Science

Engineers are Studying Birds' Nests

Debbie Blicher is Senior Producer of Talkin’ Birds.

When Talkin’ Birds Senior Producer Debbie Blicher was in fourth grade, her class was challenged to design a vehicle that would allow an egg to survive a two-story drop without cracking. She and her partner had both watched birds build nests, so they cradled their egg in loosely packed, shredded paper—a sort of spherical nest—inside a paper lunch bag (even then, Debbie recycled!). Theirs was the only egg that survived the drop.

In view of this triumph, Debbie is pleased to learn that Dr. Hunter King, a University of Akron experimental soft matter physicist and assistant professor of polymer science and biology, has received a three-year, $260,000 grant from the National Science Foundation’s (NSF) Division of Civil, Mechanical and Manufacturing Innovation to study “the collective mechanical interactions of disordered, randomly packed elastic filaments.” In other words, twigs packed together. In other, other words: birds’ nests.

Birds’ nests have to withstand weather changes, swaying trees, repeated impact from birds sitting on or entering them, and other mechanical factors—all without damaging the eggs they contain. As King puts it, “Nests are lightweight, soft, flexible and shock-absorbent, but made up of hard, durable components – properties which are ideal for packaging materials.”

In the abstract submitted to the NSF, King and his collaborators from the University of Illinois at Urbana-Champaign (Illinois) state that they’re investigating how birds’ nests hold their shape as a “result of a subtle interplay between geometry, elasticity and friction” and point out that this question has not yet been thoroughly studied.

King’s graduate assistant Nicholas Weiner is conducting a series of experiments to analyze the behavior of randomly packed filaments in response to various perturbations. The collaborators at Illinois will attempt to duplicate his findings through computer simulations

Understanding how nests work could fuel advances in civil engineering and architecture, among other disciplines—not to mention packaging.

King plans to collaborate with the Akron Zoo to set up cameras and record birds building their nests: the original engineers at work.

So the next time a kid you know is participating in the “egg drop” challenge, think of birds nests and Dr. Hunter. And who knows? Maybe the kid will grow up to get an NSF grant. (Or to be Talkin’ Birds Senior Producer.)

A Link Between Bird Brains and Our Brains

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

When we call someone "bird-brained," we might be right. New research indicates that the brains of birds, primates, and even some reptiles may have evolved from cells that started out the same.

In mammals, the outer layer of the brain—called the neocortex—is where most higher-order processing happens. When we move, use spatial reasoning, or speak, we're using our neocortex. In birds, a region of the brain known as the dorsal ventricular ridge, or DVR, is responsible for higher-order processing. But rather than being a thin layer on the brain's surface, it consists of clusters of cells called nodes. The avian DVR is so different from the mammalian neocortex that scientists figured that there was little relationship between them, if any.

Odd as it may seem, embryos of most vertebrate species start out looking similar. Birds, primates, reptiles--anything with a spine--all look alike in the early stages of development. Now, new research from the University of Chicago indicates that some of the cells in the neocortex and the DVR start out as the same kind of cell, growing in the same region of the embryonic brain. (This means that, before each of us was born, we had brain cells that could have grown up to belong to birds.) (Or, if you're Ray, maybe they actually did!)

In 2012, Dr. Clifton Ragsdale and his team of researchers at the University of Chicago discovered that certain genetic markers in brain cells of the mammalian neocortex matched with genes in the cells of several bird DVRs. A new study at Ragsdale's lab, led by graduate student Steven Briscoe,  found that other neurons in the DVR share molecular signatures with a kind of communication cell in the neocortex called an IT neuron. These IT neurons help the neocortex communicate among its various layers and from one side of the brain to the other. 

"The structure of the avian DVR looks nothing like the mammalian neocortex, and this has historically been a huge problem in comparative neuroscience," Briscoe explains. "Our identification of IT neurons in the bird DVR helps to explain how such different brain structures can give rise to similar behaviors."

