The company has 450 rentals, about 10 percent more than it had last year. Occupancy has spiked from about 85 percent to 99 percent, MacDonald said. High demand has left little inventory in the peak February and March months on Siesta Key and Anna Maria Island, which had a strong season last year compared to the rest of the region. And so far, this season looks like it will top it, vacation rental agents said. "We are loaded," said Erin Heckler, marketing manager for Island Real Estate of Anna Maria Island, which has 250 rental properties and few available in February and March despite adding 20 more rentals since last year.