Archipelago Research Articles

Spatial connectivity of reef manta rays across the Raja Ampat archipelago, Indonesia.

The reef manta ray Mobula alfredi is present throughout most island groups that form the Raja Ampat archipelago, Indonesia. The species is protected regionally and nationally and is currently managed as a single homogeneous population within the 6.7 million ha archipelago. However, scientific evidence is currently lacking regarding the spatial connectivity and population structure of M. alfredi within this archipelago. Using network analysis and an array of 34 acoustic receivers deployed throughout Raja Ampat between February 2016 and September 2021, we examined the movements of 72 subadult and adult M. alfredi tagged in seven regions of Raja Ampat. A total of 1094 M. alfredi movements were recorded and were primarily concentrated between nearby receiver stations, highlighting frequent local movements within, and limited long-distance movements between regional acoustic receiver arrays. Network analysis revealed highly connected nodes acting as hubs important for M. alfredi movements. A community detection algorithm further indicated clusters within the network. Our results suggest the existence of a metapopulation comprising three demographically and geographically distinct subpopulations within the archipelago. They also reveal the importance of Eagle Rock as a critical node in the M. alfredi movement network, justifying the urgent inclusion of this site within the Raja Ampat marine protected area network.

Late Holocene climate dynamics in the Azores archipelago

The location of the Azores Archipelago makes this group of islands an excellent setting for investigating past long-term temperature and precipitation changes in the central North Atlantic region. Here, we present a chironomid-based quantitative temperature reconstruction and a record of oxygen isotope composition of chironomid head capsules for the last ca. 1200 years, based on the Lake Prata core (São Miguel Island, Azores). Chironomids from Lake Prata show that the temperature trend is aligned with the prevailing past global temperature trends, indicating warming during the Medieval Climate Anomaly (MCA; ca. 950–1300 CE) and subsequent cooling during the Little Ice Age (LIA; ca. 1300–1800 CE). Furthermore, changes in lake water oxygen isotope composition from chironomid head capsules were recorded with more positive δ18O values (18.2 ± 0.2‰) during the MCA and more negative values (varying between 14.8‰ and 17.6‰) during the LIA, indicating a positive shift in the precipitation-evaporation balance and/or heavier precipitation in winter relative to summer. Our study revealed that, in subtropical regions with a temperate oceanic climate and low thermal variation, there is a limited correlation between the isotopic composition of precipitation and temperature. Additionally, the temporal sequence of oxygen isotope values obtained from chironomid head capsules closely corresponds to variations in precipitation seasonality inferred from distinct climatic proxies. This consistency underscores the robustness of quantitative reconstructions and indicates that δ18Ochironomid records are promising for future investigations, especially in the context of lakes located on oceanic islands characterised by limited thermal variability.

Processing water birds for food at the Island of Kökar in the Baltic Sea during the medieval and early modern period (ca. CE 1400–1700)

AbstractFew studies have been made of the specific importance of waterfowl as food in the Baltic Sea during the late medieval and early modern period. This study shows the seasonal importance of water birds to island and coastal inhabitants living in the middle of the Baltic Sea during the late medieval and early modern periods (ca. CE 1400–1700) and practical implementations for interpretation of cut and chop marks. The paper is based on a bird bone assemblage retrieved from a remote ecclesial site on the island group of Kökar, which is part of the Åland Islands, as well as historical documents and local specialist knowledge. The site was established by Franciscan friars somewhere in the mid‐15th century. Documents indicate that the friars had landownership, income from taxing nearby fisheries, and the right to seal tithe. These assets were taken over by the crown in the mid‐16th century due to the Reformation and a parish church was established on the same site after the friary was dissolved. The bone assemblages from the site include birds, mammals, and fish. The material shows a relatively small number of chicken bones in relation to waterfowl, allowing one to look closer into the structural food economy around water birds for the area. The bones also show several cut and chop marks, which have been analyzed to explore the possible processing of these birds. The results show that fowling was concentrated to a couple of species most likely during spring when these species were abundant. The placement of the cut and chop marks indicates that a large number of birds were likely processed at the same time.

