Climate and body size influence nest survival in a fish with parental care

1. The current study examined the effect of broad-scale climate and individual-specific covariates on nest survival in smallmouth bass over a 20-year period. 2. Large-scale climate indices [winter North Atlantic Oscillation (NAO) and winter El Ni?o/Southern Oscillation (ENSO)] and body size of parental males were important covariates in nest survival along with nest age and a quadratic trend in survival. 3. We did not find an effect due to a habitat covariate (total effective fetch) or a phenology covariate (degree-days at start of nesting) on nest survival. 4. Male size in the second half of the nesting season was a more influential covariate on nest success than male size in the first half or throughout the nesting period. 5. We present evidence showing that winter NAO/ENSO indices establish limnological conditions the following spring that influence thermal stability of the lake during the nesting period. 6. The combined climate and body size covariates point to nest survival as a function of lagged climate-scale influences on limnology and the individual-scale influence of bioenergetics on the duration of parental care and nest success.     

Climate forcing of diatom productivity in a lowland,eutrophic lake: White Lough revisited

1. In cultural landscapes, lake response to climate can be masked by land‐use change and nutrient loss from their catchments. Palaeolimnological methods were used to reconstruct the ecological response of diatoms in a eutrophic lowland lake (White Lough, Co. Tyrone, Northern Ireland) to altered nutrient P loading and precipitation variability over c. 100 years. 2. ²¹⁰Pb‐dated sediment cores were analysed to determine diatom assemblage variability, biogenic silica concentration, geochemical phosphorus concentration and accumulation rate. Manure P and agricultural N surplus data were collated from documentary sources. Long‐term trends in annual temperature and precipitation were derived from the Armagh Observatory. 3. Diatom community turnover from 1890 until c. 1960 was limited, and assemblages were dominated by Aulacoseira subarctica; after this date, changes primarily reflected a eutrophication sequence owing to increased diffuse nutrient inputs associated with intensification of land use (external P loading increased by a factor of three). 4. Diatom and biogenic Si profiles were compared with North Atlantic Oscillation (NAO) records, an index of regional weather patterns. Biogenic Si exhibited a c. 7‐year cycle, which tracked a cycle of similar timescale in the Armagh climate record for dry summers. In turn, this cycle was related to the variation in the NAO. 5. Monitoring data from 1971 to 2007 of nitrate exports from the Blackwater River showed that these too followed a roughly 7‐year cycle at least up to 2000, in which dry summers were followed by sharp increases in nitrate export. It is argued that diatom production in White Lough reflects the cyclic behaviour in nitrate loading and the constraints that nitrogen availability places on the spring diatom bloom in a lake that is dominated by cyanobacteria.     

Large-Scale Temperature Patterns in Past Centuries: Implications for North American Climate Change

Recent climate reconstructions are analyzed specifically for insights into those patterns of climate variability in past centuries with greatest impact on the North American region. Regional variability, largely associated with the El Nino/Southern Oscillation (ENSO) phenomenon, the North Atlantic Oscillation (NAO), and multidecadal patterns of natural variability, are found to mask the emergence of an anthropogenic temperature signal in North America. Substantial recent temperature anomalies may however indicate a possible recent emergence of this signal in the region. Multidecadal North Atlantic variability is likely to positively reinforce any anthropogenic warming over substantial parts of North America in coming decades. The recent magnitudes of El Nino events appear to be unprecedented over the past several centuries. These recent changes, if anthropogenic in nature, may outweigh the projection of larger-scale climate change patterns onto the region in a climate change scenario. The implications of such changes for North America, however, are not yet clear. These observations suggest caution in assessing regional climate change scenarios in North America without a detailed consideration of possible anthropogenic changes in climate patterns influencing the region.     

