In northern Cambodia, giant ibis, white-winged ducks and other rare species have helped ecotourism take flight in recent years. Just two decades after their near extinction, the population of giant ibis has grown to about 300 birds, bringing in thousands of visitors to remote areas of the country. This tourism has provided an important economic catalyst, generating critical revenue for rural communities and conservation initiatives.

But now, in Cambodia and other wild places around the world, ecotourism is in the crosshairs of a new threat — COVID-19, the disease caused by the novel coronavirus. The consequences for both wildlife and people are still unfolding and expected to be far-reaching.

"A major source of income for rural communities has suddenly been cut off," said Jeremy Radachowsky, director of the Mesoamerica and Western Caribbean Program for the Wildlife Conservation Society. "It's going to have an especially large impact on budgets for protected areas and wildlife, which also happen to be some of the most important investments we can make to avoid future pandemics."

Why? Because, he said, "degradation of natural ecosystems and wildlife trafficking facilitate the spillover and spread of zoonotic diseases."

Or as the World Economic Forum website puts it: "It is no coincidence that the destruction of ecosystems has coincided with a sharp increase" in infectious diseases.

Added Midori Paxton, head of ecosystems and biodiversity at the United Nations Development Program, "Intact nature gives us air, water and food and serves as a 'natural vaccine' to reduce the frequency and intensity of future outbreaks."

Since the coronavirus outbreak, investments in nature are in jeopardy as resources are diverted and tourism dollars supporting conservation dwindle. Most world travel destinations have experienced shutdowns as borders have been closed, visas restricted and quarantines enforced to limit the spread of the virus. National parks, game preserves and wildlife sanctuaries in Africa, Asia and beyond have closed. The closures have led to reduced protection for wildlife and lost incomes as rangers, guides, drivers, cooks, animal caregivers and others have been let go. The U.N. World Tourism Organization estimates a decline of international tourism of 60% to 80% by the end of the year compared with 2019, with trillions of dollars and millions of jobs lost.

"The biggest concern in the short term is continued investment in ecotourism and rural areas to make up for lost revenue streams and jobs," said Johan Robinson of the U.N. Environment Program, noting that the global cutbacks due to covid-19 could last a year or more.

The collapsed tourism economy adds new stressors on top of ongoing challenges from vanishing habitats to climate change to human encroachment. Already, the International Union for the Conservation of Nature and the U.N. Development Program have reported an increase in natural-resources exploitation and illegal killings of wild animals and threatened species.

In Costa Rica, a new ecotourism initiative to help conserve the once-common white-lipped peccary — similar to a wild boar — has seen few visitors. Meanwhile, the white-lipped peccaries are increasingly endangered because of the hunting of the large animals and deforestation. In Namibia, a cheetah conservation center can no longer rely on tourist visits to help fund operations. In Gabon in March, the government closed its great-ape parks to tourists because of COVID-19, as have other African countries. The closures have drained funds from efforts to protect critically endangered gorillas and other great apes. In Sumatra, ecolodges can't provide their usual support to a sanctuary for nearly extinct Sumatran rhinos and a nearby elephant hospital.

In the wading pools, swamps, marshes and rainforests of northern Cambodia, tourists used to visit in hopes of catching sight of the critically endangered giant ibis, characterized by their height and silver-tipped wings notched with black crossbars, and other wildlife. Their visits have generated thousands of dollars for community funds and conservation programs, according to the Wildlife Conservation Society. But now the local economy is in limbo, and this spring the group reported that several giant ibis were killed for their meat, as were white-winged ducks, painted storks and other wild animals.

International agencies and organizations are scrambling to respond to the crisis and reduce incentives to hunt, poach and illegally clear land for farming, timber or other resources. Wide-scale socioeconomic stress related to COVID-19 has added to the pressure, with the World Food Program estimating millions of people worldwide are now living close to starvation and resorting to whatever options are available to survive.

"If the supply of money from tourism dries up, rangers might be laid off, leave the bush and look for other ways to feed their families," said Chris Thouless, director of research for Save the Elephants. "If someone sees an elephant, for instance, they might shoot it as an investment even if they cannot immediately get money for the tusks, and hunting for bush meat may increase."

Across Africa, with many countries dependent on a wildlife tourism industry that brings in billions of dollars, the outlook is equally grim. "The situation is pretty bad," UNEP's Robinson said. "Most of the parks have been closed, and there are no tourists and no safaris. It's a huge loss of income, and a lot of lodges don't know if they are going to make it."

Similarly across Central and South America, conservationists are seeing increases in deforestation, poaching and sudden disruptions to long-established businesses and ways of life. In Ecuador, the wildlife-rich Galápagos Islands have had few visitors this spring, and the tourist-based economy has seen thousands of jobs lost.

In response, organizations are ramping up support. The Lion's Share nonprofit, for example, is awarding small grants to ecotourism-dependent communities in developing countries. Other groups are tapping reserves and emergency funds to keep employees on the payroll and ensure staff and partners in the field have food, water and other supplies.

Continued international cooperation and global support for conservation is also seen as vital, including such programs as the U.S. Fish and Wildlife Service's Rhinoceros and Tiger Conservation Fund, as government priorities are diverted by the crisis.

"Funding from governments and existing private sector is not going to be enough," Robinson said. "Estimates already indicated that more than double the pre-covid government and philanthropic investments were needed for effective global conservation."