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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2010.06.021 Byline: Hans Van Dyck (a), Sofie Regniers (b) Abstract: Oviposition site selection can be viewed as an act of parental care; it is a life history trait with significant consequences for offspring development and success. Herbivorous insects may adopt different strategies for spreading their eggs (e.g. single oviposition events versus egg clustering). Host plant use results from the interplay of available cues and the responsiveness of the ovipositing female. We studied how egg-laying behaviour of individual females resulted in the egg distribution patterns observed at the population level in the ant-parasitic butterfly Maculinea alcon. Eggs are laid on marsh gentians, Gentiana pneumonanthe, but survival also depends on the presence of Myrmica host ants as young caterpillars leave the host plant and survive only after being adopted by ants. Several studies have focused on egg distribution patterns, but less so on the behavioural mechanisms behind the oviposition patterns. Our observational data show evidence for some level of egg clustering, as predicted by the obligate myrmecophilous lifestyle. There was no evidence of egg-laying avoidance when gentians already carried several eggs. Phenological time windows for oviposition on individual flower buds and gentians were much wider than reported before. Detailed tracking of egg-laying females in the field showed high rates of oviposition and suggest relatively high average levels of fecundity compared to fully herbivorous lycaenid butterflies. Results are discussed in relation to adaptive oviposition strategies of this highly specialist ant parasite of conservation concern. Author Affiliation: (a) Behavioural Ecology & Conservation Group, Biodiversity Research Centre, Earth and Life Institute, Universite Catholique de Louvain (UCL), Belgium (b) Evolutionary Ecology Group, Department of Biology, University of Antwerp, Belgium Article History: Received 30 March 2010; Revised 7 May 2010; Accepted 17 June 2010 Article Note: (miscellaneous) MS. number: 10-00226R

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2006.12.020 Byline: Thomas Merckx, Hans Van Dyck Abstract: The ability of an organism to find new habitat is likely to contribute to dispersal success in different landscapes. We compared the ability of male speckled wood butterflies from two types of landscape to orientate towards forested habitat as a behavioural assay of the ability to perceive forested habitat at a distance (25-200m). This field release-experiment showed that butterflies of fragmented agricultural landscape origin were better able to orient towards habitat at a greater distance than butterflies of continuous woodland landscape origin. They followed more linear tracks, displayed flight angles that deviated less from orientation towards habitat, and showed orientations that were significantly directed towards habitat at greater distances than butterflies of continuous landscape origin. Attraction was facilitated when target habitat had a high profile. Our behavioural experiment provides novel insights into landscape connectivity and points to interpopulation differences in the ability to find habitat associated with landscape type. Author Affiliation: (a) Laboratory of Animal Ecology, Department of Biology, University of Antwerp, Belgium (a ) Biodiversity Research Centre, Ecology and Biogeography Unit, University of Louvain (UCL), Belgium Article History: Received 27 September 2006; Revised 15 November 2006; Accepted 19 December 2006 Article Note: (miscellaneous) MS. number: 9121

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.anbehav.2004.12.005 Byline: Thomas Merckx, Hans Van Dyck Abstract: Visually cued mate location behaviour in insects such as butterflies is typically classified by 'wait or seek' dichotomies. Perching males adopt a sit-and-wait strategy at a particular spot rising to intercept passing females (which is often done in an aggressive territorial way), whereas patrolling males are permanently on the wing searching for females. The potential influence of changes in landscape caused by habitat fragmentation on mate location behaviour has only rarely been addressed. We investigated this behaviour among populations of the speckled wood butterfly, Pararge aegeria, living in continuous woodland versus highly fragmented agricultural landscape with hedgerows and small patches of woodland. In the latter landscape males showed higher levels of aggressive fast take-offs (an indicator of territorial perching), but also higher levels of displacement (an indicator of patrolling). In an independent census, behaviour intermediate between perching and patrolling was much more frequent in the agricultural landscape than in the woodland landscape. Our results suggest that the dichotomy of perching versus patrolling as typically observed in woodland fades away in highly fragmented agricultural landscape. We discuss our results in relation to differences in densities and thermal properties of both types of landscape. Author Affiliation: (*) Laboratory of Animal Ecology, Department of Biology, University of Antwerp, Belgium (a ) Biodiversity Research Centre, Ecology & Biogeography Unit, Catholic University of Louvain (UCL), Belgium Article History: Received 20 September 2004; Revised 18 November 2004; Accepted 2 December 2004 Article Note: (miscellaneous) MS. number: 8283

The phenotype wing color affects male territorial, interactional and mate selection behavioral strategies in the speckled wood butterfly. Pale males engage in short flights, spend a lot of time resting in a sunlit patch, and exhibit both conspecific and non-conspecific interactions. Darker males engage in frequent flights, spend very little time on one sunlit patch, spend more time in basking than resting, and are more likely to leave the forest. Pale males are aggressive and territorial perchers, and dark males are mainly patrollers. The effect of wing morphology on male behavior is discussed.

