Showing papers on "Occupancy published in 2006"

Occupancy Estimation and Modeling. Inferring patterns and dynamics of species occurrence

Abstract: Numerous studies rely on occupancy or presence/absence data, e.g. understanding and predicting species distribution under diverse scenarios of climatic change and land use, dynamics of fragmented populations and metapopulations, and dynamics of invasive species. While presence/absence data can often be seen as just a simple either/or dichotomy, there is a fundamental asymmetry: we can often be pretty sure that a given species is present after observing it, but being sure of its absence is much more difficult. This book addresses many of the important issues related to this asymmetry and how this should be taken into account to make proper inferences about patterns and processes. To ignore the uncertainty inherent in assessing absence leads to biased conclusions and potentially harmful decisions. The book has 10 chapters focusing on general and specific issues relevant to presence/absence data. The first chapter is a general introduction to scientific approaches in ecological sciences, and the general principles exposed are relevant to most students, researchers and managers, particularly before they embark on their own studies. The second chapter gives details on the various kinds of uses of occupancy data. The third chapter is a quick overview of basic principles of statistical inference, relying on the very extensive experience of the different authors of the book. It strikes a difficult balance among different approaches, and I very much liked the pragmatic view advocated here. The next six chapters focus on increasingly more complicated modelling strategies and designs, starting with models for single species and single seasons (chapters 4 and 5 of which the latter includes heterogeneity in detection probabilities), design considerations for single-season studies (chapter 6), single-species and multiple-seasons studies (chapter 7) and finally studies addressing patterns and processes at the community level (chapters 8 and 9). All chapters include detailed examples, and software exist for implementing most of the analyses described. Chapter 10 looks at a wide range of issues that need to be addressed in future studies, and PhD students looking for interesting topics should definitely read this chapter! I very much enjoyed reading this book. The authors’ unique experience in designing field studies, analysing various data sets, and developing and implementing new statistical methods is clearly reflected in their balanced view throughout this work. What is stressed are principles and models, not 'ready-to-use' recipes. This probably implies a high level of investment on the short-term, but a large benefit on the long-term. Ecology relies increasingly on more sophisticated designs and analytical methods, and this book is a good example of this trend. It can be used both as a classroom textbook and as a useful reference readily available on your bookshelf. The only criticism I could have concerns the topics covered and the restriction to animal populations and communities, clearly many of the ideas and methods discussed are relevant to plant ecologists too!

Estimating Site Occupancy and Detection Probability Parameters for Meso‐ And Large Mammals in a Coastal Ecosystem

Abstract: Large-scale, multispecies monitoring programs are widely used to assess changes in wildlife populations but they often assume constant detectability when documenting species occurrence. This assumption is rarely met in practice because animal populations vary across time and space. As a result, detectability of a species can be influenced by a number of physical, biological, or anthropogenic factors (e.g., weather, seasonality, topography, biological rhythms, sampling methods). To evaluate some of these influences, we estimated site occupancy rates using species-specific detection probabilities for meso- and large terrestrial mammal species on Cape Cod, Massachusetts, USA. We used model selection to assess the influence of different sampling methods and major environmental factors on our ability to detect individual species. Remote cameras detected the most species (9), followed by cubby boxes (7) and hair traps (4) over a 13-month period. Estimated site occupancy rates were similar among sampling methods for most species when detection probabilities exceeded 0.15, but we question estimates obtained from methods with detection probabilities between 0.05 and 0.15, and we consider methods with lower probabilities unacceptable for occupancy estimation and inference. Estimated detection probabilities can be used to accommodate variation in sampling methods, which allows for comparison of monitoring programs using different protocols. Vegetation and seasonality produced species-specific differences in detectability and occupancy, but differences were not consistent within or among species, which suggests that our results should be considered in the context of local habitat features and life history traits for the target species. We believe that site occupancy is a useful state variable and suggest that monitoring programs for mammals using occupancy data consider detectability prior to making inferences about species distributions or population change.

