On the proliferation of Eurasian Collared-Doves in Orange County

A Eurasian Collared-Dove in Anaheim on Sunday

Orange County is different every time I visit. New housing developments encroach ever deeper into the hills. Trees are "trimmed" (read: mutilated) further and further into oblivion. And there are always more Eurasian Collared-Doves. 

This is going to make me sound old, but here goes. I remember when things were different. There was a time when Eurasian Collared-Doves were not common in Orange County. When I moved here in 2007, they were downright difficult to find. Over the last few years, they've become commonplace. In fact, I saw one the other day a mere mile from my house. I predict that I will soon add this species to my almost legendary Hood List. 

This expansion is hardly surprising, given hemispheric trends for this species. Want a good laugh? Check out the dove's map in the original Sibley. It is rapidly expanding west, east, north, south. "Collared-Dove," I told Joel as we crossed the Michigan-Indiana state line in early January, "Will probably be the first new species we see." Sure enough, dozens greeted us at a rest stop in central Illinois. Their coos serenaded us at every piss stop across the country--Missouri, Oklahoma, New Mexico, Arizona, California. Then we flew to Mexico--and there, too, the streets echoed with their calls. And they were verminous in the Dominican Republic. I just can't get away from them.

Let us consider their conquest of Orange County. First, courtesy of eBird, here is an overview of their North American range.

This next map shows Eurasian Collared-Dove records in southern California up to the year 2005.Very sparse in Orange County, with greater numbers up north towards Los Angeles.

Fast forward to 2011. Things are filling in slowly in Orange County, though the species seems to be increasing rapidly up north in Los Angeles County and in western Riverside County.

And finally, all records up to the present (red pins indicate records from the past month.) Explosion. Blietzkrieg. The Collared-Dove has conquered Orange County. 

Using eBird to track the expansion of this species may be deceptive, since the dove's invasion of Orange County coincided (or slightly preceded) the widespread adoption of eBird by birders. Fortunately, Christmas Bird Count data for Orange County is readily available online (thanks, Sea and Sage Audubon). The data support my general impressions that (1) Eurasian Collared-Doves first began appearing in Orange County in roughly 2005, and (2) that the population has rapidly increased since then--particularly since about 2010.

In past decades, a different dove reigned in Orange County--the Spotted Dove. They were abundant through the 90's (the 1990 Coastal CBC recorded upwards of 250), but their population crashed. The last surviving Spotted Doves overlapped with the pioneering Collared-Doves in the early 2000's. It is fun to speculate about the rise and fall of two nonnative doves in Orange County--did the Collars drive out the Spots? At least in the context of Orange County, I find this hard to believe--by the time the Collared-Doves showed up, the Spotted Doves had already been gone for years. But, who knows? 

And will the Eurasian Collared-Dove share the Spotted Dove's fate in Orange County? I doubt it--I foresee the dove expanding further, saturating the county--nay, the country-- interminably.

Map Monday: Hooded Merganser

Hooded Merganser is a long-time favorite species of mine--at the age of eight, I made a watercolor copy of Jim Arnosky's Hooded Merganser painting in Watching Water Birds. I saw my first one on November 27th, 1999, at Belle Isle in Detroit, Michigan.

"Homies" are uncommon in southern California. Finding one is always a treat, but it won't send you scrambling to document and report it. A flock of five hens has been fishing at the neighborhood lake this week (a long-overdue addition to my neighborhood list), causing me to wonder about their range...

First, the general purpose eBird map. They are widely spread across the Lower 48, the Rocky Mountain-ish area comprising the weakest link.

Summer (Jun-Jul) distribution. Aha. Here it seems we have another coverage issue. I bet if platoons of high-intensity eBirders swept through Northern Canada, we'd have solid purple from Lake Superior to Churchill. Notably, the bird seems to be present in most of the places it winters with the exceptions of the Southwest and the far South.

And, winter (Dec-Feb). I'm struck by the concentration on the immediate East Coast.

