 The preferred habitat for the blue iguana is rocky , sunlit , open areas in dry forests or near the shore , as the females must dig holes in the sand to lay eggs in June and July . A possible second clutch is laid in September . The blue iguana 's herbivorous diet includes plants , fruits , and flowers . Its coloration is tan to gray with a bluish cast that is more pronounced during the breeding season and more so in males . It is large and heavy @-@ bodied with a dorsal crest of short spines running from the base of the neck to the end of the tail . 
