Bird Food Source Alert: Declining Insects

In recent years, we've seen well-documented declines in domesticated honey bees, monarch butterflies, and other insects that attract a lot of attention. But we haven't really noticed the moths, beetles, and other insects that flitter and crawl through our everyday life. Birds, however, probably notice their decline a lot, since they're a major food source. 

A recent story in the journal Science documents a new set of data gathered mostly by amateur entomologists in western Europe. These folks have tracked insect abundance at more than 100 nature reserves since the 1980s, and the news is not good.

This group of amateurs, named the Krefeld Entomological Society (after their location in Germany) has seen the insect catches in their traps fluctuate every year. This is normal. But in 2013, they noticed that one of their longest-running sites showed a decline by mass of almost 80%. The numbers were just as low in 2014. In fact, the group found dramatic declines across more than a dozen other sites, even in reserves where plant diversity and abundance had improved. 

The group has installed more traps each year since 2013. They've also begun working with university-based researchers to look for correlations with weather, changes in vegetation, and other factors. Unfortunately, no simple cause for the decline has yet emerged.

If you don't like bugs, you're probably asking, "Why does this research matter?" The answer is that other creatures eat insects—such as birds. Dave Goulson, an ecologist at the University of Sussex in the United Kingdom, explains, "If you're an insect-eating bird living in that area, four-fifths of your food is gone in the last quarter-century." No matter what your opinion of bugs, this is important news.

No one knows what this research in western Europe means for insects elsewhere. But we at Talkin' Birds think that anything that affects the food chain for birds anywhere is worth investigating for the good of us all. 

A male hoverfly on a Bermuda Buttercup. (Photo: Wikimedia Commons; author: Alvesgaspar.)

A male hoverfly on a Bermuda Buttercup. (Photo: Wikimedia Commons; author: Alvesgaspar.)

The Connecticut Warbler: Migration Marathoner

The Connecticut Warbler was our Featured Feathered Friend on a recent show. We described it; pointed out how a Sean Connery character misidentified it in a major motion picture (Finding Forrester); and talked about the fact that the bird is named for a state where it’s not often found. But we’ve since learned something new and amazing about the Connecticut Warbler, thanks to a story in the August issue of BirdWatching Magazine. The story quotes bird biologist Emily McKinnon about new evidence that the Connecticut accomplishes feats of migratory flight similar to those of the Blackpoll Warbler, which is a North American migration champion. The new research shows that, like the Blackpoll, the Connecticut Warbler travels long distances non-stop over the Atlantic Ocean on its journey to its South American wintering grounds, flying for at least 48 straight hours over the bounding main—and that’s only part of the trip! Check out the article for all the details. 

Connecticut Warbler.jpg

Barn Owls: The Secret to Great California Wine

Before you get worried, we'd like you to know that no owls are harmed in the making of fine California wines. In fact, they get paid well — in rodents. 

Rodents like to eat grape vines, and Barn Owls like to eat rodents. Many Napa Valley wineries control rodents by putting up nest boxes to establish Barn Owl populations. Researcher Sara Kross from the University of California Davis says that more than 99% of prey items in barn owls’ diets on the farms she studied were agricultural pests — mice, voles, and pocket gophers. Fewer of these pests means easier growing for grapevines.

Welcoming Barn Owls allows wineries to reduce or eliminate the use of rodent poisons. It's important to note that, if poisons must be used, they should be used with care, since an owl that eats a poisoned critter will ingest the poison, too.  

Intrigued? You can read more about Kross's research here, including where to get nest boxes of your own. 

Wildlife Biologist Carrie Wendt says, "When it comes to wine making, owls are part of the whole process, because they’re rodent-devouring machines."

Wildlife Biologist Carrie Wendt says, "When it comes to wine making, owls are part of the whole process, because they’re rodent-devouring machines."

An Elusive Bird Heard and Seen in Venezuela

The American Bird Conservancy reports that an international team of researchers has solved one of South America's great bird mysteries: that of the elusive Táchira Antpitta.  It's a small, brown bird that had not been seen since the 1950s, listed as Critically Endangered and even thought to have gone extinct.

