Metrics for quantifying how much different threats contribute to red lists of species and ecosystems.

Red lists are a crucial tool for the management of threatened species and ecosystems. Among the information red lists provide, the threats affecting the listed species or ecosystem, such as pollution or hunting, are of special relevance. This information can be used to quantify the relative contribution of different threat factors to biodiversity loss by disaggregating the cumulative extinction risk across species into components that can be attributed to certain threats. We devised and compared 3 metrics that accomplish this and may be used as indicators. The first metric calculates the portion of the temporal change in red list index (RLI) values that is caused by each threat. The second metric attributes the deviation of an RLI value from its reference value to different threats. The third metric uses extinction probabilities that are inferred from red list categories to estimate the contribution of a threat to the expected loss of species or ecosystems within 50 years. We used data from Norwegian Red Lists to test and evaluate these metrics. The first metric captured only a minor portion of the biodiversity loss caused by threats because it ignores species whose red list category does not change. Management authorities will often be interested in the contribution of a given threat to the total deviation from the optimal state. This was measured by the remaining metrics. The second metric was best suited for comparisons across countries or taxonomic groups. The third metric conveyed the same information but uses numbers of species or ecosystem as its unit, which is likely more intuitive to lay people and may be preferred when communicating with stakeholders or the general public.

Medidas para cuantificar la contribución de las diferentes amenazas a las listas rojas de especies y ecosistemas Resumen Las listas rojas son una herramienta crucial para la gestión de los ecosistemas y las especies bajo amenaza. Entre la información que proporcionan estas listas, son de mucha relevancia las amenazas que afectan a los ecosistemas o especies en la lista, como la contaminación o la cacería. Esta información puede usarse para cuantificar la contribución relativa que tienen los diferentes factores de amenaza para la pérdida de la biodiversidad mediante la disgregación del riesgo de extinción acumulado de varias especies en componentes que pueden atribuirse a ciertas amenazas. Diseñamos y comparamos tres medidas que logran esto y que pueden usarse como indicadores. La primera medida calcula la porción del cambio temporal en los valores del índice de listas rojas (ILR) causado por cada amenaza. La segunda medida les atribuye a las diferentes amenazas la desviación de un valor del ILR de su valor de referencia. La tercera medida usa probabilidades de extinción inferidas a partir de las categorías de las listas rojas para estimar la contribución de una amenaza a la pérdida esperada de especies o ecosistemas dentro de 50 años. Usamos datos de las Listas Rojas de Noruega para probar y evaluar estas medidas. La primera medida sólo capturó una porción menor de la pérdida de la biodiversidad causada por amenazas porque ignora las especies cuya categorías no cambia. Las autoridades gestoras se interesan con frecuencia en la contribución de una amenaza a la desviación total del estado óptimo. Medimos lo anterior con las medidas restantes. La segunda medida fue la mejor para comparar entre países y grupo taxonómicos. La tercera medida comunicó la misma información, pero con los números de especies o ecosistemas como su unidad, lo cual probablemente sea más intuitivo en términos sencillos y pueda preferirse para comunicarse con los actores o el público en general.

A joint climate and nature cure: A transformative change perspective.

Climate change has considerably dominated science-policy dialogue, public debate, and subsequently environmental policies since the three "Rio Conventions" were born. This has led to practically independent courses of action of climate change mitigation and biodiversity conservation actions, neglecting potential conflicts among outcomes and with missed opportunities for synergistic measures. Transformative governance principles have been proposed to overcome these limitations. Using a transformative governance lens, we use the case of the Norwegian "Climate Cure 2030" for the Land Use, Land-Use Change and Forestry (LULUCF) sector to, first, illustrate the mechanisms that have led to the choice of climate mitigation measures; second, to analyze the potential consequences of these measures on biodiversity and greenhouse gas (GHG) emissions; and, third, to evaluate alternative measures with potential positive outcomes for biodiversity and GHG emissions/removals. We point to some mechanisms that could support the implementation of these positive actions.

Centennial relationships between ocean temperature and Atlantic puffin production reveal shifting decennial trends.

The current warming of the oceans has been shown to have detrimental effects for a number of species. An understanding of the underlying mechanisms may be hampered by the non-linearity and non-stationarity of the relationships between temperature and demography, and by the insufficient length of available time series. Most demographic time series are too short to study the effects of climate on wildlife in the classical sense of meteorological patterns over at least 30 years. Here we present a harvest time series of Atlantic puffins (Fratercula arctica) that goes back as far as 1880. It originates in the world's largest puffin colony, in southwest Iceland, which has recently experienced a strong decline. By estimating an annual chick production index for 128 years, we found prolonged periods of strong correlations between local sea surface temperature (SST) and chick production. The sign of decennial correlations switches three times during this period, where the phases of strong negative correlations between puffin productivity and SST correspond to the early 20th century Arctic warming period and to the most recent decades. Most of the variation (72%) in chick production is explained by a model in which productivity peaks at an SST of 7.1°C, clearly rejecting the assumption of a linear relationship. There is also evidence supporting non-stationarity: The SST at which puffins production peaked has increased by 0.24°C during the 20th century, although the increase in average SST during the same period has been more than three times faster. The best supported models indicate that the population's decline is at least partially caused by the increasing SST around Iceland.

