Baiting blackbirds (Icteridae) in stubble grain fields during spring migration in South Dakota

Abstract

Blackbirds (Icteridae) annually damage US$5-8 million of ripening sunflower in the northern Great Plains. Baiting blackbirds with avicide-treated rice during spring migration might reduce the regional breeding population. In March and April 1996-1997, we simulated a baiting program in eastern South Dakota to compare attractiveness of rice-baited plots placed in fields of corn and soybean stubble. Blackbirds used plots in corn stubble more often than plots in soybean stubble and chose rice-baited plots over unbaited reference plots. We conclude that blackbirds can be successfully baited with avicide-treated rice placed in corn stubble. r

Non‐target organism risk assessment of MIR604 maize expressing mCry3A for control of corn rootworm

“…1999). Blackbirds are also common in maize stubble where they forage for spilled kernels and weed seeds (Linz et al. 2003).…”

“…Blackbirds typically slit open husks with their bills and puncture kernels in the milk stage (Steffey et al 1999). Blackbirds are also common in maize stubble where they forage for spilled kernels and weed seeds (Linz et al 2003). Therefore, the concentration of mCry3A in kernels was used to estimate the exposure of wild birds to mCry3A via cultivation of MIR604 maize.…”

Attractiveness of brown rice baits to non‐target birds in harvested corn and soybean fields

“…During the 1980s, DRC‐1339‐baited rice was successfully developed for baiting blackbirds in Louisiana to protect sprouting rice 8. In the following decade, DRC‐1339‐baited rice was used to develop baiting strategies for reducing the number of spring‐migrating blackbirds in North Dakota and South Dakota 5. The only two quantitative studies conducted in our study area showed that non‐blackbird (non‐target) use of rice‐baited plots in harvested corn fields was low 9, 10.…”

“…The study area was in Brookings, Miner and Lake counties in eastern South Dakota. This area was chosen because it is considered to be the most northern region where migrating flocks of blackbirds are large enough to warrant a baiting program 5. Eastern South Dakota lies in the Coteau Des Prairies physiographic region in the Central Lowland province 16.…”

“…In response, the US Department of Agriculture is investigating the compound DRC‐1339 (3‐chloro‐4‐methylaniline, 3‐chloro‐ p ‐toluidine hydrochloride) as a potential tool for managing spring‐migrating blackbird populations. This research is concentrated south of the main sunflower‐growing areas of North Dakota and northern South Dakota where large concentrations of blackbirds are found prior to breaking up into progressively smaller groups as they migrate to breeding areas 5. Reducing the size of this regional population during spring, prior to the breeding effort, might be an effective solution for reducing blackbird damage to sunflower 5…”