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Showing posts with the label Bird Sound

Grassland of the Pipit

 

 

A word of advice: record the places you go. It is easy to forget how remarkable everyday sounds are until you are far away, both in distance and in time.

Below is one of the only sound recordings I made during my 2015 field season in the grasslands of Alberta, Canada. One of my tasks for that research project was to conduct line transects where I would write down every bird seen and heard while walking a predetermined line for a set amount of time. Before doing each line transect there is a buffer period where you are required to be still, watch, and listen. On this morning I set up my cheap Zoom H2 field recorder to document the buffer period.

(Headphones recommended)

At the time I was new enough to birding that I didn’t fully realize I wouldn’t get to hear many of these grassland birds' songs again for a long time, including Savannah Sparrows, Grasshopper Sparrows and Long-billed Curlews. All of these birds stop during migration or even spend winters in Arizona, but while they're here they are mostly quiet. Grassland birds are often cryptic in plumage and habits, usually staying well hidden in the grass. During breeding season, however, they fill the air with song.


The bird that I treasure most from this recording is the Sprague’s Pipit. This is a bird that I have seen exactly once in my life, though I heard them skylarking most mornings in the summer of 2015. In their breeding displays they fly up into thin air, high enough to become essentially invisible from the ground. With wings spread they float downward while delivering a descending cascade of song, loud enough to be heard from the ground where judicious females watch and listen. They then flap up to regain their lost altitude and do it again. And again. And again. Displaying males repeat this process for between a half hour and three hours or more at a time. It is an incredible physical feat; just imagine singing at the top of your lungs while sprinting up a mountain. This only adds to what is for me an aesthetically awesome feat; these kaleidoscopic songs seem to emanate from the sky itself, the particularly expansive sky found above rolling grassland that extends beyond sight in every direction.

Grasslands of Alberta Canada

Sprague’s Pipits, along with most grassland birds, are in steep decline. There has been an estimated 73% population loss since 1970 – there were nearly four times as many Sprague's Pipits 50 years ago. Destruction and fragmentation of native grassland by development, overgrazing, and invasive species are all taking their toll. But you probably already knew that. You find a similar story everywhere you look when paying attention to the non-human world. One becomes inured to this kind of statistic. Yet the birds are still there and that is something to celebrate. Enjoy it! They return year after year to fill the world with magic. They're right out there, go see!

And when you get a chance, record them. As you return to recordings, they accumulate meaning and significance as time goes on and it is nice to have a document, however imperfect, of a place in time. I haven't been back to the grassland of the Sprague's Pipit, but with my recordings I can revisit the scenes and the feelings I felt at the time: excitement and anticipation, my first field season, running through every sound I could hear, attaching names to each one so I would be ready for the official start of the transect, the feeling of wonder at the variety of life and sound in this "empty" land at this ungodly hour. And returning to a recording allows a relaxed appreciation of the whole, how all the pieces combine, sonically and ecologically, without having to focus on assigning labels to each thing before they slip away. With knowledge of the scarcity of these sounds in my life since and in a predicted future, I listen with hungry ears. With each new experience of listening, I am more tightly bound with these creatures, giving me renewed energy to do what I can to protect their habitats from blind destruction and help find a balance for life to coexist.

The Phainopepla is a curious bird




The Phainopepla is a curious bird. Their tall crest and feathers of silky black or gray are accentuated by piercing blood-red eyes. They reveal luminous white wing patches in their somewhat slow yet buoyant flight. In the Sonoran Desert they fiercely defend their clumps of desert mistletoe from intruders with an inquisitive “Wert?” A charming and charismatic bird at first glance, the closer one looks into any aspect of its natural history, one realizes the veracity of Allan Philips' claim in The Birds of Arizona: "Phainopeplas have no respect for the rules."

