Seasonal changes in the territorial behaviour of the satyrine butterfly Lethe diana are mediated by temperature

The territorial behaviour of butterflies often changes with temperature. The satyrine butterfly Lethe diana has three generations a year, and males display territorial behaviour in the May–June and September–October generations, but not in the July–August generation. This study investigated the relationship between this seasonal change in mate-locating behaviour and thermoregulation. When L. diana was able to hold a territory, thoracic temperature ranged from 23.8 to 33.6°C. This temperature was mainly influenced by environmental temperature based on air temperature, solar radiation, and wind, and metabolic heat was estimated to increase thoracic temperature by about 5°C in the May–June generation. When environmental temperature at a territorial site was within this range of the thoracic temperature minus the metabolic heat (approximately 5°C), L. diana males held territories. Since territorial sites were selected irrespective of the temperature, L. diana could not hold a territory when the temperature of the territorial site exceeded the threshold. In July–August, the temperature of the territorial site was almost always above the suitable range. These results suggest that seasonal change in territoriality of L. diana is due to behavioural thermoregulation. Electronic Publication     

Seasonal fluctuations in butterflies and nectar resources in a semi-natural grassland near Mt. Fuji, central Japan

We investigated seasonal fluctuation patterns in species and individuals of adult butterflies and flowering plants providing nectar in a semi-natural grassland in central Japan. We considered their interrelationships and implications for conservation. The semi-natural grassland included different vegetation structures and management regimes, including: (1) firebreaks where the grass was mowed and removed, (2) plantation areas that were mowed, (3) unpaved roads with mowed banks, (4) abandoned grassland, (5) scattered scrub forest, and (6) the surrounding forest. The sites with management (e.g., firebreaks), plantations and banks of the unpaved road sustained a larger number of butterflies and flowers than sites without management, such as the abandoned grassland, scrub forest and surrounding forest. The number of butterflies increased in the firebreak in June and at all sites in August and September. The firebreak sustained flowers in the spring, and the plantation area and banks of the unpaved road sustained flowers primarily in August and September, which was correlated with the distribution of butterflies. The different treatments such as mowing or mowing with removal of grass induced different numbers of flowers of each species affecting the habitat of adult butterflies through a season. On the other hand, the shrub tree species composing the scrub forest were host plants for the larvae of certain butterfly species. Our results suggest that heterogeneous environments with different human management or different vegetation structure or both could support habitat for various butterfly species, depending on the season and the seral stage.     

Haying and grazing effects on the butterfly communities of two Mediterranean-area grasslands

Grasslands are usually the most suitable environment for butterflies, but have been also traditionally used for productive activities. This paper compares the impact of mowing and grazing on butterfly biodiversity in two S Italian (Campania) grasslands, at Campo Somma (CS) and Pianoro di Prada (PP) located at an identical altitude of 850 m. These grasslands have an area of approximately 6 ha each and are at a 3 km distance from each other. They share similar climate and are both surrounded by woods, mainly of sweet chestnut. CS is managed for haying and is mown once a year, in June. PP is used for sheep and cattle grazing. Weekly transects were made from April to September in 2008 and 2009, during the butterfly flight activity. We analysed data from eight monthly transects by Kruskal–Wallis and Mann–Whitney tests. We observed 45 butterfly species at PP, and 28 at CS. Diversity indexes were significantly higher at PP, whereas evenness was similar. The monthly comparisons of species richness showed that, except for April, PP values were always significantly higher. Species abundance was significantly higher at PP in June, July and August. In all months, except in April, the Shannon–Wiener index was also significantly higher at PP, as was Simpson’s index in May, June and September. Dominance index differed significantly only in May, June and September, whereas evenness was never significantly different between the two grasslands. These data show that, as concerns butterflies, the impact of mowing was much stronger than that of grazing.     

