The king of the jungle is in trouble. Populations of African lions (Panthera leo leo) have declined by 42 percent over the past 21 years, according to data released this week by the International Union for Conservation of Nature (IUCN).

The information comes through the latest update to the IUCN Red List, which continues to identify lions as “vulnerable to extinction” (one step short of endangered). That’s mainly because conservation efforts have resulted in an 11 percent growth in lion populations in Botswana, Namibia, South Africa and Zimbabwe. Most of these southern populations live within fenced reserves which have reached their carrying capacity and can’t support additional lion numbers.

Outside of those four nations, things aren’t as good. Lion populations have fallen in most other countries, with an average decline of 60 percent. The worst hit has been the West African population of lions, which has now been classified as critically endangered. A study published last year found that only about 400 lions remained in the 17 nations of West Africa.

Lion threats vary across their range, but the IUCN identifies a few major causes for the decline. For one thing, many of the animals that lions eat are also disappearing due to habitat loss and the growth of agriculture to feed Africa’s growing human population. That’s put the lions into far greater levels of conflict with humans. The IUCN found that lion predation of livestock can cost a Kenyan rancher $290 a year, a huge hit in a country where the gross national income per capita is just over $1,100. Farmers frequently—and according to the IUCN “indiscriminately”—kill lions that have attacked or their flocks or out of fear that they may attack livestock in the future.

In addition, a growing international trade in lion parts has fueled lion poaching and commercial hunting. According to the Born Free Foundation, the number of lion parts and whole lions exported from Africa between 2009 and 2013 was double the amount shipped during the previous five years. This is currently legal under the Convention on Trade in Endangered Species (CITES), which allows lion trade under certain permits. Lion bones are used in traditional Asian medicine and have been in increasing demand to replace bones from tigers, which are in even worse shape than lions.

The IUCN points out that many lion populations are well-protected and live within some of Africa’s most important tourism sites. These populations probably aren’t going away any time soon. Many others, however, lack any protections and will undoubtedly continue to decline, if not disappear, over the coming years.

Born Free has called on CITES to enact greater restrictions on the lion trade and for the U.S. Fish and Wildlife Service to implement its overdue promised protections for African lions, which were announced last October. Those two steps could help reduce the trade, but additional on-the-ground conservation efforts are also required. The IUCN says that many regional conservation strategies have been established and are working, but advises that more political will and funding are required to save lions throughout Africa.

Previously in Extinction Countdown:

Photo by Diana Robinson. Used under Creative Commons license