"And there isn't any need for you to doubt it"
-Rum Tum Tugger
Pencil sketch of Phainopepla
Phainopepla nitens – sketch by the author


"Wert?" call

The Phainopepla song is a modest volume series of burry and polyphonic phrases, evocative of blackbird and shrike vocalizations in their complexity. Those that work closely with Phainopepla have noted a bizarre vocal behavior when they're distressed while being handled: they unleash a near constant stream of loud (and very convincing) imitations. These include a variety of hawk and other predator calls, perhaps in an attempt to distract or frighten, but they also mimic a wide variety of small harmless songbirds. Investigating this behavior, there is a study that shows a variety of imitations mixed with alarm calls is most effective at rallying other nearby species to help mob a predator. When threatened, the Phainopepla vocally simulates a multi-species scolding mob attempting to drive a predator away. This in turn helps manifest a real mob with real birds. Avian aural Twitter bots.

Under normal circumstances one rarely hears these imitations in the field though. I had no idea Phainopeplas were mimics at all when I encountered a lone male singing from the top of a palo verde in the Phoenix Mountains Preserve in January 2019. I could hear the louder burry phrases typical of their song but interspersed throughout were quiet sounds I couldn’t quite make out. I snuck myself under the tree where the bird was singing and with the assistance of my microphone I then could hear what he was muttering.  Listen below:



After some introductory phrases he launches into a series of imitations at around 17 seconds in what is referred to as their Quiet Song. In this two minute clip I hear imitations of at least a dozen species, from desert dwelling critters like Curve-billed Thrasher and Harris’ Antelope Squirrel to a variety of higher elevation forest birds like Spotted Towhee, Cassin’s Kingbird, Tree Swallow, and Western Wood-pewee. Unlike the famous mimic, the Northern Mockingbird, which belts out its collection of imitations at the top of its lungs, the Phainopepla whispers them. They can’t be heard from more than a stone’s throw away, so who are they for? Sometimes quiet songs serve to strengthen pair bonds when birds are in close proximity – but I didn't see any other Phainopeplas nearby. Was he practicing?  I doubt it – they sound pretty crystallized to me. When listening to the extended recording he uses the same imitations many times with very similar phrasing and delivery. Was he feeling threatened, either by me or something else? Again, I doubt it – giving quiet imitations of birds that are currently hundreds of miles away doesn't seem like an effective mob-eliciting strategy in this context. Whatever the case may be, the function or meaning of imitation seems to be flexible in different contexts. They are very impressive though, why be so coy about it?

"And there isn't any need for me to shout it"
-Rum Tum Tugger

Wait a minute, how is this desert-breeder imitating so many forest birds to begin with? Without doing any research we’re already clued-in to a fascinating aspect of this bird’s natural history just by listening to his peculiar quiet song. Clearly, this male has been around. He has seen (and heard) some things.

While Phainopepla are fiercely territorial, mistletoe berry-loving, desert-breeding birds in winter and early spring, they largely vacate the premises by early summer. Around the same time, they are found in mid-elevation riparian and oak woodland habitat, sometimes hundreds of miles away. There they are social creatures, forming loose colonies, nesting together in the same trees, eating berries from the same bushes. They incorporate many more insects into their diet. They’re like a different bird.

For almost a century people have wondered whether these were distinct populations of Phainopepla or the same birds breeding twice a year in different habitats. There are still many details to be worked out but a recent study has shown GPS-tagged desert-breeding Phainopepla do migrate to the expected higher elevation habitats each year and there is no discernible genetic difference between populations in each location. This strongly suggests the same birds breed in both habitats. Aside from a handful of very interesting outliers, most other North American birds are constrained by various environmental, physiological, and behavioral limitations and only have one chance per year to breed. If Phainopeplas are in fact itinerant or migratory double-breeders, “[They] would be behaviorally flexible –in migration, breeding, and social-structure– to a degree not documented in any other North American bird” (Chu, M. and G. Walseberg, Birds of the World, 2020). As for the rules and constructs, generalizations and metaphorical boxes we try to fit birds into, the Phainopepla indeed has no respect for them.

