A New Medium for The Science of Birds

It is often said that to improve is to change, and to perfect is to change often. After a good long run here on blogger, I think it's time for some change. In spite of the beautiful and immersive new design of this blog, I've recently felt compelled to explore new platforms to post essays. Above all others stood an innovative new platform that has almost created its own niche: Medium.

Medium stands out in its extremely minimalist, immersive reading and writing experiences. There are no distractions in Medium essays, only a focus on the beauty of words and associated images. Romanced by this experience, along with its nearly social-media-website build, I made the switch.

Check out these screenshots from scolling down this blog's latest iteration (as a Medium Publication):

Beautiful, isn't it?

So, while some posts may still end up here in the future, I will be posting new essays on Medium from now on. In fact, I already have! After porting some of the best of this blog's content to a Medium publication--named The Science of Birds for consistency's sake--I have already published three new essays. The first is about the rewards of museum work, the second is about a powerful way to predict extinction, and the third is about the secret language spoken by birds' feathers.

I think most of you will find Medium's simple and stunning reading experience as exciting as I have. Even though the reading won't be done here, as always, I invite you to read on, all ye curious.

Innovation: Connecting Birds and People

In the many annals of ornithology, one of the hallmark discoveries is how intelligent birds really are. Crow communication, for example, is just a few criteria short of fitting the definition of language. A Finch in the Galapagos (okay, it's really a tanager), uses tools. Green Herons use bread as bait to bring in fish. We could say confidently that most birds exhibit complex social structures, sophisticated foraging strategies, and unique methods of communication. As a class, birds are stacked with brain power.

But one question in particular has caught scientists' attention recently. It's one of those tantalizing questions that ties volumes of what we know about bird intelligence into one sentence: do birds innovate? 

A Woodpecker Finch using a tool in experimental conditions.
© 2010 California Academy of Sciences

Well first, let's start by defining innovation. Innovation is to "make changes in something established, especially by introducing new methods, ideas, or products." Really, there are two important parts here: to modify and introduce. Innovation is to tinker with the way the world (or you) works, and then to share that with others, who then go on to use that change. It implies creativity on the part of the innovator, and learning on the part of everyone else. This learning is why innovation is such a buzz word in our culture; we crave innovation, crave changes, and when a powerful or relevant change is introduced, it can have a huge effect on our culture.

So let's review. Key words in innovation are modify, introduce, learn, and culture. Good work.

Now let's apply that to birds by taking apart the original question (do birds innovate). Do birds have the capacity to modify some established method? Do these birds then introduce that modification to other birds? Do those other birds learn modification? Can that modification spread through the culture of an avian social group?

Wow, these are some exciting questions. We know that birds are intelligent, but just imagine if the culture of, say, a familial flock of passerines paralleled human culture's response to innovation. We have our Steve Jobs and Bill Gates, or Thomas Edisons and Henry Fords, our Francis Bacons and Benjamin Franklins; what of birds?

Well, it turns out that in social birds, innovation is very much a reality.

A recent study published in the journal Nature aimed to answer some of these questions about just how much birds are influenced by innovation. Rather than focusing on the experimentally tricky question of whether birds innovate, they instead focused on whether social avian culture parallels human culture in relation to innovation. Observationally, it should be relatively easy to answer the question of whether birds innovate. It seems relatively easy to conclude that if you watched crows for a long time, you would observe some sort of new behavior. Crows, for example, may observe a human tossing aside food, and then make those leftovers a frequent part of their foraging. There are numerous other examples; the meat of the question, then lies in the realm of whether or not birds learn that behavior.

Great Tit. Image credit: Luc Viatour / www.Lucnix.be

This learning is exactly where the Nature study (from here on out, Aplin et al.) focused. They sought to understand how foraging traditions--go-to methods of foraging that are learned from other individuals--are established in a social species (Parus major, a.k.a. Great Tit, a Eurasian counterpart to North American chickadees). Let's dive in:

The authors of Aplin et al. started by introducing alternative foraging methods (the innovation) into individual groups of Great Tits, doing so by teaching two individuals per group. Thereafter, they tracked individuals of the group to determine the outcome of that "seeded innovation". If Great Tits don't learn innovations in the way described above, the seeded innovation would be limited to the individual it was taught to, and in all likelihood, would fall out of use. If they do learn innovation, then the behavior would spread across the group and would become a foraging tradition.

So what happened? What are the results? This is where it gets fascinating. The seeded innovation spread rapidly in each group, being utilized by an average of 75% of the individuals in all groups. This means, to fill in that number, that 414 individuals were observed utilizing the seeded innovation 57,909 times. By the end of the experiment, the groups were heavily inclined to use the seeded innovation. Not only that, but the seeded innovation lasted through 2+ generations even with high turnover rates in each group. And BOOM! We have experimental evidence of foraging tradition establishment. Pat on the back, get yourself something nice, meet for happy hour to celebrate.

But wait, there's more! Scientists have a funny habit of squeezing as much "interestingness" out of their data as possible, and in this case, they did just that. Aplin et al.'s data also demonstrated social conformity. Just like it's cool in human culture to have the latest iPhone, it became cool in Great Tit culture to use the seeded innovation. After first learning the innovation, the birds continually chose its use of their use of their personal learning. In other words, tits deliberately used the "cool" innovation over what, in their experience, may actually be a better foraging strategy. In this way, the tradition enforces social conformity. Great Tits in flocks experiencing the seeded innovation consistently conformed to the social norm of that group by using their innovation more than their own strategies. Sounds eerily...human. Or perhaps we're eerily bird. I'll leave that one up to you.

