A view from above : changing seas, seabirds and food sources

In this review we summarize what is known about mechanisms by which climate change may be affecting the populations of seabirds around the UK. Breeding success and adult survival are the key factors affecting changes in seabird populations, and food intake is implicated as a major determinant of both. The diet of most UK seabird species is almost exclusively sandeels, small clupeoid fish or zooplankton and it is clear that the marine pelagic food web is the key ecological system determining food supply. Hence, we develop the review by first considering how climate changes may affect primary production, and then examine how this propagates through the food web to zooplankton and fish culminating in fluctuations in seabird numbers. A trend of increasing numbers of many seabird species since 1970, particularly puffins, guillemots and razorbills, appears to have been reversed since 2000. The proximate cause of the recent declines seems to be a succession of 5 years of low breeding success for a range of species due to a shortage of food, especially sandeels. However, the connection with climate change remains uncertain, though there are indications that declines in the productivity of sandeel populations may be linked in some complex way to warming sea temperatures. The main conclusion is that no part of the marine food web, including fisheries, can be considered in isolation when trying to understand and predict the consequences of climate change for seabirds. Impacts can be expected in all parts of the system, and all parts of the system are interconnected

Behavior Patterns of the Adult Alfalfa Weevil in Cache Valley, Utah

The alfalfa weevil, Hypera postica (Gyllenhal), was first found in the United States in Salt Lake City, Utah, during 1904 (Titus, 1910b). It spread form this point of original introduction and partially infested Cache Valley by 1912 (Titus, 1913). The alfalfa weevil has become one of the more important insect problems currently affecting American agriculture. Recently, this problem has attracted national attention because of the development of resistance to insecticides by the alfalfa weevil, the outlawing of certain pesticides for use on forage crops and the rapid spread of the alfalfa weevil to new areas. With this increased attention, many discrepancies have appeared in different reports of the alfalfa weevil\u27s biology. The results of studies in the eastern United States often do not agree with those of studies which were made in Utah and vicinity during the early part of this century. In order to investigate the discrepancies or differences, and to determine the behavior patterns of the alfalfa weevil in Cache Valley, this study was undertaken. It was conducted from June, 1965 to August, 1966. The main topics investigated were the adult alfalfa weevil\u27s flight activities, reproduction, daily field activities, seasonal history including diapause, and respiration under controlled conditions

Reproductive performance of resident and migrant males, females and pairs in a partially migratory bird

We thank everyone from the Centre for Ecology & Hydrology (CEH) who contributed to data collection, and Scottish Natural Heritage for access to the Isle of May National Nature Reserve. We thank the Scottish Ornithologists’ Club (SOC) for their support, and all volunteer observers, particularly Raymond Duncan, Moray Souter and Bob Swann. HG was funded by a Natural Environment Research Council (NERC) CASE studentship supported by CEH and SOC, FD, SW, MPH, MN and SB were funded by NERC and the Joint Nature Conservation Committee, and JMR was part-funded by the Royal Society. Finally, we thank the Associate Editor and two reviewers for constructive comments on the manuscript. The data are available from the Dryad Digital Repository https://doi.org/10.5061/dryad.532j0 (Grist et al., 2017)Peer reviewedPublisher PD

Latin bitrades derived from groups

A latin bitrade is a pair of partial latin squares which are disjoint, occupy the same set of non-empty cells, and whose corresponding rows and columns contain the same set of entries. Dr\'apal (\cite{Dr9}) showed that a latin bitrade is equivalent to three derangements whose product is the identity and whose cycles pairwise have at most one point in common. By letting a group act on itself by right translation, we show how some latin bitrades may be derived from groups without specifying an independent group action. Properties of latin trades such as homogeneousness, minimality (via thinness) and orthogonality may also be encoded succinctly within the group structure. We apply the construction to some well-known groups, constructing previously unknown latin bitrades. In particular, we show the existence of minimal, $k$-homogeneous latin trades for each odd $k\geq 3$. In some cases these are the smallest known such examples.Comment: 23 page

Assessing the vulnerability of the marine bird community in the western North Sea to climate change and other anthropogenic impacts