Latitudinal variation in seagrass communities with special emphasis on post-tsunami status in the Andaman and Nicobar archipelago, India.

We studied spatial variation in seagrass communities in the Andaman and Nicobar archipelago (ANI), India using latitude as a surrogate variable. We classified the ANI into five latitudinally distinct island groups: North & Middle Andaman, Ritchie's archipelago, South Andaman, Little Andaman, and the Nicobar archipelago. We evaluated the Importance Value Index (IVI) for species to determine the ecologically dominant seagrasses within each Island group. Later, we related our findings to investigate the three decadal pre- and post-tsunami status of seagrass habitats in the ANI which were severely impacted by the Indian Ocean tsunami of 2004. Six of the 11 observed species, such as Halophila ovalis, Halophila beccarii, Halophila minor, Halodule pinifolia, Thalassia hemprichii, and Cymodocea rotundata, dominated the seagrass population among all island groups. Seagrass composition significantly varied across the five investigated latitudinal gradients. Seagrass communities in 'Ritchie's Archipelago and Nicobar' and 'South Andaman and Little Andaman' revealed the highest and lowest variation. Further, Ritchie's Archipelago and Nicobar had the highest species richness (n = 10), followed by North & Middle Andaman (n = 8), and the lowest in South and Little Andaman (n = 6). Despite similar species richness and composition, Nicobar contributed to the highest seagrass coverage compared to the lowest recorded in the Ritchie's Archipelago. Our observations on the re-colonization of disturbed areas by early successional and historical species suggest recovery of the seagrass population in the ANI post-disturbance. Lastly, co-variates associated with latitude as a surrogate warrant further investigation.

Dissecting coral recovery: bleaching reduces reproductive output in Acropora millepora

AbstractIncreasingly frequent and severe bleaching events driven by climate change are decreasing coral populations worldwide. Recovery of these populations relies on reproduction by the survivors of such events including local and upstream larval sources. Yet, corals that survive bleaching may be impaired by sublethal effects that suppress reproduction, reducing larval input to reefs, and consequently impeding recovery. We investigated the impact of the 2020 mass-bleaching event on Acropora millepora reproduction on inshore, turbid reefs in Woppaburra sea Country (the Keppel Islands), to improve our understanding of the effects of bleaching on coral populations. A. millepora experienced high bleaching incidence but low mortality across the island group during this event and thus constituted an ideal population to investigate potential sublethal effects on reproductive output. Six months after the heat wave, and just prior to spawning, we collected, decalcified, and dissected samples from 94 tagged A. millepora colonies with a known 2020 bleaching response, to investigate the relationships between stress severity and reproduction. Despite having regained their pigmentation, we detected a significant reduction in fecundity in colonies that had bleached severely. Considering the impact of the bleaching event on the coral population sampled (i.e., mortality, bleaching severity and colony size), coupled with reductions in fecundity, we estimated a total decrease in population-level reproductive output of 21%. These results suggest that reduced reproductive output may impact recovery of coral populations following bleaching and should be considered alongside traditional estimates of coral mortality.

Global evidence of rapid flash drought recovery by extreme precipitation

Flash drought affects agricultural activities and water availability. However, the rate of flash drought development and termination and their controlling mechanisms remain mostly unexplored. Using climate reanalysis (ERA5) datasets, we examine the flash drought development and recovery rates in seventeen climate regions across the globe during the 1981–2020 period. In most global climate regions, flash drought recovery (25.2 percentile/pentad) is faster than its development rate (17.2 percentile/pentad). The tropical and sub-tropical humid areas, particularly eastern North America, northern South America, South Asia, Southeast Asia, and the Islands groups, are the hotspots of rapid flash drought development and faster recovery rates. In most climate regions, flash drought development and recovery rates have considerably increased during the recent two decades. Pluvial events (heavy-to-extreme precipitation) associated with increased soil moisture and decreased atmospheric aridity vapor pressure deficit are the primary driver of the rapid flash drought recovery. Globally, 10 of 17 regions showed the dominance of extreme precipitation in flash drought recovery, primarily due to an increase in the frequency of extreme precipitation. A fraction of flash droughts terminated by extreme precipitation has increased significantly across the most regions during 1981–2020. Considering the increase in flash drought frequency, development rate, and rapid termination, the compound risk of flash droughts followed by extreme precipitation and flooding has enhanced. The abrupt transition from flash drought to wet conditions makes drought and flood management more challenging, with consequences for agriculture and water resources.