Occupancy-based zoning climate control system and method

Abstract: A control system for managing a heating, ventilating and air conditioning (HVAC) system based on occupancy of an area is provided. The occupancy may be determined by anticipated programming based on time of day zoning, and/or by actual sensed occupancy. In the later, the control system includes an occupancy sensor that communicates with a programmable thermostat. The occupancy sensor is disposed in the area and senses a state of occupancy of the area. The programmable thermostat instructs the HVAC system to adjust the temperature of the area within the structure based on the state of occupancy of that particular area to enhance occupant comfort and energy efficiency. The thermostat may also include programming modes or scripts that may be run to adjust operational control when abnormal occupancy conditions are sensed. Controllable dampers may also be used by the thermostat to achieve micro zoning control of the HVAC system.

Effect of Forest Structure and Fragmentation on Site Occupancy of Bat Species in Missouri Ozark Forests

Abstract: Changes in structure and arrangement of forests may influence the distribution of bat communities by affecting roosting and foraging habitat. Using Anabat bat detectors, we determined presence of bat species at 316 sample plots in southeastern Missouri, USA, through qualitative identification of echolocation calls collected. We used maximum-likelihood estimation techniques incorporating detection probabilities into estimation of site occupancy by species of bats. We compared a priori models at 2 geographic scales using information theoretic methods. At the local-site scale, eastern pipistrelle (Pipistrellus subflavus) and red bat (Lasiurus borealis) occupancy was most influenced by structural characteristics of forested areas, whereas Indiana bats (Myotis sodalis) were influenced most by density of large-diameter snags that could provide roosting habitat. At the landscape scale, occupancy of Indiana bats was directly related to amount of nonforested land cover. Northern long-eared bat (M. septentrionalis) occupancy was inversely related to edge. These data describe implications of forest fragmentation and provide information that can be used when integrating forest-management practices into bat conservation.

The roles of landscape context, niche breadth, and range boundaries in predicting species responses to habitat alteration

Abstract: Extant species in human-dominated landscapes differ in their sensitivity to habitat loss and fragmentation, although extinctions induced by environmental alteration reduce variation and result in a surviving subset of species with some degree of ‘resistance’. Here, we test the degree to which variable responses to habitat alteration are (1) essentially an inherent property of a taxon subject to constraints imposed by its geographical range, as suggested by Swihart et al. (2003), (2) a function of the landscape in which a species occurs, or (3) a function of spatial trends occurring on large scales. We used data collected on 33 vertebrate species during 2001–04 across the upper Wabash River basin, Indiana, in 35 square ‘landscapes’, each 23 km2 in size. Six species of forest rodent, six species of grassland rodents, seven species of bats, eight species of aquatic turtles, and six species of amphibians were sampled at 504, 212, 590, 228, and 625 patches, respectively. The fraction of patches of primary habitat (e.g. forests for tree squirrels, wetlands for aquatic turtles) occupied by a target species was used as a response variable. On a basin-wide scale, 47% of variation in proportional occupancy among species could be explained by taxon-specific variables; occupancy rates were related positively to niche breadth and negatively to the proximity of a geographical range boundary. After controlling for species effects, landscape-level occupancy rates varied significantly for 16 of 33 species, with variation partitioned among landscape variables alone (mean = 11% of variation), spatial trend variables alone (26%), and both variable sets jointly (8%). Among landscape variables, percentage forest cover positively affected occupancy rates of three bat species and a tree squirrel. Variation in occupancy rates among landscapes was consistent with large-scale spatial trends for 13 species. Our findings demonstrate the general importance of niche breadth as a predictor of species responses to habitat alteration and highlight the importance of viewing the effects of habitat loss and fragmentation at multiple spatial scales.

Distributions of habitat suitability and the abundance-occupancy relationship.

Abstract: Positive abundance‐occupancy relationships (a relationship between the number of sites a species occupies and the average density of individuals in occupied sites) are widespread through a range of taxa. The simplest model for this is the “vital rates” model, which proposes that habitat suitability varies spatially; increasing average habitat quality thus leads to simultaneous increases in average densities within occupied areas, as well as the total area that is habitable. This model has not been tested. We develop a general analytical version of this model and show that it predicts that the skewness of population size or aggregation of individuals within sites should vary systematically with density and occupancy, depending on the distribution of habitat suitability, and that the variance in occupancy should be highest at low densities. We compare these predictions with data from the British Trust for Ornithology’s Common Birds Census, and we find systematic changes in both variance and skewne...