Abstract: In nature, ovipositing females may be subjected to multiple extrinsic and intrinsic environmental factors simultaneously. To adequately assess a species response to environmental conditions during oviposition it may therefore be necessary to consider the interaction between multiple intrinsic and extrinsic factors simultaneously. Using the butterfly, Pararge aegeria, this study examined the combined effects of extrinsic (temperature and flight) and intrinsic (body mass and age) factors on ovarian dynamics, egg provisioning and reproductive output, and explored how these effects subsequently influenced offspring fitness when egg-stage development occurred in a low humidity environment. Both temperature- and flight-mediated plasticity in female reproductive output was observed, and there were strong temperature by flight interaction effects for the traits oocyte size and egg mass. As females aged, mean daily fecundity differed across temperature treatments, but not across flight treatments. Overall, temperature had more pronounced effects on ovarian dynamics than flight. Flight mainly influenced egg mass via changes in relative water content. A mismatch between the physiological response of females to high temperature and the requirements of their offspring had a negative impact on offspring fitness via effects on egg hatching success. [Copyright &y& Elsevier]

Copyright of Basic & Applied Ecology is the property of Urban & Fischer Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The unambiguous recognition of a species’ habitat is a matter of debate. For terrestrial species, habitat is often defined as physical patches of a certain vegetation type in a matrix of non-habitat. Ecological resources that make up the habitat of a species may, however, only cover subsets of vegetation types or can be spatially dispersed in a complex way over different vegetation types. Here we present and test a procedure to recognize and delineate habitat according to a resource-based approach instead of a vegetation-based approach. We used the green hairstreak butterfly (Callophrys rubi) in a heathland landscape as a study case. Our resource-based habitat approach selects those zones that comprise essential resources and conditions within an appropriate spatial window. Variables that were retained in a logistic regression model were used to calculate larval, adult and combined habitat indices in a GIS, taking into account thermal constraints on resource-use, as this is a key habitat aspect for this heliothermous insect. To group different (and sometimes scattered) ecological resources into functional habitat zones, we derived a measure of space-use from mark-release-recapture data. By least-cost modelling this spatial window was adapted to the nature of the vegetation between sets of resources. The habitat zones that were delineated using this approach matched the observed distribution of butterflies significantly better than did a classic approach based on vegetation types with host plants only. Our approach provides concrete output for conservation purposes, like recognizing zones with the highest potential for habitat restoration. [Copyright &y& Elsevier]

Copyright of Basic & Applied Ecology is the property of Urban & Fischer Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wild flower diversity and abundance are strongly reduced in intensive agricultural landscapes. Flower-visiting insects may, therefore, experience limited nectar quantities and qualities. Adult insects that rely on energy-rich nectar income for flight, survival and reproduction are expected to be much more affected than insects that rely on their larval reserves. We dealt with this issue at the intraspecific level by comparing the responses of several life-history traits to different nectar diets between meadow brown butterflies ( Maniola jurtina ) originating from relative intensively managed and extensively managed agricultural landscapes. We used outdoor flight cages in which we simulated factorial treatments of low/high nectar quality and low/high quantity. Survival was highest in the high nectar quantity and quality treatment. Individuals from intensive landscapes were heavier, which is in line with predictions on increased capital breeding, and they survived better than those from extensive landscapes, of which the females lost body mass in all treatments. Females from intensive landscapes were able to buffer, or even increase, their body mass in the high nectar quantity treatments, but the differences with females from extensive landscapes disappeared under low nectar quantities (independent of nectar quality). In males, body mass losses were always larger for individuals from extensive landscapes compared to individuals from intensive landscapes. Forty percent of the females showed complete reproductive failure in the low quantity/low quality treatment compared to c . 7% in the other treatments. In the low quantity/low quality treatment, realized fecundity decreased strongly in females from intensive, but not extensive landscapes. Egg size was not affected by landscape of origin in the high-quality nectar treatments, but showed very different responses relative to landscape of origin in the treatments with low-quality nectar. Our results showed strong effects of reduced nectar supply on fitness-related traits, and responses were different between butterflies originating from landscapes with contrasted nectar diet. Hence, different levels of agricultural intensification changing the quantity and quality of the local nectar supply could pave the way for ecological differentiation of the organism’s behaviour, physiology and life history. [ABSTRACT FROM AUTHOR]

Understanding connectivity among populations in fragmented landscapes is of paramount importance in species conservation because it determines their long-term viability and helps to identify and prioritize populations to conserve. Rare and sedentary species are particularly vulnerable to habitat fragmentation as they occupy narrow niches or restricted habitat ranges. Here, we assess contemporary interpopulation connectedness of the threatened, myrmecophilous butterfly, Maculinea alcon , in a highly fragmented landscape. We inferred dispersal, effective population sizes, genetic diversity and structure based on 14 locations of M. alcon in Belgium and the Netherlands using data from 12 microsatellite loci. Despite the reported sedentary behaviour of M. alcon , we observed moderate levels of contemporary dispersal between patches, but only in landscapes where populations were located within a distance of 3 km from neighbouring populations. Estimates of effective population sizes ( Ne ) were very low (ranging from 1.6 to 17.6) and bottleneck events occurred in most of the studied populations. We discuss the functional conservation units delineated based on a former mark-release-recapture study, and formulate appropriate conservation strategies to maintain viable (meta)populations in highly fragmented, anthropogenic landscapes. [ABSTRACT FROM AUTHOR]