Antpittas are reclusive birds that are easier heard than seen. Unfortunately, the team had no sound recordings, so no one knew what to listen for. They did know where to search for it, though. Eventually, they picked up the distinctive sound of an antpitta that they had never heard before, deep in the mountainous forests of western Venezuela, and were then able to identify the bird from previous descriptions.

Similar habitat can be found nearby in Colombia, and the scientists think the species might also occur there. They’re now working to determine the bird’s full range and habitat requirements, and how best to ensure its continued survival.

Click here for the full story. 

 

 

Flowers that Attract Hummingbirds Confuse Bees

Flowers pollinated mostly by hummingbirds seem to have evolved to confuse bees rather than to attract hummingbirds. So says a recent paper in the journal Ecology, "'Hummingbird' floral traits interact synergistically to discourage visitation by bumble bee foragers,"

Here are some starter facts. Flower preferred by bees ("bee" floral variants) tend to be upright and have blue or purple coloration, since bees have trouble seeing the color red. "Bird" variants, meanwhile, tend to be horizontal with red or orange coloration. Also, bee flowers yield small amounts of concentrated nectar, while bird flowers give pollinators larger amounts of dilute nectar. 

Robert Gegear, assistant professor of biology and biotechnology at Worcester Polytechnic Institute (WPI), wanted to understand how flower characteristics combine to influence the decisions bumblebees make about which flowers to visit. In other words, What kinds of flowers encourage or confuse bees? 

For the first step of the study, Gegear and his team of students trained bees to forage on arrays of paper flowers that all had the same color, orientation, and type of nectar reward. The bees learned that every color and orientation combination yielded the same reward.

The team then gave the bees arrays in which flowers of one color/orientation combination contained nectar and the other combinations contained distilled water. Gegear and his students recorded how long it took the bees to learn which flowers were worth visiting. 

The bees took longer to learn about certain combinations than about other combinations. That is, fake flowers that would favor birds in real life were more confusing for bees than fake flowers that would be better for bees in real life.

Why? Gegear explains, "These data suggest that the reason bee-to-bird evolutionary transitions are often accompanied by a floral shift to classic 'bird' trait complexes is because bees have a particularly difficult time combining red with other sensory traits, including nectar rewards." In other words, bees have a hard time recognizing red flowers, so any trait associated with red flowers is not worth their time to learn, even if learning would mean a greater nectar reward.  

Then where do hummingbirds come in? Well, if bees tend to ignore flowers that are difficult for them, then other pollinators, such as hummingbirds, make their move. Gegear says, "In the case of the two species of Mimulus, the costs associated with bird combinations are much greater than the costs associated with bee combinations, so bees avoid them to increase their foraging efficiency....When you put all this together, you find that 'bird flowers' are really 'anti-bee flowers' that function by exploiting specific sensory and cognitive limitations." That is, hummingbirds forage where bees don't bother to forage. 

Like most pollinators, bees are not genetically programmed to visit only particular flowers; instead, they seek to gather the most nectar in the least time however they can. In other words, they're generalists. From the plant's perspective, however, the best pollinator is a specialist in that plant. (Think of a building toy, like Lego, that clicks only with itself, which forces shoppers to buy only that one brand of building toy.) By combining particular floral characteristics, plants manipulate pollinators to become specialists because generalizing becomes a waste of time. In Gegear's words, "From an ecological perspective, an ideal pollinator is one that always forages on flowers of the same type so pollen is transferred effectively. In reality, pollinators are generalists and they should simply forage randomly. So the big question has been, how do plants get the pollinators to do what they want?"

Gegear suggests that most hummingbird-pollinated flowers once had bee-pollinated ancestors. He says his study shows that at least two floral characteristics had to change for the bird flower Mimulus cardinalis to evolve from the bee flower Mimulus lewisii, and that those changes served to discourage bees.  

Regardless of the flower, we can be kind to pollinators by avoiding pesticides in our gardens and by providing shelter and water for pollinators.

Do Power Lines Help Birds?

