Conservation of moths in The Netherlands: population trends, distribution patterns and monitoring techniques of day-flying moths

The loss of butterfly diversity in north-western Europe has been studied extensively but much less is known about the status of other macrolepidoptera. The present paper presents results of the research on mainly day-flying larger moths carried out by Dutch Butterfly Conservation in The Netherlands. Research started in 1992 with a public campaign and a mapping programme, leading to an increase in the number of records of macrolepidoptera. Results from the mapping programme on day-flying moths showed a strong general decrease in The Netherlands, comparable with the loss of butterfly diversity. Transect counts have been undertaken since 2000 for a few species and this method is sufficient to measure trends over time if the moth densities are high enough. Another research component was to focus on marshland habitats in The Netherlands. Fifty-five characteristic marshland moth species were selected and the relative abundance of nearly all these species has declined. These trends were compared with four other countries in the Atlantic biogeographical zone. The relative abundance of the majority of marshland moths in The Netherlands was found to be higher than those in other European countries, so that The Netherlands has a special responsibility for the conservation of the moths of its marshes. Moreover, we emphasise that, next to butterflies, moths can be of great use in nature conservation because of their potential significance as indicator species in endangered habitats.     

Cerulean Warblers in the Ozark region: habitat selection,breeding biology,survival, and space use

Cerulean Warblers (Setophaga cerulea) are a species with declining populations that exhibit regional variation in habitat selection and demographic rates. The Ozark region of the south‐central United States likely provides important habitat for Cerulean Warblers, but little is known about their breeding biology in that region. We studied Cerulean Warblers in riparian forests of the Ozarks of Arkansas from 2018 to 2020. We assessed multi‐scale habitat selection for vegetative and topographic features, documented their breeding biology, estimated within‐season and annual apparent survival, and estimated territory sizes. We found that Cerulean Warblers selected riparian habitat characterized by large‐diameter trees across all spatial scales. Contrary to the results of previous studies, males appeared to avoid white oaks (Quercus spp., Section Quercus) at the territory scale, but this avoidance may reflect an underlying preference for riparian habitat. Our logistic‐exposure estimate of nest survival (0.32; 85% confidence interval: 0.21–0.46) was similar to the median of estimates reported in previous studies. Our results indicate that maintaining riparian forests with large trees is important to provide suitable habitat for Cerulean Warblers in the Ozark region. Because of similarities in habitat selection among regions, some management practices from other populations, including retaining large trees and promoting a heterogeneous canopy structure, may be useful for managing for Cerulean Warblers in riparian areas of the Ozarks. However, selection for topography and tree species by Cerulean Warblers in our study also suggests that region‐specific management strategies will be beneficial. Finally, our demographic rate estimates for this population should prove valuable in future full‐annual‐cycle population modeling efforts.     

Bat head contains soft magnetic particles: Evidence from magnetism

Recent behavioral observations have indicated that bats can sense the Earth's magnetic field. To unravel the magnetoreception mechanism, the present study has utilized magnetic measurements on three migratory species (Miniopterus fuliginosus, Chaerephon plicata, and Nyctalus plancyi) and three non‐migratory species (Hipposideros armiger, Myotis ricketti, and Rhinolophus ferrumequinum). Room temperature isothermal remanent magnetization acquisition and alternating‐field demagnetization showed that the bats' heads contain soft magnetic particles. Statistical analyses indicated that the saturation isothermal remanent magnetization of brains (SIRM_{1T_brain}) of migratory species is higher than those of non‐migratory species. Furthermore, the SIRM_{1T_brain} of migratory bats is greater than their SIRM_{1T_skull}. Low‐temperature magnetic measurements suggested that the magnetic particles are likely magnetite (Fe₃O₄). This new evidence supports the assumption that some bats use magnetite particles for sensing and orientation in the Earth's magnetic field. Bioelectromagnetics 31:499–503, 2010. © 2010 Wiley‐Liss, Inc.