The wild bison roaming Catalina Island are a major attraction for the nearly 1 million tourists who visit the Channel Island's most popular destination every year. But managing the number of bison so that the herd remains healthy and doesn't endanger the health of the rest of the Island has been a major challenge for wildlife biologists.
Fourteen bison were brought to Catalina Island on Christmas Eve in 1924. Today the herd is successfully managed to a population around 150 with a contraceptive.
Credit: Photo by Jack Baldelli, courtesy Catalina Island Conservancy.
A new study by the Catalina Island Conservancy scientists, published in the December supplement of the Journal of Zoo and Wildlife Medicine, reports that the Conservancy's contraception program proved effective in managing the herd's numbers. Previously, more than two-thirds of the cows delivered calves every year. After receiving the contraceptive, the calving rate dropped to 10.4% in the first year and 3.3% the following year.
The Conservancy's study demonstrated for the first time that this type of contraceptive will work in a wild herd, a finding that can help improve bison management programs throughout the United States.
"The success of the Catalina Island Conservancy's bison contraception program demonstrates the innovative approaches our scientists undertake in fulfilling our commitment to being responsible stewards of the land and the Island's resources," said Ann Muscat, Catalina Island Conservancy president and chief executive officer. "By proving the effectiveness of this humane approach to herd management, this research will be a benefit to bison herds throughout the U.S. It also lays the groundwork for further contraceptive studies in other wild species."
The bison were first brought to the Island in 1924 for a movie. Over the years, they became an iconic symbol of the Island's culture. But with no natural predators, the herd grew to some 600 animals. The Catalina Island Conservancy, which protects 88% of Catalina Island, had previously conducted studies that found the Island could support only about 150 to 200 bison. To control the herd's size, the Conservancy had been periodically conducting roundups and shipping bison to the mainland.
"Shipping the bison to the mainland was costly, and it raised concerns about the stress on the animals during shipment and the expansion of the herd beyond ecologically sustainable numbers between shipments," said Julie King, director of conservation and wildlife management and a co-author of the contraception study. "We launched the contraceptive program because it is a humane and cost-effective solution to managing the herd and protecting the Island's resources."
Beginning in 2009, the Conservancy's scientists injected the female bison with porcine zona pellucida (PZP), a contraceptive that had been used for fertility control in zoos, wild horses and white tail deer. In addition to substantially reducing the number of new calves, the PZP had no apparent effect on pregnant females or their offspring. The Conservancy's scientists continue to study PZP to determine if the female bison can regain their fertility after a period of time without the contraceptive.
"The bison contraception program is a good example of trying to reach a balance with cultural, aesthetic or recreational needs and uses and cost-effective natural resource management to maintain the health of the ecosystem," said John J. Mack, chief conservation and education officer. "Because humans have been living and changing the Island for thousands of years, the Conservancy is always seeking new approaches to ensuring the long-term use and ecological health of Catalina Island."
The Catalina Island Conservancy was formed in 1972 and is one of California's oldest land trusts. Its mission is to be a responsible steward of its lands through a balance of conservation, education and recreation. The Conservancy protects the magnificent natural and cultural heritage of Santa Catalina Island, stewarding approximately 42,000 acres of land deeded to the Conservancy in 1975, 62 miles of rugged shoreline and more than 80 miles of trails. It operates the Airport in the Sky, Wrigley Memorial & Botanic Garden and two nature centers. Twenty miles from the mainland, the Island is home to more than 60 plant and animal species found nowhere else in the world.
Patricia J. Maxwell | EurekAlert!
Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University
Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses