Perched on a strong branch, the 150-kilo (330-pound) beast greedily pulls more leaves from the tree to his mouth with a slow but powerful movement before lumbering down the trunk. Soon he dozes off calmly.

After two years of a total shutdown due to the Covid-19 pandemic, the executive secretary of the National Parks Agency (ANPN) has decided to resume public observations of Gabon's gorillas, hoping the iconic species will serve as a "loss leader" to boost niche tourism.

That Kamaya and his family of about 10 individuals are so used to humans is the outcome of long labours by a team of trackers and scientists who also collect data.

They work to win funds to protect a species threatened with extinction and to attract foreign visitors.

Spending one hour with Kamaya and his group costs 300,000 CFA francs, (450 euros, almost 500 dollars), on top of charges for access to the site and accommodation.

Loango Park, which covers more than 155,000 hectares (380,000 acres) of the densely forested country, offers ample reward for a 4-5 hour road journey from Port-Gentil, the second city, followed by the track and a final stage by boat.

Though steep, the price is much lower than that paid to see the mountain gorillas in Uganda or Rwanda. It also generates income to manage protected areas that provide a safe place for the animals.