Can Ontario’s Birds Help Fight the Emerald Ash Borer?

​The emerald ash borer (EAB) needs little introduction to Ontario residents. This infamous pest is one of the most notorious in the area and is thought to have been responsible for the death of millions of ash trees throughout Ontario. Originating from Asia, the destructive and dangerous pest is believed to have arrived in North America in 2002. While it brought terror to every ecosystem it infected for many years, recently it has been in the news for new reasons. The long battle to mitigate their impact has often been more failure than success, but now there’s a reason to believe that forest birds have a big role to play in controlling their numbers. For the first time, there’s genuine hope that a natural predator can help keep EAB numbers down.

Signs of EAB in a Tree

​The emerald ash borer tends to primarily attack ash trees. Once adult insects have identified a suitable tree, they mate and lay their eggs on the tree bark. Hatchlings are born hungry and begin to burrow themselves inside the tree, in search of food. They’ll feed on nutrient-rich ash tree tissue, but this is devastating for the tree. 
 
The delicate tissue which transfers water and nutrients throughout the tree is disrupted and damaged, and the tree suffers greatly. The leaves which need the water and nutrition to remain healthy begin to wilt and die. Therefore, the single most obvious indication of EAB infestation is canopy thinning, which will eventually lead to branches dying completely and falling from the tree. You’ll also find split bark, D-shaped exit holes, unusual branch sprouting, and more significantly, woodpecker marks.

What Role Do Birds Play? 

​Ironically, EAB and their larvae can also be nutritious food for other animals – none more so than birds. These birds are primarily woodpeckers (three different species) and nuthatches. Woodpeckers work their way up and down the length of a tree, looking for many different types of insect to feed on. When EAB infest a tree, they do so in great numbers: woodpeckers looking for a good feed are attracted to ash trees in particular for their high concentration of nutritious insects.
 
Studies have shown that in any given forest, woodpeckers will spend more time working on ash trees because of this. Remarkably, EAB-eating birds will also identify trees which are in the poorest state of health and begin there: the greater the decline in the tree, the more beetles there are likely to be.

Can Birds Really Help Control EAB? 

Despite this, many thousand ash trees are still perishing throughout Ontario. Although woodpeckers and other EAB-consuming birds are eating beetles and reducing the numbers, they are doing so in already-infested trees. Many of the trees they hunt in are beyond the point of recovery, and so the trees are still dying. 
 
That being said, up to 85% fewer adult emerald ash borers will leave that infested tree in search of a new one. Although the current tree hasn’t been saved, fewer pests are able to leave the tree and infest new trees in the surrounding area. These birds may not be able to save the trees, but it seems that they can finally provide a control measure in the battle against these notorious pests.
 
If you suspect that your tree is infested, call one of our expert technicians at Martin’s Tree Services straight away. The sooner we identify an EAB infestation, the quicker we can help to remove it. Our full protection plan will inspect, assess and treat your tree before the damage becomes too great to repair. Even if it isn’t the suspected EAB infestation, we’ll still be able to diagnose the problem and improve the health of your tree.