December was unusually warm. In fact, it was record warm. And not just barely… records were shattered. The average temperature for the month was 38F. Not only was that a ridiculous 9 degrees above normal, it smashed the previous record of 24.8F (set in 2001). Surprisingly, despite the everlasting warmth, record daily highs were rare. Christmas Day was an exception, however, when temperatures soared to 62 in Portland, crushing the previous record high of 53, set just last year.

Our first measurable snow of the season didn’t fall until December 29th – the second latest date on record. Those 5-8 inches in southern Maine finally ushered in “real winter” and hopefully set the stage for a return to more normal conditions (although the last few days have once again been 5-10 degrees above normal).

Not surprisingly, such an unseasonable month resulted in some very-unseasonable birding. A variety of “lingering” or perhaps more accurately “pioneering” as Ned Brinkley, editor of North American Birds once dubbed it warblers in particular were making headlines.

So I decided to do a December Warbler Big Month. Because, well, warblers in December! In Maine!

With Tennessee, Yellow (2!), Nashville (2!), Common Yellowthroat, and Wilson’s on December 6th, I was half-way to my newly-set goal of 10 species for the month. The unusually mild fall has allowed more “lingering” birds to survive longer, and normal November hotspots are still hot (literally and figuratively).

Unfortunately, I waited until December 8th to decide to embark on this silly little hunt, so I had some catching up to do. There were some relatively easy ones (Yellow-rumped Warblers overwinter in a few places, along with “known” Blackburnian and Pine Warblers). That meant I just need to find an Orange-crowned Warbler (the second most-regular December warbler after Yellow-rumped) and then one other stray.

So off I went…

Not wanting to take any species for granted, I twitched a Pine Warbler that was reliably coming to a feeder in Brunswick on the 10th. I had to wait all of three minutes for it to arrive on my way back from walking Sasha. If only they were all this easy!

The next day I was once again at the Saco Yacht Club, looking for the Blackburnian Warbler (which I saw on Nov 30th – one day too early!). Activity didn’t pick up until the fog finally lifted after 10am, but I ran out of time. I did, however, enjoy another visit with the Tennessee, and 1 each of Yellow and Nashville Warblers. 2-3 Ruby-crowned Kinglets were also present, and a Yellow-rumped Warbler dropped in: my 7th species of the month! That and the Western Tanager were the consolation prizes (yes, I did just relegate the tanager to a consolation prize…shame on me… but I “needed” the Blackburnian!).

I worked hard for an Orange-crowned Warbler in Portland on the 13th to no avail, but I did turn up the continuing Nashville Warbler along the Eastern Promenade (oh look, Portland ravaged vegetation here, too!) and a Gray Catbird on Sheridan St. I also took time to go visit the continuing Ross’s Goose along Stroudwater St in Westbrook – the third I have seen in Maine, and only the 6th or 7th state record.
(Phone-scoped image)

Continuing the quest, I had high hopes for the Southern York County Christmas Bird Count on the 14th. With a great territory that almost always turns up a good bird or three, Jeannette, Kristen Lindquist, and I worked the marsh, thickets, neighborhoods, and beach of the “Moody” sector. And we did indeed have a great day, including the 2nd Count Record Clay-colored Sparrow, the 5th Count Records of Baltimore Oriole and Lesser Scaup (21 – also a record high), and 6th Count Record of Dickcissel. But alas, not a single warbler. We didn’t even get a Yellow-rumped – for the first time, as there was virtually no fruit on the bayberry bushes along Ogunquit Beach or anywhere else.

When my friend Evan Obercian found a Yellow-throated Warbler at the Samoset Resort in Rockport on the 13th, my goal was definitely in sight (this was the “additional rarity” I needed), but in the weeks before Christmas, finding time was going to be a challenge. Luckily, a break in my schedule – and the rain – came on Thursday the 17th, so I got an early start and headed east.

I met up with Evan and Kristen and we wandered the grounds of the Samoset for almost two hours. I was not happy to find a stiff onshore breeze when I arrived, and it was increasing over the course of the morning. Then the mist rolled in, and soon, a steadier drizzle. There were not a lot of birds around (other than Canada Geese and Mallards on the golf course), and I was beginning to work on a plan to come back again. And not long thereafter, it called!

We spotted it in an isolated cluster of Scotch Pines, very near where Evan first saw it (and where we walked by 3 times already this morning). We followed it for about 30 minutes as it relocated to another grove before heading over to the hotel building, where it proceeded to forage in the sheltered porches of the four story building! Presumably gleaning insects from old webs in the corners and around furniture, clearly this bird had figured out a novel way of finding sustenance – especially on such a snotty day.

It was my 8th warbler of the month.

