FACTBOX-Five facts about maple syrup

(Reuters) - Maple syrup producers in New England see their livelihoods endangered by a warmer climate. Here are five facts about producing maple syrup:

* The United States last year produced 1.4 million gallons (5.3 million liters) of maple syrup, with Vermont accounting for 31.7 percent of the total, ahead of New York and Maine. Canada's syrup industry is growing rapidly and it produces far more syrup than the United States.

* A maple tree typically needs to be about 40 years old and 10 inches in diameter before it can be tapped. Exceptionally large trees may take two taps.

* In New England, maple trees typically start producing sap in February or March, with the season starting later further north. In most years, the season lasts about a month, until the trees blossom.

* Each tap typically produces about 10 gallons (37.9 liters) of sap per season, which is enough to make about 1 quart (0.9 liter) of syrup. The sap is boiled to release water and concentrate its sweetness.

* Maple syrup is eaten on pancakes, waffles and oatmeal, and is also made into candy. In New England, a regional delicacy calls for hot maple syrup to be drizzled onto snow directly outside the sugarhouse and eaten as candy.

(Compiled by Scott Malone in Ludlow, Vermont)