“For he will do as he do do
And there's no doing anything about it”
-Rum Tum Tugger

Roseate Burrow #18




In the Summer of 2019 I worked on Stratton Island in Maine for National Audubon's Project Puffin. There were no puffins but many birds bred on the island including four species of tern. While Common Terns were the most...common, there was a sizeable Roseate population in the center of the colony, a few Arctic Terns scattered throughout, and Least Terns on the sandy beach landing.

We had many intimate and intense interactions with the terns that summer. We regularly checked nests, counted eggs, weighed, measured and banded chicks all while the adult terns screamed in our ears, pecked the tops of our heads with surprising force, and aggressively covered us with tern excrement.

Typical tern greetings in slow motion

It wasn’t all chaos though. We also spent a lot of time in platform blinds throughout the colony which allowed us to observe the birds in relative peace. Courtship dances, copulation, eggs hatching, chicks hopping up and down awkwardly flapping their wings. We watched certain chicks get fed over and over while others starved. We watched curious birds wander too far from their nest only to get pecked viciously by their neighbors. We also watched many birds take to the sky on fresh wings, over time gaining the grace and buoyancy of their parent's flight.  The blinds allowed us to observe the entire breeding process in all its messiness.

A view from the blind

The blinds were still a bit removed though. Towering several feet over the colony, we watched through binoculars and spotting scopes. With nearly four thousand terns before eggs even started to hatch, the sound of the colony was, in a word, extra. Any attempt to hear one specific bird was masked by the sounds of hundreds of other vociferous squawkers. What we couldn’t hear were the quiet tern sounds – not necessarily an oxymoron.


Partway through the season we were visited by Bob McGuire (a world class sound recordist, just check many of the audio credits on the Sibley Birds app), who helped open my eyes to the magic of remote recording or "drop rigs." One morning at camp he excitedly passed around his headphones for us to listen to what he had just recorded. The concept was simple enough, he had hidden small omnidirectional microphones in the rock burrow of a Roseate Tern then watched from a distance. When we slipped on the headphones we heard the terns like we never had before.

Omnidirectional mics have several benefits: They’re small and hideable, have low self-noise, and are less susceptible to wind noise. However they have one drawback for isolated species recordings: omnidirectional mics record in all directions equally so the passing lobster boat or obnoxious bird or any other noise will be picked up as if the microphone is pointed directly towards it. What I hadn’t considered was the inverse-square relationship between distance and intensity of sound: if you half the distance between a mic and a sound source, the intensity of sound will be four times greater. The trick is getting the mic close enough to the subject.

The next evening I tried it out myself:

(Headphones Recommended) -- Recorded with Zoom H5 and FEL Clippy XLR EM172s

The recording starts with the sound of a typical alarmed tern colony. Common and Roseate Terns yell in the distance and then return to their nests all riled up. It is past sunset, fiery clouds fading into the dark blue night. We hear the parent Roseate Tern return, giving its piercing alarm call and aggressive chatter just outside the rock burrow, making sure neighbors keep their appropriate distance. Switching to the more social "chevink" call at 1:03, it heads into the burrow. Moving from left to right in the stereo field, the adult is greeted by its 3-5 day old chicks with quiet scratchy calls. After the initial excitement they all quietly mutter to each other. When I hear this I imagine the adult tern settling down as the chicks huddle and squeeze underneath to rest in the warmth of their parent’s puffed out body feathers. All is calm in burrow #18. Neighboring terns also quiet down and we hear the distant rhythmic crashing of ocean waves. Of course, it never fully settles for long – tern colonies are only varying levels of raucous at all hours and trouble is never too far off.


This is likely the first of many posts about the sounds of Stratton Island and is just one of many examples of this recording technique. Normally field recording attempts to capture and recreate what we can hear, but remote "drop rig" recording can allow us to hear what we otherwise couldn't. Paradoxically, the technology that removes us can also embed us more deeply with our subject, allowing a peek into intimate social interactions with the emotional salience afforded by sound. We hear what birds whisper when we're not around.



