Archive for category Field Notes

The Final Countdown: Taking Stock of an Endangered Butterfly

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It’s late August. Here at the Antioch Dunes National Wildlife Refuge, the fall’s late bloomers have unfurled their petals to entice the pollinators hustling these parts. An assemblage of honeybees joined by their kith and kin patrol the petals, self-absorbed in their singular mission to collect nectar and, with it, a pinch of pollen. Among them idle Acmon blues, hairstreaks, and cabbage white butterflies, each showing off their own rendition of mosaic-scaled wings intricately tatted with eye spots, patches, and splashes of color. And overseeing the morning rush hour under way swoop dragonflies, hovering and bearing down on their targets like predator drones.

But all of these are distractions from our purpose here today. It’s late August, the peak flight period of the federally Endangered Lange’s metalmark butterfly. And we’re here to count butterflies.

Shortly after arriving at the refuge, U.S. Fish and Wildlife Service refuge biologist Louis Terrazas takes my wife Sarah and I aside and asks if we’d like to see a Lange’s metalmark butterfly before the training gets underway. You see, I’ve visited the Antioch Dunes National Wildlife Refuge perhaps a half-dozen times or more between now and when I first wrote about the  dunes for Bay Nature magazine in 2005. But in all those visits, I had never made it to the dunes in August or September, when the Lange’s emerge from their chrysalis as imagoes (the mature butterfly) and begin their short-lived adult lives.

It’s a short walk down the sandy road into the Pit Floor, and then a few feet off-trail into a meadow of delicate Antioch Dunes buckwheat, the Lange’s host plant. It’s no more than a few seconds before Louis spots a butterfly pin-balling off invisible barriers in the Lange’s trademark erratic flight. The butterfly – a female, judging by its larger size – alights on a buckwheat bloom and flexes her wings. That’s one of the Lange’s stand-out traits – the other butterflies that frequent these dunes are more close-lipped, keeping their wings tucked in the upright position rather than splayed for the world to see. But the Lange’s is anything but shy. Once they’ve landed, they typically stay put for minutes at a time, long enough for Sarah to preserve on film (a flashcard, really…) portraits of this vanishing species.

Back at the orientation, USFWS refuge biologist Susan Euing takes charge, giving the assembled volunteers the rundown on the census we’re about to undertake. Despite this being a butterfly count, only Lange’s metalmark butterflies count during today’s transect surveys, so we have to be able to discern between our target and the other butterflies in flight. Then we’re assigned tally counters, metal pucks with a push-button that activates the 4-digit odometer to keep track of each Lange’s we come across in our surveys.

Outside the protective fold of the Pit Floor where we’re puttering around, readying our gear, the Delta winds whip the air in swirling eddies, the gusts arriving from every which way. It’s these winds that first distributed the Antioch Dunes here from their glacial-ground origins in the Sierra over 500,000 years ago, piling them along the south bank of the San Joaquin River in dizzying drifts some 120 feet above sea level and as much as 800 feet inland. At one time some 5,000 to 8,000 years ago, these sands extended along the San Joaquin River for two miles, then skirted the eastern flanks of Mount Diablo south along the western edge of the San Joaquin Valley and continuing on to connect with the Mojave Desert.

This connectivity acted as a corridor for an array of true desert plant and wildlife species that radiated north and adapted to the unique environs of the Antioch Dunes. In time, too, this connectivity was severed, leaving the new inhabitants of the Antioch Dunes to survive on their own. Such isolation lead to specialization and speciation, laying the groundwork for endemism – where a species becomes localized until it becomes confined and belongs exclusively to a certain location. Among those endemic species were the Antioch Dunes evening primrose (Oenothera deltoids howellii), the Contra Costa wallflower (Erysimum capitatum angustatum), and the Lange’s metalmark butterfly (Apodemia mormo langei).

