This winter hardly qualifies as an "invasion" year for Snowy Owls, but the recent appearance of a bird in East Warren, the winter's first documented sighting, triggered a stream of enthused birders. Many were treated to excellent views of the obliging bird, which was often perched on a compost pile behind the general store. The owl was last reported on February 26.
Other winter visitors from areas to Vermont�s north during the past week included flocks of as many as 200 Bohemian Waxwings in Essex, Williston, Weston, and 5 other towns. Single Northern Shrikes were reported from Ferrisburg, Waterbury, East Warren, and Chittenden. Boreal finches reported from various locations statewide included Pine Grosbeaks, Evening Grosbeaks, and Common Redpolls.
Other notable bird sightings from around the state included several rare waterfowl: a Greater White-fronted Goose on Shelburne Bay, and a male Tufted Duck and female Barrow�s Goldeneye in South Hero. A solitary Snow Goose lingered well north of its usual winter range among a flock of 250 Canada Geese in Proctor.
Early signs of spring included a Turkey Vulture in Milton, a singing Winter Wren in Thetford, 7 Eastern Bluebirds in Pownal and 2 in East Dorset, numerous reports of American Robins, and the season�s first Red-winged Blackbirds in West Brattleboro, Corinth, and South Burlington. Despite recent temperatures, these species indicate that winter is on the wane.
Conservation Biology Dept., Director
Please note that her comments about Bicknell's Thrush sensitivity to climate change are a bit exaggerated, but only because they don't account for a lag time in the response of forest habitat to changing temperatures.
Wednesday, March 01, 2006
Location: Northcentral Bolivia
Weather: The usual (really hot and humid, I don`t even want to know the
Records were made to be broken, but we didn´t imagine we´d break our own so quickly. In my last missive I boasted about the Bobolink night roost we found consisting of approximately 60,000 birds, the largest concentration of this species ever reported.
Today we not only counted an additional 10,000 in the same roost, but we also found a new roost of another 40,000 Bobolinks only a mile or so away, for a total of 110,000 Bobolinks! Furthermore, our estimates are very conservative. We count birds as they leave the roost, but there are always some that stay and are not included in the count. More importantly, however, is that access is so limited due to a scarcity of roads and infrastructure, that there may be other roosts we`re still not aware of.
According to a few of the locals, the Bobolinks have always been here. Although rice production is brand new in this area and the Bobolinks are clearly taking advtange of it, the word is that they have always come here to feed on a native grasses. Have they always been present in such large numbers? Nobody seems to have paid enough attention back then to be able to answer that question.