Feeling the Loss of a Good Friend
My good friend and a life long birder, Candace Stuart, died on Saturday in a terrible traffic accident in Denver, Colorado. Candace was the owner of the Wild Bird Center Store in Denver and was a wonderful person, sharing her vast knowledge of birding and feeding wild birds with everyone.
The world needs more people who are steadfast champions for nature in the way that Candace was. We can’t afford to lose even one person with as much integrity, understanding and compassion such as she possessed.
The accident was caused by a “cops and robbers” car chase. I realize that everything was done “by the books”, as they say, in terms of “chase protocol”. Still, it doesn’t really make it right. We have lost someone far more precious and wonderful as a result.
A favorite organization of Candace’s was the Wild BIRD Information and Rehabilitation of Denver. They are an organization that will certainly feel the loss of their dear friend in many ways. Please feel free to visit their website to see the good things they do. Candace would be excited if you had an interest in them because they do so many good things.
As birds migrate, oil spill effects may travel
Migratory shorebirds affected by 2010 BP oil spill could hurt ecosystems in Canada Prairies, Great Plains, Great Lakes & Arctic
TULANE (US) — The full impact of the 2010 Deepwater Horizon oil spill may still reveal itself as bird migration spreads the disaster far from the Gulf Coast.
The largest-ever accidental release of oil into marine waters could impact earth’s ecosystems for years to come—and not just along the 650 miles of the northern Gulf of Mexico coastline directly affected by the spill.
“More than one million migratory shorebirds representing 28 species were potentially exposed to Deepwater Horizon oil during their 2010-2011 nonbreeding season,” says Caz Taylor, assistant professor and a population ecologist at Tulane University.
“Although only 8.6 percent of the shorebirds trapped from fall 2010 to spring 2011 showed visible signs of oiling, nonlethal effects and degradation of habitat can affect populations in ways that carry over into subsequent seasons.” Continue reading
Many Protected Areas Face Threats in Sustaining Biodiversity
PHILADELPHIA — Establishing protection over a swath of land seems like a good way to conserve its species and its ecosystems. But in a new study, University of Pennsylvania biologist Daniel Janzen joins more than 200 colleagues to report that protected areas are still vulnerable to damaging encroachment, and many are suffering from biodiversity loss.
“If you put a boundary around a piece of land and install some bored park guards and that’s all you do, the park will eventually die,” said Janzen, DiMaura Professor of Conservation Biology in Penn’s Department of Biology. “It’s death from a thousand cuts.”
The international team of researchers, led by William Laurance of Australia’s James Cook University, conducted 262 interviews of field biologists and environmental scientists who had extensive experience working in tropical forest reserves. In all, the interviews incorporated results from 60 protected areas in 36 countries. Continue reading
Monarch Butterflies: Wing Color May Determine Flight Performance
The distinctive orange and black wings of monarchs (Danaus plexippus) have long been known to advertise their bitter taste and toxicity to potential predators. Recent work also showed that both the orange and black coloration of this species can vary in response to individual-level and environmental factors. Here we examine the relationship between wing color and flight performance in captive-reared monarchs using a tethered flight mill apparatus to quantify butterfly flight speed, duration and distance.
In three different experiments (totaling 121 individuals) we used image analysis to measure body size and four wing traits among newly-emerged butterflies prior to flight trials: wing area, aspect ratio (length/width), melanism, and orange hue. Results showed that monarchs with darker orange (approaching red) wings flew longer distances than those with lighter orange wings in analyses that controlled for sex and other morphometric traits. This finding is consistent with past work showing that among wild monarchs, those sampled during the fall migration are darker in hue (redder) than non-migratory monarchs.
Together, these results suggest that pigment deposition onto wing scales during metamorphosis could be linked with traits that influence flight, such as thorax muscle size, energy storage or metabolism. Our results reinforce an association between wing color and flight performance in insects that is suggested by past studies of wing melansim and seasonal polyphenism, and provide an important starting point for work focused on mechanistic links between insect movement and color.
Citation: Davis AK, Chi J, Bradley C, Altizer S (2012) The Redder the Better: Wing Color Predicts Flight Performance in Monarch Butterflies. PLoS ONE 7(7): e41323. doi:10.1371/journal.pone.0041323
Editor: Chuan-Chin Chiao, National Tsing Hua University, Taiwan
Received: January 25, 2012; Accepted: June 20, 2012; Published: July 25, 2012
Copyright: © 2012 Davis et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The authors have no support or funding to report.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: akdavis@uga.edu
Courtesy Public Library of Science
Study finds songbirds migrate on strict schedule
One of the songbirds studied is the wood thrush. Photograph by Kevin Fraser
A new study by York University researchers finds that songbirds follow a strict annual schedule when migrating to their breeding grounds – with some birds departing on precisely the same date each year.
The study, published in the journal PLoS ONE, is the first to track the migration routes and timing of individual songbirds over multiple years. Researchers outfitted wood thrushes with tiny geolocator “backpacks”, recording data on their movements.
Spring departure dates of birds heading from the tropics to North American breeding grounds were surprisingly consistent, with a mean difference of only three days from year to year, the study reports. Fall migration, however, was far less predictable. Males on average flew faster than females, and first-timers lagged behind those with more than one journey under their wings.
The geolocators, which are smaller than a dime, are mounted on birds’ backs with thin straps looped around their legs. The devices measure light, allowing researchers to estimate latitude and longitude by recording sunrise and sunset times.
