Dear All,
What with the horrendous metal monoliths detracting the scenic
pleasures of previously unspoilt grasslands within the Athi Basin in
Nairobi National Park, I thought that this short article would be of
interest to those with a concern, and we should all be concerned. Of
course Nairobi NP is not the only Park or reserve so affected,
Best to all
Brian


The Secret Way Power Lines Have Been
Scaring Wildlife

While power lines seem like mundane structures to us, researchers have
come up with a new explanation
about why animals are avoiding them.
Scientists have noted in the past that animals in varied habitats
avoid power lines, even long after they're
built, but weren't sure exactly why because they're easy to pass by
and aren't associated with people. One
explanation was that they avoided the open areas that were cleared to
build power lines because they
would make them vulnerable to predators. However, this theory wouldn't
apply to a species like reindeer
who live in open tundra.
Now a team of researchers from the University College London (UCL),
Moorfields Eye Hospital, London,
UIT The Arctic University of Norway and the University of Oslo in
Norway believe they have come up with
the answer and that UV light is the culprit. Their findings were
published in the journal Conservation
Biology.
High-voltage power lines emit flashes of UV light when buildups of
ionized gas are released at insulators
and points along cables. While these flashes are invisible to the
human eye, a number of species can see
them. Now researchers believe animals are seeing power lines as
flashing streaks of light cutting across
the landscape.
While it's been known that birds, fish, and some reptiles and
amphibians were sensitive to UV light,
another recent study found that a variety of mammals, including dogs
and cats, can see some level of UV
light. Reindeer, who have adapted to survive the dark Arctic winters,
are particularly sensitive to it.
"New information about animal vision along with the characteristics of
power lines provides strong
evidence that the avoidance may be linked with animals' ability to
detect ultraviolet flashing on power lines
that humans cannot see and which they find frightening," said
Professor Glen Jeffery, UCL Institute of
Ophthalmology, in a
Researchers now believe these flashes are making power lines appear as
scary looking lines that are
impacting wildlife around the world by altering migration routes,
fragmenting habitats and cutting off access
to grazing land, which is a theory that would be particularly
applicable to reindeer.
"The loss and fragmentation of habitat by infrastructure is the
principle global threat to biodiversity - it is
absolutely major. Roads have always got particular attention but this
will push power lines right up the list
of offenders," Dr. Nicolas Tyler, an ecologist at UIT The Arctic
University of Norway, told the Guardian.
Not only are these sparks bad for wildlife, but they're also a sign of
inefficiency and are early indicators of
problems. Power companies use helicopter-mounted cameras to try to
find them and fix issues, but won't
be able to eliminate them entirely. According to Jeffrey, even with
our ability to see what the UV cameras
pick up, it's still only a glimpse of what animals see.
Researchers hope that this discovery will at least help with future
decisions about where power lines are
placed. According to the Guardian there is a plan to build a 186 mile
power line through Norway, and they
hope their work will encourage power companies to work with reindeer
herders on its placement.