A team of researchers in New Hampshire and Maine are investigating whether birds move into land that has been cleared along the route of a power line or has recently been logged. “Our goal is to get a better understanding for how these habitats function in our landscape,” says wildlife specialist Matt Tarr of the University of New Hampshire Cooperative Extension.

The study is being funded by the federal Natural Resources Conservation Service. A more controversial source is the National Fish and Wildlife Foundation’s New England Forests and Rivers Fund, to which the utility Eversource is a contributor. The controversy is that Eversource has proposed the Northern Pass energy transmission project, which entails building a 192-mile electricity transmission line from Pittsburg to Deerfield, New Hampshire. Property owners and tourism officials, among others, have criticized the project. 

Tarr explains that the study isn’t intended to find benefits in building a transmission line. Rather, it's to help determine how birds use the forests that emerge after such a project is built. Tarr's research could help inform policymakers as they work to create more young forests for birds and other species. It will focus on 24 transmission line rights-of-way and 12 logged areas in southeastern New Hampshire and southern Maine. “We might find these rights of way aren’t used as we think they are for mature forest birds," explains Tarr. "That would be important for us to know.”

Starting in late May, Tarr and his colleagues will catch songbirds and band them, then track them over the next two years. Tarr says as many as 40 songbird species nest in young forests, and another group nests in mature forests. Additional evidence suggests young birds that have just left the nest will often live in young forests while their development finishes. In some parts of the country, these younger forests have been found to provide food sources and protection for birds. 

We here at Talkin' Birds are all for the peaceful coexistence of humans with birds and other creatures. We appreciate careful research that leads to wise decisions. We wish Matt Tarr and his team good luck and clear results. 

 

Quiet, Please: How Human Noise Affects Wild Places

People better at birding by ear than by eye can find it maddening to try to hear songs and calls over traffic noise. We wait for the bird to raise its voice once the rattling trucks have passed--only to discover that someone has fired up a leafblower nearby, drowning out everything the way radio static drowns out music.

As annoying as unwanted human noise is to us, it's devastating to other creatures. For example: if birds can't hear one another, they can't alert one another to approaching danger or attractive mates or good food sources. Prey animals can't hear predators in a noisy environment, which means more of them get eaten, affecting the ecological balance. Human noise pollution affects plant reproduction by scaring away birds that help distribute seeds, according to a recent paper in the Proceedings of the Royal Society of London B.

Rachel Buxton, an acoustic ecologist at Colorado State University, succinctly explains the essential problem with noise: “It really doesn’t have any boundaries.” Buxton and her colleagues reported recently in the journal Science that noise from humans at least doubles the background sound levels in most protected areas in the United States. “When we think about wilderness, we think about...going to see outstanding scenery,” says co-author Megan McKenna. “We really should think about soundscapes, too.”

Buxton and McKenna and their team used a model for predicting noise based on sound measurements taken all over the country by the National Park Service. Individual scientists hiked in to more than 400 listening stations to set up the equipment, each of which included a sound level meter and a recorder. Each recorder ran for 30 days, collecting every sound. The recordings were then analyzed by acoustic specialists. The researchers then constructed a model for predicting noise by figuring out which sounds were associated with geographic features such as elevation, annual rainfall, proximity to cities, highways and flight paths. By subtracting out natural sound sources, the scientists estimated the amount of noise pollution for each specific wilderness area.

The findings were mixed. Protected areas did show much lower levels of human-caused sound than the "buffer zones” of unprotected land near them, suggesting that these buffer zones really do insulate parks. But 63 percent of the protected areas showed an increase in sound levels of at least three decibels caused by noise pollution. Since decibels are logarithmic, three decibels indicates a doubling of background noise. More than a fifth of protected areas experienced 10 extra decibels of human noise. Sadly, the majority of areas considered “critical habitat” for endangered species were among the regions that dealt with the worst noise.

McKenna said that parks are taking steps to reduce human sounds, such as implementing shuttle systems to reduce the number of cars and posting library-style “quiet” signs. But the problem of pervasive traffic sound—all those low-frequency rumbles from ground and air—is not so easily solved. Buxton suggests that parks look into “quiet pavement” to muffle the sounds of rolling tires and establish noise corridors to align airplane flight paths with highways.