Abundance, spatial variance and occupancy: arthropod species distribution in the Azores

Abstract: 1 The positive abundance-occupancy and abundance-variance relationships are two of the most widely documented patterns in population and community ecology 2 Recently, a general model has been proposed linking the mean abundance, the spatial variance in abundance, and the occupancy of species A striking feature of this model is that it consists explicitly of the three variables abundance, variance and occupancy, and no extra parameters are involved However, little is known about how well the model performs 3 Here, we show that the abundance-variance-occupancy model fits extremely well to data on the abundance, variance and occupancy of a large number of arthropod species in natural forest patches in the Azores, at three spatial extents, and distinguishing between species of different colonization status Indeed, virtually all variation about the bivariate abundance-occupancy and abundance-variance relationships is effectively explained by the third missing variable (variance in abundance in the case of the abundance-occupancy relationship, and occupancy in the case of the abundance-variance relationship) 4 Introduced species tend to exhibit lower densities, less spatial variance in these densities, and occupy fewer sites than native and endemic species None the less, they all lie on the same bivariate abundance-occupancy and abundance-variance, and trivariate abundance-variance-occupancy, relationships 5 Density, spatial variance in density, and occupancy appear to be all the things one needs to know to describe much of the spatial distribution of species

A spatially explicit approach to estimating species occupancy and spatial correlation.

Abstract: 1. Understanding and predicting the form of species distributions, or occupancy patterns, is fundamental to macroecology and is dependent on the identification of scaling relationships that underlie the patterns observed. 2. Occupancy-abundance models based on the negative binomial distribution and Taylor's power law are spatially implicit, rather than explicit, as they include no information on the relative positions of individuals. Here we present a spatially explicit model, the spatial scaling occupancy (SSO) model, to estimate species occupancy and spatial correlation, based on join-count statistics, or a pair approximation, approach. This model provides a spatially explicit description of species range size and aspects of range structure. 3. Occupancy data from Drosophilidae species inhabiting a decaying fruit mesocosm were used to test the SSO model. Predictions from the spatially implicit and explicit models were largely equally accurate. The SSO model is thus more efficient as it is less data demanding, and more informative as it provides an estimation of spatial correlation. 4. The results also showed that species distribution patterns differ when examined with spatially implicit vs. explicit approaches; the scaling relationship between occupancy and local density identifies a focal grain for studying the scale-dependent nature of ecological relationships; and the longer the length of the sample edge, the higher the occupancy observed under conditions of spatial aggregation. 5. The SSO model presents a step towards a general scaling model for occupancy, and demonstrates that the inclusion of spatially explicit information in macroecological models warrants further attention.

The effects of survey protocol on detection probabilities and site occupancy estimates of summer breeding anurans

Abstract: Recent declines in amphibian populations have created an urgent need for large-scale, long- term monitoring efforts and many anuran monitoring programs have been established that utilize calling surveys. Calling surveys can be effective monitoring tools; however, differences among survey protocols may bias survey results. Failure to take into account detection probabilities when monitoring anurans can lead to inaccurate inferences about site occupancy, since non-detections in survey data do not necessarily mean that a species is absent unless the probability of detection is 1. We used a likelihood-based method, in the form of the computer program PRESENCE, to estimate detection probabilities and site occupancy rates for summer-breeding anurans in the Western Piedmont of North Carolina. Using detection data from calling surveys, we evaluated how detectability and site occupancy for five anuran species were influenced by 1) time spent listening at each site, 2) number of surveys per site, and 3) sample- and site-specific covariates. We found considerable variation among species with regards to detection probability and site occupancy across survey duration and sampling occasion. Although 13% of all species detection occurred after 3 min, longer surveys did not significantly increase detectability of individual species. We found that detectability varied more with sampling occasion than with survey duration for each species. Covariates had differing effects on occupancy and detectability among individual species. Multiple surveys per site within a season are necessary to eliminate biased detection probabilities, but we found that 3- or 5-min surveys were adequate for detecting all species breeding at the time of the survey.