Dr. Ragsdale sums up the study this way: "What this research shows is that [birds are] using the same cell types with the same kinds of connections we see in the neocortex, but with a very different kind of organization."

In fact, it suggests the possibility that birds and primates evolved intelligence independently, starting with the same cell types and developing different brain structures.

The original article includes data on alligators too! Want to read it? Find it here: "Neocortical association cell types in the forebrain of birds and alligators," Current Biology (2018).

Birds, Like People, Suffer from Loud Noise

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

A new study in Proceedings of the National Academy of Sciences indicates that birds respond like humans do when exposed to constant loud noise. Researchers found that adults and nestlings of three species in the wild showed signs of chronic stress caused by human noise pollution. 

Most birds exposed to constant loud noise will simply leave an area; this study looked at what happens to the birds that stay. Lead author Nathan Kleist conducted the research while a Ph.D student in evolutionary biology at the University of Colorado-Boulder, along with co-author Rob Guralnick, associate curator of biodiversity informatics at the Florida Museum of Natural History.

The research team, led by Kleist, set up 240 nesting boxes at three specific distances from gas compressors on property in New Mexico. The team tested levels of the stress hormone corticosterone in three species: Western Bluebird, Mountain Bluebird, and Ash-throated Flycatcher. The researchers found that the louder the noise from the gas compressors, the lower the birds’ baseline corticosterone levels in all three species.

Christopher Lowry, study co-author and stress physiologist at CU Boulder, explains: Although it seems odd that the corticosteroid levels would be low, lab studies of chronic stress in humans have shown that low corticosterone can signal stress so intense that the body has to reduce baseline levels of the hormone to protect itself (so that there's room for it to shoot up if needed). In fact, when these birds experienced sudden stress, their corticosteroid shot up high and came down only very slowly, like it does in chronically stressed humans.

In the noisiest environments—the ones closest to the compressors—nestlings had smaller body size and reduced feather development. In Western Bluebirds, the species that showed the greatest noise tolerance, fewer eggs hatched than expected.

“These birds can’t escape this noise," says Guralnick. "It’s persistent, and it completely screws up their ability to get cues from the environment." For example, adults rearing chicks can't tell whether it's safe to leave the nest for food. Guralnick explains, "Just as constant stress tends to degrade many aspects of a person’s health, this ultimately has a whole cascade of effects on their physiological health and fitness.” 

Since noise at natural gas fields is not unusually loud compared with human noise in many other parts of the country, this study has implications for protecting wildlife and even human health. The researchers suspect that if other species react the way these species did, bird populations could decline if we humans become noisier.

“This study shows that noise pollution reduces animal habitat and directly influences their fitness and ultimately their numbers,” Guralnick said. “By doing so, it makes it harder for animals to survive. Taken together, that’s a pretty damning picture of what human-made noise can do to natural populations of animals.”

Flowers that Attract Hummingbirds Confuse Bees

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

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?

Debbie Blicher is Senior Producer of Ray Brown's Talkin' 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. 

 

Ravens Act Sneaky, Like People Do

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

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 Zealand Yellowhammers "Speak" with Obsolete Dialects

Debbie Blicher is Senior Producer of Ray Brown's Talkin' Birds.

Our Talkin' Birds Senior 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.

 

 

 

 

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. 

 

Oxpeckers Might Really Be a Pain, Not a Boon

We've all seen those photos of large animals on the African savannah with birds on their backs, right? And we've heard that those birds, aptly called Oxpeckers (family Buphagidae), have a symbiotic relationship with those animals, eating the ticks that would otherwise bedevil them?

Well, the truth is not so simple. Oxpeckers do eat ticks, but they eat only one species (the Blue Tick) and they prefer to eat them only after they've already laid their eggs. Oxpeckers eat earwax, which might help the host animals hear better, but decreased earwax could lead to increased ear infections. Worst, Oxpeckers pick at the open wounds in the hides of the host animals and have even been known to make the wounds themselves. (Ick!)

