The Northeast Pacific subpopulation of the humpback whale migrates every winter-spring to Mexican waters to breed; however, their use of habitat in the Mexican Pacific remains unknown. We investigated the spatial ecology of the humpback whale in the Mexican Central Pacific (MCP) and connections with other Mexican areas. Surveys to search for humpback whales were conducted in winter-spring 2010–2019. The number of individuals, type of group, and activities were recorded, and flukes were photographed to differentiate individuals observed at Mexican areas. A total of 15,384.4 km were travelled in MCP waters and 462 groups of humpback whales were sighted. The dominant group were single and pairs, observed mainly off Colima coast. The principal activity was traveling, and the least frequent activity was likely-feeding. A total of 420 individuals were photo-identified, and through their sighting history, it was possible to calculate that only 2.14% (1.67–12.5%) of them showed site fidelity; this indicates that the MCP is a transit zone to other reproductive areas. A photographic catalog of 798 individuals from Socorro Island was also analyzed to compare with the MCP catalog, but there were no photo-recaptures between two areas. The comparison with catalogs of 302 individuals from the Guerrero coast and 1,459 individuals from Banderas Bay resulted in interchange indices of 1.02E–06 and 2.93E–07, respectively. The MCP is part of the breeding ground of humpback whales, but it seems to be a transit area that does not offer optimum conditions for permanence and sustained habitat use, possibly due to regional anthropogenic activities.

Haliotis cracherodii is the only abalone species listed as critically endangered (IUCN Red List) and protected under the Endangered Species Act (ESA) since 2009. The population started decreasing in the mid-1980s throughout its biogeographical range due to the “withering syndrome” disease. The objective of this study was to evaluate the thermoregulation of the black abalone, establishing its preferred temperature, locomotion displacement, and critical thermal maximum (CTMax). The preferred temperature (PT) was 13.8 °C. The theoretical temperature for optimal growth of the black abalone was 14.3 °C. The locomotion displacement in the gradient had an interval of 137 to 83 cm h^–1. CTMax was evaluated, the first abalone detached from the substrate at a temperature of 25.4 °C and the last one at 31 °C; CTMax of 50% was calculated at 29.7 °C. These data will allow us to maintain and condition the black abalone in captivity with the final goal of producing seed for the restoration of disease-impacted populations on the Baja California Peninsula. ENSO events may also affect the survival of black abalone. We extrapolated the Thermal Safety Margin (TSM) = (28.8 – 18.31 °C) = 10.49 °C in weak ENSOs, but in stronger ENSO the TSM value diminishes to 3.17 °C suggesting that black abalone may be vulnerable to climate change.

The rivers of tropical islands are colonized by amphidromous species. The order Gobiiformes presents the major diversity in these teleost communities. The genus Rhyacichthys forms a particular group within this order, with the presence of several plesiomorphic characters but also because it constitutes the sister group of all other Gobiiformes. The genus Rhyacichthys includes two valid species: Rhyacichthys aspro (Valenciennes, 1837) and Rhyacichthys guilberti Dingerkus & Séret, 1992 which are only found in the western Pacific (e.g., Vanuatu, Indonesia, Japan). The aim of the present study consists of the taxonomic revision of the genus, in which more than two species are suspected, using integrative taxonomy. Morphomeristic and molecular analyses (partial mtDNA, 7134 bp) were conducted on recent and collection specimens, including type specimens. Short fragments of mtDNA (<130 bp) were obtained for type specimens of R. aspro and R. guilberti. These results allowed us to highlight morphological and genetical differences between the two valid species and to resurrect a third one. This integrative approach helped to clarify relations within the genus and its distribution range with a better understanding for this poorly studied group.

