The farmer and the mouse fight, the black kite crested vulture bleeds and buries with it! More than 60% of raptor samples have been tested for rat poison, according to a study conducted by PUST

964 sharing

A sick black kite, which had lost its flying demeanor, lay with its mouth slightly open and closed in the conservation wildlife reception center of the University of Science and Technology, while veterinarians were given emergency antidote injections and transfusions. after some rescue, the black kite still could not return to the embrace of the sky and died in vain on the cold medical table.

The black kite, which died in vain in Donggang in 2013, was tested. The results of the report showed that rat poison was found in the dead bird, which was composed of Brodifacoum, and internal bleeding was confirmed by veterinary autopsy. The Bird Ecology Research Laboratory of Pingtung University of Science and Technology (hereinafter referred to as "the Bird Ecology Laboratory of Pingtung University of Science and Technology") confirmed that the black kite was the first bird of prey to die of rat poison poisoning in Taiwan's bird research records.

The death of the black kite opened a large-scale investigation of rat poison residues in birds of prey in Taiwan. The Prevention and Inspection Bureau invited the Bird Ecology Research Office of the University of screen Science and Technology, the Research and Conservation Center of endemic Biology, the Taichung Wildlife Conservation Society, the Road killing Society and other units to jointly test and test 21 raptor species and more than 200 liver samples collected across Taiwan from 2010 to 2018. The results showed that there were 10 species of raptors and more than 60% of the samples detected rat poison residues, indicating that rat poison generally entered Taiwan's ecological food chain. This research paper was published in Science of The Total Environment, an authoritative journal in the field of environmental science in 2019.

Compared with other birds of prey that hunt live rats, black kites also pick up rat carcasses for food, so the Bird Ecology Research Office of Ping Science and Technology University also calls on farmers to pick up rat carcasses to avoid indirect poisoning caused by black kites. (photo courtesy of / PUST Bird Ecology Laboratory) the black kite study of PUST shows that rat poison anticoagulant causes bleeding

Since 2011, the Bird Ecology Research Laboratory of Ping University of Science and Technology has been engaged in the research of black kites, and then one after another received poisoned black kites, so they tried different testing items to confirm the death of black irises. "Raptors are poisoned by their food." Lin Hui-shan, a researcher at the Bird Ecology Research Office of Ping University of Science and Technology, points out that relevant tests are based on the food sources of raptors, including pesticides, rat poison, banned aquatic drugs, and even heavy metal residues.

"as there were no pesticides in the Donggang black kite in 2013, coupled with symptoms of bloody stool and stomach bleeding, we wondered if it had eaten poisoned mice. Is it due to internal bleeding caused by anticoagulants in rat poison? " Said Hong Xiaoyu, the first author of the paper and a researcher at the Bird Ecology Research Office of Ping University of Science and Technology.

Led by Sun Yuanxun (right), a professor at Ping University of Science and Technology, the Bird Ecology Research Laboratory has been engaged in raptor research for a long time, followed by researcher Hong Hsiao-Yu on the left. (photo / Chen Pinjun) Snake eating rats were poisoned, and birds of prey died of visceral bleeding

The rat poisons currently approved in Taiwan are all anticoagulants. After prey poisoning, the blood clotting function in the body is destroyed, so it will not stop bleeding, including oral bleeding, subcutaneous hematoma, anemia, and so on. The internal organs of poisoned animals will gradually bleed, and it will take about 5 to 10 days to die, which is chronic poison.

The laboratory found that live rats, rodent carcasses or birds of prey that feed mainly on snakes were at high risk of rat poison poisoning. Among the five common species of raptors in plain and low altitude areas, the rate of rat poison detected in the staple food black-winged kite samples was as high as 90%, and the average concentration detected was the highest (0.211 ppm). In addition, black kites, which have the habit of eating animal carcasses, and crested vultures, which are staple food snakes, are the second in detection rate and average concentration, respectively, which indirectly proves that snakes that feed on rats may be one of the important links in the food chain to transmit rat poison, causing big crested vultures to follow in poisoning.

