Thursday, March 31, 2011
Photo: Kent seeing eye-to-eye with a mist-netted Sharp-shinned Hawk.
Wednesday, March 30, 2011
It has been accepted for 80 years that American elms (Ulmus americana) are tetraploids, trees with four copies of each chromosome. But there have also been persistent but dismissed rumors of trees that had fewer copies—triploids, which have three copies of chromosomes, or diploids, which have two copies.
Now botanist Alan T. Whittemore and geneticist Richard T. Olsen with USDA's Agricultural Research Service (ARS) have proven beyond question that diploid American elms exist as a subset of elms in the wild. Their findings will be published in the April edition of the American Journal of Botany. Whittemore and Olsen work at the U.S. National Arboretum operated by ARS in Washington, D.C.
American elms once lined the country's streets and dominated eastern forests until they succumbed by the millions after Dutch elm disease arrived in the United States in 1931. Yet elms are still one of the most important tree crops for the $4.7 billion-a-year nursery industry, especially since the introduction of a very few new trees with some tolerance to the disease. American elms remain popular because of their stately beauty, their rapid leaf litter decay and their ability to stand up to city air pollution.
It was one of the disease-tolerant elm trees—Jefferson, released jointly by ARS and the National Park Service in 2005—that put Whittemore and Olsen on the trail of the diploid.
"Jefferson is a triploid. To get a triploid elm, we thought there had to be a diploid parent out there somewhere in the wild that had crossed with a tetraploid," said Whittemore.
To settle the question, the two scientists tested elm trees from across the species' eastern and central U.S. range. About 21 percent of the wild elms sampled were diploid; some grew in stands with tetraploids, while others were larger groupings of diploids.
The small amount of genetic data now available suggests that at least some tetraploid and diploid elm populations have diverged significantly from one another, which strengthens the possibility of the diploid trees having genes for disease resistance that the tetraploids don't have, Whittemore said.
"We can't say yet whether this is a distinct race of U. americana or if we are really talking about a separate species," he said. "That's a job we will tackle this summer."
Source: USDA press release by Kim Kaplan
Thursday, March 24, 2011
In recent months, Vermont has experienced a pronounced increase in Barred Owl sightings, as these nocturnal predators struggle to hunt successfully for small mammalian prey under the deep snow. Reports of Barred Owls around the state have been numerous, with some sightings occurring in unexpected venues.
Listen to Vermont Public Radio's interview with VCE's Chris Rimmer and other bird experts around the state to learn more about this winter's Barred Owl phenomenon.
Please report any Barred Owl observations (and sightings of other birds) on Vermont eBird, which is coordinated by VCE. If you encounter a Barred Owl in distress, please contact the Vermont Institute of Natural Science's wildlife rehabilitation facility.
Photo: a Barred Owl in easier times, courtesy of Steve Faccio.
Thursday, March 17, 2011
Spring is just beginning to unfold at our headquarters in Vermont, but in other places it is already in full swing. While we patiently (or not) wait for the snow to melt and the Woodcock to take over the fields, we can already experience spring, coming to us live from Nebraska.
The Platte River Valley is the most important stopover for Sandhill Cranes, and right now it is host to astounding numbers of these ancient birds that have flown from southwestern US and Florida wintering grounds. The cranes roost at night in this shallow river, taking advantage of the protection the sandbars afford from predators like coyotes. Nearby farmlands and wet meadows offer an abundance of food, critical to cranes refueling for the next leg of their journey to parts north, from Alaska to Nunavut.
The Rowe Sanctuary's live "crane cam" located on the Platte River just east of Kearney, NE is full of activity all day, but you'll see and hear mind-boggling numbers of cranes around dawn and dusk. Here on the East Coast that currently translates to peak activity roughly around 7:30 - 8:30am (lift-off is apparently around 8am) and 8:30-9:30 pm.
In stark contrast to the Platte River, Vermont sees only occasional visits from Sandhill Cranes, and the first nest for the state was only recently documented, in 2005 in Bristol. The pair eventually succeeded in raising young in 2007, and have continued to nest each year. Although Vermont lies east of the species' typical breeding range, birders may very well be able to look forward to additional breeding attempts in the future; populations have been expanding for decades and new breeding records have been sprouting up in recent years in the Northeast.