This is a stunning discovery. Why? This is the first time that anyone has demonstrated the existence of social norms in foraging strategies. Ultimately, to use the words of Aplin et al., this is an extremely "complex cultural behavior", and it is found in as ostensibly simple an activity as foraging. What's more, this discovery suggests that perhaps we're just hitting the tip of the iceberg. If as well known a species as Great Tit exhibits a sense of cultural norms that we've missed all these years, what other species do the same? Imagine the species that may be living with cultural norms right under our noses!

In all likelihood, there's a lot we're missing. But don't lose optimism. This also means there's a lot yet to be found. There are many behavioral discoveries just waiting for people like you and I; we just have to get out there and look.

In behavior, you never know what you will find. But I assure that whatever it is, it will change the way we look at living things, at nature, and at ourselves. Studying behavior is an intimately human endeavor, liable to churn out ideas that inspire us to reflect in new ways.

So maybe the question shouldn't be "what will I discover?" Maybe instead it should be "who will I be?"

Cheers, everyone. Thanks for reading.

Nature beckons. What's out there for you to discover?

A Simple Way to Make Gmail Work For Birders

I am a frenetic reader of too many RSS feeds, an obsessive user of read-later and schedule-your-tweet apps, an incessant downloader of pdfs and pictures. In short, I am about as information overload as they come. Just for what could be boiled down to mental stimulation, I attempt to tackle information from more internet sources than any sane human should.

My ever-growing research archive. Notice the scroll bar on
 the far right...I have A LOT to read

Why? In an attempt to internalize as much ornithology as possible, I follow research from a growing international community of people and institutions. Some of the fruits of this process make their way here, and most make their way to Twitter. It's quite a task, as there is a surprisingly huge volume of bird-related research published weekly. But you know how it is...oh the things we do for curiosity.

Let's take a step back...how do I have time for this? When I wake up every morning, after the European ornithological institutions have already been tweeting ornithology for hours, I have tens of abstracts and blogs to sift through. Trouble is, I have neither the time nor the focus for it at that time of day. For that reason, I robotically save unread research into the app Pocket, doing so with the assumption that I will read and share (tweet or blog) later. Right now, I have around 160 pieces of research waiting. They are ready for when the thirst of curiosity stimulates my attention. It is an act of constant collection, letting the research come to me and making it available when I'm ready to digest. But there's a lot. Will I ever get caught up? Forget that pointless question. The point is that it is possible to take what would normally be information overload, and make it manageable.

Sightings are constant.

This process, perhaps one peculiar to me, mirrors something all birders do. Similar to my indiscriminate consumption of research, most birders sift habitually through an endless stream of bird sightings. And like with the research, the sightings are reported from a constantly growing variety of sources. Unexpected as it may seem, birders have utilized the internet in full by constantly sharing their findings with others. In doing so, birders are building a vast network of individuals collectively monitoring the world's avifauna, and anyone has access to it. As I write this, via Facebook, a Snowy Owl was just found on the Milwaukee lakefront. Via eBird, there's a Fork-tailed Flycatcher in Texas. Via various birding listservs, there's a Western Grebe along the Chicago lakefront, a Cassin's Kingbird in New York City, and a Lark Sparrow in Massachusetts (I originally wrote this post in a slightly more birdy time of year). This doesn't count posts made on Twitter, regional birding forums, or personal blogs. Almost by the minute, new posts are made about birds everywhere.

The value in following sightings is obvious: knowing what's around helps you understand bird phenology, which in turn helps you predict when the birding will be best. And then, of course, there's the value it provides for birders looking to chase rare birds. In the end, regardless of why you follow sightings, the challenge is juggling the many sources of sightings to stay up to date.

But as with everything internet, it really is too much. Just as there's too much research published weekly to stay completely apprised, there are too many people reporting too many sightings from too many places. How do we keep track of the important bits that maximize our birding and feed our curiosity, while cutting out the noise from all the other sources?

A difficult question, but it's one I may have an answer to.

Like what I did with my research process above, we need to make the grand volume of sightings work for us rather than the other way around. We need sightings sent to us, earmarked so that they don't clutter the other information streams we manage in our lives (it's 2015...there are plenty).

Before we get into the process itself, there's one simple decision to make: what is relevant? Many of us follow the local birding listservs, get eBird alerts, and look at Facebook groups. Living in Illinois and being who I am, I look at sightings from IBET, eBird Needs Alerts and RBA's, Facebook's ABA Rare Bird Alert Group, and Illinois Birders' Forum. Your chosen sources may be different than mine; what's important is that you identify what is relevant to you.

Having identified the sources above as relevant to me, I could just bookmark them and hop from one to the next. But with that many sources, this "hopping" requires a lot of time, and ultimately I leave the endeavor with little stuck in my mind. So instead, using Gmail, I adopted the following process. For the sake of convenience, I'll divide it up into a series of how-to "steps" with pictures: *Note that these are based on the sources I chose as relevant. Your sources and ability to subscribe may be different.

1. Subscribe to your relevant sources - I subscribed to everything from IBET, all my eBird alerts (I get 7 different kinds), the Facebook bird groups I follow, SurfBirds, and Illinois Birders' Forum. This is the most complicated step, but on each of these sites you can subscribe such that emails from that source go to a specified Gmail address. It must be the same Gmail address.
2. In Gmail settings, create a label/folder in Gmail called "Sightings".
   