齐云山国家级自然保护区蝴蝶群落多样性

为研究齐云山国家级自然保护区蝴蝶群落多样性, 2016年4月至2018年10月, 作者在江西齐云山国家级自然保护区不同生境选取5条长2,000 m的固定样线进行了每年6次、累计18次的蝶类多样性调查。共记录到蝴蝶6,946只, 隶属5科106属189种, 其中东洋界种类是优势类群(183种, 占总种数的96.8%)。蛱蝶科的种类最多(81种, 占42.9%), 其物种丰富度指数(R = 8.42)、多样性指数(H′= 3.21)和优势度指数(D = 0.60)较高, 属于优势类群。齐云山国家级自然保护区蝴蝶个体数从4月开始逐渐增加, 到6-7月基本稳定并维持到10月;物种数在4-10月基本稳定, 具有较高的多样性指数。保护区内不同生境观测样线的蝴蝶种类和数目有较大的差异: 针阔混交林的桐江样线蝴蝶种类(126种, 占66.7%)及数目(1,945只, 占28.2%)最多, 其物种丰富度指数(R = 16.51)最高; 常绿阔叶林的上十八垒样线蝴蝶数目相对较少(905只, 占13.0%), 但是蝴蝶种类相对较多(103种, 占54.5%), 所以多样性指数(H′= 3.93)和优势度指数(D = 0.85)较高; 农田和果园生境的三角潭样线由于生境简单且人为干扰强度较大, 蝴蝶物种数相对较少(97种, 占51.3%)。研究表明: 江西省齐云山国家级自然保护区的蝴蝶区系组成以东洋区为绝对主导的分布类型, 蝴蝶群落多样性与生境类型有明显的相关性, 季节性的农耕活动、除草剂农药的大量使用、寄主植物的大量砍伐等人类活动威胁到蝴蝶的多样性及蝶类群落结构的稳定性。     

Impact of logging on the richness and diversity of forest butterflies in a tropical dry forest in Thailand

Studies on the impact of logging on tropical forest butterflies have been almost exclusively conducted in moist forest habitats. This study considers the impacts of small-scale logging on butterfly communities at three sites of varying disturbance intensity in a tropical dry forest in western Thailand. Butterfly species richness was similar at all sites, but the abundance of butterflies and diversity of the butterfly community decreased with increased logging disturbance. The recorded decrease in diversity at the relatively large sampling scale used lends further support to the hypothesis that disturbance effects are scale dependent. Species abundance data for butterflies fitted a log-normal distribution at all sites, but also a log-series distribution at the two disturbed sites. These analyses suggest a more complex butterfly community at the undisturbed site, but also that log-series and log-normal distributions may not to be sufficiently sensitive to be useful indicators of community changes following logging. Community ordination separates both the butterfly species and transect samples into three distinct regions corresponding to the three study locations. Ordination axes are correlated with tree density, understorey cover and understorey plant richness. Species with the smallest geographic ranges tend to be the least abundant and occurred most frequently in the undisturbed site. The observed diverging responses to disturbance among butterfly families diminishes the value of butterfly communities as biodiversity indicators, and forest managers should perhaps focus on restricted range species or of groups of recognized sensitive species for this purpose.     