Lange’s metalmark butterfly (Apodemia mormo langei) • Courtesy G. Kareofelas, Bohart Museum of Entomology, University of California, Davis

At the Antioch Dunes, there’s an even greater assemblage of insects found here alone (dune “endemics”), many of which have since eclipsed into extinction. But at the time, the Lange’s, the wallflower, and the primrose represented the three species whose scarcity warranted their protection, leading to their listing under the Federal Endangered Species Act in 1976 (Lange’s) and 1978 (both plants) and the formation of the Antioch Dunes National Wildlife Refuge in 1980.  Even today, the Antioch Dunes remain the only federal wildlife refuge in the United States established for the protection of plants and insects.

We know so much about the insect fauna of the Antioch Dunes from the swarm of entomologists who have been drawn there over the last two centuries after the dunes became acclaimed among naturalists for their untold abundance of insect life. In 1955, the dunes even found their way onto the pages of Life magazine in the way of a fold-out six-panel feature spread illustrated by famed artist Dr. Walter Linsenmaier.

But in all those years of study and collection, the dunes were also being exploited for their exceptional sands. Beginning in the late 1800’s, various and sundry sand mine operations made a business of removing sand by way of train cars on dedicated Atcheson, Topeka, and Santa Fe Railroad spur lines. Following the 1906 Great Earthquake, demand for sand intensified the demand for manufacturing bricks. By the late 1970’s, the once-towering pillars of sand had been depleted in most places to bare earth. The quarries continued removing sand up until the very day the refuge was formally established in 1980. Today, the mined-out Pit Floor is a stark reminder of the exploitation that took place over the last 200 years, an example of the depths – literally – the mine operations excavated the dunes to extract sand.

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These days, the refuge is divided into two separate units, which bookend the Georgia-Pacific gypsum plant in their midsts. The westerly Stamm Unit, a 55-acre parcel shaped like the handset of a rotary phone, and the easterly Sardis Unit, a square 12-acre parcel. One either side of the units hulk industrial compounds: the Kemwater North American Company to the east, the Fulton Shipyard to the west, and a city wastewater treatment plant and transfer facility to the south. The Sardis Unit, east of the Georgia-Pacific gypsum plant where drywall is manufactured, is perpetually dusted in a fine white powder, which leaves everything downwind looking flocked – your boots, pant cuffs, and the west-facing surface of every branch and leaf blade. Every footstep ignites a ‘poof!’ of powder.

Fortunately, there is no rabble of white-winged Lange’s haunting the gypsum-confectioned Sardis Unit. In fact, since 2010, the Sardis Unit is the only of the two parcels that continues to support Lange’s metalmark butterflies. But for whatever reasons, the Lange’s are more prolific on the central and eastern boundaries of the Sardis Unit, especially in the protective bowels of the Pit Floor.

All of this bears out during the butterfly count. Beginning on the plateau east of the Pit Floor, we line up at arm’s length in much the same way rescuers might during a search party, except the bodies we’re searching for are the size of a quarter and winged. In 1999, the peak count numbered 2,342 in a single day; last year, the 2012 peak count numbered 32 individual butterflies.

In the shadow of the monolithic PG&E tower, our first few Lange’s imbue us with hope that we can top last Thursday’s peak count of 23 butterflies. As the day progresses, our day’s count climbs in fits and spurts. After knocking off the upper terraces, we drop into the Pit Floor where the buckwheat plants erupt in thickets. So too do the Lange’s, which appear to be thriving in this metalmark Mecca. Every butterfly we glimpse brings us to a momentary standstill as we key out the individual’s traits: cabbage, cabbage, buckeye, Lange’s! Each Lange’s is assigned a volunteer as a babysitter to make sure there’s no double-counting if the butterfly flushes and skitters ahead of our transect. Although they’re nowhere near as abundant as we’d like, by day’s end we’ve tallied 28 Lange’s, topping last week’s peak count.

This doesn’t break any records, but at least we didn’t get skunked. And it marks an upward swing from last year, reassuring us that even if things aren’t getting markedly better, they’re also not getting markedly worse. The counts will continue through September until the butterfly’s short lives are spent and the flight period sets for the season. And next year, a new wave of volunteers – myself included – will take up the front lines in the uphill battle against extinction.