Dr. Paul Weeks has researched the Red-billed Oxpecker (Buphagidae erythrorhynchus) in Zimbabwe, publishing two studies in 1999 and 2000. Neither one indicates that animals benefit much from Oxpeckers.

Weeks separated cattle into two matched groups, then prevented Oxpeckers from coming into contact with one of the groups. At the end of two weeks, he compared the health of the animals. 

The cattle in the control group (the ones with the Oxpeckers) did not have significantly fewer ticks than the experimental group (the protected ones). What the control group DID have was less earwax and more wounds. Net benefit to the animals? Zilch, or at least close to it. 

So the next time you see one of those Oxpecker-and-rhino photos touted as showing "the beauty of symbiosis," go ahead and snort like a rhino. 

Birds Plan Their Flight Path on the Wing

You round a corner onto a city street, and you realize you need to drive between a bunch of trucks parked on the right and the busy traffic lane on the left. So what do you do? You slow down and drive carefully, adjusting your speed as you go. 

Research at the Queensland Brain Institute (QBI) has shown that birds will interrupt their wing beats to raise their wings or tuck them against their bodies when flying through a narrow gap, reducing their width very precisely. (Don't you wish you car could do that?) But it also shows that they don't slow down while making these adjustments. So how do they manage to make them at the right time? 

Researchers QBI's Visual and Sensory Neuroscience Laboratory analyzed the flight of budgerigars—parakeets (Melopsittacus undulatus)—as they flew through narrow gaps of varying width. Dr. Ingo Schiffner and Hong Vo filmed the birds, then did 3D reconstruction of their flight, which revealed that the birds seemed to plan ahead—1.4 meters ahead, in fact. (That's about 4.6 feet). And they even knew to fly a little higher because they'd drop later when interrupting their wingbeats. In other words, the parakeets made flight decisions well in advance of the obstacles. 

Even though the birds did some fancy flying, they didn't slow down. In another study, when parakeets flew through gradually tapering tunnels, they switched between what looked like two pre-set speeds, which Dr. Schiffner refers to as "low maneuvering" and "high cruising," bearing out the finding that they seemed to plan ahead, seeing and estimating the width of the tunnel.

This research might be especially helpful as we (humans, that is) design and build aircraft capable of unmanned flight. Current guidance systems are based on research in insects, but birds seem to have a different set of capabilities. 

The research is published in Biology Letters and  Scientific Reports.

Citizen Science with House Sparrow Eggs

House Sparrows (passer domesticus). Some of us enjoy their resilience, cheerful presence, and ubiquitous "Cheep!" Some of us can't stand seeing them everywhere, including in the nesting boxes we've set out for bluebirds. Love them or hate them, the fact is that they are an invasive species, brought here from England in the mid-19th century and thriving ever since in populated areas—often at the expense of other songbirds. 

A new citizen science project is now making use of House Sparrow eggs in ways that should satisfy both friend and foe.  The Sparrow Swap, out of the North Carolina Museum of Natural Sciences, asks volunteers for House Sparrow eggs to test for pollutants. The aim is to discover whether these birds, often regarded as pests, can help us monitor our environment. Meanwhile, taking eggs from nests provides another research opportunity, namely population control. Participants are given fake eggs to swap for real ones in hopes that the nesting sparrows will try to hatch them rather than build a new nest when they discover their original clutch has vanished. If this protocol works, it will provide the basis for an environmentally safe way to reduce the number of House Sparrows. 

Want to know more or participate? Look for "The Sparrow Swap" on Facebook or check out this website. 

 

Birds of a (Red) Feather

Red birds stand out more than birds of other hues, so they get eaten more often than their drab relatives. So is having red feathers a good idea? And what makes birds red in the first place?

Recent research indicates that there are, in fact, advantages to being red, and they go far beyond being pretty to look at. It has been known for some time that birds with red feathers often have extra-sensitive cones (color-sensing vision cells) in their retinas, which may make it possible for them to see food sources that other birds can't. Some red birds have also been found to have cells in their livers that help with detoxification of harmful substances, potentially allowing their owners to eat a wider variety of foods than non-red birds. Perhaps because of these two advantages, birds with red coloring are more desirable mates than their non-red buddies in multiple species. 

