Home-range use patterns and movements of the Siberian flying squirrel in urban forests: Effects of habitat composition and connectivity

Peer reviewe

Enhanced Graph Rewriting Systems for Complex Software Domain

International audienceMethodologies for correct by construction reconfigurations can efficiently solve consistency issues in dynamic software architecture. Graph-based models are appropriate for designing such architectures and methods. At the same time, they may be unfit to characterize a system from a non functional perspective. This stems from efficiency and applicability limitations in handling time-varying characteristics and their related dependencies. In order to lift these restrictions, an extension to graph rewriting systems is proposed herein. The suitability of this approach, as well as the restraints of currently available ones, are illustrated, analysed and experimentally evaluated with reference to a concrete example. This investigation demonstrates that the conceived solution can: (i) express any kind of algebraic dependencies between evolving requirements and properties; (ii) significantly ameliorate the efficiency and scalability of system modifications with respect to classic methodologies; (iii) provide an efficient access to attribute values; (iv) be fruitfully exploited in software management systems; (v) guarantee theoretical properties of a grammar, like its termination

Changes in the distribution of red foxes (Vulpes vulpes) in urban areas in Great Britain: findings and limitations of a media-driven nationwide survey

Urbanization is one of the major forms of habitat alteration occurring at the present time. Although this is typically deleterious to biodiversity, some species flourish within these human-modified landscapes, potentially leading to negative and/or positive interactions between people and wildlife. Hence, up-to-date assessment of urban wildlife populations is important for developing appropriate management strategies. Surveying urban wildlife is limited by land partition and private ownership, rendering many common survey techniques difficult. Garnering public involvement is one solution, but this method is constrained by the inherent biases of non-standardised survey effort associated with voluntary participation. We used a television-led media approach to solicit national participation in an online sightings survey to investigate changes in the distribution of urban foxes in Great Britain and to explore relationships between urban features and fox occurrence and sightings density. Our results show that media-based approaches can generate a large national database on the current distribution of a recognisable species. Fox distribution in England and Wales has changed markedly within the last 25 years, with sightings submitted from 91% of urban areas previously predicted to support few or no foxes. Data were highly skewed with 90% of urban areas having <30 fox sightings per 1000 people km-2. The extent of total urban area was the only variable with a significant impact on both fox occurrence and sightings density in urban areas; longitude and percentage of public green urban space were respectively, significantly positively and negatively associated with sightings density only. Latitude, and distance to nearest neighbouring conurbation had no impact on either occurrence or sightings density. Given the limitations associated with this method, further investigations are needed to determine the association between sightings density and actual fox density, and variability of fox density within and between urban areas in Britain

Within-season changes in habitat use of forest-dwelling boreal bats

Bats utilize forests as roosting sites and feeding areas. However, it has not been documented how bats utilize these habitats in the boreal zone with methods afforded by recent technological advances. Forest structure and management practices can create a variety of three-dimensional habitats for organisms capable of flight, such as bats. Here, we study the presence of boreal bats in a forest forming a mosaic of different age classes, dominant tree species, canopy cover, soil fertility, and other environmental variables, throughout their active season in the summer using passive ultrasound detectors. Our results indicate a preference for mature forest by Eptesicus nilssonii and a pooled set of Myotis bats. Both groups of bats also showed temporal changes in their habitat use regarding forest age. In June and July, both groups occurred more often in mature than young forests, but from August onwards, the difference in occurrence became less evident in Myotis and disappeared completely in E. nilssonii. In addition, E. nilssonii was more often present in forests with low canopy cover, and its occurrence shifted from coniferous forests to deciduous forests during the season. The results reflect the within-season dynamics of bat communities and their ability to utilize different types of forest as environmental conditions change. Yet, the results most importantly emphasize the importance of mature forests to bat diversity and the need to conserve such environments in the boreal zone.Peer reviewe

Identifying the paths of climate effects on population dynamics: dynamic and multilevel structural equation model around the annual cycle

