Comparison of Bait Markers for Black Rats

Rodenticides are a necessary part of successful large-scale rodent control programs, but poor bait acceptance by rats compromises the effectiveness of many baiting programs. Non-toxic bait markers are one approach for assessing consumption and identifying the cause of failure. In single-feeding labo...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of wildlife management 1996-01, Vol.60 (1), p.202-207
Main Authors: Tobin, Mark E., Koehler, Ann E., Sugihara, Robert T.
Format: Article
Language:English
Subjects:
Animal behavior
Baits
Dyes
Gastrointestinal tract
Mammals
Materials management
Oats
Pest control
Pesticides
Rats
Rattus rattus
Rodenticides
Rodents
Solvents
Teeth
Wildlife management
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Rodenticides are a necessary part of successful large-scale rodent control programs, but poor bait acceptance by rats compromises the effectiveness of many baiting programs. Non-toxic bait markers are one approach for assessing consumption and identifying the cause of failure. In single-feeding laboratory bioassays, we evaluated metallic flakes, Solvent Blue 36 oil-soluble dye, and tetracycline hydrochloride (THC) as bait markers for monitoring consumption of oat groats by captive black rats (Rattus rattus). We detected metallic flakes (0.3% [g/g] dietary concentration) in the gastrointestinal (GI) tracts of all 12 rats examined immediately following a single 24-hour feeding trial but in only 1 of 12 rats examined 48 hours later. We easily detected Solvent Blue 36 oil-soluble dye (0.1% to 0.5% [g/g]) in subcutaneous, abdominal, and genital fat of 7 of 8 rats 2 days after feeding, but found it in only 6 of 12 rats examined 5 days after feeding. Dye applied at 1.0% and 1.5% (g/g) persisted in all 8 rats inspected 5 days after feeding, but reduced consumption (P < 0.05) at these levels suggests that concentrations ≥1% are unpalatable to rats. Dietary concentrations of THC from 0.5% to 1.0% (g/g) produced a golden-yellow fluorescence under ultraviolet (UV) illumination on the incisors and growing points of the mandibles of all rats examined 3 and 14 days after feeding. Because THC had no apparent effect on consumption (P = 0.28), it offers a reliable means of detecting consumption by black rats and thus, of determining whether poor results with rodenticides are due to poor bait acceptance.
ISSN:0022-541X
1937-2817
DOI:10.2307/3802056