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All humpback whale ( Megaptera novaeangliae ) males in a population sing fundamentally the same version of a complex, progressively changing, series of sounds at any one time – the song. The purpose of this study was to describe the relationship of humpback whale populations across the North Pacific based on song composition. Songs were collected from Philippines, Japan, Hawaii and Mexico in 2011, 2012 and 2013. The presence and proportion of 11 phrase types were compared within and between populations to investigate song similarity and change. Results included: shared song phrases across the North Pacific; variable, temporary, regional song differences; varying rate of song change; and distance a factor, but not predictor in degree of similarity. Shared phrases indicate ongoing mixing of populations throughout the North Pacific. Year to year differences in degree of similarity suggest variability in these interactions. Songs appear to diverge as populations split up and converge when they amalgamate. Song studies complicate current US management policy designating four distinct populations in the North Pacific. North and South Pacific humpback whale population structure may be comparable, although song dynamics may be different. The fluidity of song composition suggests it provides acoustic definition or identity to changing associations of whales.

During winter humpback whales converge on tropical breeding grounds characterized by shallow, warm seas. In the eastern half of the North Pacific two such breeding grounds are located along the shorelines and shallows of Mexico, and in mid-ocean around Hawaii, separated by 4,500-6,000 km of deep ocean basin. A 2018 acoustic survey by an autonomous Wave Glider from Hawaii eastward towards Mexico, at breeding ground latitudes (circa 20°N) and during peak breeding season, discovered singing whales between these locations near continuously out to mid-ocean - the first evidence of this latitudinal, tropical deep-water distribution. We report the results from a 2021 study which replicated the first half of the 2018 route and extended the survey to Isla Clarión, the westernmost breeding ground of Mexico. The portion of the 2021 survey replicating the earlier course resulted in markedly similar, near-continual detection of humpback whales from Hawaii out 2,161 km (over 1,000 nm) to mid-ocean. Detections occurred on 29 of the first 37 days eastbound from South Point Hawaii (vs. 30 of 35 days in 2018), with up to 3,000 calls a day, including multiple simultaneous singers. The 2021 extension (non-replicative portion) from mid-ocean eastward produced intermittent detections to Isla Clarión. The results, combined with recent reports of photo-identified individuals which traveled between Mexico and Hawaii in one winter season, indicate a recurring tropical offshore presence between these traditional breeding grounds - its extent and purpose to be determined.

Copris incertus Say, 1835 (Coleoptera: Scarabaeidae: Scarabaeinae: Coprini) has been described as a New World coprophagous scarab distributed from Mexico to Ecuador with large discontinuities in its range between the Yucatán province and Costa Rica. The C. incertus species complex of the Copris minutus (Drury, 1773) species group consists of C. incertus, Copris laeviceps Harold, 1869, and Copris lugubris Boheman, 1858. Based on external morphology and male genitalia, we discovered that multiple species have been classified as C. incertus. Of these species, five are new: Copris amazonicus new species, Copris brevicornis new species, Copris davidi new species, Copris moroni new species, and Copris susanae new species. Herein, we revise the organisation of the C. incertus species complex and propose a new species complex, the C. laeviceps species complex, which includes: C. davidi, Copris igualensis Warner, 1990, and C. laeviceps, formerly included in the C. incertus species complex. We provide an identification key along with species distribution maps, images of habitus, and diagnostic characters. Copris incertus Say, 1835 (Coleoptera: Scarabaeidae: Scarabaeinae: Coprini) a été décrit comme scarabée coprophage du Nouveau Monde distribué du Mexique à l’Équateur avec de grandes discontinuités dans son aire de répartition comprise entre la province du Yucatán et le Costa Rica. Le complexe d’espèces C. incertus du groupe d’espèces Copris minutus (Drury, 1773) comprend C. incertus, Copris laeviceps Harold, 1869, et Copris lugubris Boheman, 1858. D’après la morphologie externe et les organes génitaux mâles, nous avons découvert que plusieurs espèces ont été classées comme C. incertus. Parmi ces espèces, cinq sont nouvelles: Copris amazonicus nouvelle espèce, Copris brevicornis nouvelle espèce, Copris davidi nouvelle espèce, Copris moroni nouvelle espèce et Copris susanae nouvelle espèce. Ici, nous révisons l’organisation du complexe d’espèces C. incertus et proposons un nouveau complexe d’espèces, le complexe d’espèces C. laeviceps, qui comprend: C. davidi, Copris igualensis Warner, 1990, et C. laeviceps, autrefois inclus dans le complexe d’espèces C. incertus. Nous présentons une clé d’identification ainsi que des cartes de répartition pour chacune des espèces, ainsi que les images des habitus et des caractères diagnostiques.

