Bird Aversive Properties of Methyl Anthranilate, Yucca, Xanthoxylum, and Their Mixtures (original) (raw)
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Chemical repellency in birds: Relationship between chemical structure and avoidance response
Journal of Experimental Zoology, 1991
We examined how molecular structure of 24 anthranilate and benzoic acid derivatives correlated with drinking behavior in European starlings Sturnus vulgaris. The effectiveness of bird repellents was associated with basicity, the presence of an electron-donating group in resonance with an electron-withdrawing carboxylic group on a phenyl ring, and a heterocyclic ring in the same pi cloud plane as the phenyl ring. Of the benzoic acid derivatives tested in this study, methyl, ethyl, dimethyl, and linalyl anthranilate as well as anthranilic acid and 4-ketobenztriazine were repellent to birds. Water consumption was significantly reduced relative to control levels at concentrations as low as 0.05% (weight/volume) for the best repellents. Further statistical tests showed that reduction in consumption for the best repellents was absolute, not significantly different from zero consumption. Anthranilic acid isomers were moderately good repellents. The ability to generate a model predicting repellency allows for the efficient identification and development of ecologically sound, nonlethal, taxa-specific repellents to be used for the protection of wildlife in agricultural and industrial applications.
Bird repellents: interaction of chemical agents in mixtures
Physiology & Behavior, 1998
studies characterize the concentration-behavioral response for odorants, tastants, and irritants. However, to achieve ecological validity, interaction of agents in mixtures must be considered. Equiresponse and equimolar molar models of interactions have been proposed, and methods for testing whether agents in mixture interact independently have been evaluated. Yet these averaging models cannot a priori predict whether agents will interact antagonistically, independently, or synergistically. I studied the bird repellent properties of several structurally similar and well-described trigeminally mediated avian irritants, singly and in mixture. Compounds within a chemical class, in which the electron withdrawing groups were similar, interacted independently to produce their repellent effects, e.g., 2-amino methyl benzoate v methyl-2-methoxy benzoate, and o-aminoacetophenone v 2-methoxy acetophenone. The response to mixtures drawn from compounds of dissimilar chemical class, e.g., 2-amino methyl benzoate v o-aminoacetophenone, interacted antagonistically at concentrations below 10 mM, suggesting meditation by a different mechanism within the trigeminally mediated sensory modality. At 10 mM and near saturation of the solutions, there was no evidence of interaction between agents, suggesting responses became saturated. These observations underscore our previous findings for the importance of the molecular properties of the carbonyl group for aromatic bird repellents and suggests the possible existence of multiple receptor mechanisms for avian trigeminal repellents. These data also underscore the importance of attending to interactions of agents in mixtures when designing repellents as tools for the management of wildlife and resolution of conflicts between humans and wildlife.
Avoidance of bird repellents by mice ( Mus musculus
Journal of Chemical Ecology, 1993
It is believed that mammalian chemosensory irritants are not aversive to birds and vice versa. Nevertheless, few avian repellents have been tested against mammals. For that reason, we evaluated the efficacy of 1.0% w/v methyl anthranilate, orthoaminoacetophenone, 2-amino-4′,5′-methoxyacetophenone, 2-methoxyacetophenone, and veratryl amine as mouse repellents in 3-hr no-choice drinking tests. Relative to ingestion of plain water, all test substances significantly reduced (P
Reconciling sensory cues and varied consequences of avian repellents
Physiology & Behavior, 2011
We learned previously that red-winged blackbirds (Agelaius phoeniceus) use affective processes to shift flavor preference, and cognitive associations (colors) to avoid food, subsequent to avoidance conditioning. We conducted three experiments with captive red-winged blackbirds to reconcile varied consequences of treated food with conditioned sensory cues. In Experiment 1, we compared food avoidance conditioned with lithium chloride (LiCl) or naloxone hydrochloride (NHCl) to evaluate cue-consequence specificity. All blackbirds conditioned with LiCl (gastrointestinal toxin) avoided the color (red) and flavor (NaCl) of food experienced during conditioning; birds conditioned with NHCl (opioid antagonist) avoided only the color (not the flavor) of food subsequent to conditioning. In Experiment 2, we conditioned experimentally naïve blackbirds using free choice of colored (red) and flavored (NaCl) food paired with an anthraquinone-(postingestive, cathartic purgative), methiocarb-(postingestive, cholinesterase inhibitor), or methyl anthranilate-based repellent (preingestive, trigeminal irritant). Birds conditioned with the postingestive repellents avoided the color and flavor of foods experienced during conditioning; methyl anthranilate conditioned only color (not flavor) avoidance. In Experiment 3, we used a third group of blackbirds to evaluate effects of novel comparison cues (blue, citric acid) subsequent to conditioning with red and NaCl paired with anthraquinone or methiocarb. Birds conditioned with the postingestive repellents did not avoid conditioned color or flavor cues when novel comparison cues were presented during the test. Thus, blackbirds cognitively associate pre-and postingestive consequences with visual cues, and reliably integrate visual and gustatory experience with postingestive consequences to procure nutrients and avoid toxins.
