Uganda’s Rare Tree Climbing Lions and Endangered Primates Threatened By Climate Change

Elephants in an area infested by the invasive sickle bush. The
Uganda Wildlife Authority fears that the management of the shrub
could be a challenge as the plants rapidly colonise grasslands in
the Queen Elizabeth National Park, the country’s most diverse park.
Credit: Wambi Michael/IPS

By Wambi Michael
KASESE, Uganda, Jun 12 2019 (IPS)

As climate change leads to increased temperatures in East
Africa, a thicket of invasive thorny trees with the ability to
withstand harsh climatic conditions have begun threatening
Uganda’s second-largest park, home to a rare breed of tree
climbing lions and one of the highest concentrations of primates in
the world.

The Queen
Elizabeth National Park
forms part of the Greater Virunga
Landscape, considered the richest part of the African continent in
terms of vertebrate species. The park is Uganda’s most diverse
and boasts 5,000 species of mammals, including: 27 primates such as
chimpanzees, red-tailed and monkeys, and baboons; birds;
amphibians; reptiles; hippos and elephants.

But conservation experts at the Queen Elizabeth National Park
are fighting to stop the spread of Dichrostachys cinerea, commonly
known as sickle bush.

There is a fear that the further spread of of the shrub, which
has a long tap root and various lateral roots that make it
difficult to remove, could further place at risk the already
endangered species that exist here. A recent  Intergovernmental Science-Policy Platform
on Biodiversity and Ecosystem Services (IPBES) 
report
found that there is massive loss of biodiversity globally that
could “undermine human well-being for current and future
generations,” according to Sir Robert Watson, the outgoing chair
of the IPBES.

Though not new to the country or the region, the invasive plant,
which is native to South Africa and known for its medicinal uses,
has begun spreading rapidly across the park, taking up in recent
years an estimated 40 percent of the almost 2,000 square kilometres
that the park covers.

Edward Asalu, the chief warden here, told IPS that the spread of
these thickets was affecting animal settlements in this
ecologically diverse part of the country.

“This issue is being studied but we know that it is largely
linked to climate change,” he said, alluding to the increased
temperatures in the country. He added that higher levels of carbon
dioxide in the atmosphere also contributed to the fast spread of
the sickle bush.

According to a climate risk assessment
report
 on the country by the Climate and Development Learning
Platform, which aims to integrate climate change into development
programming, “climate projections developed for Uganda …
indicate an increase in near-surface temperature for the country in
the order of +2°C in the next 50 years, and in the order of
+2.5°C in the next 80 years.”

Robert Adaruku is a tour guide with the Uganda Wildlife Authority
(UWA)
and has noted that increased temperatures have affected
the growth of the sickle bush.

“As the temperature goes high, such kinds of plants like the
sickle bush are able to survive in a hotter environment are able to
expand. Because the weather or environment will be favouring their
expansion,” he told IPS.

The sickle bush and its recent rapid growth due to increased
temperatures has led it to become the latest threat to Uganda’s
wildlife conservation efforts. Credit: Wambi Michael/IPS

Thicket drives away animals
The spread of the sickle bush is evident as one drives along the
road overlooking the Kazinga Channel, a 32 kilometre stretch of
water that joins Lake George and Lake Edward. The channel has
previously been considered the ideal spot to view game.

A lonely male elephant is spotted in the early afternoon under a
thicket of sickle bush. There is no grass underfoot.

Asalu told IPS the thickets were not easily penetrated by most
animals and that “grazers like antelopes, warthogs and buffalos
are avoiding those thickets because they can’t find food under
there.”

“We have areas which were grasslands but are now being taken
over by thickets. Animals, especially the herbivores, like open
areas where they can be able to see the carnivores trying to eat
them. That is why you cannot find them in area colonised by the
sickle bush,” Asalu explained.

Adaruku explained that he first noticed the sickle bush in the
park way back in 1997. “The sickle plants were there but on a
very small scale. As time goes on it has been able to expand and
colonise this area.”