Ocean warming and anthropogenic activities such as fishing, shipping and marine renewable developments are affecting marine top predators. Research has focussed on the impacts of single stressors on single species, yet understanding cumulative effects of multiple stressors on communities is vital for effective conservation management. We studied a marine bird community (45 species; 11 families) that used the Forth and Tay region of the North Sea for breeding, overwintering or migration between 1980 and 2011. Local sea surface temperature (SST) increased significantly over this period, with concomitant changes in lower trophic levels. Simultaneously, the region has been subject to fishing pressure and shipping disturbance and is a priority area for renewable energy developments. We used colony-based and at-sea data to quantitatively assess relationships between SST and counts, productivity and survival of 25 species for which sufficient data were available for analysis. For the remaining species, we applied a qualitative approach using published population trends, published climate relationships and foraging sensitivity. In total, 53% of species showed negative relationships with SST. Trends in counts and demography were combined with climate vulnerability to give an index of population concern to future climate warming, and 44% of species were classified as high or very high concern, notably cormorants, grebes, skuas, shearwaters, terns and auks, as well as species breeding in the region. Qualitative assessments of vulnerability to fisheries, pollutants, disturbance (including introduced predators), marine renewables and climate found that 93% of species were vulnerable to ≥2 threats, and 58% to ≥4. Our results indicate that the majority of birds in this region of the North Sea face an uncertain future, potentially threatening the resilience of this important marine bird community

There are asymptotically the same number of Latin squares of each parity

A Latin square is reduced if its first row and column are in natural order. For Latin squares of a particular order n there are four possible different parities. We confirm a conjecture of Stones and Wanless by showing asymptotic equality between the numbers of reduced Latin squares of each possible parity as the order n → ∞

Genetic structure in the European endemic seabird, Phalacrocorax aristotelis, shaped by a complex interaction of historical and contemporary, physical and nonphysical drivers

Geographically separated populations tend to be less connected by gene flow, as a result of physical or non-physical barriers preventing dispersal, and this can lead to genetic structure. In this context, highly mobile organisms such as seabirds are interesting because the small effect of physical barriers means non-physical ones may be relatively more important. Here we use microsatellite and mitochondrial data to explore the genetic structure and phylogeography of Atlantic and Mediterranean populations of a European endemic seabird, the European Shag, Phalacrocorax aristotelis, and identify the primary drivers of their diversification. Analyses of mitochondrial markers revealed three phylogenetic lineages grouping the North Atlantic, Spanish/Corsican and Eastern Mediterranean populations, apparently arising from fragmentation during the Pleistocene followed by range expansion. These traces of historical fragmentation were also evident in the genetic structure estimated by microsatellite markers, despite significant contemporary gene flow among adjacent populations. Stronger genetic structure, probably promoted by landscape, philopatry and local adaptation, was found among distant populations and those separated by physical and ecological barriers. This study highlights the enduring effect of Pleistocene climatic changes on shag populations, especially within the Mediterranean Basin, and suggests a role for cryptic northern refugia, as well as known southern refugia, on the genetic structure of European seabirds. Finally, it outlines how contemporary ecological barriers and behavioral traits may maintain population divergence, despite long-distance dispersal triggered by extreme environmental conditions (e.g. population crashes)

Constraints on Near-Ridge Magmatism Using \u3csup\u3e40\u3c/sup\u3eAr/\u3csup\u3e39\u3c/sup\u3eAr Geochronology of Enriched MORB from the 8°20\u27 N Seamount Chain

Our understanding of the spatial-temporal-compositional relationships between off-axis magmatism and mid-ocean ridge spreading centers is limited. Determining the 40Ar/39Ar ages of mid-ocean ridge basalt (MORB) lavas erupting near mid-ocean ridges (MOR) has been a challenge due to the characteristically low K2O contents in incompatible element-depleted normal MORB (NMORB). High-precision 40Ar/39Ar geochronology is used here to determine ages of young, basaltic lavas erupted along the 8°20\u27 N seamount chain west of the East Pacific Rise (EPR) axis that have a range of incompatible element enrichments (EMORB) suitable for 40Ar/39Ar geochronology (e.g., K2O contents \u3e 0.3 wt%). 40Ar/39Ar ages were determined in 29 well-characterized basalts sampled using HOV Alvin and dredging. Detailed geochronology and geochemical analyses provide important constraints on the timing, distribution, and origins of lavas that constructed this extensive volcanic lineament relative to magmatism beneath the adjacent EPR axis. Seamount eruption ages are up to ∼1.6 Ma younger than the underlying lithosphere, supporting a model of prolonged off-axis magmatism for at least 2 Myrs at distances as great as ∼90 km from the ridge axis. Increasing geochemical heterogeneity with eruption distance reflects the diminishing effect of sub-ridge melt focusing. The range of geochemically distinct lavas erupted at given distances from the ridge highlights the dynamic nature of the near-ridge magmatic environment over Myr timescales. Linear ridge-like (EPR-parallel) morphotectonic features erupt the youngest and most incompatible element-enriched lavas of the entire seamount chain, indicating there is a recent change in the influence of mantle heterogeneity and off-axis melt metasomatism on the near-ridge lithospheric mantle. Changes in seamount morphologies are attributed to counter-clockwise rotation and southward migration of the nearby Siqueiros transform over the last few million years