Winter North Atlantic Oscillation, temperature and ischaemic heart disease mortality in three English counties

As cold weather is an ischaemic heart disease (IHD) risk factor, year-to-year variations of the level of IHD mortality may be partly determined by inter-annual variations in winter climate. This paper investigates whether there is any association between the level of IHD mortality for three English counties and the winter North Atlantic Oscillation (NAO), which exerts a fundamental control on the nature of the winter climate over Western Europe. Correlation and regression analysis was used to explore the nature of the association between IHD mortality and a climate index (CI) that represents the interaction between the NAO and temperature across England for the winters 1974–1975 to 1989–1999. Statistically significant inverse associations between the CI and the level of IHD mortality were found. Generally, high levels of winter IHD mortality are associated with a negative CI, which represents winters with a strong negative phase of the NAO and anomalously low temperatures across England. Moreover, the nature of the CI in the early stages of winter appears to exert a fundamental control on the general level of winter IHD mortality. Because winter climate is able to explain a good proportion of the inter-annual variability of winter mortality, long-lead forecasting of winter IHD mortality appears to be a possibility. The integration of climate-based health forecasts into decision support tools for advanced general winter emergency service and capacity planning could form the basis of an effective adaptive strategy for coping with the health effects of harsh winters.     

Spring arrival response to climate change in birds: a case study from eastern Europe

This paper analyses the dependence of the first spring arrival dates of short/medium- and long-distance migrant bird species on climate warming in eastern Europe. The timing of arrival of the selected species at the observation site correlates with the North Atlantic Oscillation (NAO) index, air temperature, atmospheric pressure, precipitation and wind characteristics. A positive correlation of fluctuations in winter and spring air temperatures with variations in the NAO index has been established in eastern Europe. Positive winter NAO index values are related to earlier spring arrival of birds in the eastern Baltic region and vice versa—arrival is late when the NAO index is negative. The impact of climate warming on the bird’s life cycle depends on local or regional climate characteristics. We tested the hypothesis that differences in climate indices between North Africa and Europe can influence the timing of spring arrival. Our results support the hypothesis that differences in first spring arrival dates between European populations occur after individuals cross the Sahara. We assume that the endogenous programme of migration control in short/medium-distance migrants synchronises with the changing environment on their wintering grounds and along their migration routes, whereas in long-distance migrants it is rather with environmental changes in the second part of their migratory route in Europe. Our results strongly indicate that the mechanism of dynamic balance in the interaction between the endogenous regulatory programme and environmental factors determines the pattern of spring arrival, as well as migration timing.     

Influence of climate variability on whitefish (<Emphasis Type="Italic">Coregonus lavaretus</Emphasis>) year-class strength in a deep,warm monomictic lake

The year-class strength (YCS) of Blaufelchen (Coregonus lavaretus) in deep Upper Lake Constance was analysed for a 52-year period, from 1947 to 1998. Despite strong anthropogenic influences on the species' population dynamics due to cultural eutrophication and oligotrophication, intense fishing, and large-scale stocking, the influence of climate variability associated with the North Atlantic Oscillation (NAO) is apparent in the data set. This influence is significant although large-scale stocking of cold-bred larvae was performed to avoid a mismatch of larvae with their food. The importance of stocking on YCS, however, is unclear and was only detectable when analysing a subset of the data. In addition to climate variability a yet unidentified factor related to zooplankton suitability as food for fish larvae, and density-dependent mortality probably related to cannibalism do significantly influence YCS. The NAO seemed to influence YCS twofold, through temperature effects on egg development time and on larval growth rate. The first of these two mechanisms is related to the NAO via a time lag of 1 year due to the specific mixing dynamics of warm monomictic Lake Constance. Hence, a warm winter in the year before spawning results in earlier hatching of larvae, that is, hatching is decoupled from the actual meteorological conditions. This should make the larvae very prone to mismatch the dynamics of their food. However, we found no evidence for such a mismatch in this 52-year data set.     

Climate and climatic variability at Lake Myvatn

The climate of the Lake Myvatn region is examined through the use of weather station data, using the years from 1971 to 2000 as a reference period. Variations in mean monthly temperature and precipitation at Reykjahlid (Myvatn) are compared with variations at seven other weather stations in north east Iceland. The area is drier and colder than coastal stations and exhibits a seasonal cycle in temperature that is larger than found at the coast. The temperature is significantly influenced by the number of sunlight hours only during the summer months. During summer, the influence of a sea breeze circulation can be clearly identified.The variability of climate since 1936 is also examined in comparison with the seven other weather stations. It is found that temperature variations at the different stations are highly correlated, but for precipitation the correlation is significant but much weaker.The influence of the large scale atmospheric circulation on temperature and precipitation at Lake Myvatn is also examined. It is found that the air temperature at Lake Myvatn is most sensitive to an east-west dipole in the large scale sea surface pressure field, i.e. to a pattern that is very different from the spatial pattern associated with the North Atlantic Oscillation (NAO). Precipitation at Lake Myvatn is to some degree influenced by the NAO, but generally precipitation is associated with northerly winds and cold temperatures whereas southerly winds at Lake Myvatn are likely to be drier.     