And finally, the obligatory Southern California perspective. Most of the records (except for the Colorado River and the Imperial Valley) are within 75-ish miles of the coast. And interesting detail--there seem to be more concentrations slightly inland, in the foothills and mountains (e.g., north of Los Angeles). From San Diego County Bird Atlas: "..the Hooded Merganser avoids San Diego Bay and occurs in most other coastal wetlands only rarely...the Hooded Merganser is as likely to occur in the higher mountains as at most places along the coast."

Map Monday: Pilot Test

In an effort to revitalize this ailing blog, I'm going to try out a series of posts exploring bird distribution. I plan to post a nugget every Monday.

Let's talk about Varied Thrushes. They're cool, right? Correct answer: right. Basically, someone took an American Robin, spiffed it up with Arabian geometric designs, and replaced its jolly song with a haunting New Age whistle. Oh, and instead of lawns, Varied Thrushes inhabit fog-shrouded coastal forests. Doesn't get much cooler than that.

It so happens that this is shaping up to be an above-average year for wintering Varied Thrushes in southern California. Normally, SoCal represents the southern tip of the thrush's winter range. Orange County is blessed by perhaps one Varied Thrush in the average winter. At least ten have been spotted in the county so far this season. In the words of Doug Willick, 2014-2015 may be "one of the best flight years in memory" for Varied Thrushes in southern California.

First, let's look at a classic range map, swiped from BirdFellow.com.

Now, the analogous map from eBird. The most significant difference is the eastern occurrences--Varied Thrush is not unprecedented in the winter in the East, but it is by no means regular or expected.

Next, an eBird map showing the breeding range. The core of the breeding range seems to be British Columbia and southern Alaska. Central California (i.e., Big Sur region) seems to be the southern tip.

Next, the winter range (sightings from October through March).

And finally, a map of southern California showing individual sightings of Varied Thrush. The red pins are sightings from the last month. Many are already appearing in the coastal plain!

Introducing the Orange Big Month

Without coast, without mountains, without charisma, the city of Orange will nevertheless produce an enviable avian bounty over the next month.

A renaissance is under way—I have returned to birding regularly. Last February, I went twenty-three days without entering an eBird checklist (yes, I counted, and yes, I am horrified). At one point this summer, I found my windowsilled binoculars serving as an anchor for a gargantuan spider web. This morning, I wiped months (years?) of accumulated sand, food residue, and fingerprints from my binoculars, resurrected my high school bike from retirement, and headed to Santiago Oaks Regional Park to began the City Big Month (hereafter CBM).

A Big Year is too big of a commitment. And I want to limit myself geographically. So—from November 6^th until December 6^th, I will ransack every corner* of Orange for avian booty. Birds will be ruthlessly located, identified, and reported to eBird; my goal is 125 species. The CBM, I’m hoping, will motivate me to bird locally a lot in the next month.

A tribute to the good old days when I actually had a camera--a Western Bluebird, already battled and subdued as a part of the CBM

Santiago Oaks gave me a good start this morning: Red-breasted Sapsucker, Varied Thrush, Purple Finch. And now, if you will excuse me, I’m venturing outside to listen for the neighborhood Great Horned Owls.

* I will include Irvine Regional Park even though it isn’t in city limits. My reasoning: (1) the park’s street address is Orange, and (2) Irvine Regional Park is awesome. 

Birding--Bad for the Health

Head entombed in pillows, torso mummified in blankets, I was well along in the process of falling asleep. A dark haze swirled over my mind. The peaceful hum of traffic and the muffled booms of Disneyland fireworks ten miles distant lulled me into unconsciousness, an unorthodox yet soothing lullaby.

SCR-REEEEAAAP!

A Barn Owl shrieked a challenge to muggy night. Barn Owl vocalizations are diametrically opposed to lullabies—sharp, startling, scary. I jerked awake and glanced at my watch. Ten o’clock. I made a mental note to register this impolite owl into eBird first thing in the morning.

eBird has been the ruin of my life. I can’t even sleep without being dogged with the obsessive urge to enter checklist after checklist.

