Mast Year — Live Oaks

Live oak trees (Quercus virginiana) have been producing so many acorns this year that Florida Today has written a story about it.  Live oaks produce acorns every year, but, when they produce an especial abundance, a “bumper crop”, it is called a mast year.

Some biologists speculate that live oaks (and other trees) produce an overabundance of fruits every few years to assure that predators do not consume all of their potential progeny.  This theory is known as the satiation hypothesis.

Acorns are an important source of food for wildlife, including bears, deer, wild pigs, raccoons, rats, turkey, blue jays, and, of course, squirrels.  Blue jays and squirrels cache (hide) many acorns, often forgetting just where, which does allow for some germination.

Florida is home to 24 species of oaks with different soil and nutritional requirements.  At the Oslo Riverfront Conservation (ORCA), you will see lots of live oaks and some laurel oaks (Quercus laurifolia) in wetter places.  In dry places at the ORCA grow “scrub oaks”, smaller stature oaks adapted to very dry, sandy soils.  Endemic Florida scrub-jays are not found at ORCA, but these birds are thought to recall where they have cached scrub oak acorns and to retrieve most of them.

An average acorn contains about 4 calories.  Live oak acorns are like people; They vary in size and in shape.  Some are smaller, or rounder, or more tapered.

Mast production can be synchronized over hundreds of miles but never is countrywide.  Research conducted at Archbold Biological Station by Bucknell Professor Emeritus Warren Abrahamson found that mast production varies by species and is the result of many factors:  “It could be rain that occurred even three years before”.

Many biologists also conjecture that hurricanes (and other stresses) trigger mast production.  Hurricanes Matthew and Irma?

Whatever the reason, live oak acorn production remains in overdrive, and I am enjoying bringing home plenty of acorns for our bird feeder for the blue jays and squirrels.  Delta Dawn Dog decided that acorns were not palatable …