The North Atlantic Oscillation and the Arctic Oscillation favour harmful algal blooms in SW Europe

The ecological factors driving the occurrence of harmful algal blooms (HAB) have been traditionally analysed from a hydrological point of view, whereas the interplay between atmospheric oscillations and HAB has been scarcely explored. Here we address the possible link between atmospheric oscillations in SW Europe, using as proxies the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO) indices and the interannual variability in HAB. The yearly series (1973–2005) of mortality of water birds and fish in Doñana National Park (SW Spain) due to toxins associated with the cyanobacterium Microcystis aeruginosa, and the monthly incidence (January 1999 to December 2007) of the paralytic shellfish poisoning (PSP) toxin produced by the dinoflagellate Gymnodinium catenatum in the Rías Baixas (NW Spain), were selected as models of HAB in SW Europe. The incidences of both toxic algal events were fitted to a binary logistic regression as a function of the atmospheric oscillation indices (with different delays in accordance with each toxic event) and a favourability function was then computed. The favourability for the wildlife mortality in Doñana National Park was as a function of the AO averaged for the summer period (June–August) whereas the favourability for the incidence of PSP in the Rías Baixas was a function of the NAO recorded 1 month before the event. Since HAB have a relevant impact on ecosystems and human health, there is great interest in deciphering the ecological conditions favouring these events. Here we show that the atmospheric oscillations could be drivers of ecological processes linked to the occurrence of HAB in SW Europe. Moreover, the favourability functions relating NAO and AO indices with algal toxic events in SW Europe could be used as a powerful tool to predict toxic events.     

Birth weight,adult body size,and risk of colorectal cancer

BackgroundEvidence suggests that birth weight may be associated with colorectal cancer (CRC) risk later in life. Whether the association is mediated by adult body size remains unexamined.MethodCox proportional hazards models (Hazard Ratio (HR) and 95 % Confidence Intervals (CI)) were used to evaluate the association between self-reported birth weight (<6 lbs, 6-<8 lbs, ≥8 lbs) and CRC risk among 70,397 postmenopausal women from the Women’s Health Initiative. Further, we assessed whether this association was mediated by adult body size using multiple mediation analyses.ResultsCompared with birth weights of 6-< 8 lbs, birth weight ≥ 8 lbs was associated with higher CRC risk in postmenopausal women (HR = 1.31, 95 % CI 1.16–1.48). This association was significantly mediated by adult height (proportion mediated =11.4 %), weight (11.2 %), waist circumference (10.9 %), and body mass index at baseline (4.0 %). The joint effect of adult height and weight explained 21.6 % of this positive association.ConclusionOur data support the hypothesis that the intrauterine environment and fetal development may be related to the risk of developing CRC later in life. While adult body size partially explains this association, further investigation is required to identify other factors that mediate the link between birth weight and CRC.     

Geographic variation of body size and reproductive patterns in Continental versus Mediterranean asp vipers, Vipera aspis

