Hotter cities? Here come rats

If your city is getting stricter, climate change can be partly to blame.

In an analysis of 16 cities around the world, those who saw the largest temperature rise over the years also had more complaints about mouse over time, researchers report January 31 The advances of science. Increased urbanization was also associated with more mouse ratios. The results suggest that higher temperatures can make mice – and diseases that can spread – even more difficult to breastfeed.

Mice do not make people jump and scream: they also chew wiring and eat ancient and gardens. Their contaminated point and their deafs contaminate the food in which they are inserted, and they can spread diseases such as leptospirosis and wall tajphus. Their exploitation causes about $ 27 billion every year in the United States, and the world spends $ 500 million a year fighting a losing battle against a fluffy lube.

Jonathan Richardson, an urban ecologist at the University of Richmond in Virginia, says many of his colleagues had predicted that mouse populations would increase with climate change. But no one had data to support the prognosis.

Previous research has shown that when thousands of complaints grow, professionals block more rats – showing a population growth. Thus, Richardson and his colleagues collected complaints records of mice and pest inspection reports from 13 American cities, as well as Toronto, Tokyo and Amsterdam. Then, they looked at the mouse complaint rates for an average of 12 years in each city and compared them to the levels of urbanization (how little green space was present), socio -economic status, human population density and temperatures average over time.

Within the time frames, the team studied, about 70 percent of cities became more Rattier, with San Francisco, Toronto, New York City, Amsterdam and Washington, DC, showing the greatest growth of rodents. The strongest factor associated with a faster mouse race was the amount of a city temperature had increased over time. The second predictor of more mouse problems increased urbanization; Cities with the reduction of the green space saw that thousands of complaints grow at higher rates.

The unreasonable warm winters of climate change, says Richardson, surely buy rats extra time outside. “An extra week or two forage … That is, in some cases, all a mouse has to create once again.” And while rats need a natural habitat, a pocket park or tree boxes on the sidewalk will make it a deceit.

When people and rats share space, there is a real risk of illness, says Niamh Quinn, an advisor to human life interactions at the University of California Division of Agriculture and Natural Resources in Irvine which was not related to the study. “At one point there will be – hopefully no, but potentially – the perfect storm, where we have all these people, all of these rodents [and] Are not enough tools in our toolbox to manage them. “Leptospirosis, for example, can be deadly for people and non -vaccinated pets.

Heating weather also implies less opportunity to control population numbers, says Bobby Corrigan, a mouse rodentologist and advisor to the new study. There was once a rodent season, he says. The pest managers knew how to prepare for rats moving inside the winter and taking advantage of the lowest levels of season births. “Now it’s all year round.”