Can changes in fishery landings explain long-term population trends in gulls?

Capsule: Long-term population trends of gulls on the Isle of Canna, Scotland, showed a correlation to fish tonnage landed in a nearby port.

Aims: To assess whether gull numbers and breeding success at Canna have been influenced by the amount of fish discarded in the area.

Methods: We examined data on gull breeding numbers, breeding success and diet studied at Canna from 1969 to 2014, and data on fish landings at the nearby port of Mallaig for 1985 to 2014. We examined correlations between gull and fishery data, and performed a detrended analysis of Herring Gull Larus argentatus numbers in relation to demersal fish catch (the latter as a proxy for discard volumes).

Results: Gulls fed extensively on discards. Gull breeding numbers declined at Canna, especially between 2000 and 2006, the decline being more pronounced than seen in national totals. Gull breeding numbers correlated with demersal landings, even after detrending for long-term decreases in both.

Conclusions: Correlation between detrended Herring Gull breeding numbers and detrended demersal fish landings provided strong evidence for a causal link between fishery discarding and gull breeding numbers.     

Environmental correlates of breeding abundance and population change of Eurasian Curlew Numenius arquata in Britain

Capsule: Across Britain, breeding Eurasian Curlew Numenius arquata are less numerous and have shown greater population declines in areas with more arable farming, woodland cover and higher generalist predator abundance.

Aims: We present the first national-scale analysis of the potential drivers of Curlew population change in Britain, which is needed to guide conservation action for this globally near-threatened, declining species.

Methods: Breeding Bird Survey data and environmental predictors were used to model variation in Curlew abundance in 1995–99 and 2007–11, and population change between these periods.

Results: Arable farming and woodland cover were negatively associated with Curlew abundance and population declines. Curlew abundance was positively associated with extent of protected area coverage and gamebird numbers. Abundance and population change were positively associated with cooler temperatures and higher summer rainfall, but negatively associated with numbers of generalist predators.

Conclusions: We found support for the negative effects of intensive agriculture, forestry, increases in generalist predator populations and climate warming on Curlew abundance and population change. Effective site protection and measures to reduce generalist predator abundance may be important conservation measures, together with improving breeding habitat quality in the wider countryside.     

Future breeding and foraging sites of a southern edge population of the locally endangered Black Guillemot Cepphus grylle

Capsule: One of the southernmost populations of the Black Guillemot Cepphus grylle is currently endangered, and the risk may be exacerbated by climate change.

Aims: We evaluated the future vulnerability of the Black Guillemot by predicting the impact of climate change on the geographic distribution of its breeding and foraging range in the Baltic Sea.

Methods: We used MaxEnt, a species distribution modelling technique, to predict the current and future breeding grounds and foraging sites.

Results: We found that although the foraging range is expected to increase in the southern Baltic Sea in future, these areas will no longer be suitable as breeding grounds due to a changing climate, creating a spatial mismatch.

Conclusion: Our predictions indicate where threats to the species may be most severe and can be used to guide conservation planning. We advocate conservation measures which integrate potential future threats and focus on breeding sites across the current and future potential geographic range of the Black Guillemot.     

Assessing the impact of extreme flooding on survival in a southern European population of White-throated Dippers Cinclus cinclus

Capsule: There were only weak effects of winter flooding episodes on apparent annual survival of a White-throated Dipper breeding population in northern Iberia.

Aims: To test whether extreme winter flooding episodes affected survival in a breeding population of White-throated Dippers Cinclus cinclus.

Methods: Dippers were ringed during the breeding seasons of seven consecutive years on rivers in northern Iberia. Cormack–Jolly–Seber models were used to estimate apparent annual survival in relation to flooding during the winter periods.

Results: We obtained weak evidence for an effect of flooding during the winter on the surveyed population. Two of the six winters were characterized by having an exceptionally high discharge. Our models showed that survival in the subsequent breeding period tended to be lower, although models assuming constant survival were equally well supported.

Conclusion: Extreme flooding in winter may affect survival of some White-throated Dippers in northern Iberia, but its impact at the population level seems to be weak.     

Productivity of the Black-legged Kittiwake Rissa tridactyla required to maintain numbers

Capsule: To maintain the breeding numbers in Britain, Black-legged Kittiwakes Rissa tridactyla need to produce a mean of 0.8–1.5 fledged young per year.

