Lecture Ten - Wind Turbines Flashcards
Why are so many birds of prey killed by wind turbines in North America?
North American wind farms situated on passes between mountain ranges, which are used by migratory species such as bats and birds.
When were bat casualties first noticed at wind farms?
10 years ago
Give the company that offers statuary advice to the government on bats.
Eurobats
What are scoping studies?
Studies that take place early in the process.
What is an Environmental Impact Assessment?
How building will affect the whole environment.
Why might bats run into turbines by accident?
When flying in an open area don’t need to echo-locate, rely on vision for long-distance navigation.
Why might bats run into turbines when migrating?
Because bats migrate using higher airspace.
At what height do bats normally fly at?
Below 30m
When did we learn that bats migrate?
5 years ago
How can we determine where bats originated from?
Using stable hydrogen and carbon isotopes in the fur of bats.
Heavier isotopes tend to fall out of the sky the soonest. Hydrogen comes from the water we drink.
If hydrogen isotopes don’t match water profiles found in the same area, indicates long-distance movement.
Where were pipistrelle bats found in Exeter thought to be from?
Estonia.
Why might casualties of bats at wind farms be due to mating?
Give a species of bat that displays this behaviour.
In some species of bats, males try to occupy the tallest tree in the area to show they are the best male, and could mistake turbines for trees.
Likely in barbastelles.
What is the evidence against mating behaviour linked to bat casualties?
Most deaths of bats at turbines occur before the main display period.
Why could painting wind turbines purple protect bats?
Less attractive to insects.
What is the problem with Daily Mail’s study on wind turbine colour?
Done during the day, so diurnal species of insect, whereas bats are out at night and hunt nocturnal insects.
How can insects stuck on turbine blades affect their efficiency?
Can halve the efficiency
How many wind turbines are found in a large wind farm?
More than 5.
What percentage of dead bats were found by
a) Dogs?
b) Humans?
a) Dogs = 70%
b) Humans = 20%
What is the differences between the number of bats found at single turbines and wind farms?
- Mostly found no dead bats at single turbines
- Most of the time found bats at wind farms.
What is the searcher efficiency of
a) Humans?
b) Dogs?
a) Humans = 0.33
b) Dogs = 0.66
What does curtailment mean for bat protection?
Switching off turbines at night where risk is highest for bats.
When do most casualties happen for bats?
In low wind speed, when not much productivity at wind farms anyway - bats would not forage in high wind.
What months of the year have peak fatalities in bats at wind turbine sites?
August-October
