Unless otherwise specified, references simply to sparrows are to this imported variety.
There are, however, several differences between the "begging" behavior of sparrows and humans crying.
A 50 per cent reduction in loading would be achieved if sparrows were let in, but starlings kept out.
Today, some two hundred million starlings and a further one hundred and fifty million sparrows live there.
When given testosterone as adults, female canaries and white-crowned sparrows begin to sing.
White-crowned sparrows will copy songs from a tape if exposed to these songs between about 10 and 50 days.
Sparrow-sized buntings and redpolls, weighing 30-35 g, are the smallest and perhaps the hardiest of polar birds.
A sparrow will not show the "begging" behavior again once adult, but humans, by contrast, retain the capacity to cry throughout their lives.
