The lion (Panthera leo) was the most successful large carnivore during the late Pleistocene, when the species' range extended from South Africa, across Eurasia, and into the southern United States [1]. Today, the lion's range is restricted to Africa and one population of the Asiatic sub-species, P. l. persica, in India [2]. While the endangered Asiatic population is currently considered stable, lion populations in Africa are in decline and the African sub-species, P. l. leo, is considered vulnerable [3]. Recent analyses established that the African lion has lost at least 75% of its original habitat, with fewer than 35,000 wild African lions remaining [4]. The main drivers of lion declines are large-scale habitat conversion, prey base depletion through unsustainable hunting, and the retaliatory killing of lions due to perceived or real human-lion conflict [3]. The situation is most critical in West Africa, where lions have been considered regionally endangered since 2004 [5], and where
Of 12 PAs with management assessments, six had no budget for management activities, and where budgets existed they were much lower than required to conserve lion populations effectively [33]. PAs with confirmed or probable lion presence had larger budgets than those with lions absent, and WAP had both the largest lion population and the highest annual budget, at US$197/km2 (Table S4). WAP furthermore consistently received among the highest scores for management effectiveness of all PAs harboring lions (Fig. 4B). For PAs where data on population trends of principal lion prey species were available, WAP (represented through Pendjari NP, where annual wildlife counts are conducted) was also the only site where wildlife numbers were stable or increasing (Fig. 5). As a further indication of conservation success in WAP, this site harbors by far the largest remaining elephant population in West Africa [16], and one of the last remaining populations of the critically endangered Northwest African cheetah (Acinonyx jubatus ssp. hecki) [17]. Even so, WAP's budget is an order of magnitude below the estimated >US$2000/km2 budget required to maintain lions in unfenced PAs [33], suggesting that WAPs success may not be sustainable and will require increased funding in future.
Lions in Central and West Africa to be added to endangered species list
It is imperative to address very widespread poaching of lion prey species and illegal killing of lions by pastoralists within and around PAs [14], [51], [52]. We believe urgent priority must be given to a dual strategy that focuses on 1. increasing the numbers, expertise, and operating budgets of enforcement personnel in PAs with lions, to curb the killing of lion prey and illegal incursions into PAs by pastoralists, and 2. reducing human-lion conflict in affected communities bordering PAs, by combining improved husbandry practices with community sensitization, to reduce livestock losses to predators and ameliorate local negative perceptions of large carnivores [51]. Investment should also be directed toward developing and enhancing photographic tourism in politically stable countries such as Benin and Senegal. This will help to create and maintain economic incentives for lion conservation, and develop enduring revenue streams for PA management not wholly reliant on donor funding.
The situation for the lion in West Africa is dire. We recommend urgent revision of lion taxonomy by the Cat Classification Task Force of the IUCN/SSC Cat Specialist Group [53]. Recognition of a West-Central African sub-species is supported by recent findings establishing the principal division of extant lions within Africa, and would correctly recognize the genetic uniqueness of West African populations [8], [9]. Irrespective of taxonomic status, we recommend listing the lion as critically endangered in West Africa.
Considering the relative poverty of lion range states in West Africa, we call for the mobilization of substantial and urgent investment by the international community to assist these countries in improving management effectiveness of PAs containing lions. Lions persist in some of the largest and most intact protected landscapes in West Africa, where they co-occur with some of the last remaining populations of critically endangered mammals including Northwest African cheetahs, Western giant elands and African wild dogs. Further deterioration of those last wilderness areas in West Africa will likely cause the loss of genetically distinct populations of charismatic megafauna and further preclude already tenuous, potential future revenue streams from photographic tourism for West African nations. Without immediate action, we believe the opportunity to save both will be lost.
Now, in a move that will make it far tougher for American hunters to bring African lion trophies back home, the U.S. Fish and Wildlife Service (FWS) is adding lions to its endangered list. This will mean a measure of protection for lions under the Endangered Species Act that hasn't existed previously.