Optimizing presence-absence surveys for detecting population trends

Abstract: Presence–absence surveys are a commonly used method for monitoring broad-scale changes in wildlife distributions. However, the lack of power of these surveys for detecting population trends is problematic for their application in wildlife management. Options for improving power include increasing the sampling effort or arbitrarily relaxing the type I error rate. We present an alternative, whereby targeted sampling of particular habitats in the landscape using information from a habitat model increases power. The advantage of this approach is that it does not require a trade-off with either cost or the Pr{type I error} to achieve greater power. We use a demographic model of koala (Phascolarctos cinereus) population dynamics and simulations of the monitoring process to estimate the power to detect a trend in occupancy for a range of strategies, thereby demonstrating that targeting particular habitat qualities can improve power substantially. If the objective is to detect a decline in occupancy, the optimal strategy is to sample high-quality habitats. Alternatively, if the objective is to detect an increase in occupancy, the optimal strategy is to sample intermediate-quality habitats. The strategies with the highest power remained the same under a range of parameter assumptions, although observation error had a strong influence on the optimal strategy. Our approach specifically applies to monitoring for detecting long-term trends in occupancy or abundance. This is a common and important monitoring objective for wildlife managers, and we provide guidelines for more effectively achieving it.

Landscape history, fragmentation, and patch occupancy: models for a forest bird with limited dispersal

Abstract: We developed and tested patch occupancy models for an endemic understory bird with limited dispersal ability, the Chucao Tapaculo (Scelorchilus rubecula), in two South American temperate rain forest landscapes that differed in levels and duration of forest loss. We assessed cover changes since 1961 in each landscape and surveyed patches for Chucao Tapaculo occupancy. We then developed incidence-based predictive models independently for each landscape and tested each model reciprocally in the alternative study area. We thereby assessed the domain of model applicability and identified those predictor variables with general effects and those that varied between the two landscapes. The two models were consistent regarding variable selection, and predictive accuracy of each model was high in the landscape where training data were collected. However, the models differed substantially in the magnitudes of effects related to patch size, with larger unoccupied patches observed in the landscape with the more advanced stage of fragmentation. Due to this discrepancy, each model performed poorly when applied to the alternative landscape, potentially reflecting the contrasting stages of habitat loss. Although it was impossible to dissociate effects of level and duration of forest loss, we viewed the landscapes as representing two extremes along a continuum of fragmentation, providing insights into potential trajectories for portions of the biome where deforestation is occurring. Further, our data suggest that static equilibrium models developed from distribution patterns in recently fragmented landscapes may overestimate persistence when used as a forecasting tool, or when extrapolated to alternative landscapes where fragmentation is more advanced. Thus, we suggest that landscapes used as standards for model building should be selected with caution. We recommend that distribution patterns be obtained from landscapes where fragmentation is advanced, preferably with histories of fragmentation long enough that time-delayed extinctions already would have occurred.

Species occupancy and its course in the past: macroecological patterns in extinct communities

Abstract: Questions: What is the shape of occupancy trajectories in fossil organisms? And what is the effect of occupancy on species survival? Data studied: Occupancy and its course through time for a species in extinct large mammal communities from Italy. Search method: We tested if occupancy (the proportion of fossil sites representing a given paleocommunity where a species is present) patterns in extinct communities match a bimodal distribution as in living communities. Then we regressed occupancy on species duration to estimate its effect on long-term survival. We built a null model of random occupancy trajectories and compared it to real data. Conclusions: The occupancy–frequency distribution in extinct communities is either bimodal or right skewed. We found a positive relationship between high occupancy and species survival. We found peaked occupancy trajectories to be the norm for hoofed mammals at least.

