Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

On the loose: Urban coyotes thrive in North American cities

05.01.2006


Even in the largest American cities, a historically maligned beast is thriving, despite scientists’ belief that these mammals intently avoid urban human populations.

This animal’s amazing ability to thrive in metropolitan areas has greatly surprised scientists, says Stanley Gehrt, an assistant professor of environmental and natural resources at Ohio State University. Gehrt is in the sixth year of a multi-year study of coyote behavior in urban Chicago.

Since the study began, Gehrt and his colleagues have found that urban coyote populations are much larger than expected; that they live longer than their rural cousins in these environments; and that they are more active at nighttime than coyotes living in rural areas.



Coyotes also do some good – they help control rapidly growing populations of Canada geese throughout North America .

And while his coyote research is concentrated in Chicago , the results likely apply to most major metropolitan areas in North America . Gehrt has even seen a pack of about a dozen on Ohio State ’s campus in Columbus .

The study began in Chicago in 2000 when Gehrt was a research biologist for the Max McGraw Wildlife Foundation in Dundee , Ill. In the 1990s the foundation was increasingly inundated with complaints about coyotes taking pets and reportedly stalking children.

The number of calls grew, and in the late 1990s the Cook County Animal Control agency asked Gehrt to gather information on coyote populations in metropolitan Chicago .

The study was only supposed to last for a year.

“Nine million people live in the greater Chicago area,” said Gehrt, who is also a wildlife extension specialist at Ohio State . “We didn’t think very many coyotes could thrive in such a highly urbanized area. We also thought that the few animals that were causing problems were probably used to living around people.”

The problem with studying coyotes in general is that the animals are incredibly difficult to catch. They quickly learn how to avoid traps. But Gehrt and his colleagues distributed their traps widely throughout the greater Chicago area and successfully caught several animals. They put radio-tagged collars on the captured coyotes and then let them go.

The original estimates of the greater Chicago coyote population were woefully low. The researchers had expected to find a few small coyote packs here and there throughout the city, with total population numbers in the range of several dozen. But the animals were everywhere.

“We couldn’t find an area in Chicago where there weren’t coyotes,” Gehrt said. “They’ve learned to exploit all parts of their landscape.”

Since the beginning of the study, the researchers have caught and tagged more than 200 coyotes. They estimate that there may be somewhere between several hundred and a couple thousand coyotes living in Chicago .

Some of the animals live in city parks, while others live among apartment and commercial buildings and in industrial parks.

The funding agency, Cook County Animal Control and Conservation Medicine Coalition, renews the study every year because the researchers keep finding results that surprise them. This spring, Gehrt will publish the first round of papers from the last six years’ worth of research.

The major findings include:

  • Coyotes help control Canada geese populations. It appears that coyotes are helping to curb the booming Canada goose population in urban areas by eating the eggs from the birds’ nests.

Researchers found that, in Chicago , the annual population growth of Canada geese was reduced to an average of 1 to 2 percent per year, down from the 10 to 20 percent growth rates of a few years ago. Also, while coyotes can clean out several goose nests in one night, they don’t actually eat all of the eggs. Rather, they usually carry the eggs away from the nest and bury them, saving the eggs until later, Gehrt said.

  • The prevalence of large packs. Coyotes prefer to hunt alone, but often form packs to defend territories. Gehrt estimates that roughly half of all urban coyotes live in territorial packs that consist of five to six adults and their pups that were born that year. These urban packs establish territories of about five to 10 square miles – a fraction of the area that a rural coyote pack would cover. Consequently, the population densities in the urban area are usually three to six times higher than rural populations.

Those urban coyotes that don’t hunt in packs can cover ranges of 50 square miles or more, often in just one night. “The first solitary coyote we tracked covered five adjacent cities in a single night,” Gehrt said.

  • Urban coyotes survive far longer than their rural cousins. A coyote living in urban Chicago has a 60-percent chance of surviving for one year, while a rural coyote has a 30 percent chance of living for another year.
  • Most coyotes pose little threat to humans. The problems generally start when people feed coyotes, even if that feeding is unintentional.

“A coyote may eat the food that’s left outside for a pet,” Gehrt said. “It’s not uncommon to see a coyote pass through an urban or suburban neighborhood.

“But most coyotes aren’t thrilled about being seen by people,” he continued. “Urban coyotes are more active at night than their rural counterparts, so humans don’t see a lot of their activity. In many cases, coyotes are probably doing us favors that we don’t realize – they eat a lot of rodents and other animals that people don’t want around.”

The next phase of the study is already underway. Gehrt and his colleagues are conducting genetic study of coyotes’ social system. The researchers want to know if members of a pack are closely related – having such information could help to further explain coyote behavior.

Stan Gehrt | EurekAlert!
Further information:
http://www.osu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen

nachricht Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

Protein interaction helps Yersinia cause disease

21.08.2018 | Life Sciences

Biosensor allows real-time oxygen monitoring for 'organs-on-a-chip'

21.08.2018 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>