In january 2002, thousands of pupils recorded the numbers of different birds seen in their gardens in one hour. they sent their data to the Royal Society for the Protection of Birds who have kept data for many years.
pupils observed birds in their gardens for one hour during the last week in january.
which two factors are being controlled in this survey?
2007-01-14 17:51:37 · 6 answers · asked by pammy 1 in Science & Mathematics ➔ Zoology
Time(one hour) and Place( thier gardens) are the controls. By using multiple locations at the same time, a more accurate population estimate can be obtained.
2007-01-14 17:58:27 · answer #1 · answered by Mythos 2 · 0⤊ 1⤋
Say only one garden was chosen and only robins were seen,would it be correct to assume that all the other birds were extinct in Britain? Of course not.The more samples taken and more diverse the sample the closer it gets to mirrorring the British population.It is not an exact number but a good indication.
It is important that the time taken for the survey is the same and that the most birds seen AT ANY ONE TIME is recorded,not the total seen in the hour as you might be counting the same birds twice.My money is on House Sparrow again this year,what about you?
2007-01-14 21:19:28 · answer #2 · answered by Anonymous · 0⤊ 1⤋
Now why don't you put your brain in gear and work it out ?
It really isn't very difficult ...
What factors are being 'CONTROLLED' ... well what do you know about the Survey ... the OBSERVER, the LOCATION and the DATE and the TIME ....
Which of these factors have been chosen by the RSPB - did they choose the observers ??? No - anyone could do it ... did they choose which gardens ? No - it depended on who volunteered ... maybe they chose the DATE ??? maybe they chose the TIME ??? what do you think ???
Does no-one do their own homework these days ?
2007-01-14 18:44:25 · answer #3 · answered by Steve B 7 · 0⤊ 1⤋
Auatralia conducts a backyard bird survey on Australia Day, 26 January, every year. I saw my 73rd species in my backyard yesterday ( a channel-billed cuckoo I have been listening to for weeks) but I don't expect to see anything like that number in one hour on the 26th.
2007-01-14 20:13:58 · answer #4 · answered by tentofield 7 · 0⤊ 1⤋
It's only reliable if the pupils can correctly identify the birds.
2007-01-14 19:45:58 · answer #5 · answered by Anonymous · 0⤊ 1⤋
Because it gives a more accurate count, over a wider area.
and you find out if the birds are governed by climate change.
2007-01-14 17:55:39 · answer #6 · answered by Anonymous · 0⤊ 1⤋