Intelligent video for building management and automation

Abstract: A video processing and analysis system is coupled to a building management and control system. The video processing system provides traffic, occupancy, and other information derived from video images of sections of the building and its environs to the building management and control systems. The building systems use this information in a variety of business management applications, including maintenance scheduling, asset replacement, elevator dispatching, HVAC and lighting control, and so on, to reduce operational or maintenance costs, expedite emergency procedures, improve service levels of building facilities, and regulate the building's environmental conditions.

Relationships between distribution and abundance vary with spatial scale and ecological group in stream bryophytes

Abstract: Summary 1. We examined whether the local abundance of stream bryophytes in a boreal drainage basin (Koutajoki system in northeastern Finland) correlated with their: (i) regional occupancy; (ii) provincial distribution in northwestern Europe; and (iii) global range size. We specifically tested whether aquatic and semi-aquatic species differ in their distribution–abundance relationships. We also analysed the frequency distributions of occupancy at two spatial scales: within the focal drainage system and across provinces of northwestern Europe. 2. Regional occupancy and mean local abundance of stream bryophytes were positively correlated, and the relationship was rather strong in aquatic species but very weak in semi-aquatic species. Local abundance was related neither to provincial distribution nor global distribution. 3. Species frequency distributions differed between regional occupancy and provincial distribution. While most species were rare with regard to their regional occupancy within the focal drainage system, most of the same set of species were common and occurred in most provinces in northwestern Europe. 4. The results indicate the presence of dominants (core species) and transients/subordinates (satellite species) among stream bryophytes, highlighting marked differentiation in life-history strategies and growth form. The observed abundance–occupancy relationships suggest that dispersal limitation and metapopulation processes may govern the dynamics of obligatory aquatic stream bryophytes. In semi-aquatic species, however, habitat availability may be more important in contributing to regional occupancy.

Decline in the distribution of the Koala Phascolarctos cinereus in Queensland

Abstract: We assessed decline in the distribution of P. cinereus in Queensland over the last century using historical data from P. cinereus surveys and the Queensland State Archives to measure change in extent of occurrence and area of occupancy. Broad distribution (extent of occurrence, measured with a minimum convex polygon) has contracted by about 27% and area of occupancy (measured with a 30 minute grid) by about 31%. The degree of contraction in area of occupancy correlates with the estimated extent of habitat loss, supporting suggestions that habitat loss has been, and may still be, the major threat to koalas in Queensland. Contraction in the overall range has occurred on the northern and western margins of the distribution (the Wet Tropics, Gulf Plains, Mitchell Grass Downs, and Mulga Lands Bioregions). Distribution showed a latitudinal change during the harvest period in the early 20th century, with an increase in area of occupancy in central Queensland and a decrease in southern and northern Queensland. Th...

Differences in the umbrella effects of African amphibians and mammals based on two estimators of the area of occupancy

Abstract: Conservation organizations are collecting large-scale data regarding distribution and threats to vertebrate taxa. These data sets will enable planners to systematically identify large-scale conservation priorities; however, they will cover only a tiny proportion of living organisms. Therefore, it is essential to investigate to what extent the areas selected for conservation actions can provide protection for other species. We analyzed the umbrella effect between amphibians and mammals across mainland Africa. We built habitat suitability models within the geographic ranges of 1654 species, based on data collected in the framework of the World Conservation Union (IUCN) Global Amphibian Assessment and IUCN Global Mammal Assessment. We applied systematic reserve selection algorithms to two sets of estimators of the area of occupancy of amphibians and mammals (geographic ranges and estimated suitable areas) and thus selected four reserve systems. We then quantified the protection that each of the four systems provided for amphibians and mammals. Reserves selected for amphibians and mammals were comparable in area, with the former concentrated in the Afrotropical region and the latter more evenly dispersed. Mammal reserves left fewer gaps in species coverage among amphibians than the reverse, but amphibian reserves included a larger proportion of each mammal's area of occupancy than the reverse. For both taxa, setting reserves to include estimated suitable areas instead of ranges resulted in the clustering of reserves in the tropics. Furthermore, it efficiently protected hidden gaps (species with unsuitable portions of their range inside protected areas) in the other taxon and included a higher proportion of the area of occupancy of the other taxon. Overall, amphibians and mammals in Africa acted as an umbrella for a high proportion of species in the other taxon. Focusing on estimated suitable areas instead of ranges improved the umbrella effect of both taxa.

