Preference of birds for zinc phosphide bait formulations

BACKGROUND: House mice (Mus musculus) cause significant, ongoing losses to grain crops in Australia, particularly during mouse plagues. Zinc phosphide (ZnP) coated grain is used for control, but with variable success. In a laboratory setting, we tested if mice would (i) switch from consumption of one grain type to another when presented with an alternative and (ii) consume ZnP-treated grains when presented as a choice with a different grain.RESULTS: Mice readily switched from their background grain to an alternative grain, preferring cereals (wheat or barley) over lentils. Mice readily consumed ZnP-coated barley grains. Their mortality rate was significantly higher (86%, n = 30) in the presence of a less-favoured grain (lentils) compared to their mortality rate (47%, n = 29; 53%, n = 30) in the presence of a morefavoured grain (wheat and barley, respectively). Mice died between 4 and 112 h (median = 18 h) after consuming one or more toxic grains. Independent analysis of ZnP-coated grains showed variable toxin loading indicating that consumption of a single grain would not guarantee intake of a lethal dose. There was also a strong and rapid behavioural aversion if mice did not consume a lethal dose on the first night. CONCLUSIONS:The registered dose rate of 25 g of ZnP/kg wheat (∼1 mg of ZnP/grain) in Australia needs to be re-evaluated to determine what factors may be contributing to variation in efficacy. Further field research is also required to understand the complex association between ZnP dose, and quantity and quality of background food on efficacy of ZnP baits.

Section: Discussionmentioning

confidence: 99%

Effects of background food on alternative grain uptake and zinc phosphide efficacy in wild house mice

Henry

Brown

Weyer

et al. 2021

“…However, in spite of some variation between populations in the speed of bait carrier removal between enclosures, lentil‐shaped pellets were also heavily depleted after 12 h, which indicates high attractiveness of such pellets for common voles at the high population density considered in the enclosure trial. If the palatability of lentil‐shaped pellets was similar in the field, their application may offer some protection to birds from accidental poisoning, as pelleted bait might be less attractive to birds than wheat kernels 21. Furthermore, in contrast to wheat, where zinc phosphide is concentrated on the surface, there is a homogeneous mixture of active ingredient and bait base in pelleted bait.…”

Section: Discussionmentioning

confidence: 99%

Efficacy and attractiveness of zinc phosphide bait in common voles (Microtus arvalis)

Jacob

Budde

Leukers

2009

Self Cite

According to the results from the laboratory trial, a zinc phosphide concentration of 2.1% seemed to balance uptake/efficacy best and may be most appropriate for the management of common vole populations. This concentration is substantially lower than the concentration used in many registered products. A reduced concentration of active ingredient and the use of pellet bait instead of wheat which is highly attractive for birds may have advantages for agroecosystem health when applying zinc phosphide for rodent control.

“…Water was available ad libitum at all times in a trough in the centre of each aviary. Food was offered in plastic food racks in each corner of the aviary (details in Jacob and Leukers). During a 1 week acclimatisation period, pigeons received 100 g of a bird food mix of 40% Milo ( Sorghum bicolor ), 25% wheat ( Triticum aestivum ), 20% peas ( Pisum sativum ), 5% buckwheat ( Fagopyrum sagittatum ), 5% vetch ( Vicia spp.)…”

Section: Methodsmentioning

confidence: 99%

Assessing the effects of three potential chemical repellents to prevent bird damage to corn seeds and seedlings

Esther

Tilcher

Jacob

2012

Self Cite

Bird damage to seeds and seedlings of corn and other crops is widespread in organic farming because no adequate seed protection is available. In this study we systematically tested the effect of seed treatments with three synthetically-produced substances known to affect bird feeding behavior (anthraquinone, pulegone and methylanthranilate) in different concentrations. There was no negative effect on the germination of seeds for all seed treatments. Their repellent effect was tested by food and seedling choice (treated versus untreated) experiments with pigeons (Columba livia) in aviaries. The best treatment variants in these trails were additionally tested regarding plant growth in the field where wild birds had unlimited access.In aviaries, untreated seeds were clearly preferred over treated seeds by pigeons. The highest feeding deterrence effect occurred with the treatment variants 7.5% pulegone and 0.5% methylanthranilate. In these cases less than 5% of the daily consumption was treated seeds. In contrast, however, there was no treatment effect on seedlings. The same number of seedlings grown from treated and untreated seeds remained intact.Further replications and field experiments with additional treatment variants are being conducted at the moment. The repellent effects of some of the treatment variants indicate that further studies with the same compounds but based on plants and benefit-cost-analyses should be done to yield a bird repellent to be used for organic seed protection.