3. When the first sightings stream into your inbox, copy the email address from which they came. Then, in Gmail settings, go to filters, and then to create new filter. In the menu that comes up, paste the address from which, say, eBird alerts come from into the "From" space. For listervs, you'll do the same thing, except you'll put the email address in the "To" space. For Facebook Alerts, rather than either of those, you'll put the name of the group in the "Includes" space. You'll learn these minutiae as you go, but I guarantee it's worth it. After you hit "create filter with this search", another menu comes up where you will select "Skip Inbox" and place in Sightings. Below, all this information is illustrated step-by-step with pictures. Before you look at those, here are all the sources I have filtered into my Sightings folder as examples:
• gregneise@ilbirds.com - placed in "From" category, these are notifications from Illinois Birders' Forum
• ebird-alert@cornell.edu - placed in "From" category, these are all eBird alerts.
• webmaster@surfbirds.com - placed in "From" category, these are SurfBirds Daily Digests.
• [ABA Rare Bird Alert] - placed in "Includes" category, these are email notifications from the ABA Rare Bird Alert group on Facebook.
• [Illinois Birding Network] - placed in "Includes" category, these are email notifications from the dominant Illinois birding group on Facebook.
• ILbirds@yahoogroups.com - placed in "To" category, these are sightings from the Illinois Birding listservs

Under settings, go to Filters, and then git "Create a new filter"

This menu will appear out of the Gmail search bar. Plug in email addresses for your various Sightings Sources, and then
hit "Create filter with this search", which is pale gray and hard to see at the bottom right of the menu.

After that, your options on how to filter in the addresses you just plugged in will appear.

Finally, do this stuff!

You will see that all relevant sightings are, without any effort on your part, sent directly to a folder you designate specifically for sightings. You can go there, one central location, at any time to check up on only the sightings that a relevant to you. But this is the best part: at any time, you can search this folder for any birds you want to find. Rather than searching Facebook, eBird, and listervs separately, there's only one place to search, where all sighting sources are combined.

Note that for users of Inbox by Gmail, the process has actually been streamlined, as you can filter emails into labels (now called Bundles) by simply clicking the email, putting it into your Sightings folder, and then clicking "Always do this". 

In Yahoo, the process is similar, if not a little bit more organized. You still need to find the relevant email addresses for your Sightings Sources, and then you plug them in under the Settings Pages called Filters:

In settings, which can be found by clicking on the gear icon in the upper right-hand corner of the page, go to the filters menus.
You will have to create a new Sightings folder, and then hit add in the menu above to make a new filter.

Plug in the relevant email addresses in the appropriate places, and then next to "Then move the message to this folder", go
to the Sightings folder you've created.

Once you've gone through this one-time process, you'll find yourself in the know with minimal effort from here on out.

Pretty nifty, eh?

A Return To Discovery

Well folks, it's about time I got back to blogging.

The river of discovery beckons...

Though my hiatuses (hiati?) from blogging are never deliberate, they happen sometimes. Since you last read about ornithology here, I returned to my internship at the Field Museum's Bird Division and later to my staff position at Makajawan Scout Reservation. Perhaps the highlight of the summer, though, was experiencing the full splendor that is The Cornell Lab of Ornithology through the Cornell Young Birders' Event. The people and Lab both are inspiring, to say the least. They have an incomparable ability to feed the natural history fire in your belly; I hope to bring some of that back to you.

Since this past summer, a season that was oh so short, I've continued to make music with my tuba, explore the "wilds" of Illinois and its avifauna, and work on some projects--projects like PhenCal, an inspiration-based magazine called Manifest, and maintaining my social media outreach.

But though this blog has grown quiet, the world of ornithological research has been anything but. New research has been breaking into the scene daily, some of it so exciting that I may just have to share it with you now, synopsis-style.

There is so much being learned out there right now, but it's nice to have start with some of the most interesting bits. With an awareness of that ornithological curiosity, here's some of the fruits of my gleaning through the research, Foliage-gleaner style.

Feel free to read any or none of the following, but if you do, I encourage you to read it in pieces. It's an ambitious post, sort of like three-in-one, but hey, I'm making up for lost time.

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Pectoral Sandpipers are among the most accomplished non-passerine songsters--researchers look into how 

When one ponders why they're interested in birds, song is one of the highlights of experiencing the avian world. From familiar voices like the ethereal warbles of the Hermit Thrush, the nostalgic whistles of a White-throated Sparrow, or the bold notes of the Northern Cardinal, to exotic voices like the incomparable, sizzling gurgle of the King-of-Saxony Bird-of-Paradise, the machine-gun trill of the Brown Sicklebill, or ear-piercingly loud White Bellbird, song is one of the most distinctive facets of Aves. One little detail, however, stands out after a little extra exploration. When people talk about birdsong, most if not all of the go-to examples are songbirds (Passeriformes, or passerines for short). All the examples above, hailing from such diverse families as the Thrushes to New World Sparrows to Birds-of-Paradise to Cotingas, are passerines. Surely song can't be limited to the birds that bear its name!

As I'm sure you've guessed, it's not.

Figure 1 from the first paper cited below, highlighting the
many pieces that make a complete Pectoral Sandpiper
display. See first citation.

Song is a mate-attraction strategy. Whichever sex of a given species competes for mates of the opposite sex (most of the time it's males) is subject to sexual selection, where traits that are more attractive to potential mates are passed on, whereas less attractive traits aren't. Sexual selection is responsible for peacock tails, cardinal reds, and every complex song out there. In some species, like birds of prey, potential mates don't find self-broadcasting behaviors like song attractive. But in others--especially species that have limited time and resources to breed--self-broadcasting is an extremely useful way for the competing sex to communicate their quality and the quality of their resources through the complexity of their songs. It is, to say it with brevity, efficient. Species that require this efficiency will have sexual selection acting on behaviors like song.

Not surprisingly, then, do we find that many arctic-nesting shorebirds have elaborate songs and song displays, and one of the foremost among them is the Pectoral Sandpiper (Calidris melanotos). To quote Andrew Spencer of Earbirding,

"The classic “song” of the species is unlike any other sound on the Arctic, and any other shorebird in the New World – the male bird sits on an exposed tussock, slowly inflating its pectoral pouch and ruffling its black-based breast feathers before suddenly launching itself into the air and flying low over the ground.  Partway into the flight its wings slow into a more exaggerated butterfly flight and it begins emitting a low-pitched hooting series, pumping its head in time with each hoot while its expanded pectoral pouch hangs underneath like a bosom.  Right after the series ends it suddenly undulates up into the air a few times before circling back around and landing again.  It’s a show like no other!"