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Throughout September this year, wildlife biologists at the Antioch Dunes National Wildlife Refuge will continue to conduct their annual Lange’s metalmark butterfly counts to determine the health of this rare butterfly species. For more details and directions, visit the refuge website: http://www.fws.gov/refuge/antioch_dunes/Get_Involved/Butterfly_Survey2013.html

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Why Did the Turtle Cross the Road?

I can’t count the number of times I’ve turned the car around – or cajoled my wife or any other unfortunate driver I happen to be with at the time to do the same – after having caught a ‘glimpse’ at sixty-five miles an hour of what could only have been a western pond turtle on the side of the road. To my chagrin, my so-called turtles have always ended up being a boot or rock or junkyard scrap. I’m still unclear if if that makes me an alarmist or a wishful thinker, seeing turtles in peril where there is neither.

What to do

Once, driving home several years ago, I happened to come up behind a car that had stopped in my rural neighborhood to pick up a wayward western pond turtle. Too late, I realized what it was the front passenger had retrieved from the road. I was tailing them, working up a pitch to negotiate the turtle’s safe return, when the car lurched to a stop, all four doors flew open, and the passengers leapt from the car. Hysterical, one of them was all too eager to tell me that, moments after retrieving their prize, the put-upon turtle had proceeded to pee all over the car  while scrabbling and scratching to be released. Surprised, the young women had dropped the turtle at her feet, where the hardened prisoner made a break under the front seats for the driver’s-side, sending the passengers into a panic. They were all too glad to return their hostage, a hardy three-legged western pond turtle I dubbed “tripod” before I released it at a BLM property in a pond a short distance away.

But this Friday, traveling along Highway 84 in San Mateo County, for the first time in years I had the misfortune of being right. The turtle in this case – a mature female – lay along the roadside shoulder in an advanced state of decay. Her plastron, crushed no doubt beneath the tires of a passing car, had been flipped upward as though on a piano hinge. I can only imagine that she had first been flipped onto her back by the front tire before the rear tire pinned the anterior of her plastron and carapace against the hardtop, caving the shell like a walnut in a nutcracker.

Too often, roadways parallel waterways, acting as a barrier obstructing daily and seasonal movement and dispersal between overwintering sites, nesting grounds, and the turtle’s natal waters. There’s no telling where this unfortunate turtle was heading. To or from the nearby creek? In search of a mate or a spot to nest? I checked the shell cavity for eggs. She was running on empty.

Fortunately, not every scenario is so grim. Two weeks ago, two colleagues turned up at work on a Monday morning with photos of a mature female western pond turtle they had come across while cycling along a roadway in Marin County. Because the turtle had been found straddling the centerline, there was no telling in which direction she had been headed, so the Samaritans had relocated the turtle across the road to safety toward the nearby creek.

In this case, they did the right thing, moving the turtle out harm’s way. But scenarios like these raise a good question: what should you do if you find a western pond turtle in the road?

To help answer that question, several years ago I developed a full-color, tri-fold brochure describing our local western pond turtle, what to do if you find one, and guidance to private landowners and public land managers alike on the best ways to protect and conserve western pond turtles through proactive land stewardship. I’ve excerpted the relevant text below:

Western pond turtles leave the safety of the water more often than you might think. Turtles come to land to nest; escape drying creeks and ponds or winter floods; hibernate; find mates; and to seek out new ponds and streams.

If you come across a healthy western pond turtle on dry land that is in no immediate danger, do not disturb it. Already skittish by nature, they are especially so on land, leading females to abandon nesting attempts. Make a point of leaving (and leave!) by walking away with heavy footsteps and loud voices. If you sneak off, the turtle may wait you out – leaving it vulnerable to predators or the elements. If you find a live turtle crossing a road, safely move it to the far side in the direction it was heading.