We here are Talkin' Birds plan to drive as little as possible in protected areas, opting instead for quieter transportation such as foot and bicycle. We'll try to keep our voices down, too. And we would never dream of playing a radio in the wilderness, not even to listen to our own show. We would rather not disturb the symphony of life around us, nor its musicians. 

Want to listen to a news story on this research? Click here for a piece from NPR's Morning Edition

Ravens Act Sneaky, Like People Do

Think humans are the only creatures who can be sneaky? Think again: ravens can, too.

Imagining that others might have thoughts different from our own had been assumed to be a distinctly human ability. But new research from the University of Houston suggests that ravens can not only imagine what others are thinking but also change their own behavior according to what they imagine. Experts found that ravens hiding food were able to understand that they could be watched, even without seeing another bird, and behaved sneakily as a result.

Before you read on, you need to know that ravens hide food for later, a behavior called "caching." When they feed from an abundant source, they take some of the food with them and put it away, often in the ground, so they can return to it when times are lean. 

Researchers placed a raven in a room adjacent to a room in which someone (um, a human) pretended to prepare food. These two rooms were joined by a window and a peephole. 

When the window was closed and the peephole left open, the birds behaved as though they were being watched by a competitor: they hid their food quickly and did not return to a previous stash (which would reveal its location). When the peephole was closed, the ravens didn't hide food as quickly, and they'd use the stash multiple times. They would remain this unconcerned even when the researchers played raven sounds behind the closed peephole. In other words, the test ravens behaved differently only when conditions indicated that they were being watched.

This research matters because it demonstrates that ravens might be able to imagine what others are thinking. Until now, only animals closer to humans—such as chimps—had been shown to have this ability. 

Professor Cameron Buckner, assistant professor of philosophy at the university, says the study gives important clues to the ability of animals to engage in abstract thought and indicates that we humans are not the only creatures who understand that others have a conscious mind. 

If you'd lie to read more, here's a link to the study. 
 

New! Talkin' Birds Podcast-only Extras!

Can't get enough Talkin' Birds? Good news! We're launching podcast-only "extras" to help tide you over.

Sometimes we have stories we'd love to share with you but that we just can't fit into the weekly broadcast. So now we're sharing them anyway—via podcast. How do you hear them? Easily. 

1. If you already subscribe to our weekly show as a podcast, you'll receive these "extras" in your feed without any effort. 

2. If you don't subscribe to our weekly show podcast, you can listen directly from our Archive. It's as easy as reading this blog. On our website, click "How to Listen," then "Archive." Scroll around (or simply search on "podcast"), click, and enjoy.

Any questions? Please ask! Meanwhile, click here for our very first podcast extra.

 

Understanding the Endangered Species Act

We here at Talkin' Birds seek to keep our listeners informed about developments in the world of birds and birding, so we've written this simple explanation of the Endangered Species Act and what makes it controversial. Why now? Because lawmakers in Washington, DC are going over it very carefully these days in order to decide what, if anything, should be changed about it. We ought to warn you: If you Google "Endangered Species Act of 1973," the top two results are strongly opinionated–in opposite ways. There's a lot of argument right now. Here, we hope, is a balanced picture. 

The Endangered Species Act, or ESA, was signed into law in December 1973 by President Richard Nixon. Scientists had recognized for about a century that human activity was causing the extinction of fish, animals, and birds. While a few laws had been enacted to prevent over-hunting individual species (for instance, the American Bison), this law was the most comprehensive in that it intended to prevent and reverse extinction of all domestic endangered species, including maintaining and restoring their habitat. The Endangered Species Preservation Act of 1966 set the stage for the ESA by establishing a list of species in need of help. In 1969, the Act was emended to include species in danger of worldwide extinction. The ESA was and is more comprehensive in scope than both previous Acts. 

We bird-lovers have probably heard how the Bald Eagle, the Whooping Crane, and the Peregrine Falcon, among others, have returned from the brink of extinction because of programs supported by the ESA. Millions of acres of habitat have been preserved; eggs have been incubated; chicks have grown up to reproduce successfully. Aside from birds, species from wolves to whales have been rescued so that each may continue to benefit its own ecosystem, not to mention the other species with which it interacts. (Every species that's saved is important to several others.) We have heard much about the good the ESA does.

