OSLO - Early flowers, migrating swallows and sleepless bears are among signs that spring has arrived long ago in the northern hemisphere even as a record mild winter formally ends on Tuesday with a rare chill.

Spring officially starts on Wednesday at 0007 GMT when the sun passes north over the celestial equator but scientists say the biological clocks of animals and plants are running ahead of time, perhaps upset by global warming.

Orange trees, olives and peaches are blooming weeks ahead of schedule in Greece, geese are cutting down on migrations in Canada and the United States and bears have been unable to hibernate in Bulgaria.

Red Admiral butterflies and swallows -- usually a sign of summer after the birds spend the winter in Africa -- have been spotted early in the Netherlands after the warmest Dutch autumn and winter since records starting in 1706.

"Springs have been getting earlier for the past 60 years. Plants have been getting incredibly confused, and birds have also been confused to some extent," said Andre Farrar of Britain's Royal Society for the Protection of Birds.

Winter in the northern hemisphere was the warmest since global records began in the late 19th century, spurred by a warming trend of recent decades and an El Nino warming of the Pacific, according to the U.S. government's weather agency.

And some experts predict that 2007 could eclipse 1998 and 2005 as the warmest on record.

Scientists say that weather is always chaotic but U.N. reports project that extreme events such as droughts, heatwaves and floods are likely to become more frequent because of a warming widely blamed on use of fossil fuels.

In a parting blast of winter, snow or sleet fell in parts of Europe from Britain to Slovenia on Tuesday.


All 20 bears in a Bulgarian conservation park are awake after most skipped a hibernation normally lasting until April.

"The bears did not even try to sleep this winter. For the first time it happened to almost all of them," said Anton Paunkov, spokesman of the "Four Paws" foundation.

And the winter migration path of Canadian geese has become shorter in the last 25 years, apparently because of warmer temperatures and changing U.S. farm practices.

"Where we used to get banded geese turning up in Florida and Louisiana, now they're not making it much farther south than Ohio," said Kirk Miner of the Jack Miner Bird Sanctuary near Windsor, Ontario.

In Kew Gardens west of London, daffodils, crocuses and snowdrops have been opening early. In Britain, some birds such as chiffchaffs and blackcaps no longer bother to migrate.

Some farmers may benefit from longer growing seasons but many worry that early flowering exposes crops to late frosts or pests. Normal insect pollinators such as bees may not be around when the flowers bloom.

In Italy, a "Map of Spring" study warned that many plants were flowering 10 to 20 days earlier than normal, possibly because of global warming. Prime Minister Romano Prodi has warned farmers to prepare for drought after a warm, dry winter.

Meteo France said average temperatures from December to February were 2.1 degrees Celsius (3.8 Fahrenheit) above average -- the highest since it began collating "full and reliable" data from 22 French cities in 1950.

Among benefits, high winter temperatures may have helped keep winter heating bills down, helping limit high oil prices at about $60 a barrel.

Slovenia's capital Ljubljana had about 10 centimeters (4 inches) of snow on Monday, the most of the winter, causing railway and road traffic problems throughout the country. Ski resort operators were delighted after a soggy season.

Among other swings, temperatures in Beijing were set to climb from a chilly 7C on Tuesday to 18C on Saturday.

One man in Cyprus got twin shocks from an early spring.

Picking wild asparagus in late February, he got bitten by a snake that had apparently woken early from hibernation. Then, driving to hospital for treatment, he got stopped for speeding.