Disclaimer: I was trained and permitted to work with these birds and their safety and well-being was always my top priority. One should not approach nests if doing so would cause undue stress or have an adverse effect on nesting success. It is illegal and morally reprehensible to disrupt the nesting of birds for any reason.

Water in the Gulch




It's another hot dry day in Phoenix. Wildfires are burning across Arizona including the fifth largest fire in state history, 30 miles northeast of where I sit. The birds out the window have their beaks agape, increasing their evaporative cooling while also appearing to share my slack-jawed incredulity at the relentless low-desert summer heat.

Normally at this time of year I do biological field work in cooler climes but with many field seasons being suspended this year due to COVID-19, I am plodding through summer with the rest of Phoenix. Through the magic of digital recording, however, I’m able to time-travel to a mere three months ago: It is in the mid-60s and after a sudden early spring downpour, the normally bone-dry gulch behind my house is full of flowing water.

(Headphones Recommended) -- Recorded with Sony PCM-A10 and FEL Stereo Clippy EM172s

The somewhat unusual aural combination of flowing water with Sonoran desert regulars like a whistling Verdin, cooing Mourning Doves, and calling Curve-billed Thrashers all add up to a special and relaxing desert soundscape.

The Curve-billed Thrashers, however, were anything but relaxed. In a cholla a few feet from the flowing water was a freshly built nest and four thrashers interacting with a palpable intensity. One bird was singing constantly while the others vibrated with agitation, a stream of chatter flowing out of them. I normally find Curve-billed Thrasher songs to be extraordinary and beautiful, every bit as complex and impressive as a Northern Mockingbird’s song but more sweet and melodious (and less obnoxious). The songs in this recording, though, have a decidedly aggressive edge to them.

Curve-billed Thrasher perched in creosote
Curve-billed Thrasher Toxostoma Curvirostre – photo by the author

Most of the aggression was directed towards or instigated by the singing bird, seemingly an intruder. The other three tended to be closer to one another, though they were all moving around quite a bit. Was this a confrontation between two pairs as one would expect, or could this be a single intruder on a three-thrasher breeding arrangement? As far as I know, cooperative breeding has not been described in Curve-billed Thrashers, but in other species like the familiar Acorn Woodpecker or the less familiar but more closely related White-breasted Thrasher, kiddos will often assist their parents with the care for young.

Without any distinguishing marks on the birds to tell them apart I can only guess what was going on. As two of the thrashers locked their feet and claws onto each others bodies, not letting go as they tumbled down from tree branch to razor-sharp cholla spines, one thing was clear: there was not room for all four thrashers near this nest.

It is easy to idealize the life of birds. We intuit that a singing bird is a happy bird and there are studies that show singing does activate the reward centers in a birds brain – they enjoy it. However, bird song can also express extreme aggression in life-and-death circumstances. Birds live complex and dynamic lives and we are only just beginning to unravel their complexity.

Whitewater Draw Mystery




Listen to this:

(Headphones recommended)

It's been over a year since I recorded this in March 2019 and I’m only just beginning to understand what it is.

We arrived in the dark of night, the graded dirt road violently vibrating my Honda Fit. After a few minutes of straining to hear, I turned off the radio and listened to the sound of every piece of my car and body rattle.  We pulled into the dirt parking area, shut off the engine and stepped outside. Suddenly free from the confines of the car, our ears began to open up beyond the immediate vicinity, expanding outward in every direction into the darkness...until we heard them.

My girlfriend Nell and I had come to Whitewater Draw on the last night of February to experience the Sandhill Cranes that winter at this 600-acre wetland in the southeast corner of Arizona. A huge striking bird, I had only previously seen handfuls of migrating cranes off rural county roads outside Phoenix. Hearing tens of thousands of them at night though, distant, yet filling the darkness with their prehistoric trumpeting croaks and screams was awe-inspiring.

