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!
How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
24.05.2017 | Physics and Astronomy
24.05.2017 | Physics and Astronomy
24.05.2017 | Event News