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Rat eradication has become a common conservation intervention in island ecosystems and its effectiveness in protecting native vertebrates is increasingly well documented. Yet, the impacts of rat eradication on plant communities remain poorly understood. Here we compare native and non-native tree and palm seedling abundance before and after eradication of invasive rats (Rattus rattus) from Palmyra Atoll, Line Islands, Central Pacific Ocean. Overall, seedling recruitment increased for five of the six native trees species examined. While pre-eradication monitoring found no seedlings of Pisonia grandis, a dominant tree species that is important throughout the Pacific region, post-eradication monitoring documented a notable recruitment event immediately following eradication, with up to 688 individual P. grandis seedlings per 100m2 recorded one month post-eradication. Two other locally rare native trees with no observed recruitment in pre-eradication surveys had recruitment post-rat eradication. However, we also found, by five years post-eradication, a 13-fold increase in recruitment of the naturalized and range-expanding coconut palm Cocos nucifera. Our results emphasize the strong effects that a rat eradication can have on tree recruitment with expected long-term effects on canopy composition. Rat eradication released non-native C. nucifera, likely with long-term implications for community composition, potentially necessitating future management interventions. Eradication, nevertheless, greatly benefitted recruitment of native tree species. If this pattern persists over time, we expect long-term benefits for flora and fauna dependent on these native species.

Marine megafauna are difficult to observe and count because many species travel widely and spend large amounts of time submerged. As such, management programmes seeking to conserve these species are often hampered by limited information about population levels.Unoccupied aircraft systems (UAS, aka drones) provide a potentially useful technique for assessing marine animal populations, but a central challenge lies in analysing the vast amounts of data generated in the images or video acquired during each flight. Neural networks are emerging as a powerful tool for automating object detection across data domains and can be applied to UAS imagery to generate new population‐level insights. To explore the utility of these emerging technologies in a challenging field setting, we used neural networks to enumerate olive ridley turtles Lepidochelys olivacea in drone images acquired during a mass‐nesting event on the coast of Ostional, Costa Rica.Results revealed substantial promise for this approach; specifically, our model detected 8% more turtles than manual counts while effectively reducing the manual validation burden from 2,971,554 to 44,822 image windows. Our detection pipeline was trained on a relatively small set of turtle examples (N = 944), implying that this method can be easily bootstrapped for other applications, and is practical with real‐world UAS datasets.Our findings highlight the feasibility of combining UAS and neural networks to estimate population levels of diverse marine animals and suggest that the automation inherent in these techniques will soon permit monitoring over spatial and temporal scales that would previously have been impractical. [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]

Ashy Storm-Petrels (ASSP) breed in a range restricted to the southern California Current, from Mendocino County in northern California, United States, to the Coronado Islands in northwest Baja California, Mexico. Approximately half the global population nests on the California Channel Islands, but nesting at one of them, Anacapa Island, had not been recorded before this study. In 2011, 10 years after rats were eradicated, we conducted a study to determine the breeding status of ASSP on Anacapa Island. We used habitat searches coupled with acoustic sensors to assess potential nesting areas and conducted mist netting to determine general presence. We found one active nest containing a nearly fledged ASSP chick in 2011, representing the first breeding record for the island. [ABSTRACT FROM AUTHOR]

The number and scale of island invasive species eradications is growing, but quantitative evidence of the conservation efficacy of passive recovery is limited. We compare relative abundances of breeding birds on Hawadax Island (formerly named Rat island), Aleutian Archipelago, Alaska, pre- and post- rat eradication to examine short-term (<1 year post-eradication) changes due to rodenticide application, and medium-term (5 years post-eradication) changes due to the absence of invasive rats. In the short term, Bald Eagle ( Haliaeetus leucocephalus) numbers decreased from 24 individuals pre-eradication to two individuals <1 year post-eradication, but recovered to 10 individuals (42 % of pre-eradication) 5 years post-eradication, with all individuals nesting (63 % of the pre-eradication nesting). Five years post-eradication relative abundances of most terrestrial birds surveyed using point counts either significantly increased [Gray-crowned Rosy Finch ( Leucosticte tephrocotis), Lapland Longspur ( Calcarius lapponicus), Snow Bunting ( Plectrophenax nivalis), Song Sparrow ( Melospiza melodia)] or did not differ [Pacific Wren ( Troglodytes troglodytes)]. Shorebirds also increased 5 years post-eradication with Black Oystercatchers ( Haematopus palliates) increasing fivefold, and Rock Sandpiper ( Calidris ptilocnemis) nesting increasing from one to five nests. We confirmed two species of ground nesting seabirds [Tufted Puffin ( Fratercula cirrhata) and Leach's Storm-petrel ( Oceanodroma leucohoa)] as nesting (puffin) or engaged in courtship behavior (Storm-petrel) 5 years post-eradication. Our results indicate that despite the short-term impact on Bald Eagles, and without further human intervention, most terrestrial and marine birds have newly-colonized, re-colonized, or increased in abundance following the eradication of invasive rats. [ABSTRACT FROM AUTHOR]

The article discusses the study that documented a second Bryan's Shearwater Puffinus bryani from Midway Atoll, recorded during 1990-1991 and 1991-1992 winters, and examines at-sea records in central and eastern North Pacific Ocean to know habitat selection, vocalizations and at-sea distribution. Topics discussed include vocalization from crevice with an accumulation of artificial concrete and coral rubble, at-sea records not confirming small shearwaters as Bryan's Shearwater.

Background: Declines in biodiversity and ecosystem health due to climate change are raising urgent concerns. In response, large-scale multispecies monitoring programmes are being implemented that increasingly adopt sensor-based approaches such as acoustic recording. These approaches rely heavily on ecological data science. However, developing reliable algorithms for processing sensor-based data relies heavily on labelled datasets of sufficient quality and quantity. We present a dataset of 1,575 dawn chorus soundscape recordings, 141 being fully annotated (n = 32,994 annotations) with avian, mammalian and amphibian vocalisations. The remaining recordings were included to facilitate novel research applications. These recordings are paired with 48 site-level climatic, forest structure and topographic covariates. This dataset provides a valuable resource to researchers developing acoustic classification algorithms or studying biodiversity and wildlife behaviour and its relationship to environmental gradients. The dawn chorus recordings were collected as part of a long-term Northern Spotted Owl monitoring program; this demonstrates the complementary value of harnessing existing monitoring efforts to strengthen biodiversity sampling., New Information: This dataset of dawn chorus soundscape recordings is one of the few open-access acoustic datasets annotated with non-biotic and both interspecific (across species) and intraspecific (within species) bird, mammal and amphibian sonotypes and the first that is paired with climatic, forest structure and topographical covariates extracted at recorder locations. This makes it a valuable resource for researchers studying the dawn chorus and its relationship to the environment.