The recent decline in insect diversity and abundance and the consequences for associated ecosystem functioning and services have attracted growing attention. Especially highly anthropogenic regions are affected by rapid biodiversity changes including significant losses. Two decades ago, we suggested that Flanders (northern Belgium) was Europe's worst case scenario for butterfly diversity loss with habitat destruction, fragmentation and nitrogen deposition as major causes (Maes and Van Dyck, 2001). To analyse changes since the second half of the 20th century, we used >2.5 million distribution records to calculate trends in distribution during the last three decades. By linking these trends to the species' ecology using multi-species indicators for a set of ecological and life-history traits, we determined the most important drivers policy makers and nature managers should focus on. Species showing the strongest expansion are woodland specialists and polyphagous species. On the other hand, sedentary species of nutrient-poor biotopes such as heathlands and semi-natural grasslands showed a decreasing trend, despite the ongoing policy focus and conservation efforts. We discuss our results with regard to challenges and bottlenecks for the conservation of butterflies and other insects in anthropogenic regions. Multispecies Change Indices (MSCI ± se) for biotope preference of butterflies in three decades compared to a reference period (1951–1990). On average, specialist species of heathlands showed a continuous decline compared to the reference period 1951–1990. Specialist species of woodlands, on the other hand, showed a continuous increase since the period 1951–1990. The dashed lines indicate the (arbitrary) thresholds for increases (+100 %) or decreases (−50 %) compared to the reference period 1951–1990. The figures in grey indicate the number of species in each period and each biotope class. The grey dots indicate the mean MSCI and the trend is given in white in the dots: + = increase, +∼ = moderate increase, ∼ = stable, −∼ = moderate decrease, − = decrease, ?+ = potential increase, ?− = potential decrease. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Red Lists are used to assess the extinction risk of species based on quantitative IUCN criteria. For the compilation of a new Red List of butterflies in Flanders (north Belgium), we collated ca 800,000 distribution records and applied the IUCN Red List criteria to this small region (ca 135,00km2). We also explored the effect of spatial resolution on the outcome of the Red List assessment by alternatively using 1×1km2 and 5×5km2 grid cells for geographic range size and trend calculations. We determined conservation hot spots in Flanders based on the Red List status of the species composition in each grid cell. The new Red List classified 20 butterflies (out of 68 resident species) as Regionally Extinct, six as Critically Endangered, five as Endangered, seven as Vulnerable and seven as Near Threatened. The remaining 23 species were classified as Least Concern. Using coarse instead of fine grain grid cells would have classified ten species in a lower Red List category. Compared with the previous Red List, nine species were classified in a lower and 12 in a higher threat category. In total, 218 1×1km2 grid cells were considered as (very) high butterfly conservation priority sites. The application of the new IUCN criteria in a small region such as Flanders resulted in a Red List that offered challenging opportunities for the conservation of butterflies in particular and biodiversity in general. [Copyright &y& Elsevier]

Abstract: Purpose: Temperature profoundly impacts on distribution and habitat-use of organisms. The development of ectothermous caterpillars does not depend on host plant quality only, but also on the availability of suitable thermal conditions. Selection for thermally favorable microclimates (i.e. behavioral thermoregulation) is a primary mechanism of temperature control, and caterpillars can be either (or alternately) temperature conformers (i.e. passively adopting ambient temperature conditions) or thermoregulators (i.e. able to some extent to elevate or decrease their body temperature relative to ambient temperature). Here, we addressed the functional significance of different structural vegetation elements for the behavioral thermoregulation by caterpillars of two butterfly species. Results: Weather conditions influenced the caterpillar detection probability within host plant patches, indicating that caterpillars can hide and use suitable microclimates provided by vegetation structures to cope with weather variations. This is why we (1) evaluated the heterogeneity in temperature conditions provided by these structures, (2) quantified the influence of ambient temperature and light intensity on caterpillar body temperature, and (3) tested how position on structure, substrate color and exposition influenced caterpillar body temperature. As expected, vegetation structures provided heterogeneous temperature and sun exposition conditions, while caterpillar body temperature was dependent on ambient temperature and light intensity. But body temperature was additionally influenced by the position on vegetation structures, substrate color and exposition. Conclusions: These results suggest that there is no unique and fixed structure in the vegetation subsuming the best thermal conditions for caterpillars. We argue that a better understanding of the thermal properties of vegetation structures is essential for correctly understanding caterpillar habitat-use and the behavioral mechanisms driving their body thermoregulation. Conceptually this means that thermal conditions should be included in the definition of a species'' functional habitat. Practically this may influence the choice of appropriate habitat management for species of conservation concern. [Copyright &y& Elsevier]