宁夏贺兰山自然保护区蝴蝶群落多样性及其环境影响因子

宁夏贺兰山自然保护区蝴蝶群落多样性及其与环境因素的关系,2017年5-9月采用样线法对贺兰山东麓6类生境和不同干扰类型10条样线的蝴蝶群落结构及其多样性季节动态进行调查。共记录蝴蝶5科36属45种,蛱蝶科Nymphalidae的属和物种数最多,为17属19种;凤蝶科Papilionidae最少,仅1属1种。菜粉蝶Pieris rapae、云粉蝶Pontia daplidice、斑缘豆粉蝶Colias erate和小檗绢粉蝶Aporia hippia是该地区的优势种,个体数量分别占总个体数的11.76%、11.63%、11.21%和10.17%。不同生境样线优势类群和常见类群不同。蝴蝶的栖息地偏好与寄主植物有关,蝴蝶的生境分布类型可分为生境广布型、湿润平原型、荒漠半荒漠草原型和山地森林型。蝴蝶群落Shannon-Wiener多样性和丰富度指数以灰榆疏林草地生境最高,优势度最低。各物种在生境内的季节变化趋势与不同生境植被生长季节相关,高峰期为7-8月。不同调查时间蝴蝶的优势种和常见种不同。物种数以7月份调查最多,有33种,占全年调查总物种数的73.33%;5月份调查最少,有20种。蝴蝶群落Shannon-Wiener多样性和丰富度指数以8月份最大,5月份最小。蝴蝶成虫发生类型分为全年发生型、春季型、夏季型和夏秋季型。不同生境和季节发生的优势种可以作为对生境状况进行评估的指示类群。采用CCA分析物种分布与微环境因子的关系,海拔对蝴蝶物种多样性分布格局有显著影响。蝴蝶丰富度与海拔、温度、风速显著正相关。适度干扰有利于蝶类多样性增加,较强的人为干扰会影响蝶类栖息环境,降低蝶类多样性。因此,生境差异性和干扰与蝴蝶群落的物种多样性密切相关,维持贺兰山垂直植被带的生境异质性和保持适度干扰是保护蝴蝶多样性的关键。     

Relationships between the age of northern Kantou plain (central Japan) coppice woods used for production of Japanese forest mushroom logs and butterfly assemblage structure

To discern mechanisms maintaining the diversity of grassland and forest butterflies in coppice woods managed for the production of Japanese forest mushroom logs, we investigated the butterfly fauna in cut-over land tracts shortly after felling and 5 year later, and in forest stands 10, 15, and 25 year after felling (here, we use the term “forests” when referring to the chronosequence of these treed stands). Butterfly species richness and diversity (H′) and the densities of individuals were highest in cut-over lands 5 year after clear-cutting, followed by 25-year-old forest stands. In forests, the richness and densities of forest butterfly species were higher than were those of grassland species. Among forest stands of different ages, forest butterfly species’ richness and the densities of individuals were highest in 25-year-old woods nearing felling time. Some forest butterfly species were observed only in forests. The species richness and densities of grassland butterflies were much higher in cut-over lands 0 and 5 year post felling than in forests; grassland species were rarely found in stands ≥10 year old. Thus, cut-over lands seem to function as temporary habitats for grassland species. Furthermore, the number of forest butterfly species was the same in cut-over lands 5 year after felling and in 25-year-old forest stands; the densities of forest butterfly species was higher in these cut-over lands than in the forest stands. Forest butterfly species living on cut-over land 5 year post felling sipped flower nectar, laid eggs on host plants, and practiced territorial behaviour involved in mate finding. Hence, these cut-over lands functioned as important habitats for various developmental stages of forest butterflies. In conclusion, traditional coppicing in woods for production of Japanese forest mushroom logs is very important for the maintenance of diversity in grassland and forest butterfly species.     

西双版纳热带植物园蝴蝶的多样性及变化

中国科学院西双版纳热带植物园（简称“版纳植物园”）保存着上万种植物,且生境多样,具有较高的蝴蝶多样性。本研究选择三类代表性生境：片段化雨林、次生林和专类园,聚焦于环境指示物种蝴蝶这一类群,通过样线法系统调查一年内蝴蝶多样性及其变化。观测结果显示：蝴蝶在版纳植物园内全年发生,共调查到其成虫5科126属218种6 015头,其中蛱蝶科多样性最高。蝴蝶种类及数量随月动态变化,生境间有差异,7-8月种类和数量达到最高峰;1月种类最少,而5-6月数量最低;每月均出现的种类仅有12种,绝大部分种类分散发生于不同月份。影响蝴蝶群落多样性的气候因子中,月最高温显著影响蝴蝶群落的物种丰富度和数量,月最低温显著影响物种丰富度、香农多样性和辛普森多样性,月平均温仅显著影响香农多样性。在版纳的三个典型季节中蝴蝶多样性存在差异,雨季物种丰富度最高,干热季香农和辛普森指数最高;雨季和雾凉季蝴蝶群落组成差异大,仅雾凉季与干热季的蝴蝶群落呈现中等程度相似。此外,在片段化雨林、次生林和专类园这3种不同生境中,蝴蝶群落组成也存在差异,蝴蝶物种丰富度和香农指数在次生林中最高,而辛普森指数则是片段化雨林最高;仅次生林与片段化雨林的蝴蝶群落呈现出中等程度相似。本研究揭示了版纳植物园蝴蝶群落的种类组成与月动态变化规律,并明确了不同季节和生境中蝴蝶群落的多样性变化,可为区域蝴蝶多样性观测及保护提供参考依据。     

