The second episode continues the investigation of plate tectonics by discussing the phenomena of earthquakes and volcanism:
Recent news from Bird Conservation Research, Inc. about its work on the conservation of birds and on the promotion of environmental education.
Sunday, September 15, 2013
AP ENVIRONMENTAL SCIENCE VIDEOS
Bird Conservation Research, Inc. has been pioneering new approaches to online education with a video series that focuses on the AP Environmental Science Curriculum. The first episode uses the evolution of birds as a point of departure for examining large scale Earth phenomena. It then introduces the topic of Earth Systems and Resources and focuses specifically on plate tectonics:
The second episode continues the investigation of plate tectonics by discussing the phenomena of earthquakes and volcanism:
The second episode continues the investigation of plate tectonics by discussing the phenomena of earthquakes and volcanism:
Tuesday, August 6, 2013
STUDY OF GEOGRAPHIC BIRD DIVERSITY PATTERNS NOW AVAILABLE
The second major paper to arise from the Forest Bird Survey of Southern New England is now available for free download from the Bird Conservation Research, Inc. web site as well as from Bird Conservation Contributions- the scientific journal of BCR. This paper, FACTORS INFLUENCING GEOGRAPHIC PATTERNS IN DIVERSITY OF FOREST BIRD COMMUNITIES OF EASTERN CONNECTICUT, USA, explores patterns uncovered during four years of summer and winter studies. The abstract follows:
At regional scales, the most important variables associated with diversity are latitudinally-based temperature and net primary productivity, although diversity is also influenced by habitat. We examined bird species richness, community density and community evenness in forests of eastern Connecticut to determine whether: 1) spatial and seasonal patterns exist in diversity, 2) energy explains the greatest proportion of variation in diversity parameters, 3) variation in habitat explains remaining diversity variance, and 4) seasonal shifts in diversity provide clues about how environmental variables shape communities. We sought to discover if our data supported predictions of the species-energy hypothesis. We used the variable circular plot technique to estimate bird populations and quantified the location, elevation, forest type, vegetation type, canopy cover, moisture regime, understory density and primary production for the study sites. We found that 1) summer richness and population densities are roughly equal in northeastern and southeastern Connecticut, whereas in winter both concentrate toward the coast, 2) variables linked with temperature explained much of the patterns in winter diversity, but energy-related variables showed little relationship to summer diversity, 3) the effect of habitat variables on diversity parameters predominated in summer, although their effect was weak, 4) contrary to theory, evenness increased from summer to winter, and 5) support for predictions of species-energy theory was primarily restricted to winter data. Although energy and habitat played a role in explaining community patterns, they left much of the variance in regional diversity unexplained, suggesting that a large stochastic component to diversity also may exist.
Friday, July 12, 2013
JULY BCR NEWSLETTER HIGHLIGHTS ENDANGERED SPECIES
The full color, downloadable July newsletter of Bird Conservation Research, Inc. may be accessed at our web site's publications page. Read about the latest progress on the Forest Bird Survey of Southern New England, and also about Eskimo Curlews and Ivory-billed Woodpeckers.
Tuesday, May 28, 2013
IVORY-BILLED GHOST BIRDS
I have tucked away in an old file a letter addressed to me
from James Tanner. He was someone who I
had known of since my early teens, although when I initially corresponded with him I didn’t let on that I did. Back
in the days before computer generated form letters, he replied to me with a
personal and eminently polite note concerning the graduate program at his
institution.
At that early point in my scientific career, I was debating
in whose footsteps I might wish to follow.
Would it be those of Tanner- the last individual to study the Ivory-billed
Woodpecker- a guide across the Styx into the world of ghosts? Or, alternatively, would it be with someone who could tutor me
in the practical and possible? My
decision turned out to be somewhere between those opposing poles- I would
follow an individual who had already left this world, John Sage, a founder of the American Ornithologists Union who was ending
his career about the time that Tanner was beginning his. He was also student of Connecticut birds, so continuing on his distributional studies was something that I could actually do. Back in the early 1970s,
when it was still possible to sit in a university collection room alone and
unsupervised, I would spend my late evenings in front of Sage’s hand-written
catalogs and his tray of preserved Passenger Pigeons, contemplating the
individual who had collected them. To
this day, I continue largely in Sage’s shadow (see this work here).
