Seeing that the earth has an estimated less than 1% of animals that have ever existed currently living on it, it is an extremely hard question to answer.
England
is it that there are signs that by 2100, most species will be extinct.
Australia
You can't answer this question as bird species are going extinct all the time...
Most become extinct because they can not adapt to changes in their environments. Those that can don't become extinct.
north america
Bald eagle
... No chipmunks are not extinct, there are 25 different species of chipmunk and most are listed as "of least concern" according to the endangered species act.
About 35 - 150 species of life become extinct everyday. Most due to deforestation (loss of rainforest).
structures
they got extinct
when there are no living members of a species the species is said to be "extinct".