Occupancy

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

Changes in occupancy, niche breadth and abundance of three Gyrinus species as their respective range limits are approached

Abstract: Three widely distributed Gyrinus species were studied in seven different habitat types over a wide range of latitudes in northern Europe. All three species have a broad habitat range and are opportunistic exploiters of temporary and fluctuating habitats. The distribution range of the two southern species, G. natator and G. substriatus, overlaps with that of the boreal-subarctic G. opacus in south-central Sweden, creating an inland area of sympatry, where all three species coexisted in 10% of the waters sampled. For the two southern species occupancy increased with distance from their respective range limits. The occupancy level of G. opacus in its southernmost inland zone was higher than those of the other two species in their respective northernmost zones. Levels of maximum occupancy were similar for all species. Patterns of habitat occupancy partly differed within and between species. Although temporary pools, which represented the most unpredictable habitat, were highly frequented in the south by G. substriatus, occupancy levels associated with them declined sharply before reaching the northern range limit. The niche breadth of the two southern species increased as the distance from their respective northern range limits increased and was broadest for G. substriatus in southern Sweden, north of its geographical range centre (southern Poland), where pollution has no doubt severely affected the original distribution. The habitat range of G. opacus did not change as its southern range limit was approached, but fewer habitat types appeared to be used in the very far north. Abundance of all three species in temporary pools increased with distance from their respective range limits, and there was a regional correlation between occupancy and abundance for G. substriatus and G. natator in this habitat.

DA-HOC: semi-supervised domain adaptation for room occupancy prediction using CO 2 sensor data

Abstract: Human occupancy counting is crucial for both space utilisation and building energy optimisation. In the current article, we present a semi-supervised domain adaptation method for carbon dioxide - Human Occupancy Counter (DA-HOC), a robust way to estimate the number of people within in one room by using data from a carbon dioxide sensor. In our previous work, the proposed Seasonal Decomposition for Human Occupancy Counting (SD-HOC) model can accurately predict the number of individuals when the training and labelled data are adequately available. DA-HOC is able to predict the number of occupancy with minimal training data, as little as one-day data. DA-HOC accurately predicts indoor human occupancy for a large room using a model trained from a small room and adapted to the larger room. We evaluate DA-HOC with two baseline methods - support vector regression technique and SD-HOC model. The results demonstrate that DA-HOC's performance is better by 12.29% in comparison to SVR and 10.14% in comparison to SD-HOC.

Influence of fire and salvage logging on site occupancy of spotted owls in the San Bernardino and San Jacinto Mountains of Southern California

Abstract: Fire over the past decade has affected forests in the San Bernardino Mountains of southern California, providing an excellent opportunity to examine how this disturbance, and subsequent post-fire salvage logging, influenced California spotted owl (Strix occidentalis occidentalis) breeding-season site occupancy dynamics there and in the nearby San Jacinto Mountains. Using occupancy survey data from 2003 to 2011 for all-detections and pairs-only data, we estimated annual extinction and colonization probabilities at 71 burned and 97 unburned breeding-season sites before and after fire, while controlling for confounding effects of non-fire-related temporal variation and among-site differences in habitat characteristics. We found no statistically significant effects of fire or salvage logging on occupancy dynamics of spotted owls of southern California. However, we found some evidence that fire and logging effects could be biologically meaningful. For pairs data, the model-averaged mean of fire-related effects on colonization and extinction probabilities resulted in a 0.062 lesser site-occupancy probability in burned sites 1-year post-fire relative to unburned sites. Post-fire salvage logging reduced occupancy an additional 0.046 relative to sites that only burned. We documented a threshold-type relationship between extinction and colonization probabilities and the amount of forested habitat (conifer or hardwood tree cover types) that burned at high severity within a 203-ha core area around spotted owl nests and roost centroids. Sites where approximately 0–50 ha of forested habitat within the core area burned at high severity had extinction probabilities similar to unburned sites, but where more than approximately 50 ha of forested habitat burned severely, extinction probability increased approximately 0.003 for every additional hectare severely burned. The majority (75%) of sites burned below this threshold. Sites where high-severity fire affected >50 ha of forested habitat could still support spotted owls, so all burned sites should be monitored for occupancy before management actions such as salvage logging are undertaken that could be detrimental to the subspecies. We also recommend that managers strive to reduce human-caused ignitions along the wildland–urban interface, particularly at lower elevations where owl sites are at higher risk of extinction from fire. © 2013 The Wildlife Society.