Because many other prey animals become difficult to hunt or hibernate in winter, the snowshoe hare’s role in the ecosystem becomes critically important in winter. If population numbers drop, it would likely have a ngative affect on owls and many other species.

Because many other prey animals become difficult to hunt or hibernate in winter, the snowshoe hare’s role as a prey animal in the ecosystem becomes critically important in winter. If population numbers drop, it would likely have a negative affect on owls and many other species.
Photo Credit: Denali National Park and Preserve licensed CC BY 2.0 (via CBC)

Climate change affecting predator-prey balance

Share

It seems climate change could throw the delicate natural balance of predators and prey, off kilter.

Two biological mathematicians studied the relationship between a predator, the great horned owl, and a prey animal, the snowshoe hare.

Lead author Rebecca Tyson of the University of British Columbia told CBC radio that, “just by increasing the length of the summer relative to the lengths of the winter, a previously stable predator-prey relationship could become unstable — driving one species extinct”.

Research supervisor Frithjof Lutscher is a professor in Mathematical Biology Ecology and Evolution in the Department of Mathematics and Statistics at the University of Ottawa.

Listen
Frithjof Lutscher (PhD) University of Ottawa, biological mathematician
Frithjof Lutscher (PhD) University of Ottawa, biological mathematician © supplied

The hare as it turns out, is a keystone species for the reason that so many different predators in an ecosystem rely upon them. One of those species is the great horned owl. They keep each other in balance.

But when something like climate change, which is happening rapidly, changes one of the equation variables, what effect or effects might that have?  That’s what the researchers studied.

The findings were published in the  November issue of the science journal, The American Naturalist under the title. “Seasonally Varying Predation Behaviour and Climate Shifts Are Predicted to Affect Predator-Prey Cycles”. (abstract here)

One aspect they discovered was that just the fact of a warmer climate, and thus a slightly shorter winter, would throw the normal roughly ten-year swings in populations between hare and owl out of whack, and the hare population could become extinct.

Climate change could drive the great horned owl and snowshoe hare populations to extinction in Canada’s boreal forests, according to one scenario from Canadian researchers.
Climate change could drive the great horned owl and snowshoe hare populations to extinction in Canada’s boreal forests, according to one scenario from Canadian researchers. © Debra Beaton

A longer summer meant owls could catch hares and other types of prey longer, leading to greater owl numbers. In turn more owls could eventually wipe out their substantial summer, and main winter prey, the hares.

What the researchers discovered to their surprise was that a small change in climate showed a big change in predator-prey relationship. In once case, wild swings, and in another, very little. Dark blue line and dark green line owl and hare populations respectively in typical summers of 41% of the year. Light blue and light green are owls and hares in one of the two outcomes if summer was 43% of the year.
What the researchers discovered to their surprise was that a small change in climate showed a big change in predator-prey relationship. In once case, wild swings, and in another, very little. Dark blue line and dark green line owl and hare populations respectively in typical summers of 41% of the year. Light blue and light green are owls and hares in one of the two outcomes if summer was 43% of the year. © Tyson, Lutscher

In other words, what they found was that the normal mild population oscillations of the two species, could lead to surprisingly big oscillations with the slight change of just a little longer summer with a little shorter winter. Or alternatively another scenario showed the slight temperature modification might mean the natural oscillations could instead greatly flatten out.

Lynx chasing hare. If the population levels of hare were to drop, it would have a significant negative impact on other predators that depend upon them such as hare, fox, wolf etc.
Lynx chasing hare. If the population levels of hare were to drop, it would have a significant negative impact on other predators that depend upon them such as hare, fox, wolf etc. © Gov’t Newfoundland and Labrador

However, nature is an interconnected web, and looking at one very specific aspect likely does not give a proper picture.

The next phase of research will throw another variable into the mix, the more specialized snowshoe hare predator, the lynx, As the lynx depends far more on the hare, it potentially could suffer even more from a hare decline than the owls.

Additional information- sources

Share
Tagged with: , , , , , , , , , ,
Posted in Animals, Environment, International, Science and Technology

Do you want to report an error or a typo? Click here!

@*@ Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

 characters available

Note: By submitting your comments, you acknowledge that Radio Canada International has the right to reproduce, broadcast and publicize those comments or any part thereof in any manner whatsoever. Radio Canada International does not endorse any of the views posted. Your comments will be pre-moderated and published if they meet netiquette guidelines.

Netiquette »

When you express your personal opinion in an online forum, you must be as courteous as if you were speaking with someone face-to-face. Insults and personal attacks will not be tolerated. To disagree with an opinion, an idea or an event is one thing, but to show disrespect for other people is quite another. Great minds don’t always think alike—and that’s precisely what makes online dialogue so interesting and valuable.

Netiquette is the set of rules of conduct governing how you should behave when communicating via the Internet. Before you post a message to a blog or forum, it’s important to read and understand these rules. Otherwise, you may be banned from posting.

  1. RCInet.ca’s online forums are not anonymous. Users must register, and give their full name and place of residence, which are displayed alongside each of their comments. RCInet.ca reserves the right not to publish comments if there is any doubt as to the identity of their author.
  2. Assuming the identity of another person with intent to mislead or cause harm is a serious infraction that may result in the offender being banned.
  3. RCInet.ca’s online forums are open to everyone, without regard to age, ethnic origin, religion, gender or sexual orientation.
  4. Comments that are defamatory, hateful, racist, xenophobic, sexist, or that disparage an ethnic origin, religious affiliation or age group will not be published.
  5. In online speak, writing in ALL CAPS is considered yelling, and may be interpreted as aggressive behaviour, which is unpleasant for the people reading. Any message containing one or more words in all caps (except for initialisms and acronyms) will be rejected, as will any message containing one or more words in bold, italic or underlined characters.
  6. Use of vulgar, obscene or objectionable language is prohibited. Forums are public places and your comments could offend some users. People who use inappropriate language will be banned.
  7. Mutual respect is essential among users. Insulting, threatening or harassing another user is prohibited. You can express your disagreement with an idea without attacking anyone.
  8. Exchanging arguments and opposing views is a key component of healthy debate, but it should not turn into a dialogue or private discussion between two users who address each other without regard for the other participants. Messages of this type will not be posted.
  9. Radio Canada International publishes contents in five languages. The language used in the forums has to be the same as the contents we publish. The usage of other languages, with the exception of some words, is forbidden. Messages that are off-topic will not be published.
  10. Making repetitive posts disrupts the flow of discussions and will not be tolerated.
  11. Adding images or any other type of file to comments is forbidden. Including hyperlinks to other websites is allowed, as long as they comply with netiquette. Radio Canada International  is in no way responsible for the content of such sites, however.
  12. Copying and pasting text written by someone else, even if you credit the author, is unacceptable if that text makes up the majority of your comment.
  13. Posting any type of advertising or call to action, in any form, to Radio Canada International  forums is prohibited.
  14. All comments and other types of content are moderated before publication. Radio Canada International  reserves the right to refuse any comment for publication.
  15. Radio Canada International  reserves the right to close a forum at any time, without notice.
  16. Radio Canada International  reserves the right to amend this code of conduct (netiquette) at any time, without notice.
  17. By participating in its online forums, you allow Radio Canada International to publish your comments on the web for an indefinite time. This also implies that these messages will be indexed by Internet search engines.
  18. Radio Canada International has no obligation to remove your messages from the web if one day you request it. We invite you to carefully consider your comments and the consequences of their posting.

*