Although crested goshawks and collar horned owls, which are common in rural and metropolitan areas, eat rats but eat a wide range of mice, the percentage of rat poison tested is more than 50%. The detection rate and concentration of rodenticide in birds of prey are the highest in autumn and winter, and the laboratory inferred that it may be related to the annual anti-rodent week held in Taiwan in autumn. The insecticides distributed during the week are mainly Brodifacoum and Flocoumafen, which are the most commonly detected ingredients in raptors. Another common rodent poison ingredient, Bromadiolone, is mostly registered as an environmental drug, so not only for agricultural use, but also for environmental use at home.

At present, all the approved rat poisons in Taiwan have anticoagulant ingredients, and the poisoned organisms will not stop bleeding, and it will take about 5 to 10 days to die, which is a chronic poison. (photo courtesy of / Department of Bird Ecology, Ping University of Science and Technology) A crested goshawk has as many as six kinds of rat poison in its body, and wild animals suffer from it.

Almost all the rat poison approved in Taiwan since 1980 is second-generation rat poison. "in addition to being more toxic, it also accumulates in the body for a longer time." Hong Hsiao-Yu points out that the second-generation drug needs to be naturally metabolized in mice for more than 200 days, during which it is easy to pass and accumulate through the food chain. In the study, it was found that more than one rat poison ingredient was found in many birds of prey, and there was a crested goshawk with as many as six kinds of rat poison, representing repeated consumption of mice with different agents.

In addition to birds of prey, other wild animals that prey on mice, such as grass owls, stone tigers and snakes, may also suffer, and even small animals such as squirrels, white-nosed hearts, cats and dogs may die in vain. Hong Xiaoyu added: "in fact, there are a lot of pipes that can spread rat poisons. for example, farmers often mix the potions with some cereals to lure mice, but birds, even insects, slugs and snails may eat these mixtures. They are eaten by predators again (they contain rat poison in their bodies). " Therefore, in the ecosystem, the transmission path of rat poison is very diverse.

There are a variety of rat poisons on the market, all of which have anticoagulant ingredients. The prevention and inspection bureau called on farmers to reduce the use of drugs to avoid maiming non-rodent organisms. (photo courtesy of / Bird Ecology Laboratory of PUST) the first study in Asia has not been tested in Taiwan in the past.

The ecological toxicity of rat poison has been confirmed by many studies in Europe and the United States, and the use of rat poison has been restricted, but this study is the first screening study on rat poison residues in birds of prey in Asia. "Rat poison has been used for so long, and it is only in the past few years that the problem of raptor poisoning has been discovered because Taiwan has never conducted tests before."

Hong Xiaoyu explained that it is only in recent years that there have been confirmed cases of raptor rat poison poisoning in China. On the one hand, the raptor poisoning may be hit by a car or attacked by natural enemies because of weakness and slowness, and the cause of death has been misjudged; on the other hand, the inspection facility is expensive, and there are few applications for testing rat poison residues, so most testing centers do not prepare standard samples of rat poison, which cannot be tested quantitatively. Since 2013, the Bird Ecology Research Laboratory of the University of screen Science and Technology has been able to purchase standard samples for testing with funding from bird lovers.

As rat poison is not a common test item, the causes of injury or death of raptors in the past are easily misjudged. (photo courtesy of / Bird Ecology Laboratory of PUST) the seasonal trend of raptor poisoning is consistent with the government Anti-rodent week.

Studies have also shown that the seasonal trend of raptor poisoning is consistent with government anti-rodent week activities. Since 1979, Anti-rodent week has been held for more than 30 years, and the time after the late autumn harvest (about October to November) is chosen every year for the government to distribute rat poison free of charge. One of the considerations is that it will not rain and the rat poison will not get wet in the dry season. Second, at this time, the rodents are short of food, so the poison bait can catch all the wild rats.

