Area squirrels are scouring bird feeders, gardens and even the trash due to the lack of acorns this year. Oak trees from Rutherford to Kansas and beyond have produced a noticeably smaller number of acorns this year than in years past. Experts contend that it’s part of the natural ebb and flow of nature.

Tall pin oaks line Jackson Avenue from West Passaic Avenue to the railroad tracks in Rutherford. Borough Shade Tree Commissioner John Tagliabue notes that the annual tradition of being hit in the head with falling acorns on the street has taken a hiatus. "Last year, there was a huge amount of acorns around. This year, there’s not many," he said.

One borough landscaper said he cleaned up hardly any acorns from lawns this year and Tim Stanton, a Rutherford resident who is in the business of removing dead trees, noticed the absence of acorns as well.

Many like Tagliabue and Stanton attribute the light year for acorns to a natural progression, but some, like Tagliabue, were surprised to find out that the lack of acorns extends as far as upstate New York, Pennsylvania, Virginia and even Kansas.

Tree experts and enthusiasts have taken notice, but few are absolutely sure why.

Acorns are the fruit of oak trees and like any other fruit, be it apples or oranges, acorns contain seeds which sprout new trees. In addition to allowing trees to reproduce, acorns are a vital food source for many animals. In South Bergen and other urban areas, this means squirrels.

For South Bergen residents, a year without acorns simply means less yard work. From the tree’s point of view, it is not reproducing and if this were to continue for years, it could spell trouble for oak tree populations.

Most tree experts and enthusiasts believe the absence of acorns is part of the natural ebb and flow of the fruits in nature. "I have observed that it’s an off year for acorns, but I think it’s part of a natural progression. It’s something that happens pretty regularly," said Tagliabue. "Usually they vary from year to year."

Stanton, who describes himself as a tree "undertaker" and stresses that he is no arborist, agreed. "Apparently, it’s a mast year and it happens from time to time," he said. "The old folks say it’s indicative of a very harsh winter."

The 2008-2009 The Old Farmer’s Almanac did not make any reference to a lack of acorns, but did indicate that the northeast will experience a cold, snowy winter.

Stanton pointed out that when under duress, oaks produce more seeds, so the lack of acorns should not cause any alarm. "When they sense their demise, they want to propagate," he said.

One theory Stanton sought to stay away from is the notion that the lack of acorns could relate to global warming. "It certainly doesn’t tie into global warming, because that’s nonsense," he said. "If anything, it’s global cooling."

Another theory regarding missing acorns could be the particularly wet spring in the northeast. Acorns grow when oak trees are pollinated and acorns might not grow if rain washes pollen down storm drains.

The absence of acorns across the northeast and beyond makes this theory unlikely, added Tagliabue. A widespread absence of acorns is unusual for oaks and could mean the trees have an undiscovered fungal disease.

Another theory regarding the absence of acorns is that environmental factors can trigger them to produce less fruit in order to control the population of animals that eat them. "It’s believed that oaks do it intentionally as a survival mechanism," said Tagliabue.

A German zoologist, Bernd Heinrich, theorized that oaks could chemically communicate with one another through their roots and, as a unit, not produce acorns in a particular year. In the same way that oaks might produce fewer acorns to control squirrel population in a given year, oaks might produce a bounty of acorns to ensure the survival of the next generation.

Some trees, such as red oaks, only produce acorns every other year. Arborists refer to years when a large amount of acorns are produced as "bumper crops," according to Tagliabue.