During the late Palaeozoic, lithospheric thinning in part of the Alpine realm caused high-temperature low-to-medium pressure metamorphism and partial melting in the lower crust. Permian metamorphism and magmatism has extensively been recorded and dated in the Central, Eastern, and Southern Alps. However, Permian metamorphic ages in the Western Alps so far are constrained by very few and sparsely distributed data. The present study fills this gap. We present U/Pb ages of metamorphic zircon from several Adria-derived continental units now situated in the Western Alps, defining a range between 286 and 266 Ma. Trace element thermometry yields temperatures of 580–890 °C from Ti-in-zircon and 630–850 °C from Zr-in-rutile for Permian metamorphic rims. These temperature estimates, together with preserved mineral assemblages (garnet–prismatic sillimanite–biotite–plagioclase–quartz–K-feldspar–rutile), define pervasive upper-amphibolite to granulite facies conditions for Permian metamorphism. U/Pb ages from this study are similar to Permian ages reported for the Ivrea Zone in the Southern Alps and Austroalpine units in the Central and Eastern Alps. Regional comparison across the former Adriatic and European margin reveals a complex pattern of ages reported from late Palaeozoic magmatic and metamorphic rocks (and relics thereof): two late Variscan age groups (~330 and ~300 Ma) are followed seamlessly by a broad range of Permian ages (300–250 Ma). The former are associated with late-orogenic collapse; in samples from this study these are weakly represented. Clearly, dominant is the Permian group, which is related to crustal thinning, hinting to a possible initiation of continental rifting along a passive margin.

Pitman and Darling report two observations, one firsthand (RLP), of humpback whales (Megaptera novaeangliae), including calves, at Johnston Atoll, 1,330 km southwest of Hawaii (Honolulu). Stories of humpback whales at Johnston Atoll have been circulating for decades, but they have been difficult to verify. A preliminary scientific survey conducted there in 2007 reported no whale sightings. The observations raise the possibility of alternate or additional breeding grounds beyond the well-known locations in Mexico, Hawaii, and the western Pacific - locations scattered among the numerous islands, atolls, and seamounts in the tropical central-western North Pacific.

The production and use of bubble streams, nets, bursts, dribbles, and rings by cetaceans are widely documented. Bubbles are produced by the controlled exhalation of air through the blowhole(s) or from bursts of air released from the mouth. Observations indicate that bubble releases are produced in several different contexts, including agonistic, stressful, social, foraging, and sexual. Bubbles play important roles in cetacean social interactions; however, in most circumstances, their specific function has yet to be determined. Humpback whales (Megaptera novaeangliae) are well known for their use of bubbles, especially in a feeding context where lone whales or cooperative groups use a variety of bubble-based tactics to net, trap, herd, and concentrate different prey species. Vigorous use of bubbles is also a feature of humpback whale behavior on breeding grounds. The most obvious are the long bubble streams emitted by males, primarily from \"principal\"; escorts during challenges from other males. Here, Jones et al describe a different context for bubble use by humpback whales on the Hawaiian breeding grounds.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Impact cratering on the Moon and the derived size-frequency distribution functions of lunar impact craters are used to determine the ages of unsampled planetary surfaces across the Solar System. Radiometric dating of lunar samples provides an absolute age baseline, however, crater-chronology functions for the Moon remain poorly constrained for ages beyond 3.9 billion years. Here we present U–Pb geochronology of phosphate minerals within shocked lunar norites of a boulder from the Apollo 17 Station 8. These minerals record an older impact event around 4.2 billion years ago, and a younger disturbance at around 0.5 billion years ago. Based on nanoscale observations using atom probe tomography, lunar cratering records, and impact simulations, we ascribe the older event to the formation of the large Serenitatis Basin and the younger possibly to that of the Dawes crater. This suggests the Serenitatis Basin formed unrelated to or in the early stages of a protracted Late Heavy Bombardment.