If you come across a western pond turtle that appears ill or has sustained recent injuries (e.g., from a pet, vehicle, or fishing tackle), carefully transport it in a covered container to a local wildlife rehabilitation center immediately. Note where you first discovered the turtle so it can be returned to the closest watershed.

And it’s free! So download the .pdf, print, and distribute.

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Field Notes: All Cooped Up

Earlier this week – huddling groggy behind the sliding glass door waiting for the dog to conduct his business – I caught the flutter of feathers descending from across the fence into the silver maple out back. No sooner had I slid the door ajar to lean into the mute morning grey then the culprit – the neighborhood Cooper’s hawk –  startled from her perch and again took flight, exchanging the naked limb for one in the skeletal tree in our next door neighbor’s yard.

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Cooper’s hawk (Accipiter cooperii)

Over the past few years, my family has come to know this Cooper’s hawk from our occasional run-ins with her here and there. My first encounter occurred one afternoon throwing a tennis ball for the dog in the front yard. Surprised by the sudden approach of wings, I looked up from my play with the flagging dog in time to catch one of my neighbor’s domestic pigeons careening toward and then around me like a child seeking shelter behind his parent’s legs. No sooner had the pigeon swung past then my gaze was transfixed by a second bird  – the Cooper’s hawk – fast approaching me at eye level with unparalleled purpose. Today, all I can recollect of that instant is the feeling of looking down the barrel of a gun before she too was gone. She must have pulled up and out of that dive abreast of me like a top gun pilot to avoid the living room window and the towering sycamore in her flight path beyond. By the time I had gathered my wits about me, she was disappearing behind the roof tops with a little less purpose, her quarry having escaped with me as accomplice.

Our sightings of her continued: atop telephone poles shortly after sunrise, or herding pigeons during their afternoon recess. Last year, my wife called me at work to say that the Cooper’s hawk had made an appearance again on the front lawn. Called to the door by the dog’s incessant barking, it took my wife a moment to realize that it wasn’t the mailman or a passerby that had caught his attention, but the Cooper’s hawk on the front lawn with a pigeon pinned to the turf. Flustered no doubt by the barking dog, followed by the appearance of my wife at the front window, she fumbled in her attempts to launch herself into the air with her prize, until at last she let loose the frightened pigeon in a blizzard of breast feathers and gave up the chase. Two hours later, downy feathers still danced lazily on the lawn when I arrived home.

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Western screech owl (Megascops kennicottii)

The fall we moved into this house, however many years ago that was, I stepped out from behind that same sliding glass door one morning as the dog – at that time still a pup – was pushing leaves with his nose under the pretense of conducting his business. That morning, I caught another raptor in the back yard. This time, our visitor was a western screech owl. Remembering my wife’s camera on the dining room table, I somehow reached back into the house, fumbled the camera on, and slipped into the back yard in time to snap three photos before the owl had had enough of my insolence and slipped off into the inky morning. Several weeks later, eying the silver maple a little more closely late one afternoon, I happened to remark to my wife that a certain cavity looked like the ideal spot for nesting birds. Retrieving my binoculars from my field bag a few minutes later, we were both surprised when none other than the screech owl appeared peering back at us from within the hollow.

The screech owl became an autumn staple, making the dead branch her evening roost over several weeks that year and the next. But after the rotting branch succumbed to a winter storm, despite the nest box lined with wood chips I built and hung in the maple that summer, the owl hasn’t been seen since.

Although the Cooper’s hawk’s appearances are fleeting and the owl has moved on, I still have the lesser goldfinches, house finches, dark-eyed juncos, oak titmice, and chickadees that parade around the feeders to keep me company. California towhees scratch in the leaf litter below the feeder. The black phoebe returns each year to perch on the handlebars of my son’s tricycle or, now, the lawn chair beneath the maple. And the Anna’s hummingbirds that nest in the neighbors-across-the-back-fence’s yard still return throughout the year to trapline the salvias and flowering maple that line our side of the fence.

Which goes to show it isn’t always good fences that make good neighbors. On a cold winter morning, while all of us wait for spring, such friends make fine neighbors indeed.

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