Blackbird predation in sunflowers
Claire Kincaid¹ and Anastasia Kubinec², ¹National Sunflower Association of Canada, Carman, MB R0G 0J0 ²Manitoba Agriculture, Food and Rural Initiatives, Carman, MB R0G 0J0

Blackbird damage in Sunflower has been an ongoing production issue for many years. The severity of damage is hard to predict and variable within fields. Feeding tends to be in localized areas of fields close to roosting areas such as cattails and power lines.

Blackbird damage is quantifiable by assessing seed area missing on the head and number of heads affected within an area. In Manitoba over the last five years fields have been surveyed to assess sunflower heads for blackbird damage. Ten consecutive sunflower heads are assessed at two randomly selected sites within the fields using the ‘Bird Damage % Seed Loss’ chart. Over the five years, of the 81 fields surveyed 55% had between 1% and 30% yield loss due to blackbird feeding. At historical prices, financial losses can be over $100/acre for severely affected fields. Furthermore, the variability and unpredictability of blackbird damage became apparent as adjacent plants had differing levels of damage, and average damage was inconsistent from year to year. Implementation of mitigation techniques to harass blackbirds and reduce roosting has had limited effect as the birds adapt quickly.