Having received more and more attention, researchers from the U.S. and Germany banded together to look into how they do it, and they found some fascinating stuff. I'll report on just a few of them here. First, "Pecs" have evolved a vocal organ (syrinx) similar in anatomy to that of songbirds, a fascinating fact given that Pecs must have evolved this vocal complexity completely on its own. In evolution, this is called convergence. Also fascinating, Pecs show an ability to expand their esophagus similar to that found in doves and pigeons. Why? Males fill their throats with around 30 mL of air in preparation for their courtship display, though their throats have a capacity of up to 50 mL. All this just to impress females. Finally, Pectoral Sandpipers' courtship displays are incredibly ritualized: their display includes three phases, each with different vocalizations and locations (ground or in flight). Different vocalizations are directed at different individuals as well, with some meant for competing males and some for females,

Needless to say, if you bird along Pecs' migratory pathways, we would hardly recognize the same bird on their breeding grounds.

Read more here, on Earbirding, and here, in The Auk,

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Bird Nest Design - More Complex and Fascinating than you Ever Would Have Suspected

Nest design in birds is fascinating, and not just because it's, well, er, fascinating, but also because studying it forces us to rethink what we've assumed to be true. Science is, in spite of what we'd like to think, rife with assumptions. Luckily, most of these assumptions are small, insignificant, and don't influence many decisions. But, alas, they are there, and they're often cryptic. Clearing out that ambiguity can be a challenge, but when done as part of the quest to find truth rather than to be proved right, the results can be breathtakingly interesting.

Such is the case in a recent "review" paper called The design and function of birds’ nests. In this paper, the authors have systematically sleuthed through their own and a great variety of other authors' research to produce a succinct, and elegant, set of overarching themes. Quick digression. Why do I love these kinds of papers so much? If one is researching a topic, typically he/she would have to hop between a great number of potentially unconnected papers, hoping to draw the right conclusions between them all. In review papers, fulltime, professional scientists have done that for you, and they've done it with access to more research, more great minds, and more cutting edge ideas. In short, they're laying out all the research--and with it the prevailing ideas--on a particular subject for your convenience. It's good stuff.

Anyway, back to the research. In birds, there's a significant behavior that we--lay people and ornithologists--take for granted all too often: the nest. In ornithology, the prevailing assumption has been that nests are purely used by birds for nesting and nothing more. More specifically, the assumption is that nest design--and time spent building--is determined purely by natural selection, with the selective pressure, of course, being predation risk.

But there are lots of strange behaviors, found both in observational and experimental studies, that challenge seemingly obvious assumption. The best part? There are a lot of questions left to be answered. Let's dive into some of the interesting bits (read as much or as little as you please):

• Nest site selection is highly influenced by predation risk. Interestingly, birds who nest high in the forest strata are at greater risk of predation from avian predators, but much lower risk from mammalian predators. Conversely, birds that nest low in forest strata are at high risk from mammalian predators and low risk from avian predators. Birds nesting halfway up are at equal risk from both. So (#FieldSkills), if you're in an area where most of the bird species nest high, for example, it can be reasonably assumed that mammalian predation is more prevalent than avian predation. There are some other interesting observations from studies on nest placement in relation to predation risk:
  • Some birds nest near wasp nests or other aggressive species like kestrels to reduce risk of predation, even if it puts them in a certain amount of danger
  • Some birds will actively shift their nest site halfway through the breeding season if the previous site proved to be rather predator-laden. This is interesting because it indicates that nest site selection is not purely genetic/instinctive, but rather that it is a combination of instinct and learning.
  • Some birds will even track the amounts of rodents in their area and colonize more heavily in areas with heavy rodent concentrations. They do this because species that would prey on them prefer rodents, and with heavy rodent population, the predation risk is lower.
• Ground nesting birds instinctively "know" the color of their eggs and actively seek potential laying areas where their eggs will blend in
• Nests can be used to express the fitness of a potential mate...in other words, nest design is also subject to sexual selection (BIG IDEA)
• Sexual selection favors larger nests, able to house more eggs. This is in direct contrast to natural selection for small nests.
• Birds with high body condition invest more in nest building, indicating that the quality of a male's nest can be used by the female to gauge the quality of the male as a mate.
• Male starlings integrate green plant material into their nests, and females respond by integrating feathers into the same nest. This is fascinating because it indicates that females are "impressed" by male presentation of green plant material, and are actively responding by investing more in the nest.
• Birds change their nesting habits with altitude as well. Nesting high in trees, and thus closer to the sun and its head, is common in high-altitude species. These nests average more insulated as well to account for more radical changes in temperature.

A quick look at the paper.

These points are only the tip of an iceberg of interesting information in this paper (which, by the way, is open access...click the image to the right!). The most important overarching theme is this: nest design is subject to natural selection AND sexual selection. An inconspicuous nest can hide chicks from predators, but it may also leave females unimpressed. Birds designing nests have a lot to take into account to protect offspring: microclimate, color of the environment, parasites, what nest insulation is necessary, how impressive a nest may be to the opposite sex, etc. And all this is reflective of the health (quality) of the nest site selector and builder.

I don't know about you, but this stuff gets me excited. There are so many little details, so much nuance, that remind us of the staggering complexity of the world around us. What a privilege it is that we can even begin to figure it out.

I encourage you all to read the paper yourselves, and, as with any perpetual learner, to ask as many questions as possible. This paper does a good job of highlighting what's yet to be learned; seize that opportunity!

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A Flock of Genomes, plus Understanding One of The New World's Largest Groups of Birds

This section is going to kill two birds with one stone, as the content of these two studies are similar.