But as successful as the ESA sounds, it is not without controversy. Some critics argue that, of the over 2000 species listed since 1973, fewer than 2% have recovered enough to come off the list. These critics feel that these numbers are proof that the ESA isn't helpful. Further, the ESA does not address the exotic pet trade within states. This means that, even though endangered species can't be sold internationally or even across state lines, they can be "donated" between states and even sold in the same state—which they feel means that those species really aren't being protected. But the most vocal critics of the ESA say that protecting habitat from human activity is, well, restrictive to humans. When it comes down to it, they argue, is the survival of a rare animal really more important than the use of its habitat to benefit human beings? Is, say, preserving a rare fish more valuable than providing drinking water for a community's children? This is a tough ethical question, and lawmakers have wrestled with it for decades. The mining and timber industries are hit particularly hard by ESA-based restrictions. In 1978, the ESA was emended to allow for species exemptions; these keep lawmakers arguing for months in states where a rare species risks being wiped out by industry. 

This simplified explanation of the Endangered Species Act is only a start. If you'd like to learn more, we hope you'll check out these resources. We've tried to choose impartial ones, but, as we warned above, that's difficult. If you find any others you like, please let us know. As stewards of this planet and its inhabitants, let's keep one another in the loop. 

-The EPA's (Environmental Protection Agency's) summary

-The U.S. Fish & Wildlife Service's

-Wikipedia's entry on the Endangered Species Act of 1973

 

 

 

 

 

 

 

What Does the EPA Do, Anyway?

We here at Talkin' Birds like to keep our listeners in the know about anything affecting birds. We've been hearing a lot in the news lately about Scott Pruitt, President Trump's nominee to head the EPA. However, we're not hearing much about the EPA itself, so we thought we'd explain what the EPA does. 

EPA is the Environmental Protection Agency. (By the way, they don't use "the," so we'll stop too.) Their mission is to protect our health and environment, which they do in more areas of life than we had imagined. No fooling: If you check the A-Z index on their website, you'll see documents on everything from acid rain to the pesticide Worker Protection Standard. EPA researches, regulates, funds grants for, and provides information about pretty much anything having to do with the environment and human health in this country.

Environmental research: EPA has research stations throughout the United States. The scientists who work at them share findings with academic institutions, private sector agencies, and research agencies here and in other countries. 

Regulation: When the United States Congress writes environmental laws, EPA writes regulations to enforce them. EPA then helps businesses and other organizations understand and comply with these regulations so they can obey the law.

Grants: EPA uses about half their funding to make grants to nonprofits, state programs, and educational institutions. These grants go to research and environmental cleanups, among other uses. 

In case you're wondering EPA has done for birds, the answer is, "A lot." We bird-lovers are probably all familiar with such bird conservation initiatives as the North American Waterfowl Management Plan, established by EPA in 1986 and the Partners in Flight initiative to increase bird habitats in North and South America. EPA regulates use of pesticides; it was they who banned DDT in 1972 because of the harm it does to humans, wildlife, and especially birds. (In fact, EPA maintains a handy pesticide chemical database ) Then there's their data on birds and climate change: for starters, have a look at this page to see how bird wintering ranges have changed over the last fifty years. This short list above just scratches the surface how EPA benefits birds. If you'd like to see more, go to their website and search on "birds." You'll get 3,860 results. Again, no fooling. 

So why is it important to think carefully about who is in charge of EPA? Because that person controls research, regulation, and information about so much that affects the life of all Americans--not just the human ones. 

Birds Provide "Biodiversity Services" that Sustain Ecosystems

"Biodiversity" means "the variety of life in a particular habitat." Each life form, from bacterium to towering tree, plays a role in sustaining its ecosystem. Therefore, each life form matters.

There are few ecosystems on Earth with more biodiversity than a rainforest. A recent study shows that the loss of even a few species from that rainforest adversely affects its longevity. Although a forest may look healthy, if the creatures required for maintenance are missing, the forest can't regenerate if it's disturbed, and its trees will eventually die out.