The Multispace adaptable building concept and its extension into mass customisation

Abstract: UK government Policy Planning Guidance promotes optimum use of the existing building stock through mixed use in urban centres and encourages conversion of redundant office and retail space into leisure, service or residential uses. Whilst social pressures are evident in the push to more effectively utilise existing building stock, new building stock also has to meet the commercial requirements of the client, which often translates into maximum occupancy of the building. This is encouraging greater innovation in the design of new buildings to allow change of use throughout the structure’s lifetime. This paper describes the concepts surrounding an adaptable design for new buildings, along with a review of factors influencing the mode of use. The major physical parameters of storey height, building proximity, plan depth, structural design, services, fire safety, cladding and noise abatement are evaluated in the context of adaptable building use. In addition to improved building utilisation, the UK government has identified a weakness in the productivity of the construction industry. The report ‘Rethinking Construction’ (Egan, 1998) suggested that up to 80% of inputs into buildings are repeated and that parallels should be drawn with the designing and planning of new cars in the automotive sector. This suggests that improvements in quality, cost and delivery time of new structures could be achieved through mass-customisation incorporating a significant element of pre-design.

Factors influencing territorial occupancy and reproductive output in the Booted Eagle Hieraaetus pennatus

Abstract: During a 7-year research project in a forested area of southeastern Spain, we studied territorial occupancy and reproductive success in a Booted Eagle Hieraaetus pennatus population. We monitored 65 territories, gathering information on 406 occupancy events and 229 breeding attempts, including those of two potential competitors, the Northern Goshawk Accipiter gentilis and the Common Buzzard Buteo buteo. Generalized linear mixed models were used to explain occupancy and productivity, by evaluating the relative contribution of three different types of variables (habitat, competition and past events) and considering territory as a random effect. We examined a set of a priori hypothesized models, together with a number of additional models, and selected the best models following an information-theoretic approach. Our best models related territorial occupancy and productivity to previous breeding success (the fledging of one or two young), which appeared to be the most important factor determining the probability of reoccupation and the reproductive output in the subsequent year. The best occupation model revealed that the probabilities of occupancy were also conditioned by a competition variable (intraspecific nearest-neighbour distance) and two habitat variables (the location of the nest on the valley slope and the distance to the nearest forest track). Unlike the best occupation model, however, the selected model for reproductive output did not incorporate any competition variable besides previous breeding success, but included another two habitat variables (the effects of trunk height and NNE orientation).

Temporal dynamics and nestedness of an oceanic island bird fauna

Abstract: Aim To examine temporal variation in nestedness and whether nestedness patterns predict colonization, extinction and turnover across islands and species. Location Dahlak Archipelago, Red Sea. Method The distributions of land birds on 17 islands were recorded in two periods 30 years apart. Species and islands were reordered in the Nestedness Temperature Calculator, software for assessing degrees of nestedness in communities. The occupancy probability of each cell, i.e. species–island combinations, was calculated in the nested matrix and an extinction curve (boundary line) was specified. We tested whether historical and current nested ranks of species and islands were correlated, whether there was a relationship between occupancy probability (based on the historical data) and number of extinctions or colonizations (regression analyses) and whether the boundary line could predict extinctions and colonizations (chi-square analyses). Results Historical and current nested ranks of islands and species were correlated but changes in occupancy patterns were common, particularly among bird species with intermediate incidence. Extinction and turnover of species were higher for small than large islands, and colonization was negatively related to isolation. As expected, colonizations were more frequent above than below the boundary line. Probability of extinction was highest at intermediate occupancy probability, giving a quadratic relationship between extinction and occupancy probability. Species turnover was related to the historical nested ranks of islands. Colonization was related negatively while extinction and occupancy turnover were related quadratically to historical nested ranks of species. Main conclusions Some patterns of the temporal dynamics agreed with expectations from nested patterns. However, the accuracy of the predictions may be confounded by regional dynamics and distributions of idiosyncratic, resource-limited species. It is therefore necessary to combine nestedness analysis with adequate knowledge of the causal factors and ecology of targeted species to gain insight into the temporal dynamics of assemblages and for nestedness analyses to be helpful in conservation planning.

