(RNN) – Mountain goats have been getting airlifted out of Olympic National Park in Washington state, as wildlife officials conduct a long-planned removal operation of the non-native animal.
One reason for the urgency is that in recent years, the goats have grown more comfortable around people, and more aggressive as they seek out salt – in particular, the kind found in human sweat and urine.
As Olympic National Park wrote in a record of decision:
The operation began last week, The Seattle Times reported.
"We will have removed an exotic species that has impacts on fragile ecosystems," Sarah Creachbaum, the park's superintendent, told the paper.
According to the record of decision, officials are hoping to capture half of the roughly 725 mountain goats living in the area.
The park's record of decision said the goats "were introduced to the Olympic Mountains prior to the establishment of the national park, and have since colonized the entire range."
Past efforts to reduce the population moved more than 400 goats in the 1980s, from a high of more than 1,000 around the time.
Creachbaum said in a release that the goats being moved will be inserted into "sustainable populations of goats in the Washington Cascades, where goats are native, and populations have been depleted."
Officials are planning to cull the remaining half of the goat population through lethal methods.
A park official, Louise Johnson, told NPR last year that "it was just the wrong thing to do" when the goats were introduced into the area around the 1920s.
Their affinity for salt via human sources and increasing boldness in seeking it out has made them too serious a menace over time, Johnson said.
"They are lethal with those nice horns."