Expansion Speed as a Generic Measure of Spread for Alien Species.

The ecological impact of alien species is a function of the area colonised. Impact assessments of alien species are thus incomplete unless they take the spatial component of invasion processes into account. This paper describes a measure, termed expansion speed, that quantifies the speed with which a species increases its spatial presence in an assessment area. It is based on the area of occupancy (AOO) and can be estimated from grid occupancies. Expansion speed is defined as the yearly increase in the radius of a coherent circle having the same area as the AOO, irrespective of whether the increase is due to natural dispersal or anthropogenic transport. Two methods for estimating expansion speed are presented: one that requires several years of spatio-temporal observation data and explicitly takes detection rates into account; and one that can be used under a situation with sparse data. Using simulations and real-world data from natural history collections, it is shown that the method provides a good fit to observational datasets. Expansion speed has several valuable properties. Being based on AOO, it is an intuitive measure; as it only requires occupancy data, it is comparatively easy to estimate; and because it is a quantitative and generic measure, it increases the testability and comparability of impact assessments of alien species.

Modelled drift patterns of fish larvae link coastal morphology to seabird colony distribution.

Colonial breeding is an evolutionary puzzle, as the benefits of breeding in high densities are still not fully explained. Although the dynamics of existing colonies are increasingly understood, few studies have addressed the initial formation of colonies, and empirical tests are rare. Using a high-resolution larval drift model, we here document that the distribution of seabird colonies along the Norwegian coast can be explained by variations in the availability and predictability of fish larvae. The modelled variability in concentration of fish larvae is, in turn, predicted by the topography of the continental shelf and coastline. The advection of fish larvae along the coast translates small-scale topographic characteristics into a macroecological pattern, viz. the spatial distribution of top-predator breeding sites. Our findings provide empirical corroboration of the hypothesis that seabird colonies are founded in locations that minimize travel distances between breeding and foraging locations, thereby enabling optimal foraging by central-place foragers.

The stress hormone corticosterone in a marine top predator reflects short-term changes in food availability.

In many seabird studies, single annual proxies of prey abundance have been used to explain variability in breeding performance, but much more important is probably the timing of prey availability relative to the breeding season when energy demand is at a maximum. Until now, intraseasonal variation in prey availability has been difficult to quantify in seabirds. Using a state-of-the-art ocean drift model of larval cod Gadus morhua, an important constituent of the diet of common guillemots Uria aalge in the southwestern Barents Sea, we were able to show clear, short-term correlations between food availability and measurements of the stress hormone corticosterone (CORT) in parental guillemots over a 3-year period (2009-2011). The model allowed the extraction of abundance and size of cod larvae with very high spatial (4 km) and temporal resolutions (1 day) and showed that cod larvae from adjacent northern spawning grounds in Norway were always available near the guillemot breeding colony while those from more distant southerly spawning grounds were less frequent, but larger. The latter arrived in waves whose magnitude and timing, and thus overlap with the guillemot breeding season, varied between years. CORT levels in adult guillemots were lower in birds caught after a week with high frequencies of southern cod larvae. This pattern was restricted to the two years (2009 and 2010) in which southern larvae arrived before the end of the guillemot breeding season. Any such pattern was masked in 2011 by already exceptionally high numbers of cod larvae in the region throughout chick-rearing period. The findings suggest that CORT levels in breeding birds increase when the arrival of southern sizable larvae does not match the period of peak energy requirements during breeding.

Climate-driven ichthyoplankton drift model predicts growth of top predator young.

Climate variability influences seabird population dynamics in several ways including access to prey near colonies during the critical chick-rearing period. This study addresses breeding success in a Barents Sea colony of common guillemots Uria aalge where trophic conditions vary according to changes in the northward transport of warm Atlantic Water. A drift model was used to simulate interannual variations in transport of cod Gadus morhua larvae along the Norwegian coast towards their nursery grounds in the Barents Sea. The results showed that the arrival of cod larvae from southern spawning grounds had a major effect on the size of common guillemot chicks at fledging. Furthermore, the fraction of larvae from the south was positively correlated to the inflow of Atlantic Water into the Barents Sea thus clearly demonstrating the mechanisms by which climate-driven bottom-up processes influence interannual variations in reproductive success in a marine top predator.

