Ra. Brewer et al., TOXICITY, SURVIVABILITY, AND ACTIVITY PATTERNS OF NORTHERN BOBWHITE QUAIL DOSED WITH THE INSECTICIDE TERBUFOS, Environmental toxicology and chemistry, 15(5), 1996, pp. 750-753
The effects of the organophosphorus insecticide terbufos on laboratory
-reared and wild northern bobwhites (Colinus virginianus) were investi
gated in laboratory dosing studies and dose-release field trials. Labo
ratory studies yielded a terbufos LD50 of 24.4 mg/kg-body weight (bw).
All mortalities occurred within the first 24 h post-dose. Wild bobwhi
tes were trapped, administered 0, 3, 5.6, or 21 mg/kg-bw terbufos by o
ral intubation, released at their trapping site, and monitored for 14
d. Mortality, activity, and locational data were recorded. Bobwhites t
reated with 21 mg/kg-bw terbufos had significantly lower survival (p =
0.04) than control birds, while survival at the lower doses was unaff
ected. No significant differences (p = 0.06) were detected in physical
activity among treatments. The 21-mg/kg-bw dose yields an anticipated
37% mortality (or LD37) when interpolated from the LD50 slope equatio
n. After adjustment for control mortality, the 21-mg/kg-bw dose led to
44% mortality in wild bobwhites. This was a 7% higher mortality than
predicted by interpolation from the laboratory generated LD50. These r
esults indicate that there was not a substantial increase in mortality
of wild bobwhites compared to laboratory-reared bobwhites at nonletha
l or lethal, sub-LD50, doses.