BC blueberry growers lose millions of dollars each year to starling damage. These prolific and invasive birds descend on berry fields to eat the ripe fruit, causing significant damage.
Noisemakers, nets, trapping, and chemicals are tools in the arsenal of the blueberry grower for starling control, but often these solutions are incomplete, costly, and controversial. Karen Steensma, biologist, farmer, and professor at Trinity Western University, is working with farmers in BC and Washington State to re-build kestrel populations in agricultural areas and assess their potential as a natural deterrent to starlings and other pest birds.
Kestrels are the smallest falcon in North America, and the only native birds of prey that will adopt a nest box. They inhabit open fields or forest edges, and feed on insects, rodents and small birds. The small raptors are fiercely territorial and have shown promise as effective competitors against starlings in some US cherry orchards. Once kestrels are established, a single nesting pair may protect up to 10 acres.
The project started by putting up over 100 nest boxes adjoining blueberry fields in the Fraser Valley, and Whatcom and Skagit Counties, but it was clear that just providing boxes wasn’t enough. “In working with biologists, falconers, farmers and scientists on both sides of border, we found that the background populations in this region were so low that it would take years before we could get a good level of occupancy,” says Steensma.
To start building the population up, they imported young, orphaned birds from other parts of the US. Steensma and her team have released 21 kestrels south of the border since 2008, and now the birds are starting to use nest boxes in those areas. The study has also mapped land-use patterns for the region to determine where kestrels are most likely to succeed.
“The birds need habitat to nest, as well as ways to make a living – to obtain food,” says Steensma. “The young kestrels practice on flies, bees and dragonflies. That’s part of their diet. Having small rodents in the grass and the insects present, all of that makes it likely they will nest.”
Funding: $8,000 through the Agri-Food Futures Fund. (AEWF 09-023)