Sickle bush spreading rapidly across Africa and
beyond

But it is just not this park that the sickle bush is taking
over. Asalu confirmed that Tanzania’s Randilen Wildlife Management
Area
 also recently had to deal with the spread of the sickle
bush.

Quoting a study by the Centre
for Agriculture and Biosciences International (CABI)
, a
non-profit inter-governmental development and information
organisation, Asalu said that Dichrostachys cinerea spreads very
fast because it can produce up to 130 shoots from the mother
stem.

Studies from West Africa have found that the sickle bush is
mostly found in warm, dry savannahs but it can grow in more than
three climate groups.

CABI said the subspecies spreading in East Africa is thought to
have originated in countries such as Algeria, Cameroon, Ghana,
Kenya, and South Africa and is spreading all over the world.

“Dichrostachys cinerea has a high reproductive rate, meaning
that they produce many seeds throughout the year. Although not all
offspring are successful, the plants that do establish themselves
can typically expect a long lifespan due to their tolerance to
natural disturbances like fire, drought and pests,” reads part of
a 2017 report by CABI.

It added that the ability by the sickle bush to prosper on
nutrient-poor soils and disturbed areas made it very adaptive and
resilient in its native region of South Africa.

A 2017 study in the
journal Nature Communications found that alien invasive species,
like the sickle bush, have the ability to expand rapidly at higher
latitudes and altitudes as the climate warms, out-pacing native
species. The park is estimated to be 914m above sea level, while
Uganda is about 140 kms above the equator.

Geofrey Baluku is a part-time tour operator around Kilembe and
Kasese, the areas alongside the Queen Elizabeth National Park. He
is also concerned about the spread of the sickle bush.

“It is a serious problem. What will happen to this park if all
the animals go away?” Baluku said in an interview with IPS.

He told IPS that the sickle bush is not entirely new to the area
but the rate at which it is expanding was.
“We have used those same plants to treat some diseases. It is
very good soothing to tooth ache.
“But …even elephants don’t eat their leaves. Other small
animals don’t want to stay in areas colonised by sickle bush so
they move to other areas, including where there are human
settlements,” Baluku said.

Uganda Wildlife Authority wardens at one of the areas formerly
colonised by the sickle bush. The authority has undertaken
restoration efforts since July to clear the Queen Elizabeth
National Park of the shrub. Credit: Wambi Michael/IPS

A problematic plant

Dr Peter Baine, a research officer at Uganda’s invasive
species research unit, told IPS that the sickle bush forms a canopy
in a colonised area, releasing chemicals that kill the grass
underneath.

“It is quite problematic to other plants because of its
ability to spread fast, grow fast, disperse numerous seeds, and the
seed’s ability to last in soil up until a year,” he said.

Baine did not rule out the fact that its rapid spread could be
linked to climate change. He told IPS that invasive species and
climate change are two of the primary factors that alter ecological
systems.

He said the National
Agricultural Research Organisation
and UWA were conducting
studies to understand the interaction between climate change and
the sickle bush for a possible management plan to fight the
problem.

Restoration Effort

The UWA has in the past burnt the sickle bush but discovered
that the tree would sprout again after a few weeks.

Since July, the authority has embarked on a new restoration
effort, involving the uprooting and burning of the plants in
colonised areas.

About six hundred hectares of sickle bush had been uprooted by
May when IPS visited the Queen Elizabeth National Park.

Asalu told IPS that there remains a huge challenge ahead because
uprooting and burning the sickle bush requires huge financial
resources that are not readily available.

But in the meantime the current efforts for eradication are
making a difference. IPS saw a number of animals, including
buffalo and bushbucks (African antelopes), in parts of
the restored area.

*Writing with Nalisha Adams in Johannesburg

The post
Uganda’s Rare Tree Climbing Lions and Endangered Primates
Threatened By Climate Change
appeared first on Inter Press Service.

Source: FS – All – Ecology – News
Uganda’s Rare Tree Climbing Lions and Endangered Primates Threatened By Climate Change