If we measure the seasons, (26)____________in the past they have been, by ordinary natural events such as the departure of migrating birds or the appearance of the first flower,(27)____________spring now begins November and autumn ends in December.(28)____________may seem an unlikely situation to us,(29)____________fact, data shows that spring now occurs ten to thirty days earlier than it did, while research bears(30)____________thatautumnis arriving(31)____________Traditional data on phenology - the study of the timing of natural events - goes back to 1736in BritainTaken(32)____________isolation, phonological data may not mean much, but the received wisdom from ecolo is about interconnectedness. Consequently, with higher temperatures in winter, some species will breed earlier and then find that their food source has been destroyed when winter finally arrives. Competition for winter food will probably increase too, as birds stop migrating south in winter, as has already happened in a(33)____________of cases. (34)____________it is often difficult to be certain that seasonal trends are progressive and not cyclical those involved in analyzing the information see the fingerprints of global warming(35)____________this blurring of the seasons'edges