In genetics, we're in what may be called a golden age. Our ability to process huge amounts of genetic information in a short amount of time--also important: for a lower price--is growing beyond what people like Ernst Mayr and John Zimmer could have dreamed. This enormous volume of information allows us to draw better conclusions, answering questions fine and grandiose in scope. Check out this video to understand where genetics is at.

1 of the bird trees of life constructed by the
Avian Phylogenomics Project.  See second
citation, and note the number of authors.

The complete history of birds is just such a grandiose question. Scientists from around the world, with focuses as varied as the countries they hail from, recently published a collaboration around this question at a scale perhaps never seen before. The project, called The Avian Phylogenomics Project, sequenced the ENTIRE GENOMES of 48 species of birds, each representing a unique place in the bird family tree. Its aim was to understand the bird tree of life, but it didn't stop there. The project also answered questions about vocal learning, the genetic basis and history of birdsong, the loss of teeth, the molecular basis of flight, and endangered species. As I said, the scale of this project is breathtaking, answering questions previously unanswerable, and revealing links between birds, other reptiles, and even humans in the process.

The project released the bulk of its results simultaneously, producing a tsunami of head-turning curiosity throughout the scientific community and beyond. That's 28 papers nearly at once, 8 of which were specially published by the journal Science (many of these are open access!).

Wow. There's a lot to explore here, and I encourage you to do so. Really the most amazing part of this process is the level at which it allows us to ask new questions. Projects like these foster the future-ward momentum of science, and we can only dream like starry-eyed kids about where it will go next.

  

This paper is a cover story for the American
Ornithologists' Union's journal, here
featuring some of the varied members of
Emberizoidea

In a similar vein, a paper was published only a few days ago about one of the more ambiguous branches on the bird tree of life. It's a New World branch called the New World Nine-Primaried oscines, or the Emberizoidea. It includes well-known families of birds like Blackbirds and Orioles (Icteridae), Cardinals and Grosbeaks (Cardinalidae), Wood-warblers (Parulidae), New World Sparrows (Passerellidae), and Tanagers (Thraupidae). In all, the branch includes ~832 species, or 7.8% of all birds. These families have mysteriously evaded understanding by scientists since they were first described. Why? These 832 species are extremely varied, but not always in easily categorized ways. A great number of species and genera appear ostensibly similar when in fact they're distantly related. Convergent evolution, in this way, muddles our understanding of this group. Emberizoid classification history is rife with lumps, splits, and reorganizations, and there are still many outstanding questions. We wonder about questions like where their diversity originated (North or South America), when it happened, what caused it, and why they're so diverse now.

Well finally, these questions have been given a comprehensive set of answers. As demanded by the size of the group, the paper includes the largest near-species-level phylogeny ever constructed. What does this mean?  The authors constructed a tree of life for the Emberizoidea with detail down to >95% of its ~832 species. This allows us to trace the evolutionary history of almost every one of those species back to the common ancestor of the entire group.

One of the SIX similarly-sized
pieces of Figure 1, which is
the full Emberizoid tree.
See third citation.

Like with the flock of genomes, this phylogeny answers more questions than just when and where species diverge. It also tells us that the ancestor(s) of the group crossed Beringia (an area now occupied by the Bering Sea where North America and Asia were once connected) into North America around 20 million years ago. This means the whole group originated in North America and then expanded southward, diversifying along the way. What governed much of this southward movement? Little more than the Isthmus of Panama. This Isthmus has a huge effect on New World biodiversity; varying sea levels through time determine whether or not it's above sea level. When it's above, North American flora and fauna can pass southward; when it's not, North and South America are isolated.

The on and off connection of North and South America is a biological recipe for diversity, and the 832 species of the Emberizoidea today is evidence of this. But there's a lot more to it....in order to understand it, I encourage you to read the paper yourself.

When you do, remember the significance of what you're reading. Information like that in this paper has never existed before, and it will likely set the trend for how we understand the tree of life in the coming century.

The results of both of these papers have me in awe. Never before have we been able to understand the origin of species like we can today. I feel incredibly lucky to be alive when I am, to be a fly on the wall for research as grand and as discerning as this.



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Overall, look at the breadth of discovery here (and this is a tiny fraction of the ornithological research that's been published in the past 365 days)! In our time, we're coming to understand the origin of species (not to mention genera, families, orders, and classes) in a way never possible before, finding new and fascinating behaviors hidden by long-held assumptions, and learning about the unique ways that birds tick. And this is just birds! Just ornithology! Imagine all there is to discover in other fields!

Surely, this post is evidence of one thing above all else: we do not know everything. Often, in these days of the internet, I come across a certain pessimism that there's nothing left to learn. Certainly this is not true. Though Google can answer almost any question, if you dig deep enough, you can find questions of almost any scale waiting to be answered.

In this New Year, let's go digging together.

Cheers, everyone. Thanks for reading.