Research from the Department of Life Sciences at Imperial College London, published in Proceedings of the Royal Society Bshows that intensive land use, such as for agriculture and ranching, often leads to the extinction of local forest birds. These birds perform "biodiversity services" that are necessary for maintaining the rainforest's health, such as keeping down the population of plant-eating insects and dispersing the seeds of tree species. But it isn't just the individual birds species that guarantee the future health of the forest, nor is it the number of species left alive; it's the way these species interact with other kinds of life.

The research team studied the composition of bird communities from 330 study sites in the Brazilian Amazon, sampling more than 450 bird species. They also kept track of what special traits these species possessed, such as their beak size and tail and wing shape. (These traits indicate what kind of job a species has evolved to do.) Then they looked at how landscape change affected these bird populations, specifically those birds who eat insects and those who disperse seeds. 

The results were sobering. When insect-eating birds go locally extinct, leaf-eating insects can prevent young saplings from growing up into mature trees. When birds that eat certain seeds are missing, then the trees that grow from those seeds eventually go missing, too. 

Dr Joseph Tobias, senior author of the study, says that land-use management policy can positively affect forest recovery. He suggests that a forest's ability to regenerate can be preserved, even if it's largely cleared, as long as patches of primary forest survive. “Our findings are a warning flag that we can’t just look at a snapshot of forest health as it appears now—we need to think about preserving the ecosystem processes that will allow forests to survive in the future.”

Next, the team plans to examine the impact of human activity on global ecosystems by using bird traits as a window onto the effects of environmental change.  

 

New Zealand Yellowhammers "Speak" with Obsolete Dialects

Our Talkin' Birds associate producer, Debbie Blicher, learned to speak Portuguese in the Amazon rainforest outside the city of Manaus, Brazil. The people in that region speak with an accent reminiscent of the 1500's, when Portuguese was first introduced. In other areas of Brazil, the accent has evolved because of influences from other languages, local fads, and the usual linguistic wear and tear, but the people around Manaus use a Portuguese that isn't heard anywhere else. Brazilians outside the Amazon region correct Debbie's accent—once they stop laughing.

Now, research is showing that Yellowhammers in New Zealand  also "speak" with an obsolete accent. A new study published in Ecography indicates that New Zealand Yellowhammers possess some dialects that their cousins in Great Britain no longer use.  

The Yellowhammer (Emberiza citrinella) is a farmland bird native to the United Kingdom, recognizable by means of its bright yellow head. It was introduced to New Zealand in the 1860's and 1870's. The research on their song involved a citizen science project in New Zealand and Great Britain (http://yellowhammers.net) coordinated by Pavel Pipek of Charles University in Prague (the first author). Volunteers collected and submitted recordings of singing Yellowhammers with smartphones and cameras. The Prague researchers then compared the patterns of Yellowhammer dialects in Great Britain to those in New Zealand. They discovered that the birds in New Zealand use song structures no longer used in the UK. In fact, the New Zealand birds had almost twice as many dialects as their British relatives.

Why?

Pipek's team supposes this shift of dialects has something to do with the processes of the bird's population growth and decline. Over 600 Yellowhammers were introduced to New Zealand in the 1800's, where they reproduced so rapidly that they became pests, taking their songs wherever they went. Meanwhile, the Yellowhammer population in the UK dwindled, and some dialects died out with them. The result? Dialects are thriving in New Zealand that haven't been heard in the UK for up to 150 years—"a living archive," as co-author Dr. Mark Eaton says.

So next time you hear a Yellowhammer with an obsolete accent, don't laugh, and don't correct it. It's just saving a song from extinction, okay? Sheesh.

The Ancient Polar Climate—and a Giant Bird

If Santa Claus were old enough, a giant bird might have delivered his toys from the Arctic. That's right: researchers at the University of Rochester have discovered fossil evidence of a bird living in the Canadian Arctic about 90 million years ago. They published their findings in Scientific Reports, the online arm of the venerable journal Nature. 