The occurrence of variation in body size and reproductive traits of Vipera aspis was assessed by analysing 74 reproductive females of different populations, collected throughout a large part of the distribution range of the taxon, from central‐western France to central Italy. Six populations were analysed, two of plain habitats, in France and Italy, characterized by a Continental climate, whereas the other four derived from two coastal and two inland, hilly Italian habitats, respectively, showing a Mediterranean climate. Females of the French area showed the smallest mean body size, whereas the pre‐ and post‐partum body masses of females from the coolest, central Italic area were significantly higher. Litter size varied among habitats and was significantly correlated with maternal body size. If the snout–vent length feature varied largely among offspring of different habitats (with the longest size occurring in representatives of the coastal, central Italian area), the average of both body mass and total mass of offsprings did not exhibit any clear pattern among populations colonizing different habitats. Nevertheless, relative litter mass was higher in the French continental populations, and lower in the coolest, Mediterranean, Italian ones. It is worth emphasizing the positive correlation between the snout–vent length feature of females and the total litter mass to environmental factors, such as hottest month temperature and total rainfall. The available literature records that female body size affects offspring size and fecundity. If the present study bolsters this correlation, it also rules out any other effect of female body size on the offspring characteristics analysed. Finally, evidence is provided for the role of climatic factors on life‐history traits (e.g. pre‐partum body mass) of asp vipers, although confounding effects pursued, for example, by food availability may occur. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96 , 383–391.     

Long-term changes in phytoplankton, zooplankton and salmon related to climate

Recently, large‐scale changes in the biogeography of calanoid copepod crustaceans have been detected in the northeastern North Atlantic Ocean and adjacent seas. Strong biogeographical shifts in all copepod assemblages were found with a northward extension of more than ° in latitude of warm‐water species associated with a decrease in the number of colder‐water species. These changes were attributed to regional increase in sea surface temperature. Here, we have extended these studies to examine long‐term changes in phytoplankton, zooplankton and salmon in relation to hydro‐meteorological forcing in the northeast Atlantic Ocean and adjacent seas. We found highly significant relationships between (1) long‐term changes in all three trophic levels, (2) sea surface temperature in the northeastern Atlantic, (3) Northern Hemisphere temperature and (4) the North Atlantic Oscillation. The similarities detected between plankton, salmon, temperature and hydro‐climatic parameters are also seen in their cyclical variability and in a stepwise shift that started after a pronounced increase in Northern Hemisphere Temperature anomalies at the end of the 1970s. All biological variables show a pronounced change which started after circa 1982 for euphausiids (decline), 1984 for the total abundance of small copepods (increase), 1986 for phytoplankton biomass (increase) and Calanus finmarchicus (decrease) and 1988 for salmon (decrease). This cascade of biological events led to an exceptional period, which is identified after 1986 to present and followed another shift in large‐scale hydro‐climatic variables and sea surface temperature. This regional temperature increase therefore appears to be an important parameter that is at present governing the dynamic equilibrium of northeast Atlantic pelagic ecosystems with possible consequences for biogeochemical processes and fisheries.     

Influences of sex,ontogeny and body size on the thermal ecology of Liolaemus lutzae (Squamata,Liolaemidae) in a restinga remnant in southeastern Brazil

Variations in body temperature (T_b) of lizards can be partially explained by intrinsic factors such as sex, ontogeny and body size. Liolaemus lutzae is a lizard species restricted to restingas in the Brazilian coast in the state of Rio de Janeiro. Herein, we studied sexual dimorphism and influences of sex, ontogeny, and body size to the T_b of L. lutzae. Adult males were larger than adult females, probably due to both intersexual selection and intra-sexual selection. There was intersexual difference in lizards' T_b (males hotter than females), but T_b did not differ after factored out for the effects of body size. The mean T_b of juvenile lizards was higher than that of adults after factored out for the effect of body mass. It is possible that adults may have excluded juveniles from microhabitats with better thermal regimes. Also, this might have occurred due to requirements of juveniles to maintain high growth rates. Forage searching for prey by juveniles also exposes them to high environmental temperatures. Juveniles also may have higher T_b than co-specific adults (relative to body mass) to favor prey capture. In absolute values, adult lizards tended to use microhabitats with lower temperatures than that used by juveniles, possibly to avoid risks of overheating and death. Body temperature and snout–vent length were positively related, as well as body temperature and body mass, presumably caused by the thermal inertia of the bodies (trend of a body to resist to changes in its temperature). Intrinsic factors such as sex, ontogeny and body size can affect the thermal ecology of L. lutzae, despite coastal habitat features to which they are exposed also influences the body temperature of active lizards in restinga habitats.     

