Lion conservation

[Lisbeth]

Vanishing lions – a 75% decline in Africa’s iconic predators in just five decades

Posted on November 1, 2022 by teamAG in the DECODING SCIENCE post series.



Africa’s disappearing lions have been the subject of animated discussion for years, but just how dire is the situation?

Scientists now believe they have the answer: in five decades, the continent’s lion populations have declined by 75%. This according to research recently published by the University of Oxford’s Wildlife Conservation Research Unit (WildCRU).
The authors set out to establish a baseline lion population estimate and examine historic landscape connectivity for 1970 as a comparison point to assess the conservation of the species. They explain that conservation is subject to what has been termed a “shifting baseline syndrome”. In other words, current conservation efforts are often centred around present-day geographical ranges and population estimates. However, underestimating historical declines or trends could, in turn, underestimate extinction risk.

Disappearing habitats, dwindling lions

Habitat loss and fragmentation due to human population growth and agricultural expansion are among the most significant threats facing most terrestrial vertebrate families. Species surviving in fragmented and poorly connected habitats are more vulnerable to loss of genetic diversity, inbreeding depression, disease and stochastic events (such as drought). Lions are considered an umbrella species, meaning that conservation efforts aimed at their protection indirectly confer protection on other sympatric (co-occurring) species. They are also a charismatic representative of the range collapse experienced by many of Africa’s large mammals. Once widespread across Africa, previous research indicates that lions have experienced an 85% reduction in range since the early 16th century.

Reconstructing historical populations and distributions is a challenge facing many large-mammal scientists, as records are often scant and generalised. The authors selected the period around 1970 for their baseline for several reasons, including the existence of credible and detailed sources of information on lion ranges and populations. Furthermore, human population and development have burgeoned during the 50-year-period between 1970 and the present day, with the sub-Saharan human population doubling between 1975 and 2001. Using available information to construct a population density map of lion distribution, they derived an estimated population of 92,054 lions across the continent in 1970. At last count in 2016, the total surviving lion population was estimated at around 23,000 individuals (though experts believe it may now be under 20,000). This equates to a decline of 70,000 individuals – approximately 1,400 lions per year over five decades.


Figure 1: ”African lion density (N/km2) across (a) recent historical (c1970) lion distribution with population density derived from a generalised additive model; and (b) extant range showing lion population densities. Source: IUCN-SSC, 2018) (© Loveridge et al. [2022])

Disconnected lions

The researchers also examined lion subpopulations by area. Those in the Congo Basin have suffered most severely, and this subpopulation has been all but extirpated. From an estimated 1,600 lions in 1970, around 211 individuals remain – a decline of 93%. Similarly, the West and Central African subpopulations have declined by 87% (from 1,600 to fewer than 200). (The plight of the West African lion was recognised on the IUCN Red List in 2015 when they were listed as Critically Endangered.) Southern and East African subpopulations have fared slightly better but still declined by 73% and 65%, respectively. Southern populations declined from 36,000 to around 9,800, and East African from 31,000 to approximately 11,000.

Remaining lion habitats are important but understanding the landscape connectivity between these is a vital aspect of lion conservation. The researchers analysed the landscapes within lion range in terms of resistance to animal movement, accounting for various environmental and anthropogenic variables (such as rivers, towns, farms and roads). This information was used to calculate the relative probability of animal movement to compare connectivity in 1970 to the present day.

In 1970, much of the existing lion habitat was well connected, apart from already fragmented habitats in the West and Central regions. For the most part, lion range was contiguous, with the potential for a high degree of dispersal movement across the landscape. Today, lions occupy just 13% of their maximum historical range (66% of the 1970 range), with the most severe range loss having occurred in the Congo Basin and the West and Central region. These regions have experienced a “catastrophic collapse in range and habitat connectivity in the last 50 years” – with fewer, smaller, and more widely isolated patches of core and non-core lion habitat. Loss of connectivity was less severe in southern and Eastern African regions but significant – around 50% of previously connected habitat was lost in the intervening five decades. The remaining core areas of habitat are centred around larger protected areas.


Figure 3: “Maps showing landscape connectivity for c1970 and current time periods. Top panel: Landscape connectivity resistant kernels in (a) c1970 and (b) the current period. Bottom panel: least-cost paths in (c) c1970 and (d) the current period. The shaded area represents historical range extent (right-hand maps) and recent historical extent (left-hand maps).” (© Loveridge et al. [2022])

The future of lion conservation

What implications does such research have for the future of lion conservation, given that human population expansion is inevitable? The authors emphasise that even if core protected areas are secure, a lack of connectivity will result in a decline in the genetic diversity of remaining lion populations. The protection of existing wildlife corridors is critical. They also suggest that intensive meta-population (as practised in smaller wildlife areas in South Africa) may be appropriate for irretrievably isolated habitats, such as those in West and Central Africa.