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CITATIONS:

Tobias Riede, Wolfgang Forstmeier, Bart Kempenaers, and Franz Goller (2015) The functional morphology of male courtship displays in the Pectoral Sandpiper (Calidris melanotos). The Auk: January 2015, Vol. 132, No. 1, pp. 65-77. doi: http://dx.doi.org/10.1642/AUK-14-25.1

Guojie Zhang, Cai Li, Qiye Li, Bo Li, Denis M. Larkin, Chul Lee, Jay F. Storz, Agostinho Antunes, Matthew J. Greenwold, Robert W. Meredith, Anders Ödeen, Jie Cui, Qi Zhou, Luohao Xu, Hailin Pan, Zongji Wang, Lijun Jin, Pei Zhang, Haofu Hu, Wei Yang, Jiang Hu, Jin Xiao, Zhikai Yang, Yang Liu, Qiaolin Xie, Hao Yu, Jinmin Lian, Ping Wen, Fang Zhang, Hui Li, Yongli Zeng, Zijun Xiong, Shiping Liu, Long Zhou, Zhiyong Huang, Na An, Jie Wang, Qiumei Zheng, Yingqi Xiong, Guangbiao Wang, Bo Wang, Jingjing Wang, Yu Fan, Rute R. da Fonseca, Alonzo Alfaro-Núñez, Mikkel Schubert, Ludovic Orlando, Tobias Mourier, Jason T. Howard, Ganeshkumar Ganapathy, Andreas Pfenning, Osceola Whitney, Miriam V. Rivas, Erina Hara, Julia Smith, Marta Farré, Jitendra Narayan, Gancho Slavov, Michael N Romanov, Rui Borges, João Paulo Machado, Imran Khan, Mark S. Springer, John Gatesy, Federico G. Hoffmann, Juan C. Opazo, Olle Håstad, Roger H. Sawyer, Heebal Kim, Kyu-Won Kim, Hyeon Jeong Kim, Seoae Cho, Ning Li, Yinhua Huang, Michael W. Bruford, Xiangjiang Zhan, Andrew Dixon, Mads F. Bertelsen, Elizabeth Derryberry, Wesley Warren, Richard K Wilson, Shengbin Li, David A. Ray, Richard E. Green, Stephen J. O’Brien, Darren Griffin, Warren E. Johnson, David Haussler, Oliver A. Ryder, Eske Willerslev, Gary R. Graves, Per Alström, Jon Fjeldså, David P. Mindell, Scott V. Edwards, Edward L. Braun, Carsten Rahbek, David W. Burt, Peter Houde, Yong Zhang, Huanming Yang, Jian Wang, Avian Genome Consortium, Erich D. Jarvis, M. Thomas P. Gilbert, and Jun Wang Comparative genomics reveals insights into avian genome evolution and adaptation. Science: 12 December 2014: 346 (6215), 1311-1320. [DOI:10.1126/science.1251385]

F. Keith Barker, Kevin J. Burns, John Klicka, Scott M. Lanyon, and Irby J. Lovette (2015) New insights into New World biogeography: An integrated view from the phylogeny of blackbirds, cardinals, sparrows, tanagers, warblers, and allies. The Auk: April 2015, Vol. 132, No. 2, pp. 333-348.

Analyzing a Trade-Off, Swiftly

Now that we've completely our obsession with Picidae, why don't we switch over to, of all things, swifts (family: Apodidae)? Shall we?

The incredible migration of the Bar-tailed Godwit. Image
credit: USGS Alaska Science Center

If you're a researcher looking to study flight, birds are a pretty good place to start. Birds have achieved flight speeds from 200 miles per hour all the way down to 13, with everything in between. Birds have flown extended journeys well above Mt. Everest and well below the surface of the ocean, mastering flight both in the jet stream and in the most powerful of ocean currents. Certain birds have adapted to completing sustained, unbroken migrations across more than 7,000 miles of the Pacific Ocean in only nine days. Migratory birds in North America that weigh less than an ounce take on flights straight across the Gulf of Mexico twice every year. Some birds fly by barely flapping their wings at all, using thermals to soar across hundreds of miles of mountain range per day. Others flap their wings more than 80 times per second for the hovering precision needed to feed constantly on nectar. Some birds can chase fleeing forest birds through dense tangles of vegetation at 30 miles per hour, while others can pursue duck prey over arctic tundra with sustained flight speeds of 70 miles per hour. Others still can carry loads of fish that weigh up to half the body weight of the avian carrier.

Common Swift - Image Credit: Wikipedia

But perhaps one of the best places to start, amongst the overwhelming variety and splendor of bird's feats in flight, is with the birds that do it the most. Swifts--a family termed Apodidae, derived from the Ancient Greek work for "without feet"--hold the record for spending the highest proportion of their lives on the wing. The record-holder for the longest sustained flight is the Common Swift of Eurasia, ranging between 2 to 4 years of nonstop flight at certain ages.

Swifts provide a frontier to press towards in the understanding of avian flight. Being capable of such sustained flight, however, does not mean being "ideal for flight" in general, though of any bird, swifts would be fairly close to that ideal. Platonism does not work in nature, and we might as well wash that from our brains now. Everything that makes any animal what it is exists purely based on the pre-existing genetic material and how that material adapts to the conditions it finds itself in. Swifts are not ideal for flight. They are ideal for flight in "x" circumstances, or in "x" conditions.

Being able to sustain flight for years means that swifts are able to adapt to an enormous array of conditions aloft, some of which we, as land-bound primates, can't understand. Swifts must adapt to random wind shifts from calm to extreme speeds, shifts in wind direction, changes between rising and falling columns of air, differences between air above water and air above land, rain, hail, snow, sleet, fog, blinding sunshine, and they have to do so while navigating the skies and finding enough food to sustain such an effort.

Pamprodactyly - Image credit:
kidwings.com

But fear not...swifts have a slurry of adaptations to make them such masters of the sky. First, swifts have a body shape to reduce what's called parasitic drag--the drag that is inherent to any body trying to sustain lift in the air. This also means having tiny feet that don't get in the way of airflow. This lends itself to an issue: swifts are incapable of perching, but their feet have adapted to the next best thing. Because swifts can only cling to vertical surfaces of crawl along flat surfaces, they have adapted a unique and muscular toe configuration called pamprodactyly. Swifts are also capable of what's called unihemispheric slow-wave sleep, which means they can sleep with one side (hemisphere) of the brain at a time, leaving the other half awake to control flight and navigation. Behaviorally, swifts collect all of their nesting material from debris in the air, drink in flight, court, and even mate in midair.