Aims: To obtain a new estimate for the number of young Kittiwakes fledged per pair required to maintain breeding numbers in Britain in the period 1985–2015 based on field data.

Methods: The annual values of productivity in the River Tyne area of northeast England are compared with the long-term increases in numbers of breeding pairs in that area. Regressions between the annual productivity and the corresponding change in breeding numbers at 12 sites in Britain are used for the periods 1985–2000 and 15 sites for 2000–15.

Results: A long series of records of the annual productivity of Kittiwakes, where breeding pairs increased progressively over 61 years, showed that an annual productivity of 1.5 young fledged per pair was an extremely rare event. Over the periods 1985–2000 and 2000–15 regressions of the change in breeding numbers against mean annual productivity for 15 sites indicated that about 0.8 fledglings per pair were needed to maintain breeding numbers and this value remained unchanged over the 30 years, suggesting that adult mortality rates had not changed over this period of time.

Conclusion: The decline of Kittiwakes in Britain has occurred because fewer than 0.8 chicks per pair have been fledged at many sites in recent years. The mortality rate of adult Kittiwakes breeding in Britain 1985–2015 does not indicate an increase over time and so is unlikely to have been a major contributor to the decline in breeding numbers.     

Factors determining the frequency and productivity of double brooding of Barn Owls Tyto alba

Capsule: Early nesting Barn Owls Tyto alba and those that switched nest sites fledged most chicks overall because they could fit two, more productive, nesting attempts into a breeding season.

Aims: To determine the frequency and productivity of double broods in Barn Owls, and for double brooders, to determine what affects the probability of nest switching and how that affects productivity.

Methods: We monitored the first egg date of each nesting attempt, whether it was in a ‘vole year’, whether a breeding attempt was first or a second annual attempt, the number of chicks fledged from each attempt, and whether a pair switched nest sites, if breeding twice, from 602 Barn Owl breeding attempts in an area of lowland England from 1996 to 2007. General linear models were used to determine predictors of the probability that a pair had a second brood and the number of chicks fledged in each nesting attempt, and then for those owls that double brooded, which variables best predicted the probability of switching, and the number of chicks fledged from the second nest. Finally, we tested whether switching resulted in a shorter laying interval and higher annual productivity.

Results: Early nesting birds were more likely to double brood, although this was relaxed in vole years when later nesting birds also double brooded. Productivity (through increased numbers of chicks fledged or reduced chick loss) was higher the earlier a nest occurred, and there were more chicks fledged in good vole years and in second nesting attempts. Productivity, brood depletion, first clutch date and vole years did not determine whether a double brooding pair switched nesting sites. Productivity in the second nest did not change with a switch but productivity increased for early first nests and second nests with a shorter interval between the first and second nest. Switching however decreased nesting interval and nesting interval was also shorter if there were fewer fledglings from the first nest. Overall productivity was higher for pairs that switched.

Conclusions: Double brooding in Barn Owls increased seasonal productivity substantially and its occurrence depended on vole abundance or early nesting. Nest switching between broods may be a strategy for earlier laying of the second brood. Provision of alternative nest sites, close together in a Barn Owl’s home range, may allow earlier re-nesting and so increase productivity.     

Trophic strategies of Yellow-legged Gull Larus michahellis on oceanic islands surrounded by deep waters

Capsule: The diet of Yellow-legged Gulls Larus michahellis on an oceanic island, surrounded by deep waters without a wide shelf, was mainly composed of terrestrial invertebrates.

Aims: To study the trophic ecology of Yellow-legged Gulls on an island surrounded by deep waters, to quantify the importance of terrestrial prey items and their availability, and to evaluate the relative importance of nutritional values of terrestrial and marine resources.

Methods: Diet was monitored for one year. We assessed the relative contribution of the main prey items and their macronutrients through the study of pellets and faeces.

Results: Terrestrial invertebrates were the most frequently consumed prey items (frequency of occurrence (FO) 67%), followed by marine fish (Osteichthyes FO 33%). Coleoptera and Orthoptera were the most consumed terrestrial invertebrates and provided a high nutritional value. The rate of consumption of terrestrial invertebrates varied in synchrony with the breeding season, being higher in spring, indicating their potential importance for reproduction.