Though the damage done to the lions of Africa may never be fully recoverable, the researchers suggest that it is not too late to secure wildlife corridors “through integrated land use planning exercises, implementation of human-wildlife conflict mitigation strategies and enhancement of sustainable, wildlife-based livelihoods”.
“Habitat conversion and burgeoning human populations are fragmenting natural habitat across Africa,” says lead author Professor Andrew Loveridge. “Our work on African lions shows that this process of fragmentation and population decline has accelerated over the last 50 years and provides a baseline against which to measure population recovery or decline. Our future conservation efforts need to halt habitat loss and work to preserve the remaining habitat corridors linking core populations.”

References and further reading:
Loveridge A.J., Sousa L.L., Cushman S., Kaszta Ż., Macdonald D.W. (2022) “Where Have All the Lions Gone? Establishing Realistic Baselines to Assess Decline and Recovery of African Lions,” Diversity and Distributions

For more on how scientists used ancient ivory to analyse elephant population loss, read this: Of ivory, elephants, shipwrecks and slaughter

On the loss of lion genetic diversity as a consequence of population declines: Lion populations show significant loss of genetic diversity, say researchers

For a detailed explanation of the challenges involved in estimating lion populations: Counting lions: new study shows the importance of good counts for lion conservation

To support the conservation of lions in Africa, view more about the following projects:
– Desert Lion Conservation Trust
– Lion Landscapes
– Wild Entrust
– Mara Predator Conservation Programme

[Richprins]

Interesting!

[Lisbeth]

Top scientists make $3bn plea to rich nations to help conserve Africa’s lions

By Tiara Walters | 01 Oct 2023

Facing the grim reality of potential extinction, Africa’s iconic but underexposed wild lion populations are crying out for help — and for investors with deep, patient pockets.
_______________________________________________________________________________________________________________________
The cost of conserving the African lion may exceed a staggering $3-billion a year, according to new landmark findings.

Jointly led by Oxford University and the Johannesburg-based Endangered Wildlife Trust (EWT), a Nature-published study delves into the multifaceted challenges — social, political and ecological — that confront free-roaming lions. Co-produced by more than 30 authors, it is the first Africa-wide attempt to understand that threat triangle, and offer an investment framework for wild lions living across the continent.

In a Daily Maverick webinar on Thursday, the EWT’s co-lead author Sam Nicholson presented fresh approaches to conservation investments, but acknowledged some of the statistics were grim.

These big cats had vanished from 92% of their historic territories, representing one of the most significant range contractions of any species, said Nicholson, a senior scientist at the EWT’s Carnivore Conservation Programme.

phpBB [video]

From north Africa to sub-Saharan terrains and into the Middle East, the lion’s roar has fallen silent in many regions. Today, their pawprints can be traced in about 25 countries — thus, less than 10% of their former habitat.

About 62 geographical populations were identified by the study, of which 42% had barely 50 or fewer lions. Only 11% — a mere seven groups — had populations exceeding a thousand or more.

The study relied heavily on insights captured in the African Lion Database, which Nicholson manages on behalf of the International Union for the Conservation of Nature (IUCN). The database charts the ebbs and flows of lion numbers, also shedding light on human-caused deaths. Using this, the scientists could monitor and identify populations in decline and establish why the numbers were falling.

Encroachment of human civilisation, human-wildlife conflict, loss of prey and habitat, indirect poaching for body parts and the dangers of violent extremism and war had exacerbated lions’ plummeting numbers.

“This research is the first of its kind in bringing together both ecological and socio-political factors into a single index to evaluate potential conservation investments for African lions,” Nicholson stressed, highlighting past difficulties in conducting such a study, given that scientists typically specialised in one domain.

However, this investigation uniquely combined insights from multiple scientific disciplines, recognising that areas with high corruption or poverty often struggled to devote resources to conservation.

“This is critical,” she pointed out, “because the challenges faced by lions have both ecological and socio-political roots.”

Most ecologically fragile: 10 scouts, one motorbike

Across the continent, diverse patterns observed in lion populations were as striking as the apparent contradictions driving their successes and setbacks.

Africa’s most ecologically fragile population was in Maze National Park, Ethiopia. The park, a 200km2 area southwest of Addis Ababa, was home to just nine known lions, said Nicholson. The park’s challenges were compounded by limited resources; “fairly” high cattle density that likely fuelled human-wildlife conflict; and the isolation of this lion population from others.

“There’s one warden for the whole area and he has 10 scouts who share one motorbike,” Nicholson explained.