Only the sections here labeled with X contain
the swift's arms. The rest of the wings are
feathers, without any bones.
Image from Henningsson et al. 2008

Perhaps the most important adaptations swifts boast is their wings, and even more importantly, how they use them. Swifts have a fairly unique physiology of the wing: the actual arm portion of the wing is extremely short, with the wrist of the wing placed quite close to the body. Most of the wing, then, is the outer wing feathers that go from the wrist and form the tip of the wing: the primaries. In swifts, the bones that control the wingtip are also relatively large. Why? With these relatively small modifications to typical avian wing morphology, swifts have enormous control over the angle and shape of their wings, which allows them to adapt to changing conditions aloft and retain control and maneuverability. Also impressive, swifts share the ability to rotate their wings at the base with hummingbirds. This allows their wings to be fully extended--and thus to generate the most lift--on both the upstroke and the downstroke. With this sort of complexity already present in swifts, a recent study reveals one of my favorite evolutionary phenomena in swifts: a trade-off.

Swifts are renowned both for their gliding flight and their flapping flight, but both require very different physiological adaptations--contrast the wings of predominantly gliding condors with those of predominantly flapping ducks. One would expect, when looking at swifts, that they are equally well adapted to flapping flight as they are to gliding flight. Makes sense right? This way, swifts would be ideal for flapping or gliding.

But remember, there are always more conditions, more variables, to consider. In this case, we know that swifts benefit from the highest possible level of efficiency, and ultimately, this means being efficient with energy. So let's ask the important question. Which kind of flight requires the most energy: flapping, or gliding? The answer to us seems obvious. While gliding is relatively passive, flapping requires constant effort of a complex muscle system and takes much more energy. This discrepancy is where we find the trade-off--in order to maximize efficiency in flight overall, swifts must balance their efficiency at gliding with their efficiency at flapping, because, after all, they can't switch between a body optimized for flapping and a body optimized for gliding every time they switch flight styles!

This is figure 1 from the first study cited below. Dark blue
corresponds to positive lift, or upward motion, which, for
our purposes, means best possible efficiency. 

And like with all trade-offs, evolution handles this one beautifully. Because swifts spend much more energy at flapping, swift wings have adapted more towards efficiency at flapping to minimize this energy cost. They are "flapping-biased". While they may be less efficient at gliding because of this, gliding required less energy to begin with. By minimizing the energy cost of flapping rather than adapting equally to flapping and gliding, the energy cost of flying overall is less for the swifts. It's a balancing act folks, and in this one, leaning toward flapping works best. Isn't that fascinating?!

The level of complexity in animals we can sometimes take for granted, like twittering swifts spiraling overhead, is dumbfounding; we have so much to understand even just outside our bedroom windows. If we could only see the gray of the unknown in the world around us, like some strange, brain-wave-reading Google Glass app, we would see an inordinately gray world.

And in order to clear some of the gray with swifts, the scientists in the above-mentioned study only needed a curious eye, some math, and a stopwatch. Oh and a windtunnel. Don't forget the windtunnel.

Have a great day everybody.

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References:

Henningsson, Per, Anders Hedenström, and Richard J. Bomphrey. "Efficiency of Lift Production in Flapping
     and Gliding Flight of Swifts." PLOS ONE. PLOS ONE, 28 Feb. 2014. Web. 26 Mar. 2014
     <http://www.plosone.org/article/info%253Adoi%252F10.1371%252Fjournal.pone.0090170>.

Henningsson, P., G. R. Spedding, and A. Hedenström. "Vortex Wake and Flight Kinematics of a Swift in
     Cruising Flight in a Wind Tunnel." The Journal of Experimental Biology. The Journal of Experimental
     Biology, 2 Jan. 2008. Web. 26 Mar. 2014. <http://jeb.biologists.org/content/211/5/717.full>.

Bio-Control: Tying together our Woodpecker Journey

Photo by scarboroughcruiser

Invasive species are...complicated. Well, actually, they aren't necessarily complicated themselves; the situations they breed are what is complicated. Take the issue of the explosive Asian Carp population in the Mississippi, which consumes much of the food sources required by an enormous set of native fish species to survive at all. Ecological catastrophe will follow if their invasion succeeds in conquering the Great Lakes. House Sparrows, an all-too-familiar species introduced from England in the 19th-century, presents such bellicose competition for nest cavities that they will literally murder Bluebird chicks in a nest box and go on to build their nest on top of their corpses.

But one species in particular, friends, has gotten my attention, and the attention of all those with trees above their heads...trees that may be slowly but surely falling and dying out mysteriously. This invasive is the Emerald Ash Borer (EAB in short). To the chagrin of interstate firewood smugglers, Emerald Ash Borers have pervaded much of North America from their origin in Asia, and, at this point, human efforts have largely been unable to stop their silent incursion.

Adult Emerald Ash Borer
Photo by Dan Small

The problem with invasive species is what makes them invasive. Being
non-native to the area that they are invading, the often face no natural opposition at any level of the ecosystem, and are often able to out-compete native species. Being successful at invading an area means being coincidentally better adapted to exploiting that ecosystem than that ecosystem's natural occupants. It's a bad deal folks, and yes, we should be scared.

The real culprits...the larvae
Photo by David Cappaert

We should be scared because...well...take Chicago After losing an estimated 30 million ash trees in the Eastern half of the continent alone, 17% of street trees in Chicago are the ash trees that the Borers target. This means that on the city-owned property along streets alone, 85,000 trees are up for grabs to our untouchable insect invader. Not enough for you? It is estimated that 300,000 ash trees occupy private property in the city--we are facing significant holes in ecosystems and shade over our heads. Not to mention safety hazards resulting from decrepit, infested trees.

