Vertebrate pest specialist, Nevada State Department of Agriculture, Reno, NV
Pages: 6 Published: Jan 1988
Strychnine chopped cabbage bait has been used to control ground squirrels (Spermophilus spp.) in Nevada since 1975. The amount of bait present in the gastrointestinal tract of poisoned ground squirrels is unknown. One hundred forty-two stomachs of poisoned Richardson ground squirrels (S. richardsoni nevadenisis) were analyzed for strychnine. Strychnine averaged 2.3 mg (s = 2.4 mg, range 0.1 to 19.1 mg). In relation to kg bodyweight, strychnine averaged 13.0 mg/kg (s = 11.4 mg/kg, range 0.2 to 64.1 mg/kg).
Ground squirrel age, sex, body weight, and bait strength influenced (P < 0.05) strychnine mg. Age, bait strength (P < 0.01), and application rate (P < 0.005) influenced strychnine mg/kg.
Wide ranges in mg and mg/kg values may be due to other factors in addition to the variables examined. These factors include: bait distribution pattern, length of bait exposure, and susceptibility to strychnine.
Reducing application rate and bait strength lowered mg and mg/kg. Burrow baiting with 0.3% strychnine bait, 15 g per burrow, produced highest or intermediate levels of mg and mg/kg when compared to broadcast applications of 0.3% bait at 2.8 kg and 5.6 kg/ha.
ground squirrels, Spermophilus spp., strychnine, bait, nontarget, hazard, S. richardsoni nevadensis
Paper ID: STP26173S