Regs may inhibit polar bears' mating
Published: Nov. 23, 2007 at 12:37 AM
EDMONTON, Alberta, Nov. 23 (UPI) -- Canadian harvesting regulations may be making it hard for polar bears to find mates, a University of Alberta study suggests.
Canadian wildlife management policies encourage hunters to pursue male bears, conserving females while maximizing the number of bears harvested, the Edmonton university said in a news release. But harvesting based on sex selection has reduced the number of males compared to females in polar bear populations across the Canadian Arctic, said the study's lead author, Peter Molnar, a Ph.D. candidate in the university's biological sciences department.
The mathematical model developed by Molnar, under the supervision of polar bear expert and faculty member Andrew Derocher, has given the researchers the ability to predict how many male bears are needed in an area compared to the number of female bears to maintain successful mating.
The team determined if the male-to-female ratio drops below a critical threshold, the model predicts a sudden collapse in fertilization rates. The threshold depends on whether the area has a high- or low-density polar bear population.
The findings were published in the online edition of the Proceedings of the Royal Society, an academic journal based in Britain.
Canadian wildlife management policies encourage hunters to pursue male bears, conserving females while maximizing the number of bears harvested, the Edmonton university said in a news release. But harvesting based on sex selection has reduced the number of males compared to females in polar bear populations across the Canadian Arctic, said the study's lead author, Peter Molnar, a Ph.D. candidate in the university's biological sciences department.
The mathematical model developed by Molnar, under the supervision of polar bear expert and faculty member Andrew Derocher, has given the researchers the ability to predict how many male bears are needed in an area compared to the number of female bears to maintain successful mating.
The team determined if the male-to-female ratio drops below a critical threshold, the model predicts a sudden collapse in fertilization rates. The threshold depends on whether the area has a high- or low-density polar bear population.
The findings were published in the online edition of the Proceedings of the Royal Society, an academic journal based in Britain.
© 2007 United Press International. All Rights Reserved.
This material may not be reproduced, redistributed, or manipulated in any form.
This material may not be reproduced, redistributed, or manipulated in any form.
» Next in Science:
Study: Online privacy sacrificed for trust
This NASA montage of images of Jupiter and its volcanic moon Io, was taken by the New Horizons spacecraft's flyby in early 2007. The Jupiter image is an infrared color composite taken by the spacecraft's near-infrared imaging spectrometer on Feb. 28, 2007. The Io image, taken on March 1, 2007, is a nearly true-color composite. The image shows a major eruption in progress on Io's night side, at the northern volcano Tvashtar. (UPI Photo/NASA)
Jupiter and its moon Io
Latest Headlines
Most Popular
- Woman loses finger in purse snatching
- Brothers can be held in Holloway case
- Report: Teacher cell phone has nude snaps
- D.B. Cooper still a mystery after 36 years
- Obesity not just a matter of willpower
- Lebanon without a president
- This diamond ring will rock the wallet
- Illegal immigrant cop faces deportation