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Despite being one of the most widespread seabird species in the main Hawaiian Islands, little is known about the breeding phenology of the White-tailed Tropicbird Phaethon lepturus dorotheae. This is presumably due to its low conservation concern, coupled with the inaccessibility of most of its nesting sites, meaning that there are an extremely limited number of known nest sites where birds could be monitored directly. To better understand the breeding phenology of this species on Kaua'i, we reviewed data from the Save Our Shearwaters (SOS) program (a Kaua'i-based seabird rescue and rehabilitation program) to analyze when fledgling tropicbirds were recovered. We discovered 313 records of hatch-year birds in the database. Using breeding data from other populations of this species and back-dating the phenology based on these fledging records from the SOS database, we conclude that this species breeds year-round on Kaua'i. However, typically, eggs are laid between March and September (with a peak in June). Chicks hatch between April and October (with a peak in July) and birds fledge between July and January (with a peak in October). The number of tropicbird fledglings handed over to SOS has increased significantly since the program's inception in 1979, to a high of 31 fledglings received in 2016. It is not clear whether this indicates an increase in the population of this species on Kaua'i, an increase in public awareness of seabird conservation on the island, or both. Data from rescue and rehabilitation projects can be an important data resource for studying rare, cryptic, or difficult-to-access seabird species. [ABSTRACT FROM AUTHOR]

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]

Moku'ae'ae Rock Islet is located off the north shore of Kaua'i and is protected as a Hawai'i State Seabird Sanctuary. In the late 1970s it was also the site of a cross-fostering project for the endangered Newell's Shearwater, Puffinus newelli. Few avifauna surveys have been undertaken on the islet, and none since 2007. In 2013 and 2015, we conducted burrow searches across the entire islet to obtain breeding population estimates for each species and to evaluate whether the Newell's Shearwater had become established as a breeding species after the cross-fostering project. Auditory surveys were also conducted for 2 hr after sunset and 1.5 hr before sunrise, which are the peak calling periods for the Newell's Shearwater on Kaua'i. A total of seven seabird species was recorded on the islet, of which three, Bulwer's Petrel, Bulweria bulwerii; Wedge-tailed Shearwater, Ardenna pacifica; and Red-tailed Tropicbird, Phaethon rubricauda, were confirmed breeding. This is the first time Bulwer's Petrel has been confirmed breeding on Moku'ae'ae. Searches for Newell's Shearwater did not produce evidence that this species breeds on the islet, suggesting that the cross-fostering project was not successful. Although the islet is small, it represents an important refuge for seabird species. However, high levels of depredation were recorded on Bulwer's Petrel; we conclude that these were all killed by the introduced Barn Owl, Tyto alba, based on disposition of the bodies and the injuries they had sustained. Management recommendations for the islet include creation of a management plan, annual breeding bird surveys, annual rat monitoring, and Barn Owl control. [ABSTRACT FROM AUTHOR]

Abstract: Many seabird species are experiencing population declines, with key factors being high adult mortality caused by fishery by-catch and predation by introduced predators on nesting islands. In the Mediterranean, both of these pressures are intensive and widespread. We studied the adult survival of an endemic Mediterranean seabird, the Yelkouan shearwater (Puffinus yelkouan), between 1969–1994 and 2007–2010 in Malta and between 2004–2010 in France using mark–recapture methods. Mean annual survival probabilities for breeding adults were below 0.9 for all colonies and periods. Between 1969–1994, annual survival for adults of unknown breeding status was on average 0.74 (95% confidence interval: 0.69–0.80) in Malta, possibly as a result of various human disturbances (including illegal shooting), light pollution and fisheries by-catch. Over the period 2004–2010, we found strong support for variation in adult survival probabilities between breeders and non-breeders, and islands with and without introduced predators in France. Survival probabilities for non-breeders (0.95, 0.81–1.0) appeared to be higher than for breeders (0.82, 0.70–0.94), but were imprecise partly due to low recapture probabilities. In Malta, we found evidence for heterogeneity in survival probabilities between two unknown groups (probably breeders and non-breeders), and seasonal variation in survival probability. Birds were more likely to survive the period including the peak breeding season than an equally long period during which they roam widely at sea. Although annual adult survival probability was still low (0.85, 0.58–1.0), colony protection measures appear to have reduced mortality at nesting cliffs. A population model indicated that colonies in France and Malta would currently require continuous immigration of 5–12 pairs per year to maintain stable populations. Our estimates of adult survival probabilities over the past four decades are consistent with overall population declines. Threats to Yelkouan shearwaters require immediate management actions to avoid ongoing population declines in the western Mediterranean. [Copyright &y& Elsevier]