Two subspecies of lions will be added to the list. One of them, found in central and West Africa, numbers only about 900 animals and will be classified as endangered, meaning hunters will be prohibited from importing trophies.
Because of unexplained widespread population declines in Alaska, Steller sea lions were first listed under the Endangered Species Act (ESA) in 1990. In 1997 NOAA Fisheries recognized two distinct population segments, listing the eastern distinct population segment (DPS) as threatened and the western DPS as endangered. The eastern DPS has since recovered and is no longer listed, which is a significant achievement under the ESA. The western DPS remains endangered.
Steller sea lions are exposed to a variety of diseases and parasites. Adult females and pups are likely the age-classes most vulnerable to disease and parasitism. Infectious disease and parasitism likely have a relatively low impact on the recovery of the Steller sea lion's western distinct population segment. However, climate-change-related shifts in distribution of other species may expose Steller sea lions to novel disease vectors or parasites that could have large-scale impacts. NOAA Fisheries works with a variety of scientists and veterinarians to monitor disease in animals that are found dead and to sample live animals.
Contaminants that might harm Steller sea lions can occur naturally in the environment and enter ocean waters from many sources, such as oil and gas activity (tankering and pipeline transport, production, etc.), vessel accidents and sinkings (leading to loss of cargo, fuel, etc.), local industrial development, atmospheric transport, wastewater discharges, at-sea processing, runoff, toxic waste sites, nuclear testing, industrial accidents, and natural sources. Once in the environment, some contaminants move up the food chain and accumulate in top predators. Certain pollutants that Steller sea lions are exposed to have been shown to damage the immune and reproductive systems of other mammals and to negatively impact their health and survival. Of particular concern now is information showing that mercury contaminant loads of some western DPS Steller sea lion pups are relatively high in some parts of the range where declines are still occurring. Exposure to organochlorines known to affect health impacts in other species have been found in parts of the western and eastern DPSs, though impacts on Steller sea lions are not clear. Emerging environmental contaminants, such as Polybrominated diphenyl ethers (PBDEs) are known to bioaccumulate in marine mammals and thus are also a concern, though Steller sea lion exposure to these compounds is not well understood.
Our research has helped inform us about new aspects of Steller sea lion biology, behavior, and ecology and better understand the threats to Steller sea lion individuals and populations. Continued research is especially important in recovering the endangered western DPS and sustaining the recovery of the delisted eastern DPS. Our work includes:
The decline in the abundance of Steller sea lions was first observed in Alaska in the 1970s, and the rate of decline increased dramatically in the late 1980s. This decline prompted NOAA Fisheries to list the species range-wide as threatened under the ESA in 1990. Due to genetic, morphological, ecological, and population trend data supporting the overall distinctiveness, NOAA Fisheries recognized two distinct population segments (DPS) in 1997.
Steller sea lions are protected in Canada, where they are categorized as a Species of Special Concern, and in Russia, where they are listed as an endangered species under Russian legislation. NOAA Fisheries coordinates with Fisheries and Oceans Canada to monitor British Columbia populations. While the Russian government currently has no organized program of monitoring and research, NOAA Fisheries supports projects monitoring population trends and vital rates in Russia. In return, NOAA Fisheries receives high-value information needed to understand the overall status of the western population and threats to its long-term survival.
Steller sea lions are protected under both the Endangered Species Act and the Marine Mammal Protection Act. The western distinct population segment (DPS) is listed as endangered under the ESA and, therefore, also designated as depleted under the MMPA. As a result, the stock is classified as a "strategic stock".
NOAA Fisheries has a responsibility under the ESA to take action to conserve Steller sea lions that is, to use all methods and procedures that are necessary to bring the endangered western DPS to the point at which ESA protections are no longer necessary, and to sustain the eastern DPS's recovery. NOAA Fisheries, state, international, university, tribal, other federal, and other scientists use a variety of innovative techniques to better understand Steller sea lion ecology and threats to their long-term viability. Working with our many partners, NOAA Fisheries scientists use this information to identify actions to remove or reduce threats. 2ff7e9595c
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