Professor of earth sciences John Tarduno, lead author of the paper, states that his team named the fossil Tingmiatornis arctica after an Inuktikut word for "one who flies." He suggests that the bird would have resembled "a cross between a large seagull and a diving bird like a cormorant"—except that it probably had teeth. No teeth have been found yet, but this bird would have needed them to eat the large, carnivorous fish that lived in the warm waters at that time. 

Wait—warm waters? In the Arctic? You read that right. Dr. Tarduno and his colleagues speculate that the region's climate was rather like that of northern Florida today. So there would have been turtles, fish, and even proto-crocodiles in the food chain.

The T. arctica fossils were found in layers of rock above basalt lava fields. The presence of these lava fields indicates that there was volcanic activity around the time the bird existed. Those Arctic volcanoes would have released plenty of carbon dioxide which, together with methane emissions from large grazing dinosaurs, could have caused a greenhouse effect. So, yes, the weather could have been quite warm.

But what about seasonal ice? Wouldn't there have been ice in winter? Dr. Tarduno says no, because it would have prevented T. arctica from living there. 

 

We here at Talkin' Birds are excited about the find, but we don't plan to take our warm-weather vacations in the Arctic. We hope that 2017 will be a year of action to prevent climate change so that our planet's cold areas stay cold.

 

 

 

 

The World's Longest Fences

On our latest show, Ray spoke with Peter Marra of the Smithsonian Conservation Biology Institute about the harm that cats can do to bird populations. Yes, it's sad to say, but those sweet, furry critters kill billions of birds a year in the United States alone. With this sobering statistic on our minds, we were glad to read a recent news item: a five-mile cat fence has been built on Hawaii's Big Island around the Mauna Loa volcano. Whereas individual homeowners can choose to erect fencing to contain their felines, the National Park Service decided to build a single huge one to help protect the endangered Hawaiian Petrel. 

Only about 75 breeding pairs of the Hawaiian Petrel live in Hawaiian Volcanoes National Park, and cats are a serious threat to them. (Many more petrels live outside the park, but the species is still considered endangered.) Cats are not native to the Hawaiian islands, but they have taken nicely to the environment--including learning to scrabble up the sides of volcanoes to hunt vulnerable native species. The Hawaiian Islands are home to several conservation fences, of which the one on Mauna Loa is the longest. The new fence, which took four years to construct, encircles upper Moana Loa, enabling the petrels to rear their young in relative peace. It's six feet tall, with a curved top designed to be impossible for cats to climb. You can read all about the fence's construction here

Pest-proof fencing was pioneered in New Zealand and Australia, where invasive species are a recent enough phenomenon that it is often possible to tell which invader wiped out what native species. While the Mauna Loa cat fence is the longest in the United States, the longest fence of any kind in the world is the Dingo Fence in Australia, which is 3,488 miles long and protects sheep from dingo attacks.

Happy 45th Birthday, International Bird Rescue!

Here's how to clean up birds after an oil spill: First, treat the birds for shock and dehydration. Next, feed them, 'cause they might not have eaten while covered in oil, and give them any medicine they need. Then place them in warm water. Finally, when they're stable enough, wash them ever so gently with Dawn dish soap and rinse them thoroughly. 

This protocol comes from the long experience of International Bird Rescue, which got its start in 1971 when two oil tankers collided near the Golden Gate in San Francisco. The collision dumped 800,000 gallons of crude oil into the Bay and coated thousands of birds in oil. Through trial and error, volunteers figured out how to clean them up so that they stood the best chance of surviving. These volunteers eventually formed International Bird Rescue (IBR), a nonprofit that pioneers the treatment of aquatic birds that been harmed by human hands. Their method for cleaning oiled birds is now the gold standard. (And yes, the Dawn dish soap is donated.)

IBR's funding comes largely from contracts with oil companies. Their headquarters are in Fairfield, California, but they stand by for emergencies anywhere in the world. They helped clean up wildlife after the Exxon Valdez spill in Alaska and the Deepwater Horizon disaster in the Gulf of Mexico. In a typical year, they treat about 5,000 birds, some from oil spills and some from other kinds of injuries inflicted by humans.  