By contrast, Tanzania held fast as Africa’s largest stronghold, sustaining a population that surpassed 8,000.

Intriguingly, despite being the least ecologically fragile, Tanzania also had the highest human density within lion areas.

“Humans and animals overlapping doesn’t necessarily mean there’s always going to be conflict,” she observed. “With the right mitigation measures and with the right community engagement projects, human-wildlife conflict can be decreased.”

Hope from South Africa, South Sudan, Mozambique

Immense pressures on the borders of South African reserves notwithstanding, the country’s wild lions emerged as an unlikely beacon of hope, Nicholson noted.

She said the country’s roughly 3,000 lions were stable, if not increasing, and accounted for about 13% of Africa’s population. Kruger National Park provided a refuge to one of the least socio-politically fragile populations in Africa.

In places like Senegal’s Niokolo-Koba National Park and Mozambique’s Gorongosa National Park, conservation initiatives were bearing fruit, offering hope for lion numbers to expand.

Possibly the study’s most surprising, even poignant, revelation came from war-riven South Sudan.

South Sudan’s Boma National Park had a lone lion population that was Africa’s most socio-politically fragile, but the least ecologically fragile due to low human and cattle densities over a large, 20,000km2 area, and connections to Ethiopian populations.

Here the message from the data is clear: do not give up on populations just because they seem doomed by war.

Three-billion-dollar lions

The study’s grand vision to preserve wild lions in both fenced and unfenced areas across Africa carries a revised hefty price tag that could exceed US$3-billion annually — based on yearly running costs of about $500 per km2 for fenced lions; and $200-plus per km2 for unfenced lions.

This updates a $1-billion figure from a 2013 study, which assessed the cost to maintain lions within protected areas. Additionally, a 2018 study cited by Nicholson and colleagues, noted that “nearly all protected areas with lions are inadequately funded”, with deficits totalling roughly up to $2-billion.

Alarmingly, highest deficits were observed in nations with the largest protected areas with lions, such as Botswana, Mozambique, Tanzania and Zambia.

While Nicholson pointed out that funding mattered in all areas hosting lions, she urged funders to temper time frames and other expectations in regions where corruption and political instability remained rife.

As she highlighted, certain destinations, such as Yankari Game Reserve in Nigeria, presented unique challenges. High political instability, corruption and conflict made conservation more difficult and resource-intensive here.

Nicholson’s counsel? Even with considerable investment, backers needed to be prepared to play a long, lateral game.

“Financial investment may not yield the same results or the same outcomes and it’s likely going to be spent very differently — maybe addressing certain socio-political [aspects] that reduce the population’s fragility,” she advised.

The king’s predicament: declining in poorest regions

“Outside conservation circles, people are very surprised to hear that lions are declining and that some populations have gone extinct,” she remarked. While the plight of lions may be overshadowed by the rhino’s more widely publicised dire straits, both keystone species teeter at a nearly identical count of around 23,000.

Yet, comparing lion numbers with another endangered species, she offered perspective with a sliver of optimism: “There are 6,000 mature wild dogs left in Africa — I’m sure wild dog biologists would be absolutely thrilled if they had 23,000 mature individuals.”

When asked about the most effective intervention for the continent’s approximately 23,000 lions, Nicholson emphasised the necessity of a $3-billion investment. This crucial funding, she insisted, would help fortify the species’ habitats and support focused conservation strategies that cater to the unique requirements of each population.

However, most of these habitats lay in the poorest nations — the bottom quarter of global wealth rankings.

Lions attacked and ate livestock, and even people — leading the authors to challenge affluent nations to take action.

“Asking some of the world’s poorest people to maintain dangerous predators in their community is tremendously inequal and likely not sustainable,” they argued. “This research underscores the moral responsibility of wealthier nations to contribute more significantly to lion conservation and will help identify some of the factors which need to be considered to make that contribution more effective.” DM

Read the full study — “Socio-political and ecological fragility of threatened, free-ranging African lion populations” by Sam Nicholson of the Endangered Wildlife Trust, Amy Dickman of Oxford University and others in Communications Earth & Environment, a Nature journal.

Follow Tiara Walters on Instagram: @tiara.adele.walters

[Lisbeth]

The fragile kingdoms of the African lion

Posted on November 14, 2023 by teamAG



The African lion is an iconic symbol of Africa, associated with strength and majesty. In reality, the kingdom of the lion is under pressure. In a recent study, researchers have given us greater insight into what is causing concern for the remaining populations of the African lion.
_______________________________________________________________________________________________________________________
Paws for thought

• The African lion is classified as vulnerable on the IUCN Red List of threatened species;

• There has been a 36% reduction in the species range in the last 21 years;

• Population surveys estimate that ca. 20,000 to 25,000 lions are left in the wild;

• There are only 62 remaining free-ranging wild lion populations remaining in Africa, less than half of which have over 100 lions;

• Lions are now confined to 8% of their historic range distribution; and

• There are marked differences in how well lions do across different populations. Lion populations in Botswana, for example, are thriving and have increased by 12%, but in West and Central Africa, populations have declined by a worrying 66%.

