Understanding the ultimate causes of population declines and extinction is vital in our quest to stop the currently rampant biodiversity loss. Comparison of ecological characteristics between threatened and nonthreatened species may reveal these ultimate causes. Here, we report an analysis of ecological characteristics of 23 threatened and 72 nonthreatened butterfly species. Our analysis reveals that threatened butterflies are characterized by narrow niche breadth, restricted resource distribution, poor dispersal ability, and short flight period. Based on the characteristics, we constructed an ecological extinction risk rank and predicted which of the currently nonthreatened species are at the highest risk of extinction. Our analysis reveals that two species currently classified as nonthreatened are, in fact, at high risk of extinction, and that the status of a further five species should be reconsidered.conservation biology ͉ threatened species ͉ biodiversity ͉ Lepidoptera ͉ World Conservation Union Red List

We analysed the relationship between three life history characteristics (mobility, length of flight period and body size) and niche breadth (larval host plant specificity and adult habitat breadth), resource availability (distribution and abundance of host plants) and range position (distance between the northernmost distribution record and southernmost point of Finland) of the butterfly fauna of Finland. The data is based on literature and questionnaires. Often in across species studies phylogeny may create spurious relationships between life-history and ecological variables. We took the phylogenetic relatedness of butterfly species into account by analysing the data with phylogenetically independent contrasts (CAIC method). Butterfly mobility was positively related to the niche breadth, resource availability and range position. The length of the flight period was negatively related to the range position, indicating that the species at the northern edge of their distribution range have shorter flight period than species which are further way from the range edge. After controlling for the phylogenetic relatedness we found no significant correlations between body size and niche breadth, resource availability or range position. We suggest that the relationship between the length of the flight period and range position may arise as a consequence of lower hatching asynchrony in edge species as a result of lower environmental variance in larval growth conditions. Our results on the mobility suggest that there is selection pressure towards lower migration rate in species that have restricted niche breadth, low resource availability and in species that are on the northern edge of their geographical distribution range. In such species, selection against mobile individuals is likely to result from the decreased probability of finding another habitat patch suitable for egg laying

For successful conservation of species it is important to identify traits that predispose species to the risk of extinction. By identifying such traits conservation efforts can be directed toward species that are most at risk of becoming threatened. We used data derived from the literature to determine ecological traits that affect distribution, distribution change, and the risk of extinction in Finnish noctuid moths (Lepidoptera, Noctuidae). The ecological traits we examined included body size, larval specificity, length of the flight period, and overwintering stage. In addition, in monophagous species we examined the effects of resource distribution. Larval specificity, length of the flight period, and the overwintering stage each had an independent effect on the risk of extinction when the effects of other traits were controlled by entering all traits into the same regression model. Not a single trait predicted the risk of extinction when analysis was conducted without controlling for the other traits. This discrepancy among the results suggests that a single trait may not be enough to allow prediction of the risk of extinction. Instead, it seems that for successful, predictive conservation science data on several ecological characteristics are needed. Determinantes Ecológicos de la Reducción en la Distribución y del Riesgo de Extinción en Mariposas NocturnasResumen: Para la conservación exitosa de especies es importante identificar características que las predispongan al riesgo de extinción. Al identificar esas características, los esfuerzos de conservación pueden dirigirse a las especies con mayor riesgo de ser amenazadas. Utilizamos datos derivados de la literatura para determinar las características ecológicas que afectan la distribución, al cambio en distribución y el riesgo de extinción en mariposas nocturnas (Lepidopetera, Noctuidae) finlandesas. Las características ecológicas que examinamos incluyeron el tamaño corporal, la especificidad larvaria, la longitud del período de vuelo y la etapa de hibernación. Adicionalmente, examinamos los efectos de la distribución de recursos en especies monófagas. La especificidad larvaria, la longitud del período de vuelo y la etapa de hibernación tuvieron un efecto independiente sobre el riesgo de extinción cuando los efectos de otras características eran controlados al incorporar todas las características al mismo modelo de regresión. Ninguna característica predijo el riesgo de extinción cuando el análisis se realizó sin controlar a las demás características. Esta discrepancia entre los resultados sugiere que una sola característica puede no ser suficiente para permitir la predicción del riesgo de extinción. En cambio, parece que se requieren datos de varias características ecológicas para una ciencia conservacionista predictiva exitosa.