However, looking at the principle of delivering rat poison during Anti-rodent week, Hong Hsiao-Yu points out that there would have been no agricultural damage in the field without crops, and the effect of poisoned rats could not be maintained until the next year. "the breeding rate of rats is very fast, and after poisoning rats, as long as the number of rats returns in two or three months, by that time it is already spring, and crops are starting to grow again."

The Prevention and Inspection Bureau considered the different planting time of crops in different places, and responded to the suggestions of bird conservation groups to avoid the control of wild rodents in farmland during the bird breeding season, and gradually adjust the policy of field rodent control. It includes the "National rodent Control week", which has been implemented for more than 30 years since June 2015, cancels the consistent prevention and control period in different places, and can disperse the space and time for the delivery of rat poison. And stop subsidizing rat poison from 2016, cancel the common supply contract in 2018, and let counties and municipal governments purchase on their own according to demand.

The Bureau of Prevention and Inspection has gradually adjusted the epidemic prevention policy of agricultural land, with equal emphasis on ecology and production. At present, the Anti-rodent week has been cancelled and subsidies have been completely stopped. (photo courtesy of Animal and Plant Disease Prevention and Quarantine Bureau) Prevention and Quarantine Bureau called on farmers to pick up rat carcasses to avoid eating raptors by mistake.

The Bureau also called on local governments and farmers to reduce or refrain from using drugs in agricultural areas with high frequency of raptors, and to promote the correct use of pesticides, such as dosing before and at the initial stage of crop planting, putting them into plastic cans or bamboo tubes, to avoid accidental ingestion of non-rodent organisms, and to inspect the fields to pick up rat carcasses to avoid spoilage raptors.

"Policy adjustment can change some of the status quo, and production and ecology can be win-win." The Plant Disease Prevention Section of the Bureau of Prevention and Quarantine pointed out that due to the support of scientific data and gradual implementation of this policy, farmers have not reported a major epidemic of rats harming crops, and the number of black kites has also increased significantly in recent years, from 272 in 2013 to more than 500 in the past two years, which is also good news. In the future, new control technologies or safer rat baits will also be introduced, such as the chemicals containing plant fiber, which will "hang to death" due to water expansion and blockage of the gastrointestinal tract after eating, and this ingredient will not poison birds of prey or other organisms.

Although the field rodent control policy has gradually returned to the local level, the Bureau of Prevention and Inspection will still review the relevant policy on a rolling basis, such as amending the method of using rat bait in order to enhance the safety of the use of rat bait, requiring that anticoagulant rodenticide should be placed in bait stations for application. and prohibit the retail of raw materials or protoplasts for processing in the form of finished products. And amend the text description of the matters needing attention outside the package, including that the poison bait should be kept properly, such as accidental poisoning and emergency treatment, using vitamin K as the antidote and so on.

Poisoning rats and killing natural predators will increase the number of rats.

"poisoning rats is also poisoning their natural enemies. Mice reproduce very fast, so the number can come back soon, but natural enemies generally reproduce very slowly, so once the population of natural enemies disappears, it is very difficult to recover, which will lead to ecological imbalance. The number of ── mice will soar soon, and there will be no natural enemies to restrain them. Farmers will use more rat poison to suppress these mice, resulting in vicious ── that must be used repeatedly but will never be poisoned! "

Hong Hsiao-Yu says that in order to break the vicious circle, farmers must cooperate with other measures, such as placing rat traps. In recent years, the research lab has also advocated that farmers can use "one thing, one thing, one thing" biological control method to replace rat poison with birds of prey. Such as making owl nest boxes and black-winged kites.

As far as the perch is concerned, there are about a dozen places in Taiwan, such as Wufeng rice fields in Taichung, Meinung fields in Kaohsiung, and pineapple fields along the mountain road in Pingtung. The research office also provides teaching services. Hong Hsiao-Yu said: "the principle of erecting a perch in the field is to make use of the habit of raptors that like to stand at the commanding heights to attract black-winged kites to stop hunting in the fields, so as to reduce rodent damage."