The National Park of American Samoa (NPSA) was surveyed in 2011 and 2018 using point-transect distance sampling to estimate trends in landbird distribution, composition, population density, and abundance. Surveys were conducted within the Ta‘ū Unit and Tutuila Unit, each on separate islands of American Samoa. We detected a total of 14 species during surveys and there were sufficient detections of seven species to allow for density estimation and abundance within each unit. We assessed differences in density between surveys with a two-sample z-test and found significant declines of Blue-crowned Lorikeets (Vini australis) in the Ta‘ū Unit, and of Samoan Starlings (Aplonis atrifusca) in the Tutuila Unit. Density estimates of the Crimson-crowned Fruit Dove (Ptilinopus porphyraceus), Pacific Kingfisher (Todiramphus sacer), Polynesian Wattled Honeyeater (Foulehaio carunculatus), and Samoan Starling (in the Ta‘ū Unit) were also lower in 2018 than 2011, but differences were inconclusive because of relatively large variance estimates. Densities of the Polynesian Starling (Aplonis tabuensis) and Pacific Imperial Pigeon (Ducula pacifica) in the Ta‘ū Unit were higher in 2018 than 2011, but differences were similarly inconclusive. Lower 2018 densities could be due to Tropical Cyclone Gita that struck the islands just four months before the surveys. We provide indices of relative occurrence and abundance for the remaining seven species detected, which include the Many-colored Fruit Dove (Ptilinopus perousii) and the rarely detected Spotless Crake (Zapornia tabuensis)—both of which are species of concern in American Samoa.

The red-orange flowered clade of Hawaiian Hibiscus species in sect. Lilibiscus are discussed and a botanical key provided. Four species are recognised, viz. Hibiscus kokio Hillebr., H. clayi O. Deg. & I. Deg., H. kahilii C.N. Forbes, and H. saintjohnianus M. Roe. These species are uncommon or rare in nature, but vital elements in the diverse ecosystems in which they occur. Surprisingly, distinctive hibiscus species in this group are still being confused. An incomplete and contested understanding of the taxonomy of these species has hindered their conservation—both in situ and ex situ—and effective use in horticulture and landscaping. Recommendations are provided on conservation measures required to maintain and enhance genetic diversity within these four species, which are threatened by extreme weather events and climate change, invasive alien species, habitat loss, and land degradation.

Recent linguistic, morphological, and DNA studies have shown that the Polynesian hibiscus known as kaute—koute, ‘aute, and other cognates—is an undescribed eastern Polynesian Hibiscus species in sect. Lilibiscus. It is described here as Hibiscus kaute L.A.J. Thomson & Butaud, and appears to be extremely rare, if not extinct in the wild. The French botanist Jean Nadeaud (1873) recorded ‘aute in a wild state during the 1850s at the end of Pirae valley (Nahoata) and elsewhere in the interior of Tahiti where it grew on cliff faces. The original wild form—with a single whorl of petals—is also rare in cultivation, both in French Polynesia and elsewhere in the South Pacific Islands. The medicinal Polynesian double-flowered form is uncommon in cultivation and often mistaken for recently-introduced cultivars. As well as being of great cultural importance to Polynesians, kaute is arguably the most significant species in the development of modern Hibiscus hybrids and a missing link in understanding the origins of H. rosa-sinensis. Ex situ conservation measures are urgently needed in French Polynesia (Tahiti and Marquesas Islands) and, internationally, in botanic gardens, for this important progenitor species of Lilibiscus hybrids.

The behavior of hiding molted shells has not been documented in any crustacean. The White-spotted hermit crab (Dardanus megistos) inhabiting tropical coral reefs has a unique molt behavior in which it hides its outer, shed shells in the sand. Video cameras were used to capture the molting behavior. After molting, the crab folds the molted exoskeleton, pressing the cephalothorax with both forceps, and buries the shell with its walking legs, until it is no longer visible.