We at Talkin' Birds admire IBR's hard work. e recommend you have a look at the International Bird Rescue website. You'll find inspiring stories, ways to donate, and even cool birdcams. Enjoy--and celebrate. 

Birds vs. Hurricanes

You’ve probably heard about the radio-tagged Whimbrel that flew through tropical storm Irene 2011. Even if you didn't, you're probably wondering how the heck she did that. (By the way, don't try this at home: if you hang glide or do other air sports, stay somewhere safe indoors during high winds!)

It may seem obvious to say so, but birds have a lot of experience with flight. For long journeys, they tend to take off when the wind is favorable, just after the passage of a low-pressure system, when it's unlikely they'll fly into a hurricane. Sometimes, however, they're caught in the end of a hurricane’s spiral and are then blown toward the eye of the hurricane, where the winds are much lower. Once they get there, they may make an effort to stay there, because flying in that relative calm takes less energy than fighting to get out. In fact, they may remain in the eye until the hurricane dissipates. 

After a hurricane, most seabirds find their way back to shore quickly if they're not too weakened from flying so long without food. Other birds, however, can require more time to recover and then take several days to return to their usual territory. It is these birds that birders are excited to see as they pass though areas where they aren't usually found. 

As hard as hurricanes are on individual birds, their habitat feels the effect more. High winds can knock nests out of trees, knock down the trees themselves, and uproot plants that birds use for food sources. For example, hurricane Hugo wiped out 60 percent of 500 groups of birds in North Carolina in 1989, and 87 percent of trees where they lived were destroyed, according to the National Wildlife Federation. If this sounds like bad news, remember that a change in habitat means a change in composition of life there, not the end of life. Yes, birds that prefer tall trees can no longer thrive when those trees are blown down, but birds that like low growth will increase their breeding population. Unlike human destruction of habitat, natural events can cause productive transformation. 

The next time we here at Talkin' Birds hear about birds being blown around by a hurricane, we'll be concerned for the birds, of course, and we might even rush to see them if it's safe to do so. However, maybe we'll plan to visit that location in a few years and see how the entire picture has changed. How about you?

 

 

 

Eggs Might Link Birds with Dinosaurs

Paleontologists at Montana State University think that the nesting habits of some Mesozoic-era dinosaurs bear resemblance to the nesting habits of today's birds, providing further evidence that dinosaurs were the ancestors of birds. 

In case it's not at your fingertips, the Mesozoic era was a period of evolution between 230 and 65 million years ago. This period of earth's history was characterized by the appearance of dinosaurs and flowering plants. Birds of a sort existed during the Mesozoic, the most abundant being the Enantiornithines. Like today's birds, they had feathers. They partially buried their elongated eggs. (What we think of as "egg-shaped" eggs didn't appear until much later, with modern birds, and it was modern birds that began incubating them in nests off the ground.) There were also birdlike dinosaurs, among them Troodontids, or Troodon formosus. These weighed about 100 pounds and had serrated teeth. They laid hard-shelled eggs like modern birds, and they didn't bury them completely for incubation like reptiles did (and still do).

MSU paleontology colleagues David Varricchio and Frankie Jackson published a paper in August in The Auk: Ornithological Advances in which they examined the evolution of bird reproduction. The point to note: "Reproduction in modern birds is distinct among living vertebrates and many aspects of this (modern bird) reproduction mode trace their origin to (Mesozoic-era) theropod dinosaurs...but not really beyond them to more distantly related dinosaurs." In other words, reproduction links modern birds only to the most birdlike dinosaur species, which means that the latter might well have been the precursor to today's birds.  

Varricchio and Jackson published their work in The Auk, an international journal pertaining to birds, and not in a paleontological publication, in order to work toward a consensus that has divided scientists for almost two centuries. "People have argued about the bird-dinosaur connection since the 1800s," says Varricchio. "But, since then, there has been overwhelming skeletal evidence [to support the connection]. Then in 1996, we learned that some dinosaurs had feathers. Well, their reproduction follows that pattern, as well."

Why did some dinosaurs have feathers? Why did some of them incubate their eggs without burying them fully? No-one is sure yet. But what is known is that modern birds are all we have have left of a world once populated by dinosaurs.