It's a bonanza: From many acorns mighty squirrels grow

By Janet Hefler
Published: November 19, 2009

They're dropping from oak trees like raindrops, crunching underfoot on driveways, decks, and walks, and have hoarding squirrels scrambling in a combination feast and frenzy.

Black oak acorn.

Acorns appear plentiful this year, and Timothy Boland, Polly Hill Arboretum's executive director, affirms there is indeed a bumper crop. In the oak tree world, 2009 is a "Mast Year," he said, when several conditions that affect acorn production have been just right.

Oak tree flowers have no petals and are structured primarily for wind pollination, Mr. Boland explained. Last spring, in synchronicity with their environment, oak trees produced an abundance of flowers during a period of relatively dry weather, which provided good conditions for pollen spreading through the wind and being picked up through the flowers.

Acorn production was boosted by ample rainfall during and at the end of summer, when acorns sometimes drop off if trees did not get enough moisture over the year. "So the oak trees had dry weather during the pollen season, and then they had the energy reserves to produce good acorns," Mr. Boland said.

White oak acorn.

There are two general types of oak trees on the Island, the black or red oak group, and the white oak group, he explained. In the black or red oak group, scarlet oak, which has red leaves and the best fall color among the oaks, is probably the least common on Martha's Vineyard, Mr. Boland said. "They're beautiful trees, and it's interesting that if you go to Cape Cod and you head up Route 25,

you'll see thousands of scarlet oaks, but for some reason, they're not as well established here," he added.

The most dominant Island oak tree is the black oak, followed by the scrub oak. The white oak group includes white oak, post oak, and dwarf chinkapin oak.

Although not highly prized for their appearance, scrub oaks historically played a special role on Martha's Vineyard, Mr. Boland said. As a botanist who specializes in oak trees, he shared some of that history in a presentation on the Island's oak diversity and ecology at the International Oak Society's triennial meeting on October 22 in Puebla, Mexico, attended by 125 people from 15 countries.

Scrub oak acorn.

Mr. Boland reviewed the Vineyard's oak species, including two new hybrids discovered as part of the arboretum's fieldwork on the Island's flora. He also discussed a new research collaborative initiated with the Harvard Forest.

"One of the interesting aspects of Martha's Vineyard, as I told them, is that originally the [Manuel F. Correllus] State Forest was founded to protect the heath hen," Mr. Boland said. "Although the heath hen went extinct, one of its main foods was scrub oak. And one of the areas it would nest in was the scrub oak, because it was so dense and afforded good protection. So, both the acorns and structure of the group of oaks were really the dependent food source for the heath hen."

Scarlet oak acorn.

Heath hens were one of the first bird species Americans tried to save from extinction, raising awareness for conservation of other species.

Although the last Vineyard heath hen reportedly died in 1932, a large Island population of squirrels has been more than happy to take over the small game bird's acorn consuming duties.

Despite their reputations as gluttons, squirrels do have discerning palates. With this year's veritable acorn smorgasbord, they like the white oak offerings the best, Mr. Boland said. Black oak acorns will remain on the ground the longest. "They're pretty much the very last thing that the squirrels and other animals will eat, because they're loaded with a substance called tannin, and they're extraordinarily bitter," he explained.

Does that mean lazy squirrels will get stuck with the black oak acorns? "Yeah, if they don't get out there, they're going to end up with the Stouffers food of the oak world," Mr. Boland said with a laugh.

Tim Boland. File Photo by Ralph Stewart

How does that acorn saying go?

An online search for a seemingly familiar quote about acorns and oak trees revealed not just one but many variations on the same theme.

WorldofQuotes.com attributes the quote, "Tall oaks from little acorns grow" to David Everett in "Lines for a School Declamation."

However, on further examination, his observation was not the first, nor the last, among a list of quotations the website offered about oak trees.

Apparently Lewis Duncombe was on the same wavelength as Mr. Everett, when he wrote, "The lofty oak from a small acorn grows," in his "Translation of De Minimis Maxima."

Other similar versions are listed as proverbs, by nationality.

"From little acorns mighty oaks do grow" is attributed as an American proverb, while the German saying is, "Great oaks from little acorns grow." The Polish version provides a combination of both, "The greatest oaks have been little acorns."

So there appears to be at least one idea that people all over the world can agree on: big trees grow from acorns. It's a start.

With so many acorns available, squirrels and other animals bury them in caches. And just like people over 40 with eyeglasses, they often forget where they put them.

"But burying acorns helps them sprout, and hopefully we'll see a regeneration of some of our oaks that we've lost from caterpillars over the last few years," Mr. Boland said. There is a cyclic nature to acorn abundance, he added, and in the seven years he's been on the Island, this is the second strong acorn year he's witnessed.

Those looking for a reprieve from the acorn ground cover will have to wait awhile. Although the scrub oaks had very good acorn production, many are located in frost bottom areas and dropped their acorns fairly early, after a hard frost about two to three weeks ago, Mr. Boland said. In the meantime, post oaks are just now dropping their acorns.

A good year for oak trees also resulted in successful seed collection efforts by Polly Hill Arboretum. "This year we've been collecting oak seeds for some cooperative botanic gardens, which we send to them to grow in their collections, and it's been terrific," Mr. Boland said. "The seeds have been really great, particularly of post oak."