Hawai‘i’s native waterbirds are conservation reliant and need active management including predator control for the foreseeable future. The small Indian mongoose (Herpestes auropunctatus) is a detrimental predator to Hawai‘i’s native waterbirds: mongoose prey upon eggs, chicks, and adults. An effective trapping and baiting regime is fundamental in the control of this invasive predator. We examined whether DOC-200 kill traps or Tomahawk live traps are more effective in capturing mongoose. We also compared the cost efficiency of DOC-200 and Tomahawk traps. Throughout the study 114 animals were captured, of which 49 were mongoose (28 males, 14 females, 7 unknown sex). DOC-200 and Tomahawk traps did not differ in the number of mongoose captured. The trapping regime where DOC-200 traps were checked once a week proved to be most efficient ($40.70/mongoose), regimes where DOC-200 traps and Tomahawk traps were checked three times a week cost $65.20/mongoose and $102.80/mongoose, respectively. The results from our study give insight on trap preference, which can be used in other management areas that are impacted by mongoose in Hawai‘i, as well as providing cost effective trapping regimes for managers.

Landbird populations on Tinian Island have been periodically surveyed since 1982 to evaluate the status of non-native and native landbirds. We report the results of surveys in 2013 and the observed changes during 31 years in species population trends based on surveys since 1982. A total of 11 native and 3 non-native species were detected during the 2013 survey. Population sizes were estimated using point-transect distance sampling methods, and population trends were assessed using repeated measures analysis of variance for nine forest bird species. In all years, the Rufous Fantail (Rhipidura rufifrons) and Bridled White-eye (Zosterops conspicillatus) were the most abundant species, whereas the White-throated Ground Dove (Pampusana xanthonura) was the least abundant species in 1982, 1996, and 2008, and the Mariana Kingfisher (Todiramphus albicilla) was the least abundant in 2013. The less common species numbered in the low thousands included the Mariana Fruit Dove (Ptilinopus roseicapilla), White-throated Ground Dove, introduced Philippine Collared Dove (Streptopelia dusumieri), Mariana Kingfisher (Todiramphus albicilla), and Micronesian Myzomela (Myzomela rubratra). The Micronesian Starling (Aplonis opaca) and Tinian Monarch (Monarcha takatsukasae) were estimated to number in the tens of thousands. The most abundant species were the Rufous Fantail, numbering more than 100,000, and the Bridled White-eye, numbering more than 400,000. The overall trends in abundance between 1982 and 2013 showed an increase in the Mariana Kingfisher, Micronesian Starling, Rufous Fantail, White-throated Ground Dove, and Philippine Collared Dove, while populations were stable for the Bridled White-eye and Tinian Monarch. Declines were seen for the Mariana Fruit Dove and Micronesian Myzomela. These trends matched previous analyses with the exception that Tinian Monarch abundance showed an increase in the 2013 survey.

The aim of this study is to explore if sexual reproduction is present in scleractinian corals at the northern limit of their distribution (28.980° N, 113.470° W) in a zone subject to upwelling and seasonal variations in sea surface temperature, and sampling was performed from August 2018 to October 2019. We placed 42 terracotta recruitment tiles in Bahía de los Ángeles, Baja California. Coral cover was estimated, and the height, major diameter, and minor diameter of coral colonies were measured. Astrangia haimei and Porites panamensis recruits were identified on the recruitment tiles, constituting the first quantitative record for the northeastern tropical Pacific. Recruitment of P. panamensis was higher (Llave: 63.09 ± 114 ind m^–2 y^–1, Rasito: 3.21 ± 7 ind m^–2 y^–1), while A. haimei recruitment at the same sites was 3.85 ± 8 and 1.93 ± 6 ind m^–2 y^–1, respectively. Recruitment differences between locations were attributed to coral cover (the abundance of Porites panamensis is 15-fold greater in Llave than in Rasito) and colony size (P. panamensis Llave: 10.53 ± 5.93 cm, Rasito: 4 ± 0.63 cm). Both SST and Chl-a concentrations were also highly correlated with coral recruitment, with higher recruitment rates observed in the warmer seasons when high nutrient concentrations were also present. In contrast to other sites in the eastern tropical Pacific, the highest rate of recruitment was reported at this study (high-latitude coral community), which, according with the positive high latitude trend reported by other studies, is likely due to climate change.