6 research outputs found
Inter-annual variation in adult demography, but no sex bias in a large lowland population of the threatened Clouded Apollo Parnassius mnemosyne butterfly
Ecoacoustics and multispecies semiosis: naming, semantics, semiotic characteristics, and competencies
Biosemiotics to date has focused on the exchange of signals between organisms, in line with bioacoustics; consideration of the wider acoustic environment as a semiotic medium is under-developed. The nascent discipline of ecoacoustics, that investigates the role of environmental sound in ecological processes and dynamics, fills this gap. In this paper we introduce key ecoacoustic terminology and concepts in order to highlight the value of ecoacoustics as a discipline in which to conceptualise and study intra- and interspecies semiosis. We stress the inherently subjective nature of all sensory scapes (vivo-, land-, vibro- and soundscapes) and propose that they should always bear an organismic attribution. Key terms to describe the sources (geophony, biophony, anthropophony, technophony) and scales (sonotopes, soundtopes, sonotones) of soundscapes are described. We introduce epithets for soundscapes to point to the degree to which the global environment is implicated in semiosis (latent, sensed and interpreted soundscapes); terms for describing key ecological structures and processes (acoustic community, acoustic habitat, ecoacoustic events) and examples of ecoacoustic events (choruses and noise) are described. The acoustic eco-field is recognized as the semiotic model that enables soniferous species to intercept core resources like food, safety and roosting places. We note that whilst ecoacoustics to date has focused on the critical task of the development of metrics for application in conservation and biodiversity assessment, these can be enriched by advancing conceptual and theoretical foundations. Finally, the mutual value of integrating ecoacoustic and biosemiotics perspectives is considered
Habitat‐related differences in the adult longevity of two ecotypes of a specialized butterfly
The life expectancy of adult butterflies is highly diverse. Substantial
variation may be found among closely related species, and even on the
intraspecific level, where it could be associated with sex, genetic
differentiation, diet and weather conditions. We compared the
demographic parameters of populations of the regionally endangered
Boloria eunomia butterfly living in two different habitats. Across its
boreal-mountane distribution range in Europe, B. eunomia occurs in two
ecotypes associated with wet meadows and raised bogs using distinct both
larval and nectar plants. We carried out simultaneous studies of both
ecotypes through mark-recapture surveys of two large populations in NE
Poland, located close to each other. A total number of 1124 and 644
individuals were marked at the bog and meadow sites respectively, and 51
and 33\% of them were recaptured at least once. The estimated adult
population size of the bog population (about 3000) was twice as large as
that of the meadow population, which however was characterized by more
than three-fold higher density. The emergence of imagoes was highly
synchronized, and protandry was evident. The sex ratio was slightly
male-biased and the mean capture probability was significantly higher
for males. More importantly, the estimated life span of males was
considerably shorter than that of females at each site. Finally, both
sexes of the 'meadow' ecotype lived significantly longer than those from
the raised bog. The detected pattern can be related to distinct larval
food plants and/or nectar resources, different pressures from predators,
genetic variation and morphological differences affecting thermal
properties. Further investigations would be useful to reveal if the
shorter adult life span translates into reduced viability of bog
populations and consequently whether they are potentially more
threatened, at least in the southern margins of the distribution range
in Central Europe
Differential geographic patterns in song components of male Albert’s lyrebirds
Geographic variation in bird song has received much attention in evolutionary studies, yet few consider components within songs that may be subject to different constraints and follow different evolutionary trajectories. Here, we quantify patterns of geographic variation in the socially transmitted “whistle” song of Albert\u27s lyrebirds (Menura alberti), an oscine passerine renowned for its remarkable vocal abilities. Albert\u27s lyrebirds are confined to narrow stretches of suitable habitat in Australia, allowing us to map likely paths of cultural transmission using a species distribution model and least cost paths. We use quantitative methods to divide the songs into three components present in all study populations: the introductory elements, the song body, and the final element. We compare geographic separation between populations with variation in these components as well as the full song. All populations were distinguishable by song, and songs varied according to the geographic distance between populations. However, within songs, only the introductory elements and song body could be used to distinguish among populations. The song body and final element changed with distance, but the introductory elements varied independently of geographic separation. These differing geographic patterns of within-song variation are unexpected, given that the whistle song components are always produced in the same sequence and may be perceived as a temporally discrete unit. Knowledge of such spatial patterns of within-song variation enables further work to determine possible selective pressures and constraints acting on each song component and provides spatially explicit targets for preserving cultural diversity. As such, our study highlights the importance for science and conservation of investigating spatial patterns within seemingly discrete behavioral traits at multiple levels of organization