THE BREEDING PHENOLOGY AND DISTRIBUTION OF THE BAND-RUMPED STORM-PETREL OCEANODROMA CASTRO ON KAUA'I AND LEHUA ISLET, HAWAIIAN ISLANDS.

The Band-rumped Storm-petrel (BRSP) Oceanodroma castro has a large breeding range, spanning the warmer portions of both the Atlantic and Pacific Oceans. The Hawaiian population is one of the most cryptic and under-studied seabird species in the archipelago, and its breeding phenology and distribution are poorly known. We used several methods, including human auditory surveys, automated acoustic surveys, mist-netting, and data from a seabird rescue and rehabilitation program to assess the breeding phenology and distribution of BRSP on the island of Kaua'i and adjacent Lehua Islet. Our data show that the species arrives at breeding colonies on Kaua'i in late May, with birds fledging from late September to mid-November. Unlike BRSP breeding populations in the Galápagos, Azores, and Madeira, a winter breeding population was not apparent. Breeding colonies were found to be concentrated along the Na Pali coast, particularly within canyons from the Kalalau Valley to Polihale, as well as the Waimea Canyon. These areas are characterized by sparsely vegetated, very steep cliffs. Small pockets of BRSPs were also encountered in some of the wetter and heavily vegetated valleys associated with exposed rocky cliff faces. A large concentration of storm-petrel activity was also recorded on the southeastern slopes of Lehua Islet. A model created to predict Kaua'iwide distribution indicated that the key predictive variables, found in 85% of all models, were average rainfall, EVI (Enhanced Vegetation Index to assess broad vegetation types), and slope. Identifying this species' breeding phenology, range, and habitat requirements is a key step to inform conservation efforts for BRSPs elsewhere in the archipelago. In that regard, much work remains to be done. [ABSTRACT FROM AUTHOR]