So how does red happen? 

Recent research from the University of Cambridge, published in the journal Current Biology, indicates that some Zebra Finches possess a gene that allows them to convert yellow pigments in their food, called carotenoids, into a red coloring in their beaks. Interestingly, the red pigment exists at lower—almost undetectable—levels in regular, yellow-beaked Zebra Finches. 

A separate research team out of the Universidade do Porto of Portugal is working on the genetics of the red canary, a hybrid developed by canary fanciers about 100 years ago by interbreeding with the Red Siskin. One particularly intriguing finding is that the gene for carotenoid-to-red conversion exists in many, if not most, bird species, even if those birds don't appear red. The birds that aren't red still have the super-sensitive color vision and heavy-duty liver function conferred by the gene, but for some reason as yet unknown, they just don't have red skin or feathers. 

Why research red coloration in birds? Two reasons. First, it's a trait that easy to track and manipulate. Second, it's beautiful. 

City Lights Throw Migrating Birds Off Course

New research out of the University of Windsor indicates that bright city lights may cause migrating birds to zigzag rather than follow the (darker) course they might otherwise take. 

The team, headed by professor Dan Mennill, began their research by accident. Sound recording boxes had been placed around the area during a migration study, and the team noticed that the ones situated near well-lit—urban—areas picked up more bird vocalizations than the ones in dark—rural—ones. Further analysis revealed that more than three times the number of vocalizations occurred in the lit areas than in the unlit areas, indicating that three times more birds passed through the former than through the latter. Why? Perhaps because the lights made it difficult for them to see the stars by which they'd ordinarily navigate. 

Being drawn off course causes two problems for migrating birds. First, flying a less-than-direct route uses more of a bird's energy stores than flying a direct route; therefore, birds arriving at their destination are more depleted than they ought to be. Second, flying in a zigzag takes longer than flying directly, which means birds arrive later than they otherwise would—and perhaps miss a key food source or mating period. 

What can we do to help restore natural migration routes? For starters, we can turn off any unnecessary outdoor lighting at night. Mennill's team is researching other options, such as changing the intensity of street lights. Whatever they come up with, we're all for it. 

Sacrifice Mosquitoes to Rescue Hawaii's Birds?

Paradise would not be paradise without birds. Unfortunately, Hawaii's native bird population has been dwindling since the accidental introduction of mosquitoes in 1826 by a whaling vessel that dumped maggots into a stream on Maui. With mosquitoes came avian malaria, and with avian malaria came bad news for Hawaii's native birds, which had never encountered any disease like it. The U.S. Geological Survey is now saying that extinction seems to be imminent for some native species, especially on the island of Kawaii, which does not have mountains into which birds can retreat from mosquitoes. 

The Hawaiian archipelago is separated by 2,500 miles from the nearest land. It possesses a diversity of species even greater than the Galapagos Islands; and, like on the Galapagos, these organisms developed in such isolation that they weren’t adapted to the threats brought by Western explorers and immigrants. These days, 434 species of plants and animals are listed as endangered by the United States. More than half the native forest birds are already extinct.

A proposed solution is to create mosquitoes genetically engineered to die off before they reach reproductive age. A group of government officials, conservationists, and scientists in Hawaii are discussing the viability of such an idea. The U.S. Fish and Wildlife Service, which is responsible for endangered species, recently said it was looking at different recovery plans for forest birds. Among these is the mosquito method. 

A decade ago, the U.S. Fish and Wildlife service estimated the cost would be $2.5 billion over 30 years to preserve Hawaii's native forest birds. These plans included buying land and restoring habitats. But genetically modified mosquitoes could be much less expensive.