Abstract P303: Investigating the Relationship Between Cardiovascular Diseases and Major Depressive Disorder Among Asians and Pacific Islanders

Background: Poorer mental health is associated with greater cardiovascular disease (CVD) morbidity, recovery, and mortality. Experiencing CVD is also associated with poorer mental health after a CVD event. What has been less examined, is how these associations differ among disaggregated Asian and Pacific Islander (API) groups who have a lower burden of both CVD and poor mental health relative to other racial groups. Objective: To examine the association between CVD diagnosis and experiencing major depressive disorder (MDD) among API people and how it differs between racial groups. Methods: We used survey data (n=5,229) from a study of API patients in Hawai’i and California with a linked electronic health record (EHR) data. Race, sex, body mass index (BMI) and CHD, Stroke, and PVD diagnosis were obtained from EHR while MI and CAD diagnoses were from the survey. Data on health behaviors and social determinants were obtained from the survey. Multivariate logistic regression models were used to determine the association between CVD and MDD. Results: Overall prevalence of MDD was 9.2%. Non-Hispanic White people (6.1%) had the lowest prevalence while “Pacific Islander and White” people had the highest prevalence (12.8%). In the fully adjusted models (Table), people who had a stroke (OR = 1.34, p < .001), CHD (OR = 1.32, p = .01), CAD (OR = 1.35, p = .016) or PVD (OR = 1.49, p < .001) had increased odds of MDD. There was a significant interaction between CAD and increased MDD that differed for Filipino, Asian Indian, “Pacific Islander and Asian”, “Asian and White”, and “Pacific Islander and White” groups compared to Non-Hispanic White people. Conclusion: Diagnosis of certain CVDs could increase the risk of experiencing MDD with potential race group differences for CAD. Further efforts should be made to protect the mental health of patients that have experienced a diagnosis of CVD as MDD can further harm their health outcomes. Moreover, research and treatment should consider potential racial differences in the experience of depression and CVD.

Military Advancement of Chinese Unmanned Aerial Vehicles: Security Implications for India

The advanced Military UAVs have significantly all over the world in different form. The cost-effectiveness and political advantages of UAVs make it as one of the powerful weapon in 21st century. Economically, UAVs offer reduced vehicle costs, operational expenses, and pilot training compared to manned aircraft. Politically, they can lower the threshold for the use of force in various scenarios especially when it is used for grey warfare. Consequently, military UAVs are employed for bold intelligence, surveillance, and reconnaissance (ISR) missions, thereby providing an edge to the users in terms of information superiority, which can bolster influence over disputed territories. The PRC embarked on military UAV development as early as the 1950s, initially emulating technologies from the US and the Soviet Union. Presently, China competes with the US in UAV technology advancements. Employing a government-led top-down approach, China fosters vibrant cooperation among industries, academia, and the military to develop UAV capabilities, with a focus on expanding influence in the surrounding region. Since Xi Jinping assumed office in 2012, aggressive policies have been implemented to assert control over sea territories within the first island chain. The main agenda of Xi Jingping is making China AI enabled in all sectors especially in the area of Military Technologies. This is why military UAVs are anticipated to play a pivotal role in Xi’s Indo-Pacific strategy, where the PRC faces conflicts with neighboring countries. On the other joining hands with Pakistan, China continuously using its high-end drone technology against India to create internal security problems for India in form of drugs smuggling, proliferation of illegal arms and ammunition the This article delves into the significant development of military unmanned aerial vehicles by the People’s Republic of China and their utilization in confrontations with India.

