Occupancy

About: Occupancy is a research topic. Over the lifetime, 2757 publications have been published within this topic receiving 68288 citations.

Rare or elusive? A test of expert knowledge about rarity of Amazon forest birds

Abstract: Aim To offer a test of expert knowledge about rarity of twenty Amazon forest bird species following an approach that equates rarity with low site occupancy and formally accounts for imperfect species detection. We define ten pairs of closely related species, each pair with one hypothetically common and one hypothetically rare species. Our null hypothesis is that members of each pair have similar occupancy, with hypothesized differences due to detection errors alone. Location A 1000-ha plot of primary rainforest in the central Brazilian Amazon. Methods We visited each of 55 sampling sites multiple times per season for three field seasons and estimated the probability of site occupancy by each species following a maximum likelihood state-space approach that also estimates the probability that a species is present yet undetected at a site. To maximize detection and account for its variation, we employed three different sampling techniques while systematically training and testing observer's ability to recognize species. Results Occupancy estimates agree with expert predictions in all but two species pairs and show no evidence of clear temporal variation in occupancy between sampling seasons. Detection probability had a positive relation with observer ability, a strong relation to time of day across species, and a strong relation with the use of playback for some species. Detection with point counts and with autonomous recorders varied between species pairs. Main conclusions We reject the null hypothesis of equal occupancy within pairs, concluding that expert knowledge on species rarity is useful and worth eliciting. Our results replace qualitative ratings of rarity with statistical estimates of occupancy, establishing a reliable baseline for future comparisons. Besides illustrating the relevance of expert knowledge, this application to Amazonian birds illustrates a flexible approach that can be used for testing knowledge about rarity for a variety of species groups and spatial scales.

Can a Green School Building Teach? A Pre- and Post-Occupancy Evaluation of a Teaching Green School Building:

Abstract: Amid increasing interests in social metrics within green buildings, this work focuses on buildings designed to enhance environmental education, here called “Teaching Green Buildings” (TGBs). This s...

Housing occupancy and the changing size of households and dwellings in New Zealand 1951-1991.

Abstract: Progress across the last 40 years in the housing of New Zealanders is reviewed using both published and unpublished census tabulations and the SUPERMAP2 mapping facility. The topics covered include dwelling occupancy changing dwelling and household size the match between households and dwellings and crowding and its geography in Auckland and Wellington. A number of problems concerning the questions included in the successive censuses of housing are also identified and the importance of a continuing dialogue between researchers and census-takers is stressed. (EXCERPT)

Occupancy and abundance of predator and prey: implications of the fire‐cheatgrass cycle in sagebrush ecosystems

Abstract: Sagebrush (Artemisia tridentata) ecosystems are declining due to biological invasions and changes in fire regimes. Understanding how ecosystem changes influence functionally important animals such as ecosystem engineers is essential to conserve ecological functions. American badgers (Taxidea taxus) are an apex predator and ecosystem engineer in that they redistribute large amounts of soil within sagebrush ecosystems. Piute ground squirrels (Urocitellus mollis) are also an ecosystem engineer as well as an essential prey resource for many predators, including badgers. Our research objective was to evaluate the relative importance of biological invasions and fire, abiotic factors, and biotic factors on badgers and ground squirrels. We sampled 163 1-ha plots during April-June across a gradient of burn histories within a 1962 km2 study area in southern Idaho, USA. At each plot, we characterized occupancy of ground squirrels and badgers and relative abundance of ground squirrels. Additionally, we characterized soil texture, climate, connectivity and dispersal potential, fire frequency, grazing, and cover of many plant species including a highly invasive exotic annual grass (cheatgrass; Bromus tectorum). We used an integrated approach to evaluate competing hypotheses concerning factors influencing occupancy and abundance. Results suggested that occupancy of ground squirrels was positively associated with long-term precipitation, dispersal potential, and fine-grained soil. Abundance of ground squirrels was positively associated with fine-grained soil, but negatively associated with cheatgrass, fire frequency, agriculture, and shrub cover. Badger occupancy was positively associated with ground squirrel occupancy and agriculture, which indicated affinity to prey. Our results provide insight into the relative influence of abiotic and biotic factors on predator and prey, and highlight how effects change across different population parameters. Our research suggests that widespread environmental change within sagebrush ecosystems, especially the fire-cheatgrass cycle (e.g., invasion of cheatgrass and increased fire frequency) and human land disturbances, are directly and indirectly influencing ground squirrels and badgers. However, we also found evidence that efforts to mitigate these stressors, for example, establishing bunchgrasses postfire, may provide targeted conservation strategies that promote these species and thus preserve the burrowing and trophic functions they provide.

Hospital bed occupancy demystified and why hospitals of different size and complexity must run at different average occupancy levels

Abstract: Part one of this series investigated the adequacy o f current models used to forecast bed demand. This part explores the issues surrounding t he correct level of occupancy required to deliver effective and safe health care. Economy of scale as explained by queuing theory is a significant factor in understanding bed occupancy. However, irrespective of the occupancy specific to different sized hospitals an absolute maximum occupancy (even during the winter months) in the range 82% to 85% is required to maintain the level of hospital acquired infection at the minimum possi ble level.