In the morning, we were posted up by the wetland before sunrise, soaking in the sights and sounds before the cranes took off to forage in nearby agricultural fields for the morning.

Sunrise at Whitewater Draw 3/1/2019

Fun fact about Sandhill Cranes: their tracheas are elongated and coiled into their sternum. This tracheal elongation allows the cranes to have deeper, more harmonically rich voices with lower formant frequencies, making them sound even larger than they already are. The coiling around the sternum, a clever way to fit this elongated trachea into a crane body, is also thought to allow the sternum to act as a amplifying resonator. In other words, it helps the cranes croak and scream at ear-shattering volume. Cranes are amazing.



Once most of the cranes had departed for the morning we were left to wander the grounds to see what other birds and critters were around — which brings us to the aforementioned recording that has transfixed me ever since. In a tiny murky pond opposite the cranes were a pair of Northern Shovelers, striking ducks with large spade-shaped bills, and an interesting sound. I pointed my parabolic microphone towards the shovelers, slipped on my headphones and pressed record. Here it is again:



So good. A low clucking sound, sometimes phoneticized as ‘Tsook’ is the most common Northern Shoveler vocalization so that seemed to account for some of what can be heard. The grunty-smoochy sounds, however, were something I was unfamiliar with. I chalked it up to a high-intensity courtship vocalization that is only given at specific times of year (by exceptionally horny birds) and filed it away.

In the coming months, I would return to the recording and try to find any mention of this grunty-smoochy Northern Shoveler vocalization. The excellent Peterson Field Guide to Bird Sounds curated by Nathan Pieplow is my go-to resource for a concise yet near-comprehensive recorded catalogue of bird vocalizations in North America — but this sound was absent. I browsed the extensive offerings at the Macaulay Library and Xeno-Canto but still could not find this vocalization. Even the Birds of the World account had no mention of this vocalization as far as I could tell, though I often find text descriptions of bird vocalizations a bit inscrutable:

McKinney (McKinney 1970) recorded rhythmical wheezy whe or thic or quiet took notes by males during copulation; also recorded one male giving a long sighing noise at copulation. Postcopulatory behavior by males usually includes a loud, nasal paaay, followed by a series of repeated calls.
https://birdsoftheworld.org/bow/species/norsho/cur/sounds

Audio recording of birds is still a relatively young pursuit. While it is quickly gaining popularity, it is still not widely adopted by the birding world so the possibility of recording an uncommon or cryptic vocalization for the first time is a real possibility (especially when you add state or county location qualifiers). I excitedly wondered if I had made such a recording breakthrough. It wasn’t until early the next spring when I heard the sound coming from the edge of a mucky pond with not a duck in sight that I began to suspect this was no shoveler sound at all.

Growing up in Phoenix, I rarely had occasion to listen to frogs and until recently have not given them much thought. With a sneaking suspicion I got ahold of Lang Elliott’s beautiful Frogs and Toads of North America and listened to all 99 tracks and 70 minutes. I was floored. The diversity of frog sounds and their charming wonkiness were completely entrancing. Still new to frog sound ID, I could say my grunty-smoochers were probably one of a handful of leopard frog species found in Arizona. A quick perusal of the Arizona Game and Fish Department website revealed Whitewater Draw is home to the Plains Leopard Frog.


It turns out my “Northern Shoveler” recording is almost entirely non-avian. The frogs that I failed to notice were likely giving what is referred to as an advertisement call. Frog advertisement calls function similarly to bird song: establishing territory, attracting females, repelling rival males. As with most animal vocalizations though, more nuances are likely to be found with closer study. These advertisement calls were apparently ineffectual on me but through sheer bizarreness eventually drew me into the wonderful world of amphibian acoustics. This is why I love paying attention to sounds, whether they’re birds, frogs, music or especially unknown sounds, you might learn something. And it is fun.