This is not to say that Hawaiians—or we here at Talkin' Birds, for that matter—are easy with the thought of genetically tinkering with nature. But the fact remains that mosquito technology is a potential fix for human diseases such as Zika. Currently, fighting human disease gets the attention and the funding, but conservation could become just as important a use of this biotechnology.

 

Preventing Concussions: Learning from Woodpeckers

Why Don't Woodpeckers Get Headaches? is not only the title of Mike O'Connor's first book. It's also the driving question behind a new device that could help prevent concussions. Here's the problem: While helmets can prevent skull fractures, they can’t prevent concussions. The brain floats in fluid inside the skull and can therefore slosh around during impact. The solution? Consider the woodpecker. 

Dr. David Smith, CEO of Xennovate Medical, received a bit of advice from an attendee at one of his lectures in 2007. The advice was to investigate how woodpeckers manage to knock their heads against trees all day without suffering any ill effects. Smith appreciated the advice and began studying woodpeckers. 

A woodpecker has a very long tongue. In some species, the tongue is supported by bones that wrap all the way around the head. It appears that the tongue compresses the bones, and therefore the neck veins, as the woodpecker thrusts its head forward. The resulting slight increase in skull fluid volume helps keep the brain from knocking against the skull.

Smith wondered whether the same effect could be reproduced in humans, perhaps with some kind of collar. He contacted Dr. Julian Bailes—yes, the doctor played by Alec Baldwin in the 2015 movie Concussion. Bailes had testified before Congress in 2009 about head injuries in the NFL, having been team doctor for the Pittsburgh Steelers from 1988-98.

Smith and Bailes designed a collar that gently presses on the back and sides of the neck, leaving the throat unobstructed. The pressure slightly compresses the jugular vein, slowing the blood flow out of the brain. The result: the skull temporarily contains an extra teaspoon of blood. This extra teaspoon of volume, which causes no harm, reduces the amount of sloshing that the brain can do when the head is walloped.

Smith and Bailes tested their first model on rats. It worked well enough that they decided to move on to human subjects. Three years ago, Smith and Bailes invited Dr. Gregory Myer at the Human Performance Laboratory at Cincinnati Children’s Hospital to join their effort. They tested the collar with high school football players. The results will appear in a paper that Myer intends to submit for publication early next year.

Performance Sports Group, which makes Bauer ice hockey equipment and Cascade lacrosse helmets, has committed $7 million toward production of the band. More importantly, CEO Kevin Davis has such confidence in the band’s effectiveness that he’s asked his son to wear it when he plays hockey.

We hope he says "Thank you" to any woodpeckers he sees or hears on the way to practice. 

 

Nest-Building Lessons

Most birds build nests, but how do they know how to build them? It's not like there are published blueprints. Very little research has been done on how nest-building birds know what they know, but here's an intriguing study. 

Male Zebra Finches build circular, domed nests for their mates and chicks. New research at the University of St Andrews, Scotland, shows that Zebra Finch males learn to build these nests at least partly by watching other Zebra Finch males. However, they'll imitate only the males they know. 

Scientists in the School of Biology paired up female Zebra Finches with males who had never built a nest. Each pair watched the male of another pair build a nest; this male was either known to them or a stranger. While building, this male used pink or orange string, colors that Zebra Finches don't normally use. (How they got him to use those colors isn't explained. Our guess is they had him read a 1970's issue of Architectural Digest.)

When the time came for the newbie nest-builder to build his first nest, he used the same color string as the male who demonstrated--but only if the demonstrator was a familiar bird. If the demonstrator wasn't, then the newbie did not make the same color choice. 

The experiment showed that birds will turn to public information when they need to decide which materials to use to build their first nest, but only if they know the individual who provided the information. We think birds could teach human students a thing or two about doing research for school papers with Google. 

Dr Lauren Guillette of the School of Biology, lead of this study, suggests that birds might learn from one another in a way that resembles human beings' learning culture.  "This is called ‘social learning’, and can save time and effort for first-time nest-builders....Perhaps surprisingly, the birds did not always use this ‘advice’, especially if it came from a stranger. In humans, learning from those we know is one way that cultural traditions are formed, from the tools we use to the clothes we wear or the music we listen to.”