Persistent organic pollution in a high-Arctic top predator: sex-dependent thresholds in adult survival.

In long-lived species, any negative effect of pollution on adult survival may pose serious hazards to breeding populations. In this study, we measured concentrations of various organochlorines (OCs) (polychlorinated biphenyl and OC pesticides) in the blood of a large number of adult glaucous gulls (Larus hyperboreus) breeding on Bjørnøya (Bear Island) in the Norwegian Arctic, and modelled their local survival using capture-recapture analysis. Survival was negatively associated with concentrations of OCs in the blood. The effect of OCs was nonlinear and evident only among birds with the highest concentrations (the uppermost deciles of contamination). The threshold for depressed survival differed between the sexes, with females being more sensitive to contamination. For birds with lower OC concentration, survival was very high, i.e. at the upper range of survival rates reported from glaucous and other large gull species in other, presumably less contaminated populations. We propose two non-exclusive explanations. First, at some threshold of OC concentration, parents (especially males) may abandon reproduction to maximize their own survival. Second, high contamination of OC may eliminate the most sensitive individuals from the population (especially among females), inducing a strong selection towards high-quality and less sensitive phenotypes.

Short- and long-term consequences of reproductive decisions: an experimental study in the puffin.

The purpose of the present study was to inspect the response of the Atlantic Puffin (Fratercula arctica) to an experimental manipulation of the investment needed to successfully raise an offspring. We achieved this by replacing an old offspring with a younger chick, and vice versa, thereby prolonging and shortening the chick-rearing period. To examine any costs of reproduction we then followed the breeding success, the recruitment of young to the population, and the survival of parents for 11 years following the manipulation. Parents in the prolonged and shortened category had a lower breeding success than controls mainly because parents deserted their chick shortly after swapping. Among those that raised their chick, the age and body mass of foster chicks at fledging were the same in all three categories even though the parents had raised chicks for different lengths of time. The recruitment of young to the breeding population was high and independent of treatment. Likewise, the survival of adults was independent of treatment. For the 11 years after the experiment, however, the resighting rate of those that deserted their chick was clearly lower than among those that accepted their foster chick. For parents that raised their foster chick, the survival to the following year was positively related to their body mass. The results support the hypothesis that puffins have a highly flexible parental investment, which they adjust according to their own individual quality and the survival prospects of the chick.

Anthropocentricisms in cladograms.

Both written and graphic accounts of history can be biased by the perspective of the historian. O'Hara (Biol Philos 7:135-160, 1992) has demonstrated that this also applies to evolutionary history and its historians, and identified four narrative devices that introduce anthropocentricisms into accounts of phylogeny. In the current paper, I identify a fifth such narrative device, viz. the left-right ordering of the taxa at the tips of cladograms. I define two measures that make it possible to quantify the degree of anthropocentricism of cladograms, the human attention score and human rightness score. I then carry out an analysis of the presence of the different distorting mechanisms in phylogenetic textbooks. I deliberately chose two textbooks that adopted a cladistic perspective, since their authors can be assumed to be more conscious about the aim of avoiding anthropocentricisms. Three of the narrative devices are thus absent from cladistic works. However, there is a weak tendency that the resolution of cladogram branches is biased in favour of Homo sapiens. Furthermore, the human perspective is clear and highly significant in the positioning of taxa along the left-right axis of cladograms. I discuss the reasons for and implications of these biased presentations.

Tree thinking cannot taken for granted: challenges for teaching phylogenetics.

Tree thinking is an integral part of modern evolutionary biology, and a necessary precondition for phylogenetics and comparative analyses. Tree thinking has during the 20th century largely replaced group thinking, developmental thinking and anthropocentrism in biology. Unfortunately, however, this does not imply that tree thinking can be taken for granted. The findings reported here indicate that tree thinking is very much an acquired ability which needs extensive training. I tested a sample of undergraduate and graduate students of biology by means of questionnaires. Not a single student was able to correctly interpret a simple tree drawing. Several other findings demonstrate that tree thinking is virtually absent in students unless they are explicitly taught how to read evolutionary trees. Possible causes and implications of this mental bias are discussed. It seems that biological textbooks can be an important source of confusion for students. While group and developmental thinking have disappeared from most textual representations of evolution, they have survived in the evolutionary tree drawings of many textbooks. It is quite common for students to encounter anthropocentric trees and even trees containing stem groups and paraphyla. While these biases originate from the unconscious philosophical assumptions made by authors, the findings suggest that presenting unbiased evolutionary trees in biological publications is not merely a philosophical virtue but has also clear practical implications.