Summary of our present knowledge of the spider communities of the Galápagos archipelago. First analysis of the spider communities of the islands Santa Cruz and Isabela

A synthesis is given of 30 years of galapagoan spider fauna research, including an historical overview of spider sampling in the archipelago. A total of 11,437 specimens originating from 688 sampling localities are analyzed. In total 175 spider species are reported of which 152 could be identified or were described as new. The remaining 23 species could only be identified to morpho-species level and they may be new to science and thus endemic. Two basic conclusions could be made from this first analysis of the existing data. 1° Single islands or island groups can be characterized by a specific spider community, and 2° the well-differentiated climax vegetation zones of Isla Santa Cruz can also be characterized by a specific spider community.

Effects of edge-localized electron cyclotron current drive on edge-localized mode suppression by resonant magnetic perturbations in DIII-D

According to recent DIII-D experiments (Logan et al 2024 Nucl. Fusion 64 014003), injecting edge localized electron cyclotron current drive (ECCD) in the counter-plasma-current (counter-I p) direction reduces the n = 3 resonant magnetic perturbation (RMP) current threshold for edge-localized mode (ELM) suppression, while co-I p ECCD during the suppressed ELM phase causes a back transition to ELMing. This paper presents nonlinear two-fluid simulations on the ECCD manipulation of edge magnetic islands induced by RMP using the TM1 code. In the presence of a magnetic island chain at the pedestal-top, co-I p ECCD is found to decrease the island width and restore the initially degraded pedestal pressure when its radial deposition location is close to the rational surface of the island. With a sufficiently strong co-I p ECCD current, the RMP-driven magnetic island can be healed, and the pedestal pressure fully recovers to its initial ELMing state. On the contrary, counter-I p ECCD is found to increase the island width and further reduce the pedestal pressure to levels significantly below the peeling-ballooning-mode limited height, leading to even stationary ELM suppression. These simulations align with the results from DIII-D experiments. However, when multiple magnetic island chains are present at the pedestal-top, the ECCD current experiences substantial broadening, and its effects on the island width and pedestal pressure become negligible. Further simulations reveal that counter-I p ECCD enhances RMP penetration by lowering the penetration threshold, with the degree of reduction proportional to the amplitude of ECCD current. For the ∼1 MW ECCD in DIII-D, the predicted decrease in the RMP penetration threshold for ELM suppression is approximately 20%, consistent with experimental observations. These simulations indicate that edge-localized ECCD can be used to either facilitate RMP-driven ELM suppression or optimize the confinement degradation.

Disparities in the Prevalence of Psychiatric Illness in Hawaii's Houseless Population: A Retrospective Chart Review.

In the State of Hawaii, previous research has suggested that minority groups such as Native Hawaiians and Other Pacific Islanders are disproportionately affected by mental health disorders and have less access to mental health services. The purpose of this study was to determine if similar disparities in the prevalence of psychiatric disorders among different ethnic groups are also present among Hawaii's houseless population. A retrospective chart review of records from one of Oahu's major houseless outreach clinics was performed to gather patient demographics and reported histories of psychiatric diagnoses. Reported disease prevalence rates were compared between larger ethnic categories as well as ethnic sub-groups. Results demonstrated higher rates of certain serious mental illnesses among the houseless; however, several other psychiatric diagnoses were unexpectedly found to be less prevalent than in the general population. Additionally, houseless Pacific Islander groups were unexpectedly found to often have disproportionally lower rates of psychiatric diagnoses despite being identified as high risk by other studies. Overall, our findings may indicate unique ethnic trends in the prevalence of mental health disorders among the houseless in Hawaii or may suggest increased social and/or cultural barriers to diagnosis among certain groups that will require more diligent screening and culturally competent care from providers.

