The economic impacts of blackbird (Icteridae) damage to sunflower in the USA

Abstract

BACKGROUND: Blackbird (Icteridae) damage to ripening sunflower (Helianthus annuus L.) has been a persistent economic issue in the USA for the last five decades. To quantify losses, we surveyed blackbird damage from 2001 to 2013 (excluding 2004) to physiologically mature sunflower in eight states: North Dakota, South Dakota, Texas, Nebraska, Minnesota, Colorado, Kansas, and Vermont. RESULTS:We pooled data gathered during the most recent 5 years (2009 to 2013) of the survey and found losses averaged $US2.5 million and $US11.3 million for confectionery and oilseed hybrids, respectively. Three states, North Dakota, South Dakota, and Nebraska, had sufficient acreage and bird damage to warrant economic analyses using a regional economic model. The average annual total (direct plus indirect) economic impact of bird damage to sunflower production for North Dakota, South Dakota, and Nebraska was $US18.7 million, $US7.3 million, and $US2.6 million, respectively. CONCLUSION:This study provides a better understanding of the broader economic implications of bird damage to sunflower by estimating the macroeconomic impacts of lost sunflower production in the region. Additionally, the findings of this study may be used to inform decisions regarding bird management policy by providing policymakers with information to determine the downstream value of bird management and the possible benefits of improved methods that further mitigate losses.

Effects of Field and Landscape Scale Habitat on Insect and Bird Damage to Sunflowers

“…Birds may also disrupt other natural trophic cascades that benefit farmers (Grass et al, 2017). Importantly, while our results indicate a net benefit of woody vegetation along field margins for both sunflower yields and avian diversity in California, sunflowers in other regions (Peer et al, 2003;Schäckermann et al, 2014;Ernst et al, 2019) suffer from economically significant bird-damage to the same crop. Therefore, we caution that land managers and scientists should consider local climate, habitat availability, agricultural practices, and avian communities before translating our findings into management changes in other regions.…”

“…After hatching, larvae remain on the face of flowers for 8 days before boring into the developing seeds where they can cause losses of 30-60% of a crop (Long et al, 2019). Birds are the predominant vertebrate pest of sunflower crops around the world (De Grazio, 1978;Schäckermann et al, 2014;Ernst et al, 2019;Long et al, 2019). In North America, and in our study area, Icterid birds and the non-native European starling (Sturnus vulgaris) cause the most damage to sunflowers because of their omnivorous diets and behavior of foraging in large flocks.…”

Bird damage to sunflower: international situation and prospects

“…The Vertebrate Pest Conference enables exchanges mainly between North American researchers specialised in this subject (Marsh, 2008). A recent study gives a numerical evaluation of the damage caused by these birds to sunflowers in terms of yield loss and indirect economic loss to the state of North Dakota (Ernst et al, 2019). In this section, we take up the main points of this study.…”

Estimation of wildlife damage from federal crop insurance data

“…Birds consume newly planted and sprouting seeds, trample crops, and contaminate fields with feces. 24,27,30,31 The paper is organized as follows. In Section 2, we describe our data sources and our method of estimation.…”

“…In their seed stages, wheat and cotton are of particular interest to a variety of birds, including blackbirds and Canada geese. Birds consume newly planted and sprouting seeds, trample crops, and contaminate fields with feces 24,27,30,31 …”