Wavelet Occupancy Grids: A Method for Compact Map Building

Abstract: This paper introduces the structure of wavelet occupancy grids (WavOGs) as a tool for storing occupancy grids in a compact way. We have shown that WavOGs provide a continuous semantics of occupancy through scaled spaces. In accordance with the theoretical properties of wavelets, our experiments have validated that WavOGs allow major memory gains. WavOG as a compact multi-scaled tool provides an efficient framework for the various algorithms that use OGs such as robot navigation, spatio-temporal classification or multiple target-tracking. In future works we plan to apply WavOGs to the monitoring of urban traffic over large areas.

Office building characteristics and the links with carbon emissions

Abstract: Purpose – The purpose of this paper is to present research which analysed energy consumption in the Melbourne central business district (CBD) office stock and examined all buildings to identify CO2 emissions in 2005. The rationale was that, by profiling a large group of buildings, it would be possible to identify characteristics of the stock. For example, do older buildings typically emit more CO2 per square metre than newer buildings?Design/methodology/approach – This research conducted a detailed analysis of all Melbourne CBD office stock to identify which patterns and trends emerged regarding building characteristics and carbon emissions. The study examined variables such as building size, number of employees, occupancy levels, physical characteristics and building age.Findings – By examining all office stock and aggregating data, the results confirm that it is possible to identify general physical building characteristics and carbon emissions. This research confirmed that clear relationships existed w...

The trend of golden eagle territory occupancy in the vicinity of the altamont pass wind resource area: 2005 survey

Abstract: ................................................................................................ iv Executive Summary ................................................................................. 1

Fire in the boreal forest: Proximate effects on reproduction and long-term consequences for territory occupancy of American kestrels

Abstract: There is currently a great deal of interest in documenting habitat use of birds in the boreal forest, especially in response to disturbances such as harvesting and forest fires. Studies have shown that some avian species are much more common in recently burned areas, whereas others are absent. Despite this, we know little about the immediate effect of a large forest fire, and its considerable alteration of habitat, on birds during a single breeding season. In 1995, a 72,000-ha forest fire in our study area gave us the opportunity to assess the effects of fire on reproduction of American kestrels (Falco sparverius) in comparison to an adjacent control area. In addition, we also examined territory occupancy by kestrels in the burned and control areas 8 y following the fire. We found no immediate effect of the fire on body condition of adult kestrels, their ability to hatch eggs, or to fledge at least one young. Birds breeding in the area that burned, however, did fledge fewer offspring per nest, and these nestlings had reduced body mass compared to control nests, possibly because of an immediate reduction in available prey following the fire. Nonetheless, given the profound alteration of habitat following the fire, the fact than any birds remained to continue breeding is remarkable. Territory occupancy of the burned area in 2003 was similar to 1995, the year of the fire, but occupancy in the adjacent control area declined during this period. It therefore appears that the control area is becoming a less suitable habitat for kestrels as the forest continues to mature, whereas the burned area is still providing viable habitat for kestrels. We present evidence suggesting that some of the differences in occupancy between the control and burned area may be due to fewer nest predators in the burned area in 2003.

Occupancy level and productivity in rural tourism establishments: the case of Galicia, Spain

Abstract: The degree of capacity utilization affects the measurement of total productivity. This paper uses establishment occupancy level as a proxy for establishment capacity utilization. Accordingly, the authors decompose total factor productivity (TFP) growth into technical progress, changes in allocative efficiency, changes in occupancy levels, changes in technical efficiency and scale effects. The empirical results show that the occupancy level component offers the most important contribution to TFP. Policy implications are offered in light of the results.

Occupancy Estimation and Modeling

Abstract: Abstract The following critiques express the opinions of the individual evaluators regarding the strengths, weaknesses, and value of the books they review. As such, the appraisals are subjective assessments and do not necessarily reflect the opinions of the editors or any official policy of the American Ornithologists' Union.