Wind power is one
of the fastest growing forms of renewable energy around the world. In South Africa two wind farms have been
constructed and are currently operational, namely the Klipheuwel and Darling
wind farms on the West Coast in the Western
Cape. Proposals to construct many more have been
submitted mainly along the West Coast, East Coast and the Central
Karoo. Wind farms are considered integral to the development of
the green economy, which is an economy driven by technologies which reduce
emissions and pollution, enhance energy and resource efficiency, and prevent
degradation of species and ecosystems. Wind farms appear to be less harmful to
the environment than burning fossil fuels because they do not directly generate
greenhouse gas emissions. But for birds and bats, wind farms can be potential
death traps.
Throughout North America and Europe large numbers of bats die each year as a
result of the turbines at wind farms. Scientists predict that by 2020 between
33 000 and 111 000 bats will be killed each year by wind farms in the
mid-Atlantic highlands of the USA
alone. According to Kath Potgieter, Senior Field Officer for the EWT’s Wildlife
and Energy Programme, “Much research has focused on the impacts of turbines on
bird populations but little has been done on bats, despite bat fatalities at
some wind farms outnumbering bird fatalities by 10:1. Bat fatalities are caused
by more than just collisions with the turbine blades – they are also affected
by a phenomenon called barotrauma. Barotrauma occurs when the lungs of the bats
are damaged by sudden changes in air pressure close to the turning blades of
the turbines and this results in numerous losses.”
Bats are relatively long-lived mammals. One bat, weighing a mere seven grams,
lived to 41years in the wild. Because they live so long and females only have
one, or sometimes two pups per year, bat populations may take many years to
recover if their numbers are reduced. Although bats do have natural predators,
including the specialised Bat Hawk Macheiramphus alcinus the greatest negative
impacts on the species are as a result of human activities such as poisoning,
disturbing roosts, habitat destruction and now, wind farms. Misconceptions
about bats have not made them very popular creatures even though they play a
vital role in maintaining biodiversity and in the sustainability of the
environment through, among other things, acting as pollinators and seed
disperses and consuming massive amounts of potentially damage causing insects.
Whilst environmental impact assessments are conducted for all new wind energy
facility developments in South Africa, to-date, there have been no systematic
studies on the impacts of wind turbines on bats in South Africa. As a result,
conspicuous gaps in knowledge on the subject exist. Systematic and accurate
monitoring of the effects of wind farms on bat populations is thus imperative
to fill these gaps in knowledge, inform developers and develop ways to mitigate
the effects.
“The newly completed South African Good Practice Guidelines for Surveying Bats
in Wind Farm Developments, produced by the Endangered Wildlife Trust in
conjunction with independent eco-consultant and trainer Sandie Sowler;
Stellenbosch University postdoctoral fellow Samantha Stoffberg; and endorsed by
the South African Wind Energy Association; highlights the need to assess the
impact of wind farms on ecology, as well as the importance of bats in the
context of the ecosystem services they provide. In addition it provides
guidance on assessing the need for monitoring and preparing, planning and
implementing bat monitoring in respect to wind farm development. The guidelines
aim to standardise data collection and results interpretation and proactively
address any possible negative impacts before it is too late,” said Potgieter.
In January this year the EWT facilitated a Bat and Wind Farm Interaction
Training Course in the town of Greyton in the Western Cape. The course
was attended by representatives and researchers from a range of organisations
involved with bat research, conservation and monitoring. The goal of the course
was to build capacity amongst practitioners and ensure a standardised approach
to work in the field. The good practise document is designed specifically to
facilitate this.
In conclusion, Potgieter stated, “In order to ensure that vital renewable
energy advancements in South Africa are not going to have significant negative
impacts on our bat populations, it is critical that both the government and the
developers recognise the need for standardised, professional, environmental
impact assessments and that these assessments be conducted in line with
international norms.” Africa are not going to have significant negative impacts
on our bat populations, it is critical that both the government and the
developers recognise the need for standardised, professional, environmental
impact assessments and that these assessments be conducted in line with
international norms.”
Many of the world’sVultures are killed on wind farms.
Cape Vulture
The Cape
Vulture - Gyps coprotheres -
is Endemic to Southern Africa and is found mainly in South Africa, Lesotho,
Botswana and Namibia.
A large vulture with near-naked
head and neck. Adult creamy-buff, with contrasting dark flight- and
tail-feathers. Pale buff neck-ruff. Underwing in flight has pale silvery
secondary feathers and black alula. Yellowish eye, black bill, bluish throat
and facial skin, dark neck. Juveniles and immatures generally darker and more
streaked, with brown to orange eyes and red neck. The two prominent bare skin
patches at the base of the neck, are thought to be temperature sensors and used
for detecting the presence of thermals.
Calls are loud cackles, grunts,
hisses and roars.
It nests on cliffs and usually
lays one egg per year.
Monogamous colonial nester,
breeding in colonies. They nest and roost on cliffs and usually lay one egg per
year. The nest is mainly built by the female, consisting of a bulky platform of
sticks, twigs and dry grass, with a shallow cup in the centre lined with
smaller sticks and grass. It is typically placed on a cliff ledge, often using
the same site over multiple breeding seasons.
The breeding season is between
May and June with a single egg laid, which is incubated by both sexes for about
55 to 59 days. The chick is brooded constantly for the first 72 days, while
both parents feed it. It eventually leaves the nest at about 125-171 days old,
becoming fully independent about 15 to 221 days later.
Cape Vultures feed on carrion, searching aerially for a
carcass to feed on. They can eat 1.5kg at a sitting, which is over 15 percent
of the weight of an adult bird and can do this in five minutes. It slices off
flesh with the sharp edge of its bill eating it and storing some in its crop,
which can sustain it for about three days.
Vulnerable globally. It is
regionally extinct in Swaziland
and Critically Endangered in Namibia.
Its global population has decreased dramatically, the current population is
estimated at 8,000. This is thought to have been largely caused by habitat
loss, persecution for use in traditional medicine, human disturbance of
colonies, poisoning and improvements in animal husbandry resulting in a
decreased availability of carrion.
These large Vultures can be
seen on the following Aves Birding Tours/Safaris/Adventures: -
Aves Arid Birding Tour / Safari
/Adventure.
Aves Eastern Cape Birding
Tour / Safari /Adventure.
Aves Highlands / Tembe Birding Tour / Safari /
Adventure.
Aves KZN Birding Tour / Safari /
Adventure.
Aves North East Birding Tour /
Safari / Adventure.
Aves North West Birding Tour / Safari /
Adventure.
Aves Western Cape Birding
Tour / Safari / Adventure.