Climate Change Is Making It Hard for Bears to Hibernate Through the Winter

iStock
iStock

What was once a rare sight—a bear wandering outside its den before springtime—has become increasingly common, thanks to climate change. As The New York Times reports, warming temperatures are waking American black bears from hibernation earlier than ever, and in some cases, preventing them from settling down for the winter in the first place.

Hibernation is a vital part of the black bear's life cycle. When awake, a bear must consume at least 11 to 18 pounds of food per day to maintain a healthy body weight. Withdrawing for the winter allows it to survive the food scarcity that comes with the colder months.

But as climate change promotes certain extreme weather patterns in the western U.S., the region's black bear population has begun to act differently. Last year the Pine Nut Mountains in Nevada saw unusually high levels of snowfall, and the excess moisture produced an abundant pine nut crop. This past winter, snowfall in the area hit near-record lows, leaving the pine nuts exposed on the ground for a longer period. The prolonged access to food in the area meant some bears started hibernating later or just never got around to it.

Many of the bears that did eventually crawl into their dens were woken up ahead of schedule this year. According to a 2017 study, for every 1°C that minimum winter temperatures rise, bears hibernate six days fewer. In January 2018, temperatures in the Pine Nut Mountains reached 5.4°C above the 20th-century average for the region.

Some years bears emerge from hibernation during droughts, which are exacerbated by climate change, and food is hard to come by. When that's the case, bears may end up on private property, raiding people's trash cans and bird feeders and sometimes breaking into their homes. Fatal bear attacks on humans aren't common: The more likely scenario is that the so-called problem bear will be euthanized. Bear management groups will often try other strategies, like capture and release and aversive conditioning, before resorting to this option. Nonetheless, dozens of bears are euthanized by states each year.

Black bears aren't the only ursine species being forced to adapt to global warming. In the Arctic, polar bears are losing the sea ice they need to hunt marine mammals, and many of them are moving onto land in search of prey. Climate change is pushing both species of bears toward human-populated territory, which means conflicts between the bears and people will only increase from here.

[h/t The New York Times]

Scientists Find Fossil of 150-Million-Year-Old Flesh-Eating Fish—Plus a Few of Its Prey

M. Ebert and T. Nohl
M. Ebert and T. Nohl

A fossil of an unusual piranha-like fish from the Late Jurassic period has been unearthed by scientists in southern Germany, Australian news outlet the ABC reports. Even more remarkable than the fossil’s age—150 million years old—is the fact that the limestone deposit also contains some of the fish’s victims.

Fish with chunks missing from their fins were found near the predator fish, which has been named Piranhamesodon pinnatomus. Aside from the predator’s razor-sharp teeth, though, it doesn’t look like your usual flesh-eating fish. It belonged to an extinct order of bony fish that lived at the time of the dinosaurs, and until now, scientists didn’t realize there was a species of bony fish that tore into its prey in such a way. This makes it the first flesh-eating bony fish on record, long predating the piranha. 

“Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time,” Dr. Martina Kölbl-Ebert, the paleontologist who found the fish with her husband, Martin Ebert, said in a statement. “Sharks have been able to bite out chunks of flesh, but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later."

Kölbl-Ebert, the director of the Jura Museum in Eichstätt, Germany, says she was stunned to see the bony fish’s sharp teeth, comparing it to “finding a sheep with a snarl like a wolf.” This cunning disguise made the fish a fearful predator, and scientists believe the fish may have “exploited aggressive mimicry” to ambush unsuspecting fish.

The fossil was discovered in 2016 in southern Germany, but the find has only recently been described in the journal Current Biology. It was found at a quarry where other fossils, like those of the Archaeopteryx dinosaur, have been unearthed in the past.

[h/t the ABC]

These Are America's 50 Most Rat-Infested Cities

iStock.com/Pierre Aden
iStock.com/Pierre Aden

New York City, home to the subway pizza rat, is surprisingly not America’s most rodent-infested city. That dubious honor goes to Chicago, according to a new analysis spotted by Thrillist.

A breakdown of the “50 Rattiest Cities” in the U.S. has been compiled by Orkin, a pest control service with locations across the country. The company tallied up the number of commercial and residential rodent treatments it carried out in each city over a period of 12 months (September 15, 2017 to September 15, 2018) and then ranked them. While the evidence is anecdotal, as it comes from just one company, it does reveal the areas where rat exterminators are in high demand.

This is the fourth year in a row that Chicago has been named the country’s rattiest city. Orkin isn’t the first to notice the city’s rodent problem, either. In July, Chicago was reportedly dubbed the “rat capital of the U.S.” by apartment search service RentHop. It reportedly received more rat complaints than any other city last year—nearly 51,000 total. According to RentHop’s analysis, New York City came in second place, followed by Washington, D.C. and Boston.

That isn’t too far off from Orkin’s latest analysis. New York comes in at third place, just after Los Angeles, and Washington, D.C. is fourth. The biggest boom in rat populations was seen in Portland, Maine, which jumped 19 spots from last year. Chance Strandell, residential service manager for Maine Pest Solutions, told New England Cable News that milder winters may be extending the rats’ breeding period. However, it’s unclear why rats seem to be multiplying in Maine in particular.

One pregnant rat can birth up to 12 babies in a single litter, and those pups can begin reproducing at just two months old. “So after a year, a busy pair of rat parents can have 15,000 descendants,” reports KATU in Portland, Oregon (number 24 on Orkin’s list).

Charleston, West Virginia, has also been teeming with rodents, having risen 17 spots from last year. Check out the full list of the 50 most rat-ridden cities below—and if you have musophobia (a fear of rats or mice), you may want to plot your move to one of the cities toward the bottom of the list.

1. Chicago, Illinois
2. Los Angeles, California
3. New York, New York
4. Washington, DC
5. San Francisco, California
6. Detroit, Michigan
7. Philadelphia, Pennsylvania
8. Cleveland, Ohio
9. Baltimore, Maryland
10. Denver, Colorado
11. Minneapolis-St. Paul, Minnesota
12. Dallas-Fort Worth, Texas
13. Boston, Massachusetts
14. Seattle, Washington
15. Atlanta, Georgia
16. Indianapolis, Indiana
17. Miami-Fort Lauderdale, Florida
18. Hartford, Connecticut
19. Pittsburgh, Pennsylvania
20. Cincinnati, Ohio
21. Milwaukee, Wisconsin
22. Charlotte, North Carolina
23. Houston, Texas
24. Portland, Oregon
25. Columbus, Ohio
26. San Diego, California
27. Raleigh-Durham, North Carolina
28. Buffalo, New York
29. New Orleans, Louisiana
30. Norfolk, Virginia
31. Richmond, Virginia
32. Albany, New York
33. Kansas City, Missouri
34. Portland, Maine
35. Nashville, Tennessee
36. St. Louis, Missouri
37. Sacramento, California
38. Greenville, South Carolina
39. Grand Rapids, Michigan
40. Phoenix, Arizona
41. Orlando, Florida
42. Tampa, Florida
43. Burlington, New York
44. Champaign, Illinois
45. Rochester, New York
46. Syracuse, New York
47. Charleston, West Virginia
48. Dayton, Ohio
49. Memphis, Tennessee
50. Flint, Michigan

[h/t Thrillist]

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