I was back to the Saco Yacht Club with Luke Seitz the next morning, once again hoping for the Blackburnian. We worked the hillside and surrounding habitats hard, and absolutely cleaned up! The quick glimpse of a fly-by Western Tanager was more frustrating that satisfying, but we had great looks at the continuing Tennessee, Yellow, 2 Nashville, Common Yellowthroat, 2 Ruby-crowned Kinglets, and then, finally, the Blackburnian! My 9th warbler of the month!

Luke’s quote sums it up: “Let’s take a moment to appreciate what we are seeing and hearing around us right now. What. The. (Expletive deleted)!”

I had a little more time, so I made a quick trip down to Biddeford Pool. Working the neighborhood and thickets, I found a small group of Yellow-rumped Warblers (4-5), a nice addition to the day list. Besides, up until now, I had only seen one all month!

I was in the midst of plotting “Operation Orange-crowned” when I wandered over to look at a chattering Ruby-crowned Kinglet. A loud chip note caught my attention, and I looked up to see this Prairie Warbler – my 10th species of warbler for the month (and 7th of the day)!

But did you really think I would stop at 10?

Hunting for Orange-crowns in Portland and South Portland on the 21st, I turned up a Baltimore Oriole on Sheridan Street (likely the same individual that Jeannette and I found here on 11/23), and along West Commercial Street (in what’s left of the vegetation here!), I had a Swamp Sparrow, and a Field Sparrow – my 8th sparrow of the month.

Hmmm…do I need to go for 10 sparrows, too?

Obviously!

So I went to Scarborough Marsh the next day, and quickly picked up a Savannah Sparrow along the Eastern Road Trail for #9.

Jeannette and I, post-holiday madness, continued the search on the 28th, combing the coast from Kittery through Wells. While nothing new was added, we did find three different Swamp Sparrows (two at Fort Foster, 1 in York Beach), and most excitingly, we relocated the Clay-colored Sparrow that we found on the CBC – a mere one block away. Once again, however, I managed only some quick phone-binned photos.

A Northern Flicker and 5 Yellow-rumped Warblers were at Wells’ Community Park, while other highlights included 14 Sanderlings with Purple Sandpipers along Marginal Way in Ogunquit.

But before I knew it, it was December 31st. I still had yet to see an Orange-crowned Warbler (inconceivable!) for the month, and I was stuck at 9 species of sparrow. Therefore, Phil McCormack and I had a mission when we set out in the morning. We worked thickets and fields in Cape Elizabeth, with stops at various nooks and crannies in South Portland and Portland.

While we did not relocate the Lark Sparrow along Fessenden Road (it’s been a week since I have seen a report), we did have a Merlin there, and a couple of Yellow-rumped Warblers at Crescent Beach State Park. Luke had an Orange-crowned Warbler at Camp Ketcha back on the 20th, but it was rather devoid of birds today.

Throughout the day, pockets of Song and American Tree Sparrows were indicative of recent movements and concentration following the snow and ice, but we were not prepared for the concentration of sparrows at a particularly fruitful patch. In fact, it was astounding!

75+ American Tree and 50+ Song Sparrows flew out of the field, joined by 10 or so White-throated Sparrows and 20 or more Dark-eyed Juncos. A continuing female Brown-headed Cowbird was there, along with at least 80 American Goldfinches and 30 or so House Finches. A Carolina Wren sang from the woods, and two Swamp Sparrows and a female Common Yellowthroat were in the marsh…I knew my 10th species of sparrow was here somewhere!

After a teasing brief, distant but highly suggestive look, I finally found it – a Chipping Sparrow! My 10th species of sparrow in December!

Shortly thereafter, a Savannah Sparrow (my second of the month) appeared – not just our 7th species of the day, but the 7th species in this one spot! Amazing! And now I had a 7 species of sparrow day and 10 species for the month to match my 7 species of warbler day and 10 species for the month! (The Double 7/10 Split?)

But of course, I still wanted an Orange-crowned Warbler, so we kept birding (well, after a long, celebratory lunch of course), and I tried a few more OC spots in Portland after Phil departed. I still can’t believe I saw 10 species of warbler in Maine in December, and none of them were Orange-crowned, but it seems a fitting finish to the month, and the year, was the continuing Baltimore Oriole and Gray Catbird sitting in the same tree in the Sheridan St lot!

Meanwhile, some other highlights over the course of the month, of the non-warbler or sparrow variety, including more seasonal species, such as two Snowy Owls on a Saturday Morning Birdwalk on the 12th, my first Iceland Gull of the season (finally) in Old Port on the 15th, a Snowy Owl at Biddeford Pool on the 18th, Harlequin Ducks, Purple Sandpipers, and a growing legion of wintering waterbirds.