Chronosequential change in a butterfly community after clear-cutting of deciduous forests in a cool temperate region of central Japan

Transect counts of butterflies were conducted in the northern part of Ibaraki, central Japan, from 1997 to 2001 at 11 census sites, composed of successive stages of deciduous forest development: grassland (one site, early abandoned stage); cutover land (one site, 1–5 years after clear‐cutting); secondary forests (very young (two sites, 6–9 years), middle (two sites, 16–22 years) and old (two sites, 47–51 years)) and old‐growth natural forests (three sites, ≥124 years old). A total of 86 species and 8858 individual butterflies were recorded by 29 sets (406 times) of transect counts. The species richness (number of species), abundance (number of individuals) and diversity indices (Shannon–Wiener H′ and Simpson's 1–λ) of butterflies were high in the early stages (grassland, cutover land and very young secondary forests) of secondary succession. Typical natural forest species increased with the progress of succession, and the old secondary forests and old‐growth natural forests had similar species composition. In contrast, most of the typical natural grassland species were recorded only in the grassland site. In the cutover land site, the number of individuals of grassland species considerably decreased from the first to the second year; furthermore, only one typical natural grassland species was recorded. Thus, the suitable stage for grassland butterfly species lasts for only 1–2 years after clear‐cutting. Old secondary forests (approximately>50 years old) would be able to give refuge to the forest butterfly species, including typical natural forest species. Based on the results, a practical, forestry‐based plan to conserve butterfly diversity was proposed.     

Reciprocating dispersal by habitat-selecting white-footed mice

Theories of dispersal driven by density-dependent habitat selection demonstrate that putative examples of source–sink dynamics and balanced dispersal may also be explained by a more general pattern of bi-directional, reciprocating dispersal. Analyses of 19 years of data on dispersal by white-footed mice confirm the theory. Fitness of territorial white-footed mice living in an agricultural mosaic is higher in forest habitat than it is in either edge or fencerows. Density-dependent habitat selection theory predicts that if net emigration by mice flows from the forest to forest-edge during periods of population growth, animals should subsequently move from the edge to forest during population decline. The pattern of mouse dispersal varies between seasons as populations wax and wane in abundance. Mice tend, as predicted, to move from high-density forest habitat into low-density edge during periods of population increase, and from the low-density edge into high-density forest during periods of population decline. Over all years combined, dispersal by white-footed mice was balanced. Each habitat tended to gain as many dispersing individuals as it lost. The results support a conditional dispersal strategy linked to density-dependent habitat selection, but also suggest the possibility of multiple coexisting strategies.     