Want to read the original article? Find it here. 

Scrambling Eggs' Incubating Temperatures

New research indicates that climate change may affect the development of embryos in birds' eggs, especially if the birds live in a hot climate.

A team of scientists at Australia's Macquarie University studied the effects of warming atmospheric temperatures on in-the-egg development of wild Zebra Finches, Taeniopygia guttata (yes, we're discussing Zebra Finches again).    In the wild, the Zebra Finch breeds in arid and semi-arid regions throughout Australia where atmospheric temperatures regularly exceed 96.8◦F. Like all birds, Zebra Finches can lay only one egg per day. They don't start incubating them until the clutch is complete, which takes about five days.

All the eggs are incubated equally, and they tend to hatch on the same day. Why does this matter? Because the chicks who hatch first grow big first, depriving their smaller siblings of resources. 

The Australian research team suspected that warm temperatures might cause problems during the egg-laying, pre-incubation stage. If the ambient temperature were to become warm enough for eggs to develop even without an adult sitting on them, the earliest-laid eggs would hatch earliest.  They were also concerned that Zebra Finches might be reaching the upper edge of their tolerance for high temperatures--in other words, that heated eggs might not hatch at all.

To test the prediction that warmer nest temperatures trigger early development, the team set up “hot” and “cool” experimental nest chambers. Thirty-three eggs from eight clutches were removed from their parents' nests on the day they were laid and placed into one of the four chambers. They were kept cool or warm while their sibling eggs were laid, then returned to their parents, who incubated the entire clutch until hatching. 

All the experimentally treated eggs hatched following their return to the parental nest, no matter how they had been treated--that's the good news: even the "hot" eggs survived. Overall, the average developmental time was 13 days — shorter for eggs that had been placed in the “hot” nest chambers. Also, as predicted, the eggs laid early in the laying sequence developed and hatched sooner.

Now the bad news: the time to hatching was similar for eggs placed in either the natural nest chambers or in the nest-box nest chambers--just 13 days, when 14 days had been expected. In other words, even though the heat-treated eggs hatched first, ALL the nests were "hot" enough to hatch fast.

What does this mean? That the nests of birds in hot climates are already affected by climate change, and they might suffer more if temperatures increase.

How Zebra Finches Choose their Valentines

Like many birds, Zebra Finches tend to pair up and stay paired. However, how they choose their mates is a bit of a mystery. 

Whereas many animals choose their mates for certain physical traits, Zebra Finches don't seem to do so. Malika Ihle and her colleagues at the Max Planck Institute for Ornithology, in Seewiesen, Germany recently published their research into what makes Zebra Finches pair up. 

The studied 160 single Zebra Finches, allowing groups of 20 males and 20 females in an aviary to become acquainted with one another. Grooming is a sign of Zebra Finch courtship, so when pairs started grooming each other, the researchers knew that those birds were capable of pairing. They let half the couples stay together. The other half they divided into "arranged marriages." They caged all the pairs for a few months so they could develop relationships, then released them into a group aviary to raise their families. 

Over the following five months, the researchers observed as the pairs went through three breeding cycles. Then they repeated the experiment, this time allowing only one third of the birds to stay with their mates. 

The results? Couples who had chosen each other had 37% more surviving young than those who had not. Forced couples produced more unfertilized eggs, lost more eggs, and had more chicks die after hatching. Females in forced pairs were not as interested in mating as those who had chosen mates. Males in forced pairs were less interested in caring for chicks and more interested in mating with other females. 

Dr Ihle and her colleagues say that, if the finches were choosing mates for genetic reasons, more embryos would have died from defects caused by interbreeding between such a limited selection of partners. However, the difference in the survival of chicks appeared to depend on how well they were cared for by their parents. The researchers argue that the results they saw indicate that Zebra Finches select their mates based on how well they get along. We here at Talkin' Birds don't think that's a bad way to choose.