But still, thoughts of Ivory-bills never quite faded. Over the decades intervening between then
and now, I have quietly launched solitary albeit unsystematic searches for
them. In all, my searches have been
limited in scope, never reaching the magical thousand-hour threshold that seems
the minimum for recording low probability events. But still, I’ve tried and will likely try more. There are so many thousands of acres of
habitat and so few people out really looking that it has seemed just possible
that birds might survive somewhere. The
inaccessible and inhospitable nature of the species’ last known refuges-
bottomland forests- also appeared to argue that it could be persisting undetected. Suggestion has also been
made- and seems to be backed up by observed patterns of sightings and
disappearance- that any remaining birds might be nomadic, so where they are one
year is not necessarily where they are the next. Such a possibility would make documenting their occurrence doubly difficult.
Like so many others, when several years ago credible
evidence surfaced in Arkansas and Florida (in the latter case, right near where
I had been searching myself) that Ivory-bills were still extant, I was
exhaltant. I knew it. They had to be somewhere. I watched the videos and listened to the
recorded calls posted on the internet.
I found the videos modestly convincing, but the sounds? Certainly.
In their cadence and phrasing and horn-like quality, it seemed to me
that they could be nothing else. I had burned into my head those very sounds
from 1930s recordings I had listened to years before.
And then, enter the naysayers. It is a venerable tradition in academia that critique follows
assertion- tiresome and apparently self-serving at times- but most would say
essential nonetheless. In this case several groups took on the evidence presented and negated it point by point. The images could have been this, the sounds could have been that, statistical inference
indicated no no no.
One suggestion was that the sounds might have been those of blue jays. I could see why one might think so, but I disagreed. I’ve just
completed, a la John Sage, eight years of surveying Connecticut’s forest birds (see this work here) in which I detected individuals via vocalizations under varying field conditions,
topography and distance. During those
years, I counted the better part of two thousand jays and in the process heard what seems likely to be every
variation on a jay call theme.
My ears told me that those recordings were not of jays.
And then there was the issue that one of the naysayers
had not too many years before edited a volume on Connecticut birds. In that volume, it stated that it was
absolutely, positively and otherwise definitely impossible to survey quantitatively the birds of the entire state.
Well, as it turns out, I just did that, alone and on my own dime, covering over a thousand miles on foot, and not just in summer but in winter as well, and
I threw in the whole state of Rhode Island for good measure. So, assertions to the contrary aside, it was
possible. Dogged determination,
persistence and belief go a long way toward making the impossible
possible. I hope traits like these will guide the serious searchers for the Ivory-billed Woodpecker in the years that follow.
It was, thus, with some dismay that I read that one of the key institutions behind re-discovery attempts, the Cornell Lab of Ornithology (Tanner's alma mater, by the way), was discontinuing its intensive field efforts to find birds. This led me to investigate who was behind the surveys. From the photos I located, it appeared that the teams consisted principally of young students. Physical stamina is certainly an advantage in the daunting work required of a survey of this sort. I discovered my own decreasing stamina limits late last summer when, during field searches for migrant Eskimo Curlews, my legs began giving out after hour upon hour of trudging along Cape Cod dune trails. However, there is a trade-off between stamina and experience. Back in Tanner's day, the senior Arthur Allen and Peter Kellogg were out with him during those historic Ivory-bill studies. I regularly see how my own years of experience give me a substantial advantage over the less practiced in distinguishing subtleties, in understanding how to look and in detecting what others might miss. I hope this generation of senior Cornell figures has, similarly to their predecessors, made a significant field contribution to the recent efforts.
Despite professions by some of the scientific elite that the Ivory-bill is either extinct or beyond saving, my feelings remain different. What I see from published reports is a species that appears to have persisted for a century over significant portions of its former range without any human help. As our continent's supply of mature bottomland forest continues to grow, we may yet see this bird emerge from its present ghostly status back to that of a resilient and revered member of our wildlife community.
Monday, April 22, 2013
AP ENVIRONMENTAL SCIENCE LAB INTRODUCES FACTORIAL ANALYSIS OF VARIANCE
With the introduction of advanced placement courses into national science curricula, many students are now exposed to college-level content in the high school setting. This has permitted inclusion of statistical inference into the classroom- something that has historically been all but absent from high school science. Especially in a scientific world in which statistical analyses are rapidly expanding in sophistication and complexity, it is essential that prospective scientists be exposed to statistical thought early in their careers.