Conclusion: It is unusual that terrestrial invertebrates constitute a large proportion of the diet of large gulls, but they seemed to cover their trophic energy requirements during the reproductive period.     

Differential expression of circulating vascular cell adhesion molecule-1 in subjects with coronary artery disease and cardiac syndrome X without known diabetes mellitus

Context: Inflammation is one of the mechanisms underlying cardiac syndrome X (CSX).

Objectives: Few studies have compared the expression of inflammatory or adhesion molecules between coronary artery disease (CAD) versus CSX.

Materials and methods: Ninety-two CSX and 145 CAD subjects without known diabetes mellitus underwent coronary angiogram for angina.

Results: Vascular cell adhesion molecule (VCAM)-1 (median, 507 versus 431?ng/ml, p?=?0.001) was significantly higher in the CAD group. In the binary regression, VCAM-1 was a significant differential factor for CAD versus CSX.

Discussion and conclusion: Adhesion molecules might be implicated in the differential expression of macro versus microvascular coronary disease.

Trial registration number: NCT01198730 at https://clinicaltrials.gov     

Association of IL-10 (-819T/C, -592A/C and -1082A/G) and IL-6 -174G/C gene polymorphism and the risk of pneumonia-induced sepsis

Context: Association between inherited variants and the risks of sepsis is controversial.

Objective: To evaluate the risk of pneumonia-induced sepsis by examining its linkage with polymorphisms of IL-6 and IL-10.

Materials and methods: Samples were obtained from 188 pneumonia-induced sepsis patients, 162 pneumonia patients and 200 healthy controls.

Results: Subjects with IL-10 -1082 AA genotypes and IL-6 -174?CC genotype had a higher risk of sepsis and increased mRNA levels.

Conclusion: The variants of IL-10 -1082 A allele and IL-6 -174 C allele contributed to an increased risk of pneumonia-induced sepsis.     

Soluble CD40 ligand in haemodialysis patients: survival impact and cardiovascular prognostic role

Context: Soluble CD40 ligand (sCD40l) can predict cardiovascular events (CVE) and mortality in haemodialysis (HD) patients (short-, medium-term follow-up studies).

Objective: To evaluate the relationship between sCD40l and survival, CVE and mortality in HD patients on long-term follow-up.

Methods: We registered 46?HD patients’ baseline characteristics, mortality and CVE for 108 months.

Results: SCD40l correlated positively with C-reactive protein, was higher in survivors, but had no impact on survival and was not predictive for CVE or CV mortality.

Conclusion: The levels of sCD40l have no influence on survival or CVE and mortality in HD patients in a long-term follow-up.     

Mutation in the beta3 subunit of Guanine nucleotide-binding protein (GNB3) gene is not associated with Type II diabetes mellitus risk: a case–control study of a North Indian population

Context: Genetics play a major role in development and pathophysiology of Type 2 diabetes mellitus (T2DM).

Objective: To asses the association of Guanine nucleotide-binding protein (GNB3) (C825T) gene's polymorphism with T2DM.

Materials and methods: A case–control study including 400 North Indians was performed using Polymerase Chain Reaction–Restriction Fragment Length Polymorphism (PCR-RFLP) approach to analyze genetic polymorphism.

Results: No significant difference was observed in genotype and allele frequencies of GNB3 gene on comparing cases with controls.

Discussion: Our study is in agreement with studies on Polish, Japanese, Hispanic-American and Danish populations who observed no significant association between GNB3 (C825T) polymorphism and T2DM.

Conclusion: GNB3 (C825T) polymorphism is not associated with T2DM.     

Summer in the city: behaviour of large gulls visiting an urban area during the breeding season

Capsule: Large numbers of Herring Gulls Larus argentatus and Lesser Black-backed Gulls Larus fuscus from a traditional colony in the Netherlands visit an urban area for food in the chick rearing period, causing nuisance while doing so.

Aims: To assess the potential contribution of large gulls breeding in a traditional colony to gull–human conflicts in cities.

Methods: Colour-ringed gulls from a nearby colony were counted in the study area throughout the 2014 breeding season. The average numbers observed daily per species and sex were compared between different breeding phases.

