Just as differences in song can be used to distinguish one bird species from another, the pips and squeaks bats use to find prey can be used to identify different species of bat. Now, for the first time, ecologists have developed a Europe-wide tool capable of identifying bats from their echolocation calls.
The new free online tool – iBatsID – will be a major boost to conserving bats, whose numbers have declined significantly across Europe over the past 50 years. Details are published today in the British Ecological Society‘s Journal of Applied Ecology.
Working with an international team of ecologists, lead author and PhD student Charlotte Walters from the Zoological Society of London (ZSL) selected 1,350 calls of 34 different European bat species from EchoBank, a global echolocation library of more than 200,000 bat calls.
The calls were then analysed to find out which characteristics were most useful in distinguishing different bat species. According to Walters: “Lots of different measurements can be taken from an echolocation call, such as its maximum and minimum frequency, how quickly the frequency changes during the call, and how long the call lasts, but we didn’t know which of these measurements are most useful for telling different species’ calls apart.”
The 12 most useful call parameters were then used to train artificial neural networks to produce the new identification tool, iBatsID, which can identify 34 different bat species across the whole of Europe. Most species can be identified correctly more than 80% of the time, although accuracy varies because some species are much harder to identify than others. Continue reading →
On a remarkable expedition in 2008, a team of young explorers including three Cornell graduates discovered an undescribed bird in Peru. Now named Sira Barbet, the new species graces the cover of The Auk (July 2012), and receives its formal scientific description inside. Its scientific name, Capito fitzpatricki, honors the contributions of John Fitzpatrick, director of the Cornell Lab, who did pioneering work in Peru (including discovering seven new species of his own) and also helped mentor the Cornell graduates on the expedition.
Those Cornell graduates are Mike Harvey, Glenn Seeholzer, and Ben Winger; their coauthors on the Auk article include Peruvian colleague Daniel Cáceres and U.S. colleague Jason Weckstein. “Fitz’s contributions to Neotropical ornithology, and his enthusiasm for exploration, stoked our dream for the expedition,” said Winger. “He has inspired generations of young ornithologists in scientific discovery and conservation, and we are honored to name this species for him.” Continue reading →
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.
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 →
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 →
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.
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Courtesy Public Library of Science