Skip to main content
Scientific American
  • Cart 0
  • Forgot password?Loading
    Not yet registered?
  • |Newsletters
Advanced Search
  • Coronavirus
  • Health
  • Mind & Brain
  • Environment
  • Technology
  • Space & Physics
  • Video
  • Podcasts
  • Opinion
  • Store
  • Subscribe
  • Current Issue
  • Cart0
  • Sign In
  • Newsletters
      • Share
      • Latest

      Cuddly Squirrel or Gray Menace?: When Invasive Species Pose an Environmental Threat

      Scientists find themselves choosing between animals as explosions of some populations endanger others

      • Share on Facebook
      • Share on Twitter
      • Share on Reddit
      • Share on LinkedIn
      • Share via Email
      • Print
      Cuddly Squirrel or Gray Menace?: When Invasive Species Pose an Environmental Threat
      Slideshow (7) images
      View
      Credits: ©SANDRO BERTOLINO

      Cuddly Squirrel or Gray Menace?: When Invasive Species Pose an Environmental Threat

        • Share
      • MICROBES: Pathogens—microscopic organisms that cause disease—can spread in a variety of ways, from air travel to shipping. For example, tree diseases that travel via lumber supplies have devastated some native forests, such as the silver trees of Table Mountain south of Cape Town in South Africa... ©MIKE WINGFIELD
      • CANE TOAD: Introduced to Australia in 1935 to control sugarcane-eating beetles, cane toads failed in that mission and have steadily colonized more and more of the continent. With voracious appetites, they have decimated the populations of their prey and—due to a lethal toxin in their skin—would-be predators, including pygmy freshwater crocodiles, northern quolls and Australian monitor lizards known as large goannas... COURTESY OF ENVIRONMENTAL PROTECTION AGENCY, QUEENSLAND
      • FERAL PIGS: Domesticated pigs that return to their wild roots are damaging ecosystems around the world, from small islands to entire continents, like the ones shown here in Australia. In the U.S., feral pigs are rooting up vegetation and competing with native animals for resources in many states, including Texas, Oregon and Hawaii... COURTESY OF ENVIRONMENTAL PROTECTION AGENCY, QUEENSLAND
      • REINDEER: Native to the Arctic, reindeer have wreaked havoc on the sub-Antarctic island of South Georgia since their introduction in the early 20th century. And their havoc may spread if retreating glaciers continue to expand the reindeers' potential range... ©ANDREW RANKIN
      • Advertisement
      • MOUFLON SHEEP: Humans introduced these cloven-hoofed invaders to the area around the dormant Hawaiian volcano of Mauna Kea in the 1960s. The sheep have adjusted nicely to their new home, with populations steadily increasing, much to the detriment of native flora, including the highly endangered silversword plant... ©ROBERT STEPHENS
      • ZEBRA MUSSELS: The invasive mollusks hitchhiked to the Great Lakes in ballast water in the 1980s and now cluster on pipes, boats, buoys and, in the case pictured here, on a Lake Erie mussel, commonly known as a fatmucket... ©AMY BENSON
      • GRAY SQUIRREL: Since their introduction to the U.K. at the end of the 19th century, these twitchy-nosed invaders have decimated indigenous red squirrels by spreading disease and beating them out for food and other resources... ©SANDRO BERTOLINO
      • Previous
      • Next
      of
      • View all
      • Link copied!
      • MICROBES:
      • CANE TOAD:
      • FERAL PIGS:
      • REINDEER:
      • MOUFLON SHEEP:
      • ZEBRA MUSSELS:
      • GRAY SQUIRREL:
      Advertisement
      Advertisement

      Newsletter

      Get smart. Sign up for our email newsletter.

      Sign Up

      Support Science Journalism

      Discover world-changing science. Explore our digital archive back to 1845, including articles by more than 150 Nobel Prize winners.

      Subscribe Now!Support Science Journalism

      Follow us

      • instagram
      • soundcloud
      • youtube
      • twitter
      • facebook
      • rss

      Scientific american arabic

      العربية
      • Return & Refund Policy
      • About
      • Press Room
      • FAQs
      • Contact Us
      • Site Map
      • Advertise
      • SA Custom Media
      • Terms of Use
      • Privacy Policy
      • California Consumer Privacy Statement
      • Use of cookies/Do not sell my data
      • International Editions
      Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www.springernature.com/us). Scientific American maintains a strict policy of editorial independence in reporting developments in science to our readers.

      © 2022 Scientific American, a Division of Springer Nature America, Inc.

      All Rights Reserved.

      Scroll To Top

      Support science journalism.

      Scientific American paper issue and on tablet

      Thanks for reading Scientific American. Knowledge awaits.

      Already a subscriber? Sign in.

      Thanks for reading Scientific American. Create your free account or Sign in to continue.

      Create Account

      See Subscription Options

      Continue reading with a Scientific American subscription.

      You may cancel at any time.

      Sign in.