Chemical weathering along a one-million-year soil age gradient on the Galápagos Islands

The Galápagos archipelago, a chain of islands formed by hotspot-induced volcanism on the Nazca tectonic plate, exhibits pronounced gradients of rock age and climate. Here, we investigate chemical weathering along a soil chronosequence (1.5 to 1070 ka) and under humid vs. dry conditions. Our results show considerable loss of base cations already in the early to intermediate phases of weathering under humid conditions (e.g. 95 % of Na and 78 % of Mg lost from the topsoil after 26 ka) and almost complete loss from the entire profile in soils older than 800 ka. Depletion of Si was less pronounced, with topsoil losses of 24 % and 63–68 % after 26 ka and >800 ka, respectively. Under dry conditions, weathering rates were much lower, e.g. 33 % of Na and 1.4 % of Mg lost from the topsoil after 26 ka. Indices of chemical weathering, e.g. the Chemical Index of Alteration and the Ruxton Ratio, correlated well with indicators of pedogenic development, such as solum thickness, soil pH, or the ratio of oxalate- to dithionite-extractable Fe. Total weathering flux and associated CO2 consumption rates estimated from profile-scale element losses in this study exceeded catchment-scale estimates reported for other volcanic islands or global averages during the early weathering phase, but were much lower in the intermediate and late phases. Nevertheless, total C drawdown was dominated by soil organic C sequestration (70–90 % share) rather than inorganic, weathering-induced CO2 consumption during early pedogenesis (≤4.3 ka), and the relative importance switched in the intermediate and late phases (90–95 % share of weathering-induced C drawdown at ≥166 ka). Dust deposition derived from a nearby ocean sediment core was <20 % of total basalt mass loss at the young and intermediate-aged sites, but reached 40–60 % at the older sites (>800 ka). Our results suggest that (1) young volcanic surfaces are very efficient (inorganic and organic) C sinks, (2) the development of thick soil covers at advanced pedogenic stages effectively shields the underlying rocks and decelerates weathering, and (3) dust inputs become an increasingly important biogeochemical factor in such highly weathered environments.

Taraxacum pseudohamatum Dahlst. (Asteraceae, Cichorioideae) – a new naturalisation from the Chatham Islands, Aotearoa / New Zealand

Taraxacum pseudohamatum is reported from Rēkohu / Wharekauri / Chatham Island in the Chatham Islands, Aotearoa / New Zealand. This species is an addition to that island group’s naturalised flora and the New Zealand Botanical Region. It is also the second member of Taraxacum Sect. Hamatum to be recorded from the islands. The first species of that section to be recorded from the islands is Taraxacum hamatum, which is still only known from a collection made from Hokorereoro / Rangatira / South East Island. Taraxacum pseudohamatum is locally common on Rēkohu / Wharekauri / Chatham Island. The species is described using material from that island, and notes on its recognition and distinction from T. hamatum presented. The ecology of the species on Rēkohu / Wharekauri / Chatham Island is described.

Island myriads in periodic potentials.

A phenomenon of emergence of stability islands in phase space is reported for two periodic potentials with tiling symmetries, one square and the other hexagonal, inspired by bidimensional Hamiltonian models of optical lattices. The structures found, here termed as island myriads, resemble web-tori with notable fractality and arise at energy levels reaching that of unstable equilibria. In general, the myriad is an arrangement of concentric island chains with properties relying on the translational and rotational symmetries of the potential functions. In the square system, orbits within the myriad come in isochronous pairs and can have different periodic closure, either returning to their initial position or jumping to identical sites in neighbor cells of the lattice, therefore impacting transport properties. As seen when compared to a more generic case, i.e., the rectangular lattice, the breaking of square symmetry disrupts the myriad even for small deviations from its equilateral configuration. For the hexagonal case, the myriad was found but in attenuated form, mostly due to extra instabilities in the potential surface that prevent the stabilization of orbits forming the chains.

Calcium isotope variability among ocean islands reveals the physical and lithological controls on mantle partial melting

