Adventure is for the birds

Six o’clock was approaching in inconceivable leaps. You label the tubes, I’ll label the package. We send our DNA out for sequencing, which means we ship little tubes of clear liquid in an envelope to New Jersey. In a few days, we receive a computer file with strings of A’s, C’s, G’s and T’s that we carefully analyze for key differences. The last package pickup is at 6:00pm. We were running late.

I took the envelope and ran through the grand halls of my work place; past the 145 year old canoe, through the 1950’s forest, past protists and dodos and horeshoe crabs. It was a natural history themed This is your Life episode. I felt fleet-footed and brave.

This project is not a traditional adventure. No traveling to far off places to collect rare specimens, no field clothes, no tent sleeping. No plane ticket, no goodbyes. All the work occurs less than 2 miles from my apartment. Specimens are sent directly to me. Even my “time travel” to collect historical specimens involved going in some very nearby doors I had never entered. Maybe I am missing out, or maybe I am incredibly lucky.

Out of breath from my run, I reached the desk. “Did I miss package pickup?”, “No”. My mind sailed away to temporary confident places, I did it! imagine what other impossible things I am capable of? I think about these birds constantly. I regularly wonder what the complete data will show. I am dying to know. I am an over-thinker, but I am also an immovable beast, I don’t love going places like everyone around me seems to. I recently diagnosed myself as an indoor dreamer. But even though I haven’t crossed rapids, or hiked for hours, the intellectual journey is an adventure to me, one that I would gladly run through the halls to achieve.

After my focus returned, the man took my package and smiled, “the last pickup is 8:00pm”. Ashamed, exalted, I told him about my gloriously unnecessary run, and how great it felt. He told me to run back. So I did.

Bird heaven

Thousands of specimens sit in silence, waiting for a scientific research question to give them life. Birds from different decades sit together in one drawer. Birds that lived thousands of miles apart might share a cabinet. It is a time capsule, and a pile of places — it is a collapsed little world.

I have been dreaming of this starling project for months. What motivates me is not their striking beauty, or their precious handwritten specimen tags, it is looking for patterns and tracing the biological legacy of their dramatic story. I sat at my desk and stared out the sliver of almost-window, I read, and researched, and emailed about it. But what I didn’t realize is that the historical specimens that would allow me to understand how the species changed through time were sitting —without much exaggeration—on the other side of my office wall. Behind my office wall there is a bathroom, and then not far beyond that, it is bird heaven.

old little toes

Are New Yorker starlings different than Californian? I would bet yes, but how so? some do yoga, others drink too much coffee and double park? Maybe. 

We are studying starling populations throughout North America to detect genetic and phenotypic differences across the country. But, aside from detecting geographic variation, we also want to chronicle how the species has changed over time. For this, we will look inside hidden museum collections. Museum research collections are important scientific repositories for data that are otherwise inaccessible to researchers. Some specimens may represent species, or populations, that are now rare or extinct. It is critically important for the advancement of science to maintain and make available the specimens within research collections. Thousands upon thousands of specimens of birds, mammals, reptiles and fish have been collected, prepared, stored, and made available for research purposes like this project. 

We will be soon receiving 33 samples of starlings from The Field Museum. We will not receive whole birds in a bag, or a box, as we have before. The samples will consist of small pieces of old little toe pads cut from bird specimens. Some from England, others from the East Coast of the US—all old, some over 100 years. From these pieces, we will extract ancient DNA. This will bring a new dimension to our starlings study. I am thrilled.

We can answer questions like: Have North American starlings lost genetic diversity over their 100 year time here? Have some genetic groups gone extinct? Do starlings in North America have less genetic variation than those in England from the time of their original arrival in 1890? 

And I keep thinking of the hilarious Big Lebowski toe storyline: I can get you a toe by 3 O'clock. 

strange familiar birds

Their beaks are brown for winter, their plumage blurry with stars. They convene on the sidewalk for a brief bird-minute, and I stare at them as if I will be able to see urban evolution in action. I haven’t seen it yet, but I know that it is there; in their genes, in their bones, and in that walk - that rises and falls with a graceless bounding pride. What can we learn from these strange familiar birds?

The concept for this project grew out of a basic evolutionary question I had about how populations evolve. We know that a dramatic and prolonged decrease in population size results in lower genetic diversity, and stronger genetic drift for succeeding generations. But what happens to morphology under these conditions? I don’t think there is one answer for all taxa. Variation differs from species to species, and from trait to trait. Because of the stunning history of starlings in our country, I am deeply curious about the diversity of their skeletons, feathers and beaks. By bringing a cage full of lively birds from England to the US and releasing them in Central Park, an accidental evolutionary experiment began in the winter of 1890 - one that we are following up on today.

The data are coming in. Our sturnus vulgaris mitochondrial DNA sequences look clean and strong. One goal of our project is to better understand the genetic diversity of North American (NA) starlings, and compare that to other sturnus vulgaris populations around the globe. The expectation is that genetic diversity will be low in NA starlings because of the small size of their founding population (60 individuals in 1890), and their rapid expansion (to 200,000,000 in just 125 years). It is too early to tell how much, or how little variation, we have yet. I am highly hopeful that we will get solid results this year. We are lucky to have the great help of wildlife authorities throughout the country for suppling birds. And I am working together with two conscientious students who are doing careful lab work. We have started a database for recording information about each specimen. It is exciting to see it grow. Data accumulation is one of the great thrills of doing science, it’s work made visible.

