Wild Ideas: The mysteries of mast

With the holidays just around the corner, many of us may be looking forward to sharing the holidays with friends and families, perhaps cozied up to a warm fire in our fireplaces, and eating . . . and eating. However, for wildlife, finding food can be tough this time of year, and apparent shortages of some mast crops could add more stress this year.

While northern cardinals, such as the male at the feeder above, are well adapted to finding sufficient food here in Virginia in the winter, this year it may be a bit harder in some areas, according to anecdotal reports.Torindkfl via Wikimedia
While northern cardinals, such as the male at the feeder above, are well adapted to finding sufficient food here in Virginia in the winter, this year it may be a bit harder in some areas, according to anecdotal reports.

The day after the recent ice storm, I was working in my living room when suddenly an eastern phoebe began hover-gleaning just outside my window. Suspended in mid-air, it was looking for invertebrates caught in spider webs or sheltering under the eaves. When it found what it was looking for, it suddenly dived up under the eaves and flew off with its prize.

I’d thought the last of the phoebes had drifted through on their way south, so seeing this bird amid the snow and ice was a surprise. Considering its late arrival here, it was probably coming through from the Great White North on its way south. It may not have much further to go, since the northern edge of the eastern phoebe’s winter range is along the Virginia-North Carolina border.

Eastern phoebes are one of the first bird species to arrive here to breed in the spring and one of the last to leave in the fall. (To see the pattern of their migration on an interactive, animated map, search on the web for “eastern phoebe migration ebird,” which should turn up a link to such a map on eBird.org.)

In the flycatcher bird family, eastern phoebes are primarily invertebrate eaters but, like most birds, can make do with foods when their preferred food is not available. In the case of eastern phoebes, the alternative consists of berries and small seeds, which are among the mast crops wildlife depend upon. Mast is the fruit (with seed inside) produced by trees and shrubs that is eaten by wildlife. Because of their hard shells, acorns and nuts are considered “hard mast,” while berries, cherries and other soft fruit make up “soft mast.”

This year, finding enough suitable mast may be a problem for wildlife in some areas. I’ve noticed where I live many native plants, such as dogwood and grapes, did not produce mast this summer. I thought that this lack of fruiting was just a problem on the property where I live, but some other Rappahannock County residents have reported similar lack of mast on their properties from winterberry, dogwood and persimmon.

Acorn production is definitely down this year across the state, as mentioned in a recent Rappahannock News editorial. According to a Nov. 18 Virginia Department of Game and Inland Fisheries (VDGIF) press release, “Many reports from various parts of the Commonwealth indicate that the acorn crop this fall is very light.”

VDGIF chalks this up mostly to weather: “Most flowers seem to be aborted between the time of initiation and pollination. Late spring freezes and high humidity during pollination are primary causes (we experienced both of these over much of Virginia in 2013). Later, immature acorns can be lost due to summer droughts, high temperatures or insect predation.”

One of the first bird species to show up to breed in the spring and one of the last to leave, eastern phoebes are often seen hunting bugs here as late as December.Pheanix via Wikimedia
One of the first bird species to show up to breed in the spring and one of the last to leave, eastern phoebes are often seen hunting bugs here as late as December.

The VDGIF release indicates that the emergence of periodical cicadas is unlikely to be a factor in the acorn bust this year. Like the cicadas, oaks tend to be highly cyclical in their reproduction, depending on the species of oak. We’ve had good crops in recent years. In fact, in 2010 we had a bumper crop, as I wrote in my column on Oct. 28, 2010. The last big downturn was in 2008. Oaks are thought to have evolved this boom-or-bust cycle to keep ahead of predators, much like periodical cicadas have.

I’ve also heard reports of low production by hickory and walnut trees in some areas of the county, which was also the case up here on the mountain where I live. The problem doesn’t seem to be that mast is getting eaten more quickly by wildlife, but that there just wasn’t a lot produced.

From cruising around the web, I’ve found little about soft mast being a problem outside of Rappahannock. And some hard mast, such as beechnut, seems to be doing fine in many areas, including Roanoke (according to Roanoke.com).

I’ve contacted some scientists in my network to see what might be affecting soft-mass crops here. I haven’t heard back yet but will report whatever I find in this column when I do.

Since the icy weather began, I’ve been watching tufted titmice and northern cardinals carefully examining seemingly bare tree branches around my yard and wonder if they’re seeing food where I am not. Our overwintering native birds tend to be resilient and resourceful and normally don’t need us to put out food for them. However, this year they might really appreciate it.

Virginia Wildlife goes digital

VDGIF has just announced that all 62 years of its magazine, Virginia Wildlife, are now digitally archived. The issues run from January 1959 through December 2012 and cover hunting, fishing, boating and wildlife issues in the state. As a press release by the department puts it, the Virginia Wildlife archive “holds a wealth of information, historical facts, incredible photographs, maps and some of the finest wild game and fish recipes to be found anywhere.”

The issues were scanned in, through the LYRASIS Digitization Collaborative — a Sloan Foundation grant-subsidized program for libraries and cultural institutions. The digitized versions are available in a variety of formats and searchable full-text versions. To view the collections, visit   archive.org/details/libraryofvirginia (or dgif.virginia.gov/virginia-wildlife for a direct link).

Pam Owen
About Pam Owen 286 Articles

Writer, editor, photographer, and passionate nature conservationist living in Rappahannock County, in the Blue Ridge Mountains of Virginia. Two favorite quotes: By E.O. Wilson, who coined the term “biodiversity,” “Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction”; by Douglas Adams, “I love deadlines. I love the whooshing sound they make as they pass by.”