Other signs of the unseasonably warm month included a lingering Double-crested Cormorant in Portland Harbor on 12/15, a few more lingering dabblers and Great Blue Herons than usual, but surprisingly, I didn’t see a Hermit Thrush all month – had they all moved on or would some now show up as the snow and ice pushes them to coastal migrant traps? But the most unexpected of them all was the Little Blue Heron that was found in the tiny Jordan Park Marsh in Ocean Park. I stopped by to visit it on the 22nd, about two weeks into its unseasonable stay.

Unfortunately, as much fun as this month has been – and as nice as it has been to not yet wear my parka – it’s impossible for me to ignore what this all means: the climate HAS changed. While no one month – warm or cold – is “climate change,” it is impossible for any rational person to not realize that our weather has become more and more unpredictable, less and less “normal,” and prone to more and more wild swings in seasonal and within-season variability. No, a hot day doesn’t mean Global Warming, nor does a snowstorm mean there’s not (Please James Inhoffe, please go away and shut the hell up). But the trends are real, very apparent, and very much here. Now. And they are most definitely affecting birds and bird migration.

That being said, I would not use these warblers as an example of this. Instead, I think the fact that here in December and they are still ALIVE, is however, a perfect example of just how ridiculously warm our weather has been! The mechanisms that delivered these birds to the Saco Riverwalk and elsewhere are likely varied. Perhaps the deformed, crossed-bill of the Tennessee Warbler impedes its ability to efficiently forage and put on the necessary weight for its next leg of migration. Perhaps the extensive southerly winds that have ushered in this warm air also facilitated the arrival of a 180-degree misoriented migrant Yellow-throated Warbler, and I would propose, the Prairie Warbler as well (I think the rare-but-regular late fall Prairies are actually birds from our south) that were “messed up” and flew the wrong way. But it is also possible that some of these warblers are “reverse migrants” that started to go south and then turned around, but I doubt it – facultative migrants like swallows and blackbirds do it, but I don’t know of any known proof that long-distance Neotropical migrants pull it off (on purpose, anyway).

These mechanisms occur every year, and rare warblers are found at places like the Saco Riverwalk every fall. However, they’re usually found in October and November and either move on (or, more likely perish) by now. So I think what’s remarkable is not that all of these warblers are here, but that they are still ALIVE well into December – and that is most definitely due to the mild winter so far. There have still been insects to be found, there’s plenty of fruit left to consume, and fewer calories have been spent to keep up internal body temperatures, meaning there are fewer calories that need to be consumed.

Migration in long-distance, obligate migrants is not triggered by temperatures, but trigged by physiological changes directed by hormones responding to the changing length of the day. In the fall, southbound migration is triggered in part by a response to changes in fat loading to fuel these epic journeys. At some point, the controls are switched away from building the fat reserves that are necessary for migration. I don’t know at what point in the season “pioneering” warblers lose the ability (perhaps, even the “desire”) to migrate. My guess is that even if you pumped these birds full of fat, at this point, they won’t be going anywhere – this is now their winter territory, for better, or for most likely, worse.

So what does this mean besides some amazing early winter birding? Good question. Conventional wisdom says these birds are all “evolutionary dead ends” that will soon be eliminated from the gene pool (it has to get cold sometime, right? If they’re not picked off by a Sharp-shinned Hawk or all of the damn outdoor cats that hunt there). However, with the effects of Global Climate Change clearly upon us, and not reversing anytime soon (if ever), perhaps these “pioneers” are the wave of the future. Maybe someday, warblers will successfully overwinter in Maine, and return to their breeding grounds to pass on those genes.

Maybe. Afterall, without vagrancy, we would not have Hawaiian honeycreepers or Darwin’s finches; distant islands would be sans all landbirds. Perhaps phenomena like “reverse migration” and this pioneering thing will allow the next wave of adaption to a changing climate. Of course, never before in the history of life on earth, has this change occurred so rapidly, and we have little evidence suggesting long-distant migrants can adapt this quickly – it’s going to take more than a few individuals of 10 species of warblers.

Sparrows, however, aren’t obligate long-distance migrants that are “programmed” to leave at a prescribed time. Instead, they are more flexible in their movements, and being seed-eaters, they aren’t reliant on warm-weather dependent insects. As long as seeds are available, and with the complete dearth of snow, they most certainly have been, those that linger can do just fine. White-throated, American Tree, Song, and Dark-eyed Juncos are all regular parts of our winter avifauna in southern Maine, lingering or “pioneering” Swamp Sparrows are regular here and there, and every now and then a Lark Sparrow (a “drift migrant/vagrant” from the Midwest) or Field Sparrow spends the winter in the state. Field and Clay-colored are also rare-but-regular in late fall/early winter, so once again, the presence of 10 species of sparrows is also not in and of itself caused by the record temperatures, but it is most definitely another sign of how mild – and especially snow-free – it has been.

But this is all a blog for another time…this blog was supposed to be about warblers (and sparrows!). In Maine. In December. And that’s amazing. Or, as Luke said, “What. The. (Expletive deleted).”