Pest Management


JUDIE STEEVES Starling origin study continues


More bone-gathering needed to build on the success of trace element tracking.


By Judie Steeves R


esearch into the origin of the starlings that congregate in the Okanagan and Similkameen Valleys and devastate grapes and tree fruits, will continue this year, with a new grad student picking up where Jessi Neuhauser of UBCO left off when she wrote her thesis on them in 2013.


That paper reported that most of this region’s starlings had immigrated from elsewhere, but not enough data was available to determine from where they came.


Neuhauser learned that use of trace element analysis on the bones of starlings can lead to identification of their birthplace, due to geographic differences detectable in those tissues. Such chemical fingerprinting can identify their origins because of


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“differences in geology, climate, vegetation and food webs which is expressed in their tissues.


“Stable isotopes and trace elements are powerful tools that eliminate many of the inefficiencies of other techniques of tracking movement patterns,” she reported. Such a tool is


particularly useful in B.C. because it is geochemically diverse from one region to another.


Neuhauser reported that “Using trace elements in bone to trace origins of migrant species has never been done before.” She concluded that her study demonstrated the success of using trace


So, this year’s study will begin by collecting starling bones from more geographic areas. As well, starlings from throughout the Okanagan will be collected to determine whether their ‘fingerprints’ vary, and whether they are similar to the previous study year, 2010.


Connie Bielert


elements in bone to track small scale movements of the starlings with good precision.


However, the limitation she found with her study was not having enough bird bone samples from a diverse area to compare their ‘fingerprints’ to the Okanagan starling populations to determine where they were all born.


British Columbia FRUIT GROWER • Spring 2015


Starlings are an invasive species that were introduced to North America in the late 19th century. They are now firmly established throughout the continent and are one of the world’s 100 worst invasive species. Not only are they one of the most damaging pests of agriculture, they are also ecologically destructive,


forcing native songbirds from their nests and destroying their eggs. Between 2003 and 2013 nearly 544,000 birds were trapped and euthanized under the B.C. Grapegrowers’ Association starling control program, but Neuhauser reports the population is still believed to be increasing.


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