EAB infestation marks by John Marvin
Phelps

Before we move on to the science of birds, what is it that ash borers do to trees, you ask? Ash borers are problematic primarily in their larval stage. In this stage, they live just below the bark in the top layer of wood, burrowing serpentine ruts. These ruts, which I'm sure you've seen, look like tiny squiggled indentations into the wood. Why is this an issue for strong and stoic trees? This top layer of wood is extremely important to the trees and all plants; this is where the plant's vascular system is. Similar to our system of blood vessels and veins, this layer of wood contains cataracts that transport water and nutrients around the plant. Damaging it would be like damaging our blood vessels. And a badly infested tree can be entirely cut through its vascular system.

How do birds play into this, then? Woodpeckers (here they are again) specialize in feeding on larvae within this layer of wood. By preying on larvae and other insects within the bark and top layer of wood, woodpeckers help maintain the trees' health and ultimately the health of the forest. It's a great deal, you guys.

Top to bottom: male Downy and Red-bellied
Woodpeckers by Warren Lynn

But the question is this: do woodpeckers (and nuthatches, for that matter) prey upon Emerald Ash Borer larvae? Normally, part of the success of invasive species is their lack of natural predators in the area they're invading. Asian Carp are a perfect example of this; they have no predators to control their populations. Can we look to woodpeckers as a potential bio-control of invasive EAB's, one that we don't need to interfere with anymore than by preserving healthy woodpecker populations?

Here's the best part. A bunch of middle-schoolers in Ohio helped us find that the answer is a resounding yes. A group of researchers recently conducted a study to answer these questions, in which they established observation plots in Michigan and Ohio to follow the dynamics of the forest ecosystem in response to the Borers. One of these plots lay behind an Ohio middle school, where the researchers reached out to the students to be part of a multi-year citizen science project. Here's how it worked according to an article on this study by the University of Illinois at Chicago:

"A section of trees in the stand behind the school was cut down for examination each year for two years. The students searched for and painted all the holes they found in the bark of each tree—a different color each for large round woodpecker holes, for the characteristic crescent-shaped holes mature emerald ash borers make exiting a tree and for holes made by other insects.

Paint seeped through to dye the stem beneath, and after the bark was stripped the students could identify woodpecker holes that penetrated into emerald ash borer galleries, or into holes made by other bugs. The students tracked the fate of each bug that had been in the tree. Instead of relying on a statistical estimate of the insect population and thus the food source available, every bug and its fate were accounted for."

White-breasted Nuthatch by Brian Howell

And what statistics did the middle school scientists attain? In accordance with the hopes of any fan of ash trees, woodpeckers chose to prey on 85% of the Emerald Ash Borers within an infested tree. This means that woodpeckers are actively altering their prey-selecting behaviors to take full advantage of the new and increasing invasive food source. In a way, the Borers are actively invading right into the mouths of hungry woodpeckers. On top of that, another citizen science project, this one Cornell's Project Feederwatch, revealed that the populations of three woodpecker species and the White-breasted Nuthatch actually increased in areas where the Borers were increasing.

So, is it enough? After all, 85% isn't 100%, and this means that there are still Emerald Ash Borers left over in the wake of woodpecker predation. In a way, it is enough. Woodpeckers will not instantaneously snuff out the population of Emerald Ash Borers...it would be unrealistic to expect them to do so in the first place. If they could have done that, it is certain that they already would have. But they certainly will slow the increase of the Borers, and eventually, slowly but surely, as woodpecker numbers continue to increase, Emerald Ash Borer populations may be expected to decline, which eventually would lead to their disappearance. Be mindful; this is an assumption. But what a sweet dream it is to imagine that nature will do the job of eliminating one of its most virulent pests completely on its own.

What fantastic balance this is.

Like any decent science blog, I'd like to leave you with some questions. This is where we will tie together my previous two woodpecker posts.

First and foremost, think back to the post on Syrian Woodpeckers and their ecological trap within polluted, urban forest tracts. Now think back to the post before where we found that woodpeckers tie the separate continents back together--part of this is their remarkable consistency in foraging method. Everywhere you go, woodpeckers do just that: peck wood. So...

1. If woodpeckers show this consistency, might woodpeckers around cities in North America also be drawn to polluted areas because of higher concentrations of prey?
2. If this is a yes, would woodpeckers in urban areas more rapidly eat away at Emerald Ash Borer populations because of greater densities of woodpeckers paired with increased tree infestation?
3. Would the percentage of Emerald Ash Borers ultimately consumed be higher in urban forest tracts than the 85% found in Ohio?
4. Finally, if woodpeckers can limit the populations of invasive wood-boring insects and possibly eliminate them, is it possible that this isn't the first time in their evolutionary history that they've done so?

Ultimately, just food for thought. Cheers everybody. You've been great.

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Here's the article on which this post is based:

Galatzer-Levy, Jeanne. "Emerald Ash Borer May Have Met Its Match." UIC News Center. University of Illinois at 

     Chicago, 16 Dec. 2013. Web. 28 Feb. 2014. http://news.uic.edu/emerald-ash-borer-may-have-met-its-match

Piciform Pictures

So to continue my serendipitous research in Piciformes this month, I was inspired today to do some preliminary research on the Ramphastidae (toucans). One of my most prized possessions is a whiteboard, which I've been using more and more to represent my research. I've used it on everything from ID'ing Sooty from Dusky Grouse, to working out how Pleistocene glaciation affected what are now our neotropical migrants, to this, which is the fruits of my Ramphastid research today:

Here's hoping you enjoy!

Another really cool thing I found during this morning's research is a "tree" of all bird life constructed by Jetz et al. As far as infographics go, I think this one is really beautiful:

By all means, click to zoom. This image is stunningly high resolution.

So what's next? By the end of the month, I'll have another post put together about woodpeckers with an awesome question I've been brewing for a few days now.

So keep your eyes peeled, and more importantly, stay warm!