Click here to visit the webcam
- Rosalind Renfrew
Wednesday, March 09, 2011
Yet today, there is evidence of alarming pollinator population declines worldwide. Fortunately, science investigators of this crucial issue can use data collected and organized in the Butterflies and Moths of North America (BAMONA) database to monitor the health of our butterfly and moth population.
Backed by more than 287,000 verified sighting records and 3,239 images that describe 4,638 species, BAMONA is committed to collecting and providing access to quality-controlled data about butterflies and moths of North America. Dedicated volunteer coordinators, including national and internationally recognized Lepidoptera experts, verify each record. VCE biologist, Kent McFarland, is the coordinator for Vermont. The goal is to fill the needs of scientists and nature observers by bringing verified occurrence and life history data into one accessible location.
To serve its broad range of users even better, BAMONA recently launched its re-tooled website. The site was developed at Montana State University (MSU) under a cooperative agreement with the U.S. Geological Survey (USGS) National Biological Information Infrastructure (NBII) Network. VCE will soon be adding over 30,000 records from the Vermont Butterfly Survey to the BAMONA site.
BAMONA’s latest innovations are aimed at improving technologies for both data collection and data dissemination. Users can now submit records – which typically include a photograph – via the site’s new user submission form, replacing an outdated submission process that required multiple e-mails with spreadsheet attachments. As for data dissemination, verified records are now immediately available on the site’s home page. New, interactive Google-based maps enable the display of any verified sighting, including Canadian locations. Visitors can now zoom in or out and click on dots pin-pointing sighting locations on interactive maps, and see the details of each sighting record. All these features were not available previously.
For more information, go to www.butterfliesandmoths.org.
Monday, March 07, 2011
From 2002 - 2007 volunteers of all kinds searched fields and fens, mountains and meadows, even their own backyards, to document the status of Vermont butterflies. Despite their lofty status among the insects, butterflies were largely a mystery in Vermont. There was no atlas of their distribution, no scientific assessment of the threats they face, and no conservation concept for butterfly species on a statewide scale.
The most recent checklist of Vermont Lepidoptera listed 89 butterfly species in 1995. With the help from over 180 people, VBS amassed over 36,000 butterfly records from across the state representing 103 butterfly species. This work enabled biologists to determine that 34 butterfly species (33%) are of conservation concern in Vermont and gave us information on where we might begin important conservation work.
From students to landowners, butterfly enthusiasts to conservation biologists, the Vermont Butterfly Survey provides essential information about the butterflies of Vermont to help us both enjoy and conserve our natural heritage now and for future generations.
Download and view the report (PDF 12 MB):
McFarland, K.P. and S. Zahendra. 2010. The Vermont Butterfly Survey, 2002 - 2007: A Final Report to the Natural Heritage Information Project of the Vermont Department of Fish and Wildlife. 298 pp.
Thursday, March 03, 2011
Samson’s team found that if populations continue to increase at the expected rates, those who are likely to be the most vulnerable to climate change are the people living in low-latitude, hot regions of the world, places like central South America, the Arabian Peninsula and much of Africa. In these areas, a relatively small increase in temperature will have serious consequences on a region’s ability to sustain a growing population.”It makes sense that the low latitude tropical regions should be more vulnerable because the people there already experience extremely hot conditions which make agriculture challenging. An increase in temperature over the next few decades will only make their lives more difficult in a variety of ways,” says Samson.
This contrasts with Samson’s predictions about the impact of climate change on human populations in the high-latitude more temperate zones of the world, where the temperature change is expected to be greater. Because the spread of human populations along with their activities are already more constrained by the cooler conditions in these regions, the researchers expect that climate change will have less of an impact on people living in these areas.
The study also points to clear inequities in the causes and consequences of climate change: the countries that have contributed the least to climate change, based on their average per-capita carbon dioxide emissions, are nevertheless predicted to be the most vulnerable to its impacts. “Take Somalia for instance,” suggests Samson.”Because it’s so hot there, it’s already very difficult to grow things, and it will only become more difficult if the temperature rises. It’s also clear that Somalia is not a big contributor of greenhouse gas to the atmosphere. Now thanks to this map, we have concrete quantitative evidence of the disparity between the causes and the consequences of climate change at a national level.”
Samson anticipates this data could be useful for decision makers around the world in the ongoing international negotiations around climate change.”
On online version of the article was recently published by the journal Global Ecology and Biogeography. For an abstract of the article: http://onlinelibrary.wiley.com/doi/10.1111/j.1466-8238.2010.00632.x/abstract