Comparison of Primary and Secondary Repellents for Aversive Conditioning of European Starlings
ACS Symposium Series, 2000
Secondary repellents have been demonstrated to effectively reduce avian crop depredation. However, these compounds frequently are toxins and there are concerns about environmental safety. Many primary repellents are toxicologically and environmentally safer, but these chemicals are not as effective when traditional delivery methods are used. We set out to determine whether the difference in efficacy of primary vs. secondary repellents was due to differences in potency of the chemical classes or site of action within the animal. We hypothesized that the efficacy of primary repellents could be enhanced if they could be delivered directly to the gastrointestinal system, thus bypassing the peripheral senses. Our experiments were conducted on captive European starlings (Sturnus vulgaris). We showed that bypass of the peripheral senses via oral gavage enhanced the efficacy of 2 hydroxyacetophenone (2HAP), a primary repellent. However, we found that starlings were sensitive to changes in their visual environment, and that learned avoidance to a colored food cup could be mitigated by changing the cage door of the test system. Topical application of repellents to foods allowed starlings to selfmediate their exposure to the repellents. We found that methiocarb and methyl anthranilate (MA), a primary repellent, both induced food aversion learning, but 2HAP did not. Detailed analyses of feeding behavior elucidated the mechanistic differences between Methiocarb, MA, and 2HAP. Methiocarb induced gastrointestinal illness in starlings, which resulted in post-ingestive suppression of food intake, and subsequent food aversion learning. Some starlings with MA in their food also developed gastrointestinal illness, and food aversion learning. Starlings with 2HAP in their feed did exhibit reduced feeding efficiency, but these starlings did not develop gastrointestinal illness or food aversion learning. These experiments demonstrate that the location and intensity of illness are of paramount importance to induce food aversion learning.
Pen Tests of Methyl Anthranilate as a Bird Repellent in Water
1991
Two commercial (ReJeX-iTR brand) formulations of methyl anthranilate (MA), at concentrations of 0.10 -0.5096 (0 -0.32% active ingredient [a.i.]), were highly effective in repelling mallards (Anal plaryrhynchos), and ring-billed gulls detawarensis) from pools of water in pen tests. For mallards, pool entries and bill contacts with water in MA-treated pools 1.4 and 4.0% of the levels in untreated pools during a 2-choice test, and 4.2 and 8.8% of the levels in untreated pools during 1-choice test. For gulls, the repellency levels were even higher, with activity levels in treated pools being < 1% of levels untreated pools during I-and 2-choice tests. We recommend further pen tests to determine minimum effective concentrate levels and a field test to determine responses of free-ranging birds.
Tests and refinements of a general structure-activity model for avian repellents
Journal of Chemical Ecology, 1994
We tested the robustness of a structure-activity model for avian trigeminal chemoirritants. Fourteen benzoates and acetophenones were tested using European starlings Sturnus vulgaris as a bioassay. In general, the previously proposed model was a reasonable predictor of repellency (i.e., irritant potency). We found that the presence of a phenyl ring was critical to repellency. Basicity of the molecule is the next most critical feature influencing repellency. The presence of an acidic function within the electron-withdrawing functionality seriously detracts from repellency. The presence or absence of an electron-withdrawing or-donating group may potentiate repellent effects, but its presence is not critical, so long as the phenyl ring is electron rich. Our data suggest that there is an o-aminoacetophenone/methyl anthranilate trigeminal chemoreceptor in birds analogous to the mammalian capsaicin receptor. Both receptors contain a benzene site. However, birds seem to lack the associated thiol/hydrogen-bonding site present in mammals which is needed to activate the benzene site. Rather, birds may possess an associated exposed charged site that in turn may interact with the stimulus to activate the benzene site. These differences may explain the differential sensitivity of birds and mammals to aromatic irritants.
Proceedings of the Vertebrate Pest Conference
Despite a general perception that there is an abundance of nonlethal control technologies, the fact remains that there are fewer registered products and active ingredients for repellents in the U.S. than there were 10 and 20 years ago. This review discusses the technical issues relating to the discovery, formulation, and delivery of chemical repellents, and suggests future avenues of research that would improve our ability to develop effective chemical repellents.
Grazing repellency of methyl anthranilate to snow geese is enhanced by a visual cue
Crop Protection, 1996
Methyl anthranilate (Rejex-It AG-36) is formulated as a commercial goose repellent. Frequent reapplications of this product are often necessary, and the cost/application is high (2 $3OO.OO/ha). The present experiment tested the possibility that the repellency of methyl anthranilate might be enhanced by the addition of visual cues. Twelve 0.4 ha plots were assigned randomly to three treatment groups. Plots in the first group (n = 4) were sprayed with 10% Vapor Guard (an agrochemical adhesive). Plots in the second group (n = 4) were treated with a mixture of methyl anthranilate (3.4 kg/ha) and Vapor Guard. Plots in the third group (n = 4) were sprayed with a mixture of methyl anthranilate, white paint pigment (titanium oxide, Ti03, 0.9 kg/l) and Vapor Guard. From 28 November 1994 to I9 December 1995, all plots were visited at 7 day intervals to collect snow goose (Chen caerulescens) droppings along transects. Examination of feces weights/transect meter at 7 days post-treatment showed that both methyl anthranilate formulations reduced goose activity. At 14 and 21 days post-treatment, however, dropping weights were significantly lower in plots treated with methyl anthranilate and Ti03 than in plots treated with formulated methyl anthranilate alone. These results show that visual cues can enhance the durability of methyl anthranilate repellency.