Revenues from selling mountain gorilla tracking permits increased immediately after the announcement of a hike in price, Rwanda Development Board (RDB) said on Saturday.

Mountain gorillas are an endangered species with an estimated over 1,000 remaining in the world. They live in the Bwindi Impenetrable National Park in Uganda and the Virunga Mountains, a range of extinct volcanoes that border the Democratic Republic of Congo, Rwanda and Uganda.

The RDB in May 2017 announced the increase of the price of gorilla tracking permits from 750 U.S. dollars to 1,500 dollars for all visitors.

The landlocked country is seeing an "unsurprising" market reaction to the change of permit fees with a 4 percent increase of revenues in 2017 compared with 2016, the RDB said in a statement responding to a report that said the increase in permit fees led to a steep decline in visitors.

Between May and August of this year, the RDB saw increased revenues of 983,333 U.S. dollars when compared to the same period in 2017, the statement said.

The RDB did acknowledge that there was a small decrease during the low season, but said it sees a recovery in the high season.