Living on the edge: The use of fruit-feeding butterflies to evaluate edge effect on subtropical assemblages

This study evaluated how the edge effect influences the structuration of fruit-feeding butterfly assemblages in swamp forest fragments of the subtropical Atlantic Forest, Southern Brazil. Sampling was carried out twice in 10 fragments using baited traps placed in sampling units both at the forest edge and 50 m within the forest interior, with the habitats being defined by a set of environmental variables. Richness and abundance were higher for edge habitats with an effect of temperature depending on humidity and luminosity. The subfamily/tribe composition of fruit-feeding butterflies was segregated between edge and interior and was predicted by wind speed and the interaction between humidity and luminosity. Fifty meters within the forest interior is not sufficient to cause homogenization of butterfly composition between the edge and interior of swamp forest fragments, indicating distinct assemblages in each habitat. The interior harboured forest-loving butterfly groups while the edge harboured generalist sun-loving and common butterflies associated with disturbed areas, suggesting resistance to the effects of habitat fragmentation. We highlight the importance of using fruit-feeding butterfly groups, instead of species, to evaluate edge effects. We also suggest that a heterogeneous matrix with native habitats and distinct semi-natural land-use systems be maintained to manage subtropical areas by increasing connectivity within the landscape. Considering the impacts that the Atlantic Forest suffers, increased knowledge of modifications caused at small and regional scales is crucial for the maintenance of ecological processes and represents a tool for conservation planning and environmental agendas.     

Ecology of tropical butterflies in rainforest gaps

Tropical forest gaps are ephemeral and patchily distributed within forest areas and have very different light environments compared with closed-canopy forest. We used fruit-baited traps to investigate if gaps are exploited by more opportunistic butterfly species compared with closed-canopy forest. Gaps supported a higher diversity of butterflies in terms of species evenness but closed-canopy sites contained species with more restricted geographical distributions. There was little similarity between the assemblages of butterflies trapped in the canopy and those in either gap or closed-canopy sites, but the greater similarity was with gaps, and increased diversity in gaps was partly due to canopy species turning up in gaps. Dispersal rates (as measured by recapture rates) were higher in gaps and there was evidence that butterflies in gaps had relatively larger and broader thoraxes, indicating a flight morphology adapted for faster flight. These results support the notion of a distinctive gap fauna comprising more widespread, mobile species. Habitat modification that opens up the canopy is likely to result in an increase in these widespread species and a decline in understorey species with restricted distributions.     

High and dry or sunk and dunked: lessons for tallgrass prairies from quaking bogs

Northern Wisconsin bogs provide a natural experiment on butterfly population occurrence in a naturally highly fragmented vegetation type, which may provide insight on conserving butterflies in anthropogenically fragmented and degraded landscapes. We surveyed butterflies in bogs (about as unaffected by humans as possible, but naturally occurring over <1% of northern Wisconsin) primarily during 2002?C2009, with additional observations from 1986 to 2001. Different bog types had different bog-specialist butterfly faunas, but bog butterfly abundance also differed in similar vegetations among subregions. Some small isolated bogs held very high densities of specialist butterflies. Summer but not spring specialists frequented adjacent lowland roadsides and utilized a variety of non-native as well as native nectar sources. Paleo-entomology indicates that insects don??t evolve out of trouble; instead they move out of trouble. Given the low dispersal apparent today for species restricted to bogs, ??move?? might be better understood as ??hunkering?? within their vegetation as it expands and shrinks and moves around the landscape. Although bogs appeared to have more intact specialist butterfly faunas than tallgrass prairies (99.9% destroyed by human activities), bog butterflies do not live in average sites even in a relatively natural landscape. Just as bog butterflies are ??sunk and dunked?? in isolation, specialist butterflies elsewhere may have been left ??high and dry?? naturally, or are now due to human activities. Numerous studies have demonstrated that presence and abundance of specialist butterflies increase with increasing size and connectedness of habitat patches. But with long-term consistent vegetation, populations with high abundances in small isolated sites and with low numbers thinly occurring in large sites can be secure, as shown by bog butterflies.     

