A recent report from the Cornell Laboratory of Ornithology scientifically supports general observations that lots of people working with the Emerald Ash Borer have anecdotally observed: Emerald Ash Borer invasion into an area increases the numbers of woodpeckers. Walter Koenig, a senior researcher at the Cornell Lab led the study which used data from multiple years of the labs citizen-science program known as Project Feeder Watch. They compared changes in populations in areas with and without EAB infestations for several species of birds. The study revealed that woodpeckers in general, but especially Red-bellied Woodpeckers and White-breasted Nuthatches (not a woodpecker, but slightly similar feeding) increased significantly in areas with high concentrations of EAB. They noted that the infestations did not draw birds into the area, but increased reproduction and survivability of the birds broods gradually increasing numbers over a year or two.
The good news is that some woodpecker activity reduced the number of EAB larvae by up to 44 percent a huge impact. Unfortunately, EAB can produce up to 60,000 larvae in one tree, so that would still leave more than 30,000 larvae to grow, mature and spread to other ash trees. With no other native predators to assist them, the woodpeckers will likely never be able to fully control EAB. Perhaps however, the combined work of woodpeckers in concert with the parasitic wasps we are introducing at Cedar Bog could have a greater effect. We can only keep trying and hope.
See our blog from August 13, 2013 and an earlier one from May 29, 2012 which detail our wasp introductions with the help of the USDA. Click here for the full story from the Cornell Laboratory of Ornithology.
Bob Glotzhober
Senior Curator of Natural History