Climate change, species range limits and body size in marine bivalves

We use data on the Pleistocene and modern range limits of Californian marine bivalves to show that species that shifted their geographical ranges in response to Pleistocene climatic fluctuations were preferentially drawn from the large end of the regional body size–frequency distributions. This difference is not due to phylogenetic effects (i.e. dominance of extralimital species by a few large-bodied clades), differences among major ecological categories (burrowing versus surface-dwelling, or suspension feeding versus non-suspension feeding), or differences in modes of reproduction and larval development. In addition, we show that successful invasive species of bivalves in present-day marine habitats also tend to be large-bodied, despite the difference in mechanisms between present-day and Pleistocene range expansions. These results indicate that range limits of large-bodied bivalve species are more unstable than small-bodied ones, and that body size and its correlates need to be considered when attempting to predict the responses of marine communities to climate change, biotic interchanges and human-mediated invasions.     

Global biogeography and ecology of body size in birds

In 1847, Karl Bergmann proposed that temperature gradients are the key to understanding geographic variation in the body sizes of warm-blooded animals. Yet both the geographic patterns of body-size variation and their underlying mechanisms remain controversial. Here, we conduct the first assemblage-level global examination of 'Bergmann's rule' within an entire animal class. We generate global maps of avian body size and demonstrate a general pattern of larger body sizes at high latitudes, conforming to Bergmann's rule. We also show, however, that median body size within assemblages is systematically large on islands and small in species-rich areas. Similarly, while spatial models show that temperature is the single strongest environmental correlate of body size, there are secondary correlations with resource availability and a strong pattern of decreasing body size with increasing species richness. Finally, our results suggest that geographic patterns of body size are caused both by adaptation within lineages, as invoked by Bergmann, and by taxonomic turnover among lineages. Taken together, these results indicate that while Bergmann's prediction based on physiological scaling is remarkably accurate, it is far from the full picture. Global patterns of body size in avian assemblages are driven by interactions between the physiological demands of the environment, resource availability, species richness and taxonomic turnover among lineages.     

Climate change-driven body size shrinking in a social wasp

1. Climate change is expected to produce shifts in species distributions as well as behavioural, life-history, and/or morphological adaptations to find suitable conditions or cope with the altered environment. Most of our knowledge on this issue comes from studies on vertebrates, mainly endotherm species. However, it remains uncertain how small ectotherms, such as insects, respond to increased temperature. 2. This study tested whether climate change over the last 100 years (1904–2013) has affected morphological and functional traits in workers of the social wasp Dolichovespula sylvestris in the Iberian Peninsula. 3. Head width and forewing length, as well as body mass and wing area (assuming no change in shape), decreased over time and with increased mean annual temperature, even when controlling for geographical location and altitude. Interestingly, wing size decreased with a steeper slope compared with body size. If there is no change in wing shape, this would lead to an invariable wing loading (body mass:wing area ratio) over time, with potential consequences on flying ability of more recent (and thus smaller) wasp individuals. 4. These results suggest that recent climate change is leaving morphological signatures in social wasps, increasing the evidence for this phenomenon in insects. The data furthermore suggest that the known efficient thermoregulatory ability of social insect colonies may not successfully buffer the effect of global warming.     

Climate change and habitat heterogeneity drive a population increase in Common Buzzards Buteo buteo through effects on survival

The effect of changing climatic conditions on wild populations has been the subject of much recent research. Most attention has been on the direct effects of climate changes on species of lower trophic levels and on the negative consequences of climate change. However, a deeper understanding of how climate change affects apex predators is vital, as they are keystone species that have a disproportionate effect on ecosystems. Studying survival in an apex predator requires individual‐based data from long‐term studies and is complicated by the integration of climatic effects on lower trophic levels. Here we assess how climate affects the survival of the Common Buzzard Buteo buteo. We analysed the survival of 670 males and 669 females over the period 1989–2011, during which time our study population quadrupled. We used mark–recapture survival analysis of individual resightings of breeding adults to identify the environmental factors best explaining survival. A decrease in the North Atlantic Oscillation (NAO) index increased survival to an extent that largely explains the population increase. This might be caused by higher Common Vole Microtus arvalis survival in drier conditions and under snow cover. Buzzard survival appeared to increase more for males than for females, possibly due to the males' higher sensitivity to winter food availability resulting from their smaller body mass. However, we also found that the effect of NAO strongly depended on the area in which individuals lived, especially for females. This may have been caused by the recolonization of Eagle Owls Bubo bubo in some parts of our study area. This study suggests that climatic changes can have complex effects on species of higher trophic levels via an interaction with their prey.     