Results: Fluctuations in numbers of both species could be explained by breeding phase. Numbers of females of both species and male Lesser Black-backed Gulls dropped significantly during laying and incubation. Numbers peaked post-hatching, coinciding with increased engagement in nuisance events and more frequent displacements within the study area.

Conclusion: Large gulls from a traditional colony frequently visited the urban study area, especially when food demand for chick provisioning was high, suggesting that city visits are motivated by accessibility of urban food. The proportion of rooftop breeding gulls in this area is low. Therefore, measures to avoid nuisance should focus on reducing food availability rather than controlling gull breeding.     

Kleptoparasitism in gulls Laridae at an urban and a coastal foraging environment: an assessment of ecological predictors

Capsule: Kleptoparasitism in gulls occurred at a greater rate at an urban compared with a coastal site. Population density and prey size predicted the rate of kleptoparasitism at the urban site.

Aims: To investigate and assess the ecological variables associated with kleptoparasitism among gulls at urban and rural sites.

Methods: Field observations were conducted at Brancaster (coastal rural) and Billingsgate Market (urban) to examine differences in the rate of kleptoparasitism in mixed-species flocks of gulls. Four key variables (prey size, population density, season and species) were assessed as predictors of kleptoparasitism.

Results: Generalized linear models revealed significant effects on kleptoparasitism rate of site, population density and prey size, and two-way interactions between these main terms. Population density and prey size differed significantly between sites, but population density appeared to predict the rate of kleptoparasitism.

Conclusion: Kleptoparasitism may well aid invasion and increase the range of environments a gull can tolerate by helping them meet their energy needs in novel environments where normal foraging behaviours are difficult to implement.     

Should I stay or should I go? Territory settlement decisions in male Corncrakes Crex crex

Capsule: Corncrake Crex crex males shift their territories and change habitat preferences across the breeding season as a consequence of anthropogenic pressure and/or to enhance the chances of reproduction through sequential polygamy.

Aims: To examine how habitat structure changed during the breeding season, whether Corncrake males responded to those changes and which habitat features were crucial when males settled and occupied territories.

Methods: Calling male Corncrakes were surveyed six times during the breeding season. In each location where a calling male was recorded, the habitat and vegetation structure was described from one to three times during the season.

Results: Corncrake males avoided extremely wet and extremely dry habitats, whereas large sedge and reed communities were much more preferred. There were significant seasonal changes in the density of vegetation and moisture content. Males were more sedentary at the beginning of the breeding season. Males significantly changed habitat preferences in short-periods of time. However, none of the habitat-related features explained whether males stayed or left the territory.

Conclusion: Corncrakes shift their territories during the breeding season in response to anthropogenic pressure (agricultural activity) as well as changes in water levels during the year. However, territorial shifts within seasons might also be caused by the appearance of fertile females in different habitats at different stages of the breeding season.     

Soluble TREM-1 as a diagnostic and prognostic biomarker in patients with septic shock: an observational clinical study

Objectives: The impact of TREM-1-mediated inflammation was investigated in different inflammatory settings.

Methods: Secondary analyses of an observational clinical pilot study, including 60 patients with septic shock, 30 postoperative controls and 30 healthy volunteers.

Results: Plasma levels of sTREM-1 were found to identify patients with septic shock more effectively than procalcitonin and C-reactive protein. Moreover, sTREM-1 was identified to be an early predictor for survival in patients with septic shock.

Conclusion: Due to its diagnostic as well as prognostic value in sepsis syndrome, implementation of sTREM-1 measurements in routine diagnostics should be taken into account.     

Prognostic significance of insulin-like growth factor-I serum levels in acute decompensation of cirrhosis

Context: IGF-I serum levels are suppressed in cirrhosis, but its prognostic significance is unknown.

Objectives: To investigate the prognostic value of IGF-I in patients admitted for acute decompensation of cirrhosis.

Materials and methods: Cohort study that included 103 patients. IGF-I was measured by enzyme-linked immunosorbent assay (ELISA).

Results: Ninety-day mortality was 26.2% and it was independently associated with MELD, age and IGF-I. The Kaplan–Meier survival probability at 90 days was 94.3% in patients with IGF-I?≥13?ng/mL and 63.2% for patients with IGF-I?<13?ng/mL (p?=?.001).

