By Seth Borenstein
Washington (AP) – Rat infestation in many cities in the world seems to be rising, especially in Washington, and a new study guilt Heating temperaturesurbanization and other human actions.
An examination of trends and the reasons for the first type of their species in populations of rats that are difficult to take into account uses rats sighting reports in 16 cities around the world. In 11 of those cities, rats complaints have increased, according to a study in Friday magazine Scientific advances.
Based on individual trends within the cities, Washington was, with much, the leader in rats, followed by San Francisco, Toronto, New York and Amsterdam City. Washington’s rise reports trend was three times greater than Boston’s and 50% more than that of New York, according to the study. Washington city officials did not respond to comments requests.
Only three cities saw significant decreasing trends: New Orleans, Louisville and Tokyo, with the home of Mardi Gras that shows the greatest fall in rats reports. Experts said the city of Louisiana can teach others how to combat the problem of rats.
The researchers carried out a statistical analysis of the reports of ascending rats in those cities and concluded that a little more than 40% of the observed trend is due to the heating temperatures due to the burning of coal, oil and natural gas. And that is reduced to sex and food, said the main author of the study Jonathan Richardson, biologist at Richmond University.
“We are seeing these growing trends in rats in cities that are heating faster, probably because this is a small mammal that has physiological challenges in the months of cold weather,” Richardson said. “If we are heating the weather and winter begins one or two weeks later and spring comes a weeks before, that is one, two, maybe even three or four weeks throughout the year, where those rats can be by above the ground, acquiring more food and maybe squeezing one or two more Reproductive cycles. “
It is possible that an additional month does not seem much, but female rats can have a garbage every month. Each garbage is eight to 16 babies, Richardson said: “That is a recipe for the accelerated growth of the population.”
The researchers pointed out two other great statistical links, which fit known biological problems, behind more rats reports: the increase in urbanization and the most densely populated cities.
Rats like the accumulated environment and being close to people and their waste, said the study and external scientists. Basically they eat at the same table as humans, multiple experts said.
“The rat is the third most successful mammal behind humans and house mice. So he evolved and designed to live with us “, New York City Rat Zar Kathleen Corradi Said during a break at a New Orleans conference to improve pest management. “They followed humans, Homo Sapiens, on the continents and are found on all continents, except in Antarctica. Then it is considered an evil problem. “
Although rats are intelligent and highly adaptable, Richardson and other experts said they are a serious problem for people.
“When rodent populations are high, people get sick, motor vehicles are disabled, mental health fires begin, fires and food are dirty,” said Houston Rat Michael Parsons, who It was not part of the study. Rats correctly bother people due to “an innate fear caused by an organism that can get sick.”
Researchers have not had good figures on rats. Due to the way they live and hide, they are not easily counted as other creatures, so this is one of the first attempts to quantify them. The study is not really a position of rats, but of people’s complaints.
Because statistics date back to years and only cities were observed that have not changed their report methods, Richardson said that the trends they saw have scientific merit. Although Washington has the highest trend that does not mean that it has more rats or even rats, it is only that the numbers within the city are increasing faster, he said.
Several external experts said the study is legitimate, sensible and very necessary.
“This document is, with much, the greatest effort based on data to understand the changes in urban rats populations ever tried,” said Ecology Professor of the University of Drexel, Jason Munshi-South, who was not part of the investigation.
Looking at the few cities where rats reports are low can help in the fight against rats, Richardson and Corradi said. The answer is no more poison or traps, but prevention, according to the study.
“In New Orleans they make a great effort to go out to neighborhoods and make educational workshops and campaigns to talk to residents about what makes a property less likely to have rats,” Richardson said.
The recently intensified rats of New York City, which includes replacing garbage in the street bags with rats resistant containers, has not yet appeared in Richardson’s data, but the racadi of the rat said that The first results are encouraging. The city has signed people for what they call an elite squad of rats fighters, called ” NYC Rat Pack “.
It is a uphill battle.
“As our cities warm, urban and increase (increase) density, we create more resources for rats that could lead to higher increases in numbers,” said the scientist at Simon Fraser University, Kaylee Byers, in a email.
We can fight them better, but in the end people “need to coexist with wildlife in urban environments, even with rats,” said the conservation scientist at the University of Michigan, Neil Carter.
“Zero rats is impossible,” said Richardson. “But I think that an expectation that we need to live with the amount of rats we are seeing in many of these cities is also an unhealthy perspective about this problem.”
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