h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

One of the "I haven't got a clue where to start" questions that keeps me awake at night.

Along with...How would I go about calculating the number of blades of grass in the UK?

Count the wings and divide by two.

Phone the RSPB offering to sponsor them 5p per sparrow and ask how much that would come to.

Count the proportion of time that a one metre square in your garden was occupied by a sparrow and multiply by the number of square yards.

Start a kickstarter project to count the sparrows. It may not give you an answer, but the money raised may help you feel better about your ignorance.

I'm guessing a similar list would work for the grass thing, except grass doesn't have wings.

Ring the RSPB. They'll know.

Doesn't help with the grass, though. There wasn't an RSPG last time I checked.

With grass, you need a percentage of UK that is grassland/parkland/lawn (you'll probably find that if you look hard enough), and an estimate of number of blades per unit square. Decide whether you're going to count cultivated grass species (arable crops) as well as wild.

Invite them all round for carrot cake. Sparrows love carrot cake and they'll all turn up.

The RSPB reckons there are 5.3 million breeding pairs across the UK.

John Archibald Wheeler recounted a problem like that, proposed by Enrico Fermi on a visit to Hanford, WA, USA, estimating the local jack rabbit population from the roadkill count.




'Glumes' grasses have 'glumes'.

Several decades ago, the Chinese declared that sparrows were unforgivably bourgeois, so they set out to kill them. Okay, maybe the sparrows were thought to be feasting on too much of the rice crop...

That was one of agriculture's great balls-ups, like the dust bowl. Once the sparrows were almost wiped out, locusts and caterpillars spread like wildfire, and more crops were destroyed than ever. Millions of people starved to death.

The best known answer to swarming locusts is to track them till they go to ground to lay their eggs, then plough the ground, exposing their larvae.

It doesn't hurt next to herd large numbers of free range chickens into the area to finish the job.

A comparatively new technique, modern technology drastically simplifying the process of tracking the swarms, but, de facto, the way the 19th century locust swarms of the American Midwest were eradicated.




The world record for grouse hunting is held by a man who was operating an experimental test station for developing new and higher yield wheat varieties.

Sparrows were deliberately introduced into north America from England during the colonial era to help keep the streets clean.

They've engendered little complaint since.

Why do the RSPB not keep account of the number of lonely, single sparrows? Surely a better target for avian care than the happy couples.

What is the airspeed velocity of an unladen sparrow?*

<BB<

*Or indeed (African and/or European) swallow.

All British sparrers speak cockney. They also go around killing robins with their little bows and arrers.

We call them House Sparrows in my neighborhood. Many years ago, a pair of them built a nest on the underside of the canopy over my door.

There are quite a few around my place. I think they used my nest box this year, but they are so cautious about entering and leaving (and I didnt want to disturb them too much to look closely) that I'm not sure.

yes, I thank you for that one, as I was content with monitoring Sparrow numbers not actual calculating of how many and now I am going to have to look into how they are extrapolated and to what degree

too soothe me sleep with a smile on my face,if it is bugging me from now on, I shall go on 'the adding the wings and dividing by two' suggestion by silicon dioxide

The British Trust for Ornithology - BTO - rather than RSPB, do the UK bird counts based on Common Bird, Garden Bird and Farmland bird censuses which give an indication of the range and frequency of each species - there are two species of sparrow in the UK House Sparrow which declined and is now recovering in urban areas and Tree Sparrow which has had a catastrophic decline due to changes in agriculture and is now largely restricted to nature reserves. Hedge Sparrow or Dunnock is not actually a sparrow but a an Accentor (some birders refer to it as Hedge Accentor)

Sparrows are relatively easy to count as they are fairly sedentary and nest communally. Highly mobile species like overwintering waders and wildfowl are more problematic - one of the methods used to wait until they have settled fire a (blank) shotgun round photograph them as they erupt into the air and get some poor bugger to count the thousands of dots in the picture.

Counting the number of blades of grass in the UK would be relatively simple using National Vegetation Classification surveys, aerial photographs, Landsat images and a farm records to establish the total hectarage of each type of grassland and a could sized sample of metre square quadrats counting the number of blades for each grassland types, a bit of simple maths and you've got your answer

That's fine for getting estimates, which may be all you really need or want. Total accuracy is likely to be elusive, given that grass puts out new blades daily. You'd need to recount every day!