The bigger picture

Conservationists have for years described the risk of extinction for a species through quantifiable metrics, such as a change in habitat, numbers of mortalities, or percentage of the animal’s population in protected areas. But in a new study, Nicholson et al. (2023) point out that these measures are often based on assumptions. For example, just because an area has been declared a protected area by the authorities does not mean that protection is automatically conferred. Governance of protected areas varies across space and time; some reserves do not or cannot enforce this protection. Some countries do not have the resources to maintain anti-poaching units or effectively manage human-wildlife conflict. Context is always critical. In a reserve surrounded on all sides by livestock farmers, lions are more vulnerable to the consequences of human-wildlife conflict (due to lions preying on livestock) than lions in a reserve buffered by other reserves. Lions in a reserve in countries with stable political environments are more secure than lions in states facing political instability.

To integrate this notion of context, the authors introduce the concept of ‘fragility’. Fragility is, in essence, the opposite of resilience. The authors define fragility as the measure of how vulnerable to damage or harm a species is. Resilient populations bounce back after an adverse event. But fragile populations don’t.

Ecological fragility refers to those ecological factors that make a lion population vulnerable, such as lack of connectivity to other lion populations (this would impact genetic diversity and resilience to disease, etc). They then introduce the concept of socio-political fragility as defined by factors such as human population numbers, political stability and environmental policy. This novel way of assessing the fragility of different African lion populations gives conservationists a more realistic way of understanding which populations face high risk.


A pride of lions in full stride on the plains of the Serengeti, Tanzania

Where are the fragile lion populations?

Ethiopia’s Maze National Park lion population is ranked the most ecologically fragile due to its exposure to high cattle and human densities within the lions’ range. Other ecologically fragile geographic populations include Lake Manyara, Nechisar and Toro-Semiliki. In contrast, the lion populations in the Selous-Niassa (Tanzania and Mozambique) and Kavango-Zambezi (Angola, Botswana, Namibia, Zambia and Zimbabwe) systems are considered the least ecologically fragile.

When the socio-political context is considered, however, the analysis reveals that the lion populations in Somalia and South Sudan are considered the most fragile, as they score low in governance and conservation-policy categories. From a socio-political perspective, South Africa, Namibia and Botswana lion populations are considered the least fragile.

The combination of ecological and socio-political fragility gives a different index; thus, a different perspective emerges. Overall, Somalia’s lion populations were evaluated as being the most fragile, Botswana’s the least. Sadly, almost half the countries that scored a high overall fragility comprise 39% of the lion’s range and were primarily located in the northern parts of Africa. Poor governance, population pressure, conflict and poverty are prevalent in these northern countries, and these factors hinder effective conservation.

Using the lens of context to describe the fundamental fragility of this species allows conservationists to make different choices in prioritising scarce resources. For example, the DRC and Cameroon had similar high overall fragility scores, but other factors drove their scores. Cameroon lions had more increased ecological fragility, whereas DRC lion populations were considered fragile because of high political conflict and instability. Therefore, conservationists could decide to direct resources into working with the ecological fragility in Cameroon, which would arguably have more impact and be more accessible than expending resources in the high-risk environment in the DRC.

Choosing which lions to save

Conservationists understand how to deal with ecological fragility. However, addressing the more complicated context of social and political barriers that limit effective lion conservation will require a different set of tools and encompass a far more comprehensive range of stakeholders. This would require levels of involvement from stakeholders such as policymakers, local traditional leadership, international role players and law enforcement. But tackling anthropogenic pressures at a national scale can take a long time.

The study raises interesting philosophical questions about our choices in conservation. Do we direct all our resources into the low-hanging fruit, i.e., the lion populations in stable, well-resourced countries? Is this a feasible long-term strategy? Do we ignore the small (<250) lion populations found in just under half of all lion-range countries in favour of larger populations? How do we do less harm by redirecting resources? Considering that the cost of effective lion conservation would exceed US$3 billion per year, based on rough estimates, how is raising this funding feasible when almost all African lion-range countries are in the top 50% (highest poverty) of the Global Multidimensional Poverty Index?

What is clear from the study is that more systemic interventions are needed in the lion conservation arena. This paper provides the first step in understanding more about the contextual threats facing our rapidly dwindling populations of the roaring icon of Africa.