Body size, body proportions, and mobility in the Tyrolean "Iceman"

Body mass and structural properties of the femoral and tibial midshafts of the "Iceman," a late Neolithic (5,200 BP) mummy found in the Tyrolean Alps, are determined from computed tomographic scans of his body, and compared with those of a sample of 139 males spanning the European early Upper Paleolithic through the Bronze Age. Two methods, based on femoral head breadth and estimated stature/bi-iliac (pelvic) breath, yield identical body-mass estimates of 61 kg for the Iceman. In combination with his estimated stature of 158 cm, this indicates a short but relatively wide or stocky body compared to our total sample. His femur is about average in strength compared to our late Neolithic (Eneolithic) males, but his tibia is well above average. His femur also shows adaptations for his relatively broad body (mediolateral strengthening), while his tibia shows adaptations for high mobility over rough terrain (anteroposterior strengthening). In many respects, his tibia more closely resembles those of European Mesolithic rather than Neolithic males, which may reflect a more mobile lifestyle than was characteristic of most Neolithic males, perhaps related to a pastoral subsistence strategy. There are indications that mobility in general declined between the European Mesolithic and late Neolithic, and that body size and shape may have become more variable throughout the continent following the Upper Paleolithic.     

Connecting species richness, abundance and body size in deep-sea gastropods

Aim This paper examines species richness, abundance, and body size in deep‐sea gastropods and how they vary over depth, which is a strong correlate of nutrient input. Previous studies have documented the empirical relationships among these properties in terrestrial and coastal ecosystems, but a full understanding of how these patterns arise has yet to be obtained. Examining the relationships among macroecological variables is a logical progression in deep‐sea ecology, where patterns of body size, diversity, and abundance have been quantified separately but not linked together. Location 196–5042 m depth in the western North Atlantic. Method Individuals analysed represent all Vetigastropoda and Caenogastropoda (Class Gastropoda) with intact shells, excluding Ptenoglossa, collected by the Woods Hole Benthic Sampling Program (3424 individuals representing 80 species). Biovolume was measured for every individual separately (i.e. allowing the same species to occupy multiple size classes) and divided into log₂ body size bins. Analyses were conducted for all gastropods together and separated into orders and depth regions (representing different nutrient inputs). A kernel smoothing technique, Kolmogorov‐Smirnov test of fit, and OLS and RMA were used to characterize the patterns. Results Overall, the relationship between the number of individuals and species is right skewed. There is also a positive linear relationship between the number of individuals and the number of species, which is independent of body size. Variation among these relationships is seen among the three depth regions. At depths inferred to correspond with intermediate nutrient input levels, species are accumulated faster given the number of individuals and shift from a right‐skewed to a log‐normal distribution. Conclusion A strong link between body size, abundance, and species richness appears to be ubiquitous over a variety of taxa and environments, including the deep sea. However, the nature of these relationships is affected by the productivity regime and scale at which they are examined.     

Advances in laying date and increasing population size suggest positive responses to climate change in Common Eiders Somateria mollissima in Iceland

Models of climate change predict that its effects on animal populations will not always be negative, but most studies indicate negative associations between changes in climate and the phenology of animal migration and reproduction. For some populations, however, climate change may render particular environments more favourable, with positive effects on population growth. We used a 30-year population dataset on over 2000 Common Eiders Somateria mollissima at a colony in southwest Iceland to examine the response of this species to climate fluctuations. Eiders are strongly dependent on suitable climatic conditions for successful reproduction and survival. Temperatures in southwest Iceland, in both winter and summer, have generally increased over the past 30 years but have shown considerable fluctuation. We show that females laid earlier following mild winters and that year-to-year variation in the number of nests was related to the temperature during the breeding season 2 years previously. Milder summers could have positive effects on breeding success and offspring survival, producing an increase in nest numbers 2 years later when most Eiders recruit into the breeding population. In this part of their range, Eiders could benefit from a general warming of the climate.