Impacts of carbofuran on birds in Canada and the United State - Carbofuran and Wildlife Poisoning: Global Perspectives and Forensic Approaches - page 216

to which carbofuran belongs in the United States), then legally this use of carbofuran would be
a misuse even if the farmer otherwise applied the pesticide properly. Alternatively, the planting
machinery may have been used incorrectly, or it was not of the recommended type; or it may have
been used correctly but still left visible granules on the surface, a label violation. A study by the
Bayer Corporation (Fischer and Best 1995) showed that the presence of surface granules was lin-
early related to application rate, despite the use of the most up-to-date application equipment (e.g.,
T-band applicator). There is evidence that the ability of pesticide users to adequately follow label
instructions, calibrate their machinery, and actually apply the proper rates of chemicals is extremely
variable (Mineau and Clark 2008). Also, agricultural machinery is quite variable when it comes to
effi ciently incorporating granular formulations into soil (Mineau and Clark 2008). Indeed, if one
were to take the product labels to the letter, all carbofuran applications would classify as misuses.
For example, the labels for granular products used to state:
Keep out of areas inhabited by fi sh, birds and wildlife as this product is highly toxic
to such animal.
We separate the kills into the following groups, which refl ect two different modes of granule
uptake:
1) Selective uptake of granules or uptake of granules sticking to earthworms or other inverte-
brates, usually by small songbirds; and
2) Uptake of granules and drinking of contaminated water from puddles or fl ooded areas.
Waterfowl are often implicated, although any bird is potentially at risk. The larger body size
of waterfowl species makes them easier to fi nd .
8.2.2.1 Kills resulting from selective granule uptake
Available data indicate that most kills associated with selective granule uptake occurred in treated
cornfi elds. This does not refl ect a higher inherent risk from carbofuran in corn, but rather the total
area planted to corn relative to other crops in the United States and in Canada. The labeled applica-
tion rate (in grams ai/ha) for corn is similar in both countries.
8.2.2.1.2 1972-1973, corn, Wisconsin
According to Hickey (1976), growers began reporting dead sparrows soon after the US EPA registered
carbofuran for use on corn rootworm (Family Chrysomelidae ), but those reports quickly diminished.
This suggests that farmers may have come to consider these kills as a 'normal' consequence of
carbofuran use. In our many years of investigating die-offs related to carbofuran, we have often
encountered people who consider that a government registration of the pesticide indicates that it
is 'safe'.
Kleinert (1974) reported results from cursory surveys of 77 fi elds treated with Furadan 10G,
either as an incorporated band or in-furrow. This type of low-intensity survey generally has a very
low power to detect carcasses (Mineau and Collins 1988). Nevertheless, the fi eld personnel recov-
ered 13 dead songbirds and four dead small mammals (identifi ed only as 'fi eld mice').
8.2.2.1.3 21 May 1979, corn, New York
Ten American robins ( Turdus migratorius ) were found on the edge of a freshly planted cornfi eld
treated with granular carbofuran. Some robin tissue (the report does not specify if from a pooled
sample or a single bird) contained 10 ppm carbofuran in the gastrointestinal tract and 1 ppm in the
liver (Kinsinger and Lusskin 1980; Stone 1981, 1985).