Charlotte MacDonald
speaker
1,889 appearances
62 recordings
1 series
first heard Sep 2010
last heard Apr 2025
Charlotte MacDonald’s voice in public audio — every appearance, attributed to the second.
Trend
recordings per month · last 12 monthsNo recordings in the last 12 months.Older appearances are listed below; set an alert to hear about the next one.
Appearances
And out in the US, an ornithologist was writing an article called Collisions Between Birds and Windows.
matched
He reasoned that there are a lot of buildings in the US and that most buildings have windows.
matched
So he looked up the number of buildings in the whole country using US Bureau of Census data.
matched
About 100 million.
matched
He then thought, if we assume that over a year, between one and ten birds will hit windows on every building in the country and die, how many birds would that be?
matched
Yes, it features on a bird guide website and that's where the Unbelievable Truth team found it.
matched
They then took the highest number, a billion dead birds, divided it by 365 days and got their figure of more than two million a day.
matched
But I've spoken to leading bird window collision expert, Professor Daniel Clem, and he thinks people shouldn't quote this number as if it was some kind of solid fact.
matched
Yes, but Professor Daniel Clem is the ornithologist who came up with the number in the first place.
matched
Possibly.
matched
It's a figure from the British Trust for Ornithology, and a few years ago they counted the number of ringed birds found dead from hitting windows and extrapolated up to get a national figure.
matched
It's an initial estimate, they say, not robust enough to pass as a hard fact.
matched
And, well, the story starts in 1990.
matched
That year we were all dancing about to this kind of thing.
matched
I'm just setting the scene for you.
matched
And out in the US, an ornithologist was writing an article called Collisions Between Birds and Windows.
matched
He reasoned that there are a lot of buildings in the US and that most buildings have windows.
matched
So he looked up the number of buildings in the whole country using US Bureau of Census data.
matched
About 100 million.
matched
He then thought, if we assume that over a year, between 1 and 10 birds will hit windows on every building in the country and die...
matched
Showing 1161–1180 of 1,889 · page 59 of 95
← Previous
Next →