Fortunately, a simple solution exists, and, rising on an elbow from my pillows, I reached for it on the nightstand: a pair of earplugs. Nothing but the most raucous mockingbird shouting from my windowsill could disturb my slumber now. I sighed and sank back into my nest of pillows and blankets. Sleep followed quickly.

Two, Four, Six, Eight, Try To Estimate!

“How many [Ruby-crowned] kinglets?” I asked, notebook in hand, pen poised to record the official tally.

“At least a couple dozen…maybe twenty-six?” responded my girlfriend Alison, behind the wheel as we pulled away from Floral Lane, an alleged hotspot that I have thus far found to be positively underwhelming.

“Don’t be ludicrous,” I scolded. “Fourteen.”

Alison sighed.

“Come on. They were ALL over the place. I saw six in one bush.”

Seeing the validity of both statements, I conceded. “All right, fine. Sixteen.”

Both of us are notoriously strong-willed people. The debate nearly dissolved into blows, but eventually we peacefully agreed that we had, indeed, seen sixteen Ruby-crowned Kinglets on our walk. He who wields the pen holds power.

It’s a time-honored tradition of mine. Go birding, have a good time. Then, afterwards, estimate the numbers of birds you saw and punch them into eBird. How representational are these estimates—often little more than wild guesses—of the true number of birds present? Some situations offer challenges, like…

A cloud of swallows swirling back and forth over a field…thousands upon thousands of gulls blanketing the center dike at Muskegon Wastewater…a chorus of unseen Wrentits trilling from hill cloaked in chaparral…ubiquitous Black Phoebes, one standing guard over seemingly every trash can in the neighborhood.

An even greater challenge faces birders entering eBird checklists from memory: whether a species was even present or not. Did I hear any Song Sparrows on my evening walk around the evening? Well, surely I did—must have just forgotten to write it down on my little pad. How many? Well, I don’t know, but usually there seem to be about three singing males in the neighborhood, so I’ll put down three. Yeah, three, I remember them all now…

I’ve become halfway diligent at jotting down all the species I detect in a pocket notebook that I feel naked without. Recording numbers, however, is another story. Leaving the estimations to the end frequently leads to intense personal frustration (when I bird with myself) or verbal, possibly even physical conflict (when I bird with others). In addition to these negative side effects of estimation, is it even accurate? I decided to test the accuracy of my estimation on a recent evening ramble to Irvine Regional Park by carefully tallying numbers of several species.

The first thing I noticed: Black Phoebes are freaking everywhere. I encountered eleven in less than a mile of walking. On my previous four visits of comparable effort, I estimated three, six, one, and seven birds, respectively. Second observation: Cliff Swallows are impossible to count, screw this. Third observation: Mourning Doves, that’s better. Fly in a straight line, one or two at a time. I can handle this. I ended up with seventeen, compared with forty, twenty-six, eighteen, and thirty-eight on previous visits. Fourth observation: Shoot, eight-thirty, almost my bedtime...better head back.

These two case studies might suggest that my estimation powers are reasonably accurate. I do not, however, flatter myself to be convinced so easily. Oftentimes, when confronted with a species scrawled on my notepad, I am completely at loss as to how many I saw. This challenge is two-pronged. It involves memory, sometimes over hours, and it also requires synthesizing a total of birds seen over a period of time—when out birding, you see those Yellow-rumped Warblers a few at a time, not all at once. Out of curiosity, I googled “estimation games” and blew an enjoyable few minutes testing myself (http://tinyurl.com/3re74py). Embarrassingly, I nearly scored negatively on the “Count 50-99” level, but then I promptly dominated the “Count 20-50” level. It seems that I am forever doomed to be ignorant of my level of estimation skill…

One of my goals for the remainder of the summer is to be more aggressive in keeping track of bird numbers while birding and not saving the estimation for the end. It requires considerable time and diligence, both of which I seem to perpetually lack. But who knows? Perhaps, by the end of the summer, my eBird account will be spewing forth data that are slightly more accurate.