How environmental factors influence population dynamics in long-distance migrants is complicated by the spatiotemporal diversity of the environment the individuals experience during the annual cycle. The effects of weather on several different aspects of life history have been well studied, but a better understanding is needed on how weather affects population dynamics through the different associated traits. We utilise 77 years of data from pied flycatcher (Ficedula hypoleuca), to identify the most relevant climate signals associated with population growth rate. The strongest signals on population growth were observed from climate during periods when the birds were not present in the focal location. The population decline was associated with increasing precipitation in the African non-breeding quarters in the autumn (near the arrival of migrants) and with increasing winter temperature along the migration route (before migration). The number of fledglings was associated positively with increasing winter temperature in non-breeding area and negatively with increasing winter temperature in Europe. These possible carry-over effects did not arise via timing of breeding or clutch size but the exact mechanism remains to be revealed in future studies. High population density and low fledgling production were the intrinsic factors reducing the breeding population. We conclude that weather during all seasons has the potential to affect the reproductive success or population growth rate of this species. Our results show how weather can influence the population dynamics of a migratory species through multiple pathways, even at times of the annual cycle when the birds are in a different location than the climate signal.</p

Landscape homogenization due to agricultural intensification disrupts the relationship between reproductive success and main prey abundance in an avian predator

Selecting high-quality habitat and the optimal time to reproduce can increase individual fitness and is a strong evolutionary factor shaping animal populations. However, few studies have investigated the interplay between land cover heterogeneity, limitation in food resources, individual quality and spatial variation in fitness parameters. Here, we explore how individuals of different quality respond to possible mismatches between a cue for prey availability (land cover heterogeneity) and the actual fluctuating prey abundance.Peer reviewe

Model processing operations for the unified modeling language

This thesis proposes a set of model processing operations for manipulating architecture and design level software engineering models. The approach draws from well-established and widely used software modeling paradigms like class diagrams, statecharts, and interaction diagrams. The operations are based on the usually implicit dependencies that exist between models describing the same system from different perspectives, at different levels of abstraction or at different phases of evolution. The Unified Modeling Language (UML), as a widely adopted industrial standard providing a common design vocabulary, is chosen as the target modeling language. The thesis outlines categories for model processing operations and defines them based on the UML metamodel. The thesis also studies how to combine the operations to form high-level model processing tasks. The presented operation categories are transformation operations, set operations, projection operations, and conformance operations. The main targets for applying the operations are assumed to be merging, slicing, synthesis, and checking of models. The presented approach aims towards supporting incremental model development, a faster and easier creation of models, improved model consistency and comprehension, and a better customization of model processing tools. The thesis gives example usage scenarios for applying the operations and shows how they can be exploited in practice in the maintenance of real-life product platform architecture. Further, it shows that the operations can be implemented, integrated with a computer aided software engineering environment, and succesfully used during software engineering. The tools and techniques have been implemented and deployed in industrial settings

Model processing operations for the unified modeling language

This thesis proposes a set of model processing operations for manipulating architecture and design level software engineering models. The approach draws from well-established and widely used software modeling paradigms like class diagrams, statecharts, and interaction diagrams. The operations are based on the usually implicit dependencies that exist between models describing the same system from different perspectives, at different levels of abstraction or at different phases of evolution. The Unified Modeling Language (UML), as a widely adopted industrial standard providing a common design vocabulary, is chosen as the target modeling language. The thesis outlines categories for model processing operations and defines them based on the UML metamodel. The thesis also studies how to combine the operations to form high-level model processing tasks. The presented operation categories are transformation operations, set operations, projection operations, and conformance operations. The main targets for applying the operations are assumed to be merging, slicing, synthesis, and checking of models. The presented approach aims towards supporting incremental model development, a faster and easier creation of models, improved model consistency and comprehension, and a better customization of model processing tools. The thesis gives example usage scenarios for applying the operations and shows how they can be exploited in practice in the maintenance of real-life product platform architecture. Further, it shows that the operations can be implemented, integrated with a computer aided software engineering environment, and succesfully used during software engineering. The tools and techniques have been implemented and deployed in industrial settings