The chronic toxicity of 3-chloro-4-methyl benzamine HCl to birds

Abstract

3-Chloro-4-methyl benzamine HCl (DRC-1339), an avian toxicant, was fed to five species of birds for periods up to 120 days. The 30-day LC50 of uniformly treated feed for starlings was 4.7 ppm and the 90-day LC50 was 1.0 ppm. The 28-day LC50 for coturnix was 18 ppm. The 30-day LC50 for pigeons was less than 100 ppm. Pheasants fed diets containing 2% DRC-1339 baits diluted to a rate of 286 ppm of DRC-1339 died within 22 days. Bobwhite quail fed similar diets suffered some mortality at levels as low as 2.9 ppm, but most survived 10 times this dosage level for the 120-day test period. Application of the Kenaga "Index of Chronicity", resulted in the conclusion that DRC-1339 was cumulatively toxic to birds. Reproduction in coturnix was adversely affectd by treatments at 10 ppm of DRC-1339 and above. Reproduction in pigeons was adversely affectd by a treatment of 25 ppm. In coturnix, DRC-1339 caused an increased incidence of egg breakage and decreased both egg and live chick production. In pigeons, DRC-1339 caused an increase in the proportion of infertile eggs. Reproductive ability to first generation offspring was not affected when parent coturnix and pigeons were fed DRC-1339. These data emphasize the need for care in the use of DRC-1339. The bait should be used only as registered and care exercised in storage and disposal of unused baits to avoid poisoning of nontarget species.

Probabilistic model for estimating field mortality of target and non‐target bird populations when simultaneously exposed to avicide bait

“…In modeling these multiple day exposures, the cumulative toxic effect (ie cellular damage) was estimated as the sum of absorbed doses from previous days plus the dose for that day. The fraction of dose absorbed for previous exposures was calculated from European starling ( Sturnus vulgaris L) CPTH chronic toxicity studies 14. Even though nearly all of the ingested CPTH is excreted within 6 h post‐exposure,15 the cumulative effect of toxicity suggests that the cellular damage is irreversible or very slowly repaired.…”

“…Regression parameters derived for Table 1 were calculated on the basis of data presented by Schaefer et al 14 In that study, seven groups of ten starlings each were fed diets fortified with CPTH at levels ranging from 1 to 40 mg kg −1 until all birds died. Mean time to death for each treatment group ranged from 7.2 to 77 days.…”

Including ecotoxic impacts on warm‐blooded predators in life cycle impact assessment

“…Although a few studies are available on chronic toxicity data for warm-blooded species (e.g. Haag et al (1950), Schafer et al (1977) and Stomer (1970)), we used acute toxicity values (LD 50) to calculate effect factors, because the vast majority o f the experimental data available is based on short-term tests. However, chronic toxicity values are probably closer to the wild life situation.…”

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

“…DRC‐1339 is highly (LD 50 = 10–50 mg kg −1 ) to moderately toxic (LD 50 = 51–500 mg kg −1 ) to most sparrows, finches and waterfowl. However, repeated exposure to sublethal doses of DRC‐1339 can result in death for resistant birds as well 13. DRC‐1339 does not appear to affect reproduction except at levels very close to those where toxicity is expressed 13, 14.…”

“…However, repeated exposure to sublethal doses of DRC‐1339 can result in death for resistant birds as well 13. DRC‐1339 does not appear to affect reproduction except at levels very close to those where toxicity is expressed 13, 14. A single DRC‐1339‐baited rice grain is sufficient to kill smaller susceptible birds, but larger birds, such as pheasants, might need to eat 25 treated seeds to obtain a lethal dose 15.…”