Okanagan - Similkameen Starling Control Program 2010

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1 Okanagan - Similkameen Starling Control Program 2010 Introduction European Starlings are an invasive species that was introduced to North America in the late 19th century. They are widespread & abundant throughout the continent and are listed on the World Conservation Union list of the World s 100 Worst Invasive Species. Starlings are intelligent and adaptable birds. They have few natural predators and are not susceptible to disease. They exist in almost all habitat types but are most commonly associated with human habitations. Starlings form large flocks in early fall and winter and can be seen flying from roost to field in great numbers. They may fly 50 or more kilometers from roosting to feeding sites. Flocking is beneficial to individual birds because more time can be spent foraging for food rather than looking out for predators. In addition to eating and damaging tree fruit, grape and berry crops, starlings also spread diseases such as Salmonellosis, Chlamydiosis, Johne s Disease, avian tuberculosis and histoplasmosis. Starlings are very aggressive competitors and are relentless in taking over nesting cavities that would otherwise be used by bluebirds and other native songbirds. They will take any suitable site for nesting and evict any previous owner, driving native birds from their territory. They sometimes watch other birds build a complete nest before forcing them to leave. Starlings can have two broods a year with four to five eggs in a brood. Incubation of the eggs takes 12 days and the fledglings leave the nest after 25 days. The young leave to join other juveniles and form flocks that move on to other territories. Noise deterrents, such as propane cannons or electronic distress calls, and visual repellents such as reflective tape, have been used to frighten starlings away, but these birds are so

2 tenacious that they quickly learn to ignore noise and visual scare tactics. Additionally, noise devices increase potential neighbor conflicts. Netting of fields can be effective in preventing crop loss, but it is expensive and it isn t practical for tree fruits. Some producers hire commercial falconers to assist in the control of starlings in their vineyards and orchards. This is labour intensive and very costly. Native raptor species can be effective in directly preying, or chasing starlings, but consistent presence is difficult to guarantee. Starlings cause an estimated $800 million in damage to agricultural crops in N. America annually with conservative estimates of damage to vineyards and tree fruits in the Okanagan Similkameen placed at $3.5 million annually. The Pacific Northwest An informal group of researchers, growers and others representing various regions of the Pacific North West has teamed up to exchange information on current and proposed work related to bird damage to fruit. As a result of the Okanagan Similkameen trapping program and a similar program in Whatcom County Washington, which has been underway since 1997, the BC Blueberry Council has initiated their own investigation of starling populations in British Columbia and an assessment of the feasibility of a trapping program in the lower mainland. That report has just been released. Researchers from Cornell University, Michigan State University, Oregon State University and Washington State University have submitted a five-year research proposal to the USDA Specialty Crop Research Initiative. If this project goes ahead it will look specifically at bird damage to apples, blueberries, cherries and grapes. The long-term goal of the project is to provide growers with cost-effective, environmentally sustainable methods to limit bird damage. A researcher at Trinity University in Langley has partnered with the BC Blueberry Council, the Washington Blueberry Commission and the Agriculture Environment & Wildlife Fund to investigate successful techniques for encouraging native raptors, and particularly the kestrel falcon, as potential agents of control of starlings and other pest birds around berry farms in northwest Washington and southwest British Columbia. With the help of a student the program is expanding to the Okanagan with ten kestrel nesting boxes placed in vineyards over Christmas and an additional forty boxes being placed in late February.

3 Okanagan Similkameen Starling Control Research Program The Starling Control trapping program has been ongoing since 2003 in the Okanagan Similkameen. Although trapping occurs year round, winter populations continue to increase and the origins of these migrants are unknown. Having a better understanding of the dynamics of the Okanagan starling population and determining bird origins will help focus management efforts. A key component of the Program is the investigation of the starling population dynamics under the direction of Dr. Tom Dickinson of Thompson Rivers University. The objective of this work is to determine the origins of the starlings in the Okanagan & Similkameen valleys in order to focus the trapping efforts in the most effective manner and to improve certain other starling control measures. An arrangement has been made between Thompson Rivers University (Kamloops) and the University of British Columbia Okanagan (UBCO) for the work to be carried out at UBCO. A graduate student, Jessi Neuhauser, is carrying out this research using stable isotope analysis techniques under the direction of Dr. Jeff Curtis of UBCO. Stable isotope and trace element analysis is an emerging technique that eliminates many of the inefficiencies of traditional tracking methods. The use of stable isotopes relies on internal markers and the fact that isotopic signatures are picked up (e.g. eaten) from the environment in which organisms live and are incorporated into their tissues leaving a long-term record of their previous location. These isotopic patterns or chemical fingerprints and trace element profiles vary spatially across the landscape due to a variety of biogeochemical processes. This allows using feathers and other tissues to determine the origin(s) of this migrant pest. To date Ms. Neuhauser has been working to develop sample preparation methods and analytical procedures to process the samples, as well as appropriate statistical techniques. Spring and summer 2010 focused on obtaining juvenile starling samples from six regionally distinct areas of the province to create a database of chemical fingerprints to match local birds to. The sample sites for reference have been identified based on areas of different geology and/or different drainage basins. Regions with distinct geology should be chemically distinct. The aim in choosing these reference sites is to get samples from a detection grid with a resolution of between 100 km 200 km. The sites were delineated by sectioning the province on a north-south, east-west gradient. Sites were chosen on either side of prominent geological features including the Rocky, Cariboo, Coast and Monashee Mountains. This data will be modeled to predict groupings and infer the origins of birds that make up the large winter accumulations of starlings in the Okanagan and Similkameen valleys. Once reference points are established signatures of Okanagan-Similkameen migrant birds can be compared to the library and their origin determined. Knowing the source of these migratory birds will help aid in management decisions and ultimately reduce agricultural losses associated with the starling.