The First Bird

They arrived on a Wednesday, in a box labeled honey baked ham. I rushed around teaching, meeting, and answering emails. The box sat. I knew what was inside, but I needed time to open it. Time to carefully inspect the cold little bodies inside. Time to respect their terminated lives. And I wanted to be alone with them.

The box felt heavy and damp as I carried it. It was 12:14pm when I arrived in the lab to unpack my frozen gift. My hands trembled. I have been dreaming of their nuanced intraspecific diversity for many months. Subtle differences between individuals of the same species will tell us something new. It’s different than the great variation we see between wildly divergent species. It’s quieter. Newer.

I pulled through two tightly knotted plastic bags. There they were. In a heap, not a flock. In a pile, not a murmuration. One man’s trash. I lifted the first bird. It’s neck was crooked, it’s eyes gently closed. Dignified, even in death. Tawny brown head, it was a juvenile in its last autumn plumage. I set it down in the afternoon sun.

the bird that isn't a bird

“They are not considered birds, they are not considered birds”, the ornithologist repeated. They are exempt from the Migratory Bird Treaty Act. You don’t need a permit to kill them. According to the IUCN Invasive Species Specialist Group, they are one of the 100 worst invasive species in the world. European starlings in North America are reviled for their ecological, agricultural, and aeronautic troublemaking.

In 1960, a flock of ~20,000 starlings caused one of the worst airplane bird strikes in history. During take-off the birds were ingested into the engine, causing power loss, and eventually a sideways crash. Sixty-two people were killed. Starlings wreak havoc on farms. They eat the most proteinaceous plant parts, meant for cows, which effects the quality of milk production. Their guano can transmit diseases such as histoplasmosis and E.coli. They also compete with native birds for nesting sites. 

Wildlife control agencies end the lives of millions of starlings every year. These birds are killed creatively. They are trapped, gassed, poisoned, their cervical vertebrae dislocated. In 1890, when starlings first arrived in North America, their were no commercial airplanes, and many fewer cows. I wonder when they were first recognized as problematic? Perhaps not at the outset, allowing them time and space to properly invade. 

All of this is to say, we shouldn’t hate these birds. But we should be cautious not to love them either. No point in getting carried away about their beauty, gregarious nature, or skills of mimicry. That is the type of sentimental thinking that launched this invasion. But, from an evolutionary perspective, I think we have something serious to learn from our unwelcome guests. Their morphological, behavioral, and dietary adaptations are noteworthy. Their population expansion nothing short of astonishing. So, to understand some central concepts in evolutionary biology—variation within species, adaptation to novel environments, and reproductive success—it’s fitting that we turn to the starlings. Even stripped of the honor of being called a bird, and despised for legitimate reasons, the starling still has scientific stories to tell.

something about starlings

It wasn’t until I reached my office, safe from the crowds, that I knew. I sat in my chair, and stared at my lifeless companions with a new respect. I felt pleasantly betrayed. I had no idea they would elicit that reaction. When museum visitors saw them, they whispered, and pointed, and grabbed. It was as if I was wheeling around miniature feathered rock stars. People wanted a piece of them. And badly.

Starlings arrived in New York City in 1890. Sixty individuals were released in Central Park as part of an effort to populate the park with each bird mentioned in Shakespeare’s plays. It was a wonderful, awful idea. Sentimentally driven, ecologically ignorant. Today there are ~200 million starlings in North America. This is not considered good. They are an invasive species; raiding crops, outcompeting native birds, and interfering with aircraft. Part of their success lies in their dietary flexibility. I once saw two starlings fighting over a piece of prosciutto on Columbus Ave. They were both holding it in their beaks. It was strung between them like a salty ribbon in an only-in-New-York Disney scene. They flapped, and pulled, and snapped. 

Sturnus vulgaris are, what I would consider, beautiful birds. In spring and summer, they sport a striking iridescent radiance, paired with a shock of yellow beak. In fall and winter, they take on modest brown plumage, flecked with little light colored “stars”. The origin of their name. They are ubiquitous, and decidedly unspecial by ornithological standards. From an ecological perspective, they are downright hated. Starlings are remarkable for their boldness, not for their rarity. They flourish in urban environments throughout the world; Europe, South Africa, New Zealand. Starlings still live in Central Park today, and all around the museum, aggressively pecking at the grass and forming peaceful groups with their inelegant associates, the pigeons.

My four starlings were dead. Taxidermied specimens for education and research. Clustered together in silence on my rolling cart. Not singing, or flying, or behaving. I was walking through the Hall of Saurischian Dinosaurs. One of the most spectacular and impressive dinosaur exhibit halls in the world. But T. rex had nothing on my starlings. Nevermind that, evolutionarily, birds are avian dinosaurs, or that many starlings were alive and flourishing all over the museum lawn at that very moment. There is something about a specimen. The stillness. The oldness. The perceived specialness. But I think it was also a little about the birds too. One specimen was from winter, the other three summer. Spectacular in a kind of ordinary glory.