Discussion and conclusion: IGF-I levels are independently associated with mortality in acute decompensation of cirrhosis.     

The role of habitat change in driving Black Grouse Tetrao tetrix population declines across Scotland

Capsule Black Grouse declines across Scotland were greatest on less heterogeneous moorland, at low to intermediate altitudes and, more weakly, around post-thicket woodland.

Aims To examine correlates of change in abundance of Black Grouse across Scotland.

Methods Changes in abundance within 5-km squares between national surveys in 1995/96 and 2005 were modelled in relation to measures of habitat cover and woodland age derived from satellite imagery.

Results Populations across Scotland were most stable where unenclosed moorland comprised rough grassland, intermediate heather cover and at higher altitude. Declines tended to be greatest in squares which had transitioned from pre-thicket to closed-canopy woodland.

Conclusion Moorland will be most beneficial where it is heterogeneous in composition, and the role of woodland maturation in driving regional declines has support, albeit more weakly, at a national scale.     

Breeding origins and pattern of migration of Bluethroats Luscinia svecica wintering from Iberia to Senegal as revealed by stable isotopes

Capsule: Stable isotope analyses reveal some degree of migratory connectivity of Bluethroat populations wintering from Iberia to West Africa.

Aims: To identify the probable breeding origins of Bluethroats wintering from Iberia to Senegal.

Methods: Bluethroat feathers (P1) were sampled from individuals at their wintering areas. These feathers were then analysed for stable H isotopes (δ²H). We assigned individual Bluethroats to approximate geographic origin using likelihood-based assignment procedures.

Results: We observed spatial segregation between different Bluethroat populations. At wintering sites north of the Sahara Desert, Bluethroats wintering to the west came from further west origins than those which overwintered to the east. Bluethroats from central-eastern Europe overwintered either within the circum-Mediterranean region or in Senegal. We found no clear evidence supporting a sub-Saharan wintering range for birds breeding in Iberia (Luscinia svecica azuricollis subspecies).

Conclusion: North of the Sahara Desert, we found what might be a parallel migration pattern. The apparent lack of Luscinia svecica namnetum Bluethroats in Senegal suggests to some extent some kind of leap-frog migration between some Luscinia svecica cyanecula populations and the L. s. namnetum subspecies.     

Food from dumps increases the reproductive value of last laid eggs in the White Stork Ciconia ciconia

Capsule Accessing extra food from waste dumps increases egg volume and hatching mass in White Storks.

Aim To test how White Storks vary their investment in egg size, especially in last laid eggs, in relation to food availability, and to improve our understanding of the importance of extra feeding on intra-clutch variation.

Methods The study was carried out in three White Stork breeding colonies in northern Algeria. Breeding performance was recorded in 70 nests over three years. White Stork colonies situated close to chicken farms were considered to be part of a ‘pseudo experiment’ where parents had access to extra food. Egg volume, laying order, hatching order and hatching weight were recorded.

Results Egg volume and hatching mass in White Storks was significantly greater when they had access to extra food. The reproductive value of last laid eggs (fourth and fifth) doubled when females had access to extra food.

Conclusion Laying smaller last eggs within a clutch provides a mechanism to facilitate early brood reduction in the White Stork, and so should be advantageous when food is scarce. On the contrary, when females had access to extra food, last laid eggs were as big as first eggs which suggests egg size variation is adaptable to local conditions.     

Impact of CT-apelin and NT-proBNP on identifying non-responders to cardiac resynchronization therapy

Context: Assessment of response to cardiac resynchronization therapy (CRT) is essential.

Objective: To assess the predictive value of CT-apelin together with NT-proBNP in patients undergoing CRT.

Methods: Serum CT-apelin and NT-proBNP were measured by ELISA before, and six months after CRT. Primary endpoint was non-response (<4% increase in LVEF) after six months.

Results: From 81 patients, 15 proved to be non-responders. Six-month CT-apelin was superior compared to NT-proBNP in identifying non-responders by multivariate ROC (CT-apelin: p?=?0.01, NT-proBNP: p?=?0.13) and by logistic regression (CT-apelin: p?=?0.01, NT-proBNP: p?=?0.41) analyses.

Conclusion: Six-month CT-apelin might be a valuable novel biomarker in identifying non-responders to CRT that was superior to NT-proBNP.