4 The trappers and Ms. Neuhauser are also examining the differences in trapping results from year to year and season to season. The upcoming year will be pivotal in developing and analyzing starling data. The research program is funded through an Industrial Post-Graduate Scholarship from the National Science & Engineering Council of Canada (NSERC) as well as partnerships between the two campuses and support from the Agriculture Environment & Wildlife Fund through the British Columbia Agriculture Council. The Okanagan Similkameen s 2010 Trapping Deployment A drop trap at Marshall s feedlot in Kelowna An m-trap at a North Okanagan dairy farm The Okanagan-Similkameen Starling Control Program contracted 5 trappers to maintain sites and monitor starling populations and movement throughout the Okanagan Similkameen in 2010.

5 In 2009, for the first time in the program, a concentrated effort was made to trap starlings in the North Okanagan and that effort carried on through The trapper in the Regional District North Okanagan worked an average of 18 locations using multiple traps at select sites, setting up and baiting his traps from mid-march and operating them until early December. The weather makes trapping over the winter months very difficult in this region. The most lucrative sites included dairy farms, feedlots, some cow/calf operations and a meat by-products processing plant. The Regional District Central Okanagan was covered by one trapper focusing his efforts at Marshall s Feedlot, southeast of the Kelowna Airport. This location continues to be an integral part of the program combining with the surrounding orchards, vineyards and market gardens to attract large flocks of starlings into the area. The trapper used 4 m-traps and 1 drop trap at this site. He also responded to calls within the region setting up traps for short terms at localized hot spots. Three trappers covered the South Okanagan/Similkameen one at Southern Plus Feedlot in Oliver, one monitoring and trapping at various other sites in the Okanagan Falls/Oliver/Osoyoos area and one working the Naramata/Penticton/Kaleden area as well as the Similkameen Valley. The Southern Plus Feedlot has proven, over the years, to be an excellent location with vineyards on three sides and the Oliver Landfill to the east. This trapper uses up to 18 traps at this location. The other two trappers working in the South/ Okanagan Similkameen used a number of sites including poultry farms and open areas surrounded by vineyards/tree fruits, all with varying results. In total these two trappers covered up to 14 sites with 20 traps during the peak of the season. Warmer winter temperatures and less snow cover generally mean that trapping in the South Okanagan and Similkameen can be carried out year round. The trappers do however limit their locations during these slower months. Starling Capture Results The 2010-year proved to be very different from previous years. Historically bird captures fluctuate greatly early in the year depending upon snow cover, winter temperatures and the movement of birds. For example, in January 2009 the trapper covering the feedlot in Oliver captured over 1500 birds, while in 2010 the same trapper caught just over 300 birds, with the same number of traps. February & March 2010 also showed considerable declines from 2009 in the South Okanagan. The trappers observations indicated that during these months there were fewer and smaller flocks in flight in 2010 than in the previous year. However, once the nesting season was over and flocks began to form, the populations of starlings and the sizes of the flocks increased tremendously. It was not uncommon for the trappers to observe flocks of 2000 to 3000 birds, particularly in the South Okanagan and the North Okanagan. Producers and trappers were reporting sightings similar to the early years of the program. Consequently, the number of starling captures rose quite dramatically in all three regional districts as can be seen from Table 1. below.

6 Table 1. Quarterly Comparison of Starling Captures Reg. District Reg. District Okanagan Central Similkameen Okanagan Reg. District North Okanagan Total 1st qtr st qtr st qtr nd qtr nd qtr nd qtr rd qtr rd qtr rd qtr th qtr th qtr th qtr Total for year Total for year Total for year The three Regional Districts of the Okanagan Similkameen, various agriculture commodity organizations and the Agriculture Environment & Wildlife fund supplied funding for the 2010 trapping program. Program Successes A reduction in the use of propane cannons & other bird scaring devices. A reduction in damage to tree fruit and vineyard crops. A reduction in the cost of bird control measures for farmers.

7 What can everyone do to help the program? Identifying and blocking nest sites is effective in helping to control starlings and is something that everyone can participate in. Starlings prefer being close to human activity. For nesting sites they utilize urban & rural structures such as building ledges & crevices, birdhouses, warehouses, open rafters on sheds, barns, and other outbuildings, bathroom and dryer vents. They also use tree cavities, aggressively displacing native species. They prefer sites that are feet high and will re-use the same nest site in subsequent seasons. Check birdhouses to ensure that the entrance hole is less than 1.5 inches in diameter, that there is at least 7 inches from the entrance to the bottom of the bird house to protect the young of other species who are nesting in the house and remove all perches. To successfully block crevices seal them off using netting or screens. Wood, metal or plexi-glass strips can be placed at 45-degree angles on building ledges to prevent nesting. Kansas City was successful at reducing starling abundance by 60% in two years. The municipality adopted a policy of reducing nest sites within the city through mandatory building repair and modification to building design aimed at reducing nesting locations. Agricultural producers can reduce their own damage with an aggressive program to block & destroy nesting sites and also by keeping their farm clear of food (i.e., by burying unwanted fruit rather than dumping it on the ground). Education of the public, including farm workers, about the importance of the program and its value can help to reduce vandalism to traps. It is not uncommon for the trappers to find trap doors opened or traps propped up so that the birds can escape. For further information regarding The Starling Control Program Please contact: Connie Bielert British Columbia Grapegrowers Association toll free cbielert@nethop.net