Territorial behavior in the speckled wood butterflies Pararge xiphia and P. aegeria of Madeira: a mechanism for interspecific competition

Two species of speckled wood butterfly occur in Medeira. Pararge xiphia is endemic and is very similar in morphology, behaviour and general ecology to P. aegeria which was first recorded on the island in 1976. We collected behavioural data on the males of the two species at sites where the indigenous laurel forest meets non-native forest and agriculture. It is in these areas that the two species are found together in particularly high densities. Male Pararge butterflies defend sunlit areas of vegetation and attempt to exclude other butterflies. If a territorial intruder is a conspecific or the other Pararge species, extended chases or spiraling flights may take place. Interactions between the two Pararge species are longer and more likely to be escalated than those between either species and a range of other butterfly species. Pararge aegeria is more aggressive in its territorial behaviour than P. xiphia and the latter may be suffering more from the interactions. The results demonstrate that the two species are competing for space and therefore, that territorial behaviour could be a mechanism by which interspecific competition could be taking place. Any adaptive explanation for the interspecifc territoriality remains speculative but this recent and probably natural, colonization may provide an excellent opportunity to examine the role of interspecific competition in structuring communities. The arrival of P. aegeria on Madeira has created an almost unique natural experiment, the study of which will potentially avoid many of the problems traditionally associated with the study of competition.     

Nymphalid butterfly dispersal among forest fragments at Serra da Canastra National Park,Brazil

Organisms must possess good dispersal ability to persist in fragmented landscapes, as extinction in habitat patches is frequent and patches must be re-colonised to keep viable metapopulations. Thus, metapopulation maintenance is dependent on patch size and distance, although these affect species differently. In order to evaluate the ability of Nymphalid butterfly species to live in naturally fragmented small forest fragments we marked and released 3,415 butterflies in 16 of these areas separated in two networks at the Serra da Canastra National Park (PNSC), south-eastern Brazil. Subsequent recaptures in different forest fragments enabled us to assess the dispersal rates and distances for several Nymphalid species. Seventeen butterflies from 11 out of the 50 species captured were directly observed to disperse from 500 m to 870 m. Dispersal rates varied between 1 and 7% of the marked individuals and were directly correlated to the mean forewing length of each butterfly species population. The connectivity of the forest fragments through creeks appear to facilitate butterfly dispersal among fragments within micro-basins, as only one out of 50 dispersing individuals was observed to fly from one micro-basin to the other. Several species had viable populations in the small-fragment network. The distance between fragments is crucial as the coarser fragment network was unlikely to sustain viable populations of most of the species. The protection of large forest fragments located outside of the PNSC may be necessary to promote colonization of the smaller forest fragments inside the Park.     

雨雪冰冻灾害对南岭蝴蝶资源的影响

南岭国家级自然保护区巳发现蝴蝶442种,其中不乏有中国分布新纪录和新种。常绿阔叶林中有蝴蝶339种,山地常绿针阔叶林中有蝴蝶369种,山顶常绿阔叶苔藓矮林中有蝴蝶71种;这些蝶类属东洋区的有360种,占总数的81.45%;属古北区的有48种,占总数的10.86%;跨区系分布的有34种,占总数的7.69%;南岭蝶类与福建省蝶类相似百分率高达77.27%,说明两地有共同的起源与演化过程。2008年初的雨雪冰冻灾害使南岭海拨500～1000m森林生态遭受严重破坏,各种蝴蝶在林中的种群密度骤降,海拨700～800m的蝶类仅为海拨1100～1200m冻害较轻林地蝶类数量的23%;整个林区蝶类的种群密度极低,与常年相比,降低率约为90%。凤蝶科的种群在调查地段发现的只占常年见到的37.5%。     

Does Müllerian Mimicry Work in Nature? Experiments with Butterflies and Birds (Tyrannidae)1

The selective advantage of Müllerian mimicry in nature was investigated by releasing live mimetic and nonmimetic butterflies close to wild, aerial‐hunting tropical kingbirds (Tyrannus melancholicus) and cliff‐flycatchers (Hirundinea ferruginea) in three Amazon habitats (rain forest, a city, and “canga” vegetation). Only mimetic butterflies elicited sight‐rejections by birds, but protection conferred by mimicry was restricted to sites in which both predators and mimics co‐occurred, as in the case of six mimicry rings at a forest site and two at a city site. Most other Müllerian mimics released at city and canga vegetation were heavily attacked and consumed by birds. These results appear to reflect the birds’previous experiences with resident butterfly faunas and illustrate how birds’discriminatory behavior varied among habitats that differed in butterfly species and mimicry ring composition.     

