Where have all the birds gone?
Wild Ideas
My usual avian winter residents have been disappearing and reappearing. Where they go and why has been a mystery.
I began comparing notes about missing birds with a few other bird watchers. One was concerned about the low numbers he was seeing at his feeders, in mixed habitat in Huntly. Another, who had naturalized his mixed-habitat property near Washington and had 10 feeders out, reported numbers that he thought were normal. Another bird watcher with open land in Slate Mills said that the numbers of individuals and species looked normal to her on a recent walk around her property, and most of the usual crowd showed up when she put out feed in preparation for the recent snowstorm.
During the second annual Christmas Bird Count here in Rappahannock, on Dec. 15, overall numbers of birds reported did not vary much from the previous year, even though rain poured down for most of the day during this year’s count. Then again, the count parameters had a changed a bit from last year, with one large property added, and one group driving around to find birds.
Here in the forest on Oventop Mountain, in Old Hollow, I’ve either been seeing plenty of the usual birds that winter here, or I see (and hear) very few, even none. In walking around in the forest, the only birds I tend to see, if any, are winter wrens hunting along the streams and brown creepers up in the trees.
Last week, with the first snowstorm of the year heading our way, I bought a small bag of bird feed and a couple of suet cakes to put in feeders on my deck, mostly to see which birds would show up and in what numbers. Feeding birds is one way to find out which ones are around, but although the consequences of feeding wild birds is often debated, the issue is poorly researched. I usually just put out feed when snow can make foraging difficult from some birds. (AllAboutBirds. org recently had a Q&A with Australian scientist Darryl Jones, author of “The Birds at My Table: Why We Feed Wild Birds and Why It Matters,” on this issue.)
Throughout the weekend, as around 10 inches of snow fell, and up to the time I filed this column on Tuesday morning (Jan. 15), most of the usual winter species slowly and intermittently came to the feeders or were foraging around in the gardens or the forest edge. These included a pair of cardinals that continually picked off the dwindling pokeberries in one garden near my bedroom.
At the feeders were American goldfinches and northern cardinals, a red-bellied woodpecker, a slate-colored junco, a tufted titmouse, a Carolina chickadee and a few whitethroated sparrows. Except for one brief period, when nine goldfinches showed up, the numbers were lower than usual, especially for juncos, although I saw at least four of the sparrows foraging in the forest edge at various times.
A winter wren and a Carolina wren also showed up for the first time this winter, both ignoring the seed but hunting for bugs — the former gleaning bugs from under the eaves and the latter hunting around the deck and porch. The last to arrive, after also being AWOL for weeks, were a white-breasted nuthatch and a downy woodpecker, although both eschewed the feeders and instead hunted for insects in the trees near the deck.
When the number of birds appeared to seemed to be peaking, I filed a report to eBird, which collects data from bird watchers and freely shares it “to power new datadriven approaches to science, conservation and education,” according to the project’s website (ebird.org). As well as occasionally contributing data, I use eBird’s database sometimes to check numbers of a particular species, but doing that for all the birds that have been AWOL frequently would take a long time, so I haven’t dived into that yet but may do so if I can find the time.
Overall, the numbers of some birds, including juncos, at the feeders and in my yard do seem lower this year, but I haven’t kept a record. Although the sudden disappearance of birds can be alarming, I am cheered every time some reappear. While their apparent comings and goings are mysterious, I doubt most bird species are in trouble here, although a few of the more vulnerable ones can be at risk this time of year. I do wonder where the birds have been going and why — and what prompts them to suddenly reappear?
When temperatures turn bitterly cold, birds can seem to disappear because they stop activity and go into temporary winter torpor. In this state, their metabolism slows down, minimizing the need to hunt for food and potentially burning off too many calories in the process. I don’t think the temperature have been cold enough for birds to resort to this survival strategy, at least not often and all at the same time, but could the heavy rains this past year have affected their behavior?
While some birds travel hundreds or thousands of miles to the south in the fall, other species may migrate much shorter distances, moving down in elevation (as juncos do here) or to other locations close by where weather or food is better. With the varying microclimates in the county and the hollows apparently receiving more rain that other parts of the county this past year, maybe the birds here have been shifting to dryer locations during deluges or other unfavorable conditions, then coming back.
I’ll keep trying to solve this intriguing mystery. In the meantime, I plan to take advantage of some of the nature activities that are scheduled, despite the iffy weather (see sidebar online at rappnews.com/wildideas). If nothing else, it will give me a chance to talk to other nature observers about the case of the missing birds. © 2019 Pam Owen
UPCOMING NATURE EVENTS
➤ VNPS Second Sunday Walk (Buck Hollow): This walk, originally scheduled for Jan. 13, was rescheduled for this Saturday (Jan. 19, 1-3 p.m.) because of the recent snowstorm. For more on this, check my Jan. 3 column. To sign up, contact the Virginia Native Plant Society’s Piedmont chapter at piedmontvnps@ gmail.com.
➤ “Winter Tree Identification Workshop” (Saturday, Jan. 19, 1-4 p.m.): Hosted by the Clifton Institute at its property north of Warrenton, this workshop provides the tools for identifying many common trees in our area this time of year, when lack of leaves on deciduous trees makes identification more difficult. On the walk, Dr. Emily Southgate, a botanist and historical ecologist who is a senior scientist at Hood College, introduces basic terminology used in tree identification and, using trees on the institute’s property as examples, shows how to use identification books and apps. The workshop focuses on native species but may include a few nonnatives. Warm, waterproof footwear is highly recommended; also useful is a hand lens, jackknife and binoculars. At 6712 Blantyre Rd., Warrenton; register at cliftoninstitute.org/events or email education associate Alison Zak at azak@ cliftoninstitute.org.
➤ “Historical Botany” talk (Sunday, Jan. 20, 2 p.m.): The VNPS Piedmont chapter kicks off this year’s Winter Speaker Series, on historical botany, with a talk by Bert Harris, executive director of the Clifton Institute. Harris explains the organization’s plans to restore the grassland ecosystem using several strategies, including burning. The talk, at Emmanuel Episcopal Church Parish Hall, 9668 Maidstone Road, Delaplane, is free, and refreshments are provided. For more information, email piedmontvnps@gmail.com. Check for the chapter’s other walks and winter talks at vnps.org/events.
➤ Night Sky Photography Workshop (Jan. 25, 6:30-8:30 p.m.): This workshop, hosted by the Clifton Institute, offers a basic introduction to equipment and techniques used in photographing the night sky. Bring cameras, instruction books and a tripod (a couple are available to borrow). At 6712 Blantyre Rd., Warrenton; register at cliftoninstitute.org/ events or email education associate Alison Zak at azak@ cliftoninstitute.org.