Roller Skating?

I'm a bit confused regarding the number of calories actually burned by roller skating... I've looked it up, and the numbers on MFP as well as the other sources i've checked seem really high (almost 1000 calories for two hours on the rink). I'm not doing roller derby, just rolling around the rink for a while, just for fun. Obviously, it depends on speed and body weight, as well as other factors, but can anybody give me a rough estimate?