Butterfly community recovery in degraded rainforest habitats in the Upper Guinean Forest Zone (Kakum forest, Ghana)

Successful regeneration of secondary tropical forest might be crucial in the conservation of rainforests, since large areas of primary forest have been destroyed or degraded. Animal communities might play an important role in restoration of biological diversity in these secondary habitats, since some groups have high mobility and capacity for dispersal. Fruit-feeding butterflies were trapped to measure differences between butterfly communities in primary rainforest and disturbed forest habitats of different stage of regeneration including clear-cut, abandoned farmland, newly planted forest and middle-aged secondary growth. 3465 specimens representing 114 species were identified from 56 traps operated for 36 days. Extremely high values of rarefied species richness were estimated in the clear-cut habitat, due to the high number of singletons and doubletons. This was caused by a gap-effect that allowed penetration of canopy and open area species after disturbance. The differences between butterfly communities were best demonstrated through ecological composition, richness and abundance of indicator groups and habitat similarity based on Jaccard’s similarity index. The results show a clear ability of butterfly communities in degraded forest habitats to regenerate in 50–60 years after clearance.     

Male mate location behaviour and encounter sites in a community of tropical butterflies: taxonomic and site associations and distinctions

Male mate location behaviour and encounter sites have been studied in 72 butterfly species at Nagpur, India, and related to taxonomy, morphology, habitat and population parameters. Species can be placed in three broad classes of mate location behaviour: invariant patrolling, invariant perching, and perch-patrol, the latter associated with increasing site fidelity, territorial defence and male assemblages. Significant taxonomic differences occur, closely related species tending to share mate location behaviours. Morphological differences are found with heavier and larger butterflies displaying greater site fidelity and territorial defence, and differences occur between individuals of species which both perch and patrol. Invariant patrolling is particularly associated with tracks through vegetation, host plant-track distributions, and high female to male numbers observed on transects; invariant perching is linked more to edge features than patrolling, and to lower population counts on transects. Species which perch-patrol, defend territories and establish male assemblages are associated with more complex vegetation structures, and have encounter sites at vegetation edges, landforms and predictable resource (host plant) concentrations. Attention is drawn to the importance of distinctive mate encounter sites for the conservation of butterfly species’ habitats.     

Butterfly Response to Microclimatic Conditions Following Ponderosa Pine Restoration

Efforts to restore ponderosa pine ecosystems to open, park‐like conditions that predominated prior to European‐American settlement result in altered stand structure and increased landscape heterogeneity, potentially altering habitat suitability for invertebrates and other forest organisms. We examined the responses of two butterfly species, Colias eurytheme and Neophasia menapia, to microclimatic changes at structural edges created by experimental restoration treatments in northern Arizona. We monitored microclimate, including air temperature, light intensity, and vapor pressure deficit (VPD), on several mornings during butterfly releases. We placed adult butterflies at east‐ and west‐facing edges approximately one half‐hour before dawn to determine their behavioral response to microclimatic differences between east‐ and west‐facing edges. After sunrise, all three microclimatic variables were higher at east‐facing edges, and the difference in microclimate between the two edge orientations increased through early morning. For both species, butterflies placed at east‐facing edges flew earlier than butterflies at west‐facing edges. Colias eurytheme, an open‐habitat species, tended to move toward the treated forest during initial flight, while movements of Neophasia menapia, a forest‐dwelling species, did not differ from random flight. Our results indicate that butterflies respond to microclimatic factors associated with restoration treatments, while responses to structural changes in habitat vary among species, based on habitat and food plant preferences. These changes in forest structure and microclimate may affect the distribution of many mobile invertebrates in forested landscapes undergoing restoration treatments.