SANTA CRUZ SHELTERS HAVE BEEN RECEIVING DOZENS OF UNWANTED BUNNIES AFTER THE EASTER HOLIDAY.     ONE-HUNDRED-PLUS RABBITS ARE EXPECTED TO BE SURRENDERED IN THE NEXT FEW MONTHS.     RESIDENTS BUY BUNNIES AS A NOVELTY TO MARK THE HOLIDAY, BUT ARE UNABLE TO CARE FOR THEM AFTERWARDS.    SOME OF THE RESCUED RABBITS WERE INJURED DURING CELEBRATIONS.   ONE SANTA CRUZ SHELTER RECEIVED MORE THAN SIX-HUNDRED-FIFTY BUNNIES LAST EASTER.