Efforts Underway to Control Overpopulation of Island Mice, Which Are Devouring Bird Populations
CAPE TOWN, South Africa —
Mice, unintentionally brought to a secluded island close to Antarctica two centuries ago, are multiplying rapidly due to the effects of climate change. They are feeding on seabirds and causing significant damage to a protected nature reserve known for its exceptional diversity.
Currently, environmentalists are strategizing to carry out a large-scale eradication method involving helicopters and massive quantities of rodenticide to be dispersed across the entire 297 square kilometers (115 square miles) of Marion Island in order to achieve desired results.
If even a single pregnant mouse manages to survive, their high reproductive rate suggests that the previous efforts may have been in vain.
The Mouse-Free Marion project, which aims to control pests on a large scale, is considered crucial for maintaining the ecological balance of the unpopulated South African territory and the broader Southern Ocean. If successful, it will be the largest eradication effort of its kind.
The island houses significant populations of approximately 30 bird species that are important on a global scale. It also serves as an infrequently disturbed habitat for wandering albatrosses, known for their impressive 10-foot wingspans, and numerous other species.
The Prince Edwards Islands, a South African territory located in the southern Indian Ocean near Antarctica, is captured in this undated photograph of two wandering albatrosses on Marion Island. (Photo by Anton Wolfaardt via AP)
Until the early 1800s, the natural environment of the island remained untouched until mice unintentionally boarded seal hunter ships and became the island’s initial mammal predators.
According to Dr. Anton Wolfaardt, the manager of the Mouse-Free Marion project, the past few decades have seen a significant increase in the destruction caused by mice. He attributes this rise to the effects of climate change, which has transformed the once cold and windy island into a warmer and drier environment, making it a more suitable habitat for mice to thrive.
According to Wolfaardt, they are likely one of the most prosperous creatures globally. They have populated various locations. However, on Marion Island, their breeding period has been prolonged, causing a significant rise in mouse populations.
Mice do not require motivation. They are capable of reproducing at approximately 60 days old, and females can have up to four or five litters per annum, with each litter containing seven or eight offspring.
It is estimated that Marion Island is home to over 1 million mice. These mice primarily feed on invertebrates, but are increasingly targeting seabirds, including chicks and adult birds in their nests.
The image above, provided by Stefan and Janine Schoombie via AP, depicts a domestic mouse on Marion Island, located in South Africa.
One mouse can consume a bird that is multiple times larger than itself.
The conservationists captured an image of a bird sitting on top of the injured head of a lost albatross baby.
The event of mice consuming seabirds has been documented on a small number of islands around the world.
The number and rate at which mice hunt and feed on seabirds on Marion Island has significantly increased, according to Wolfaardt. This phenomenon was first observed in 2003 and has continued to rise. Wolfaardt explains that the birds do not have the ability to defend themselves against these new predators, and often remain still as the mice consume them. In some cases, the birds are attacked by multiple mice at once.
According to conservationists, without intervention, 19 species of seabirds will vanish from the island within the next 50 to 100 years.
According to Wolfaardt, this island, which serves as a vital sanctuary for seabirds, faces a precarious future due to the consequences of mice.
The eradication effort aims for seamless achievement, leaving no room for mistakes. The excessive growth of mice and rats has caused issues on other islands. In 2018, South Georgia, located in the southern Atlantic, was officially rid of rodents after a multiyear program. However, the project on Marion Island is expected to be the largest individual action taken.
Wolfaardt reported that a total of four to six helicopters will be utilized in distributing 550 tons of bait for rodents throughout the island. Flight paths will be specifically designated for the pilots, and Wolfaardt’s team will be able to monitor and trace the drops through GPS mapping.
The lure has been created to not have any impact on the soil or water sources surrounding the island. According to Wolfaardt, it will not harm seabirds that feed in the ocean and will not have detrimental effects on the environment. While certain animals may be impacted individually, their populations will eventually bounce back.
He stated that there is no ideal solution for these types of situations. There is no method that can solely target mice without any other effects.
BirdLife South Africa and the national Department of Forestry, Fisheries and the Environment have collaborated to establish a project aimed at eliminating threats to biodiversity on Marion Island. The island has been declared a special nature reserve with strict measures in place for environmental preservation. It boasts a weather and research facility, while remaining unpopulated and solely dedicated to conservation efforts.
This photograph, whose exact date is unknown, depicts a research facility located on Marion Island, South Africa. (Photo by Anton Wolfaardt, via AP)
The department emphasized the importance of getting rid of mice in order to protect the island’s unique biodiversity.
According to Wolfaardt, the project is expected to require a significant amount of planning and will likely commence in the year 2027. In addition, the funding for the project, which includes contributions from the South African government, totals approximately $25 million and final approvals from regulatory bodies are also necessary.
In the past, scientists have attempted to manage the mice population in Marion.
During the 1940s, researchers were facing numerous issues due to their presence, hence, they introduced five domestic cats onto the island. However, by the 1970s, approximately 2,000 feral cats had multiplied and were responsible for the death of 500,000 seabirds annually. To combat this problem, the cats were eradicated by administering a feline flu virus and actively hunting down any remaining cats.
According to Island Conservation, islands are essential in conservation, but also vulnerable. They refer to them as “extinction hotspots” and highlight that 75% of all extinct species inhabited islands, with 95% of those being birds.
“This is truly an ecological restoration initiative,” Wolfaardt stated. “It is a unique conservation chance where we can permanently address a threat to conservation.”
Source: voanews.com
