Conservationists are expressing concern that some of the Kingdom’s endangered birds are not reproducing this year due to extreme heat stress, inability to find enough food and habitat loss from wildfires and human encroachment.

“They aren’t able to gain enough weight” to nest and lay eggs, said Ross Sinclair, the country director of Wildlife Conservation Society.

Affected species include the white-shouldered ibis, the giant ibis and the sarus crane, which range from vulnerable to critically endangered, according to Sinclair.

“This drought is not contributing to their recovery,” Sinclair said. “Increased stress on [endangered] animals is not good news for conservation.”

Meanwhile, BirdLife International program manager Bou Vorsak said Cambodia’s endangered vultures are losing nesting trees due to logging and fires on the Eastern Plains and along the Sesan River.

Vultures are especially needed this year to clean up the many animal corpses resulting from the record heat and water shortage, Vorsak said. By scavenging, vultures clean up the environment and reduce the chance of insect-borne disease.

While WCS and BirdLife don’t expect endangered ibis, crane and vulture numbers to actually decline this year, they don’t hope to see much of an increase year either.

Endangered bird populations had been increasing almost every year over the past decade until the recent interruption.