Predation vertebrates

Although no consistently effective chemical repellent has been developed for vertebrate pests, some promising materials have been tested as repellents that are based on predator avoidance, specifically compounds from the secretions of predators. In 1995, synthetic sulfur compounds (two thietanes, a thiolane, and a substituted methyl sulfide, which were originally identified from the anal glands of the stoat, ferret, and red fox) suppressed browsing by the introduced AustraUan bmsh-tail opossum in New Zealand about as well as FEP (83). Suggestions were made that these compounds can be made more effective by the use of bitter compounds in a cocktail. 

In contrast to the controlled use of these compounds in the neighborhood of farms and human habitation, they have sometimes been used in a less controlled way against rodents and vertebrate predators, which causes problems in conserved areas. In a number of conserved islands in New Zealand, for example, bait containing brodiphacoum has been used for rodent control, both at bait stations and by aerial distribution (Eason et al. 2002). In the latter case, poisoned bait is freely available, and herbivores and omnivores, as well as predators and scavengers are at high risk. This problem will be discussed further in Section 11.6. 

When ARs have been used to control rodents and vertebrate predators in conserved areas, there have been instances of both primary and secondary poisoning. In New Zealand, such incidents have been observed on islands where bait treated with brodifacoum has been used. Casualties have included native raptors, such as the Australasian harrier (Circus approximans) and morepork (Ninox novaeseelaniae), as well as other species, such as the pukeko. Western weka (Galliralus australis), and... 

Brodifacoum, difenacoum, flocoumafen, and other superwarfarins bind strongly to proteins of the hepatic endoplasmic reticulum and consequently have long half-lives in vertebrates, often exceeding 100 days. Thus, they present a hazard to predators and scavengers that feed on rodents which have been exposed to superwarfarins. A number of species of predatory and scavenging birds have died as a consequence... 

Machado, G. et al.. Chemical defense in harvestmen (Arachnida, Opiliones) do benzoquinone secretions deter invertebrate and vertebrate predators J. Chem. EcoL, 31, 2519, 2005. 

Pesticides, and especially OCPs (DDT and its metabolytes, HCH isomers, aldrine, dieldrin, heptachlor, etc.), are seen everywhere in mammals. Table 4.7 gives data on the death of higher vertebrates from causes linked to agricultural production in the USSR. About 40% of the accidental deaths of animals, and about 80% of birds, are due to pesticides. It is difficult to evaluate how many mammals in the environment die from pesticide contamination, since sick and weakened individuals fall prey to predators [6]. 

The use of 1080 in the United States is now restricted to livestock collars on sheep and goats for protection against predation by coyotes. Other countries, most notably Australia and New Zealand, use 1080 extensively in a variety of baits to control many species of vertebrate pests. 

Invertebrate allomones that deter vertebrate predators 10.7.1 Taste aversion to invertebrate prey... 

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