Major geodynamic processes, including mantle convection and plate tectonics, govern the exchange of mass between Earth's interior and its surface. These processes drive mass-transfer mechanisms such as partial melting and crustal recycling, which have generated a lithologically and compositionally heterogeneous mantle over time. Ocean island basalts (OIB) directly sample these heterogeneities, making them excellent tools to constrain the mantle’s dynamic geochemical evolution. In this study, we probe the connection between crustal recycling, mantle mineralogy, and partial melting using the stable Ca isotope compositions of OIB, ultimately contextualizing their Ca isotope variability using conventional mantle “endmember” components including DMM, HIMU, EM-1, and EM-2. Using the state-of-the-art Nu Sapphire collision cell MC-ICP-MS, we measured the Ca isotope compositions of 27 well-characterized OIB samples from 11 different ocean island groups. By supplementing our new data with additional high-precision Ca isotope measurements from the literature, we create an expanded dataset consisting of 15 ocean islands, facilitating a global-scale investigation of Ca isotope variability among hotspots. Our findings reveal that island-averaged Ca isotope compositions form two distinct groups on the basis of their radiogenic isotope compositions. The first group, consisting of OIB with un-enriched radiogenic isotope compositions (non-EM-type), exhibits robust negative correlations with both lithospheric thickness and primitive TiO2 contents, providing compelling evidence that Ca isotopes are sensitive to the degree of partial melting (F) as well as to the effects of crustal recycling. This joint signal appears to trace the process of decompression melting beneath oceanic lithosphere of variable thickness, as recycled lithologies rich in garnet and pyroxene (i.e., pyroxenites)—which generate large solid-melt Ca isotope fractionations—disproportionally control the Ca isotope composition of the final aggregate melt when F is limited by thick overlying lithosphere. In contrast, the island-averaged Ca isotope compositions of OIB with enriched radiogenic isotope compositions (EM-type) form a distinctly light negative correlation with primitive TiO2 contents without exhibiting a relationship with lithospheric thickness. In addition to lithology-dependent partial melting effects, the Ca isotope compositions of EM-type OIB appear to be sensitive to the compositional effects of crustal recycling, which may explain their decoupling from the physical controls of partial melting. Calcium isotopes show exceptional potential for elucidating the origin of both enriched and ultra-depleted mantle sources, emphasizing the need to prioritize localities with these signatures in future studies.

Incomplete isolation in the nonbreeding areas of two genetically separated but sympatric short-tailed albatross populations

The short-tailed albatross Phoebastria albatrus, a globally Vulnerable species recovering from near-extinction, breeds mainly on 2 island groups in the north-western Pacific: Torishima and Senkaku Islands. Recently, it became clear that this is a species complex, composed of 2 populations (‘Torishima’ and ‘Senkaku’ types) that are distinct from both genetic and morphological perspectives, and which mate assortatively on Torishima. We tested the hypothesis of premating isolation as a possible mechanism for genetic differentiation and shifted breeding date in short-tailed albatrosses. Using light-based geolocation and molecular analysis, we examined whether adults from the 2 populations breeding on Torishima differed in their at-sea distribution during the nonbreeding period (June-September) and in their return dates. From 22 bird tracks collected from 12 birds over 4 yr, we identified 2 distinct nonbreeding areas: around the Aleutian Islands in the Bering Sea and near the Kuril Islands in the Okhotsk Sea. All 6 tracks of Torishima-type birds migrated directly to the Bering Sea in all years. In contrast, most of the Senkaku-type birds migrated along northeast Japan to the Okhotsk Sea (9 tracks), with the others moving to the Bering Sea (7 tracks). There was no clear difference in the dates of return to Torishima between the 2 bird types. Overall, no absolute pre-mating isolation in space or time was observed in short-tailed albatrosses, but we highlighted notable divergences in the nonbreeding distribution of both types. This result suggests that Torishima- and Senkaku-type populations should be treated as separate management units.