“It’s quite surprising that the schedules of these birds are so consistent across the entire route, with some of them departing the tropics and arriving at breeding sites in North America on the same day in different years,” says study author Kevin Fraser, a postdoctoral Fellow in York’s Department of Biology, Faculty of Science & Engineering. “Much like airplanes, there are many factors that can influence birds’ flight schedules, such as weather at departure and expected conditions at the other end of the journey. Amazingly, these small songbirds are highly consistent in their timing between years.”
Interestingly, while their departure times are precise, songbirds’ migratory routes can vary widely. “Migratory routes sometimes differed by several hundred kilometres between years, which may reflect a fine-tuning of migration in response to wind and weather conditions en route, such as during large open-water crossings like the Gulf of Mexico,” says Fraser.
Wood thrush with geolocator. Image taken in Belize. Photo by Emily McKinnon
As for arrival times, birds need to be early to lay their claim to prime breeding grounds – but not too early.
“There is intense pressure for birds to get back to breeding grounds early to secure good territories, nest sites and, of course, mating opportunities. The early birds tend to do better and raise more young. However, cool weather in early spring can reduce food availability and even survival of early birds,” Fraser says. He cautions that songbirds’ consistent timing may come at a cost.
“The concern is that birds may not be able to flexibly adjust their schedules to meet new conditions with climate change,” says Fraser. “This is a topic we’re pursuing in current research.”
The birds Fraser tracked were tagged in Pennsylvania and Costa Rica, at field research sites of his supervisor, York University Professor Bridget Stutchbury, who has studied the behavioural ecology of birds for decades. Her 2007 book, Silence of the Songbirds, details the threat to the species posed by climate change and habitat destruction.
“Numbers [of wood thrush] have plummeted in Canada by over 50 percent since the 1960s. When we lose the wood thrush, and other songbirds, we lose an integral part of the forest itself,” Stutchbury says.
The research was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), National Geographic Society, U.S. Fish & Wildlife Service Neotropical Migratory Bird Grant, Kenneth M. Molson Foundation, Schad Foundation and proceeds from Silence of the Songbirds.
The study, “Repeat tracking of individual songbirds reveals consistent migration timing but flexibility in route”, is co-authored by Stutchbury, along with Calandra Stanley, Maggie MacPherson and Emily McKinnon, graduate students in York’s Department of Biology, Faculty of Science & Engineering.
Nesting and Food Supplies Go Hand In Hand
I just read the article, copied below, on ENature.com entitled “Why Do Goldfinches Wait Until July To Nest?”. The main point of the article is that goldfinches lay their eggs to coincide with ripening of seeds that they prefer to have for their young hatchlings. It only makes sense to talk about Goldfinches now, since it is “their time” and summer is a great time to feature them (incidentally, I agree with that).
The article is brilliant in that it uses this one species as an example of how the universe plans everything. All species of birds and animals breed, lay eggs and naturally plan their calendar around a generations old cycle that they are unable to break. It is the most important concept of Bringing Nature Home: How You Can Sustain Wildlife with Native Plants
If a certain moth lays eggs at a certain time on only a certain tree, nature knows which birds need that particular larvae to feed its young and makes everything happen in a timely manner.
If the particular tree isn’t there, then the moth can’t lay its eggs, and there won’t be sufficient food for that particular bird species to eat when the time comes to feed its young.
A bird species in the news in recent years and the subject of a PBS special is the Red Knot. The entire feature entitled “Crash: A Tale of Two Species” can be viewed on-line (CLICK HERE OR THE TITLE) and does a wonderful job of explaining how this small bird knows when to leave the very southern most tip of the earth to arrive on New Jersey’s shores just in time for horseshoe crabs to lay their eggs, providing nourishment to allow the Red Knots to fly the rest of their journey to the arctic circle. Interruption of this cycle due to human actions put this delicate natural balance at risk.
Please take a few more minutes to read the article below, and consider native plants in the garden, especially trees and shrubs. Most garden centers are on board and can help you make good selections.
From ENature.com:
Why Do Goldfinches Wait Until July To Nest?
By July, most songbirds are in the final stages of raising their young, but not the American Goldfinches.
These appealing, colorful birds are just getting started.
Notoriously late nesters, goldfinches have been waiting for the thistles to bloom. When this happens in July, it signals the goldfinches that they can start building their nests which are made primarily of the silver fibers and down of thistle blooms. Generally, the nest is built in the fork of a horizontal tree limb, 4 to 14 feet above the ground.
The female builds a durable, neat cup of thistle and cattail fibers, so dense that it will hold water. In it she lays 4 to 6 pale blue to white eggs and then she incubates them for 12 to 14 days, until they hatch. The attentive male often feeds his mate while she sits on the nest.
By the time the eggs hatch, the thistle has gone to seed, which is perfect timing for feeding young goldfinches. The parents nourish this chicks by consuming the thistle seed themselves, and then regurgitating the partially digested, milk-like cereal into the mouths of their nestlings. This is as close as birds come to mammals that feed their young milk from mammary glands.
Baby goldfinches are fully feathered and out of the nest 10 to 16 days later. Almost immediately, they join their parents at bird feeders across America. That’s when many people suddenly notice so many goldfinches as the summer progesses.
Have you seen nesting goldfinches yet? Or young preparing to fledge?