The factorial analysis of variance falls under the heading of classical frequentist statistics. It has been used for many decades in fields like agricultural research to investigate effects of experimental treatments on growth, health and productivity of crops. Although it offers a reasonably sophisticated approach to examining data, the computations necessary to conduct it are well within the range of most high school students. Hence, it provides a useful tool for introducing students to statistical concepts.
A lab investigation developed by Bird Conservation Research, Inc. for the AP Environmental Science curriculum, Tomato Growth, combines a traditional agricultural experiment with factorial analysis of variance. It introduces students to experimental design and statistical concepts like null and alternate hypotheses, probability, controls and interactions. It demonstrates how statistical tests can be used to verify the existence of trends observed in graphical analysis of data.
| Statistical analysis of experimental data has long been a mainstay of agricultural research. |
Thursday, April 11, 2013
APRIL BIRD CONSERVATION NEWSLETTER NOW AVAILABLE
Welcome to the April, 2013 newsletter of Bird Conservation Research, Inc. In it, you will find news of our latest progress on analyzing data from the Forest Bird Survey of Southern New England. You will also find news about our latest products for environmental education.
Thanks to all of you who have become 2013 BCR members. Everyone who has done so will be receiving an acknowledgment shortly that can be used for tax purposes. If you haven't yet joined, you may do so simply by clicking on this link.
If you wish to download a PDF version of the newsletter, visit our web site at http://www.birdconservationresearch.org/publications/newsletters.php.
Saturday, March 23, 2013
AVIAN HABITAT SURVEY OF SOUTHERN NEW ENGLAND
The Forest Bird Survey of Southern New England, the eight year long project of Bird Conservation Research, Inc. to map density distribution of the region's forest birds, also conducted habitat surveys along its 2220 census points. The survey examined field conditions in 3417 ha of forest, a sample nearly 100 times that of periodic U.S. Forest Service surveys in Connecticut and Rhode Island.
Like the Forest Service surveys, BCR studies evaluated proportionate cover of major forest types. In addition, BCR examined forest canopy cover, prevailing tree diameter, understory density, moisture regime, and elevation. The data are to be used to seek relationships between habitat distributions and distributions of forest bird densities.
Analysis of cover types shows that the forests of Rhode Island (RI in the graph below) are dominated by xeric oak and conifer associations. Northeast Connecticut (NECT) most resembles Rhode Island in its forest composition; both these regions are extensively underlain by glacial sand and gravel. The locations most heavily dominated by oak forests are Southeast (SECT) and Southwest (SWCT) Connecticut, where lower elevations and milder climates prevail. Central Connecticut (CECT) also has a high proportion of oak forests, but has as well extensive cover by more mesic-associated mixed deciduous forests. Much of the remaining forest in heavily urbanized central Connecticut is indeed in wetter environments. Northwest Connecticut (NWCT), with the most mountainous terrain in southern New England, has less cover by oaks and more cover by conifer-hardwood forests. Such forests are generally associated with cooler, northern climates.
Like the Forest Service surveys, BCR studies evaluated proportionate cover of major forest types. In addition, BCR examined forest canopy cover, prevailing tree diameter, understory density, moisture regime, and elevation. The data are to be used to seek relationships between habitat distributions and distributions of forest bird densities.
Analysis of cover types shows that the forests of Rhode Island (RI in the graph below) are dominated by xeric oak and conifer associations. Northeast Connecticut (NECT) most resembles Rhode Island in its forest composition; both these regions are extensively underlain by glacial sand and gravel. The locations most heavily dominated by oak forests are Southeast (SECT) and Southwest (SWCT) Connecticut, where lower elevations and milder climates prevail. Central Connecticut (CECT) also has a high proportion of oak forests, but has as well extensive cover by more mesic-associated mixed deciduous forests. Much of the remaining forest in heavily urbanized central Connecticut is indeed in wetter environments. Northwest Connecticut (NWCT), with the most mountainous terrain in southern New England, has less cover by oaks and more cover by conifer-hardwood forests. Such forests are generally associated with cooler, northern climates.
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