FORMATION OF BRANCHES AT RIVER MEANDERS

When studying channel morphodynamics, the processes and forms of meandering and branching are considered independently. However, the development of meanders on large rivers is complicated by the formation of islands on their limbs and in the neartop parts. The most striking manifestation of the process is the branched-winding channels, which develop as a result of the successive formation of islands, creating spurs of meanders if attached to the coastal floodplain. The relief of the floodplains of such rivers is hollow-island in contrast to the ridged relief of typical meandering rivers. Another form of such channels of large rivers is alternating unilateral ramifications, in which the meanders of the main (highwater) branch go around the groups of islands located in a checkerboard pattern, and the channel itself in the floodplain banks remains quasirectilinear while in a branched-winding channel it forms segmental meanders. The presence of branches at a meander of the channel disperses the runoff, and decreases the amount of water in the main branch, thus affecting the parameters of the meanders.Islands are also formed in the neartop parts of meanders, where its dynamic axis shifts towards the convex coast due to the violation of continuous flow around the banks, and erodes it. In the resulting local widening of the channel, a middle center appears and, when it is overgrown, an island is formed. A local widening of the channel is formed on rectilinear «inserts» between adjacent large meanders when the floodplain and channel flows intersect during the flood, and a middle or island is also formed in it. On the upper wings of steep bends, especially forced meanders, the formation of branches is associated with the flow backwater that occurs when it approaches the bedrock bank at the top of the meander at a high angle.The formation of branchings at the meanders of a channel should be taken into account during river development as a factor that can influence the conditions of navigation and influence the channel reshaping, which is particularly important at the places where linear structures, such as bridges and pipelines, cross the rivers.

Aspects of Breeding Performance of Scopoli’s Shearwater (Calonectris diomedea): The Case of the Largest Colony in Greece

Here we report, for the first time, aspects of the breeding performance of Scopoli’s Shearwater (Calonectris diomedea) in one of its largest colonies in Europe, i.e., in the Strofades island group. We describe the chronology of the main events in the breeding cycle of this species on Stamfani Island, the largest island of this island group, including the evaluation of breeding performance and the influence of ecological factors (nesting habitat, nest type, nest-entrance orientation, and occupation rate per nest) on breeding success. The Scopoli’s Shearwater colony of Stamfani Island exhibited a high degree of breeding synchrony and nest site tenacity. The data obtained by monitoring 472 nests during five consecutive years (2008–2012), showed a breeding success (fledging per occupied nest per year) of up to 66.6%. In addition, hatching success (chick hatched successfully per egg laid) was 76.9%, and fledging success (fledging young per chick hatched successfully) was 86.8%. We also observed annual variations in breeding performance during that period. These results seemed to be influenced positively by the breeding experience of the pair. Furthermore, the type of nest site and the nest-entrance orientation were found to have an effect on breeding success rates, whereas the nesting habitat did not, indicating low predation risk by rats.

Cretaceous stratigraphy of Antarctica and its global significance

Abstract The Cretaceous Period is particularly well represented by a thick sequence of clastic sedimentary rocks exposed in the Antarctic Peninsula region of western Antarctica. This was an active margin throughout the Late Mesozoic, and in total some 7 km+ of Cretaceous sedimentary rocks accumulated in a series of fore-, intra- and back-arc basins. The Fossil Bluff Group of eastern Alexander Island can be traced from the Jurassic–Cretaceous boundary into the Upper Albian and represents a broad-scale shallowing-upward sequence from deep marine to a prominent Upper Albian fluvial interval in which high-density forests developed at a palaeolatitude of 75° S. The Cretaceous sequence exposed in the James Ross Island group continues right through the Upper Cretaceous to the Cretaceous–Paleogene boundary. The Campanian–Maastrichtian succession in particular is over 2 km in total thickness and richly fossiliferous. The improved Cretaceous stratigraphy of Antarctica is an invaluable terrestrial record of climatic change at a high palaeolatitude. This includes a gradual increase in temperature to the Cretaceous Thermal Maximum, and then a decline to the Cretaceous–Paleogene boundary. There may be no simple link between these palaeotemperature changes and Cretaceous patterns of biotic radiation and extinction.

Who, Why, When, and Where From? The Peopling of the Canary Islands and the Challenges of Archaeometry

Archaeologists in the Canary Islands have gathered substantial quantitative data from radiocarbon measurements and aDNA analyses. While undeniably helpful and necessary for apprehending past human activity, their interpretation, based on theories underpinning models developed for island chains, has lagged, leaving a gap in our understanding of processes of occupation and social network systems. The decontextualized nature of the archaeological landscape of the Canaries and a lack of consensus about proper radiocarbon methodologies are some of the factors contributing to heated scholarly debate. Here, for the Canary Islands, the author reviews the current literature on aDNA and discusses settlement theories, the chronological evidence used for occupation models, and how such perspectives align with current thinking on island colonization.