For more than three and one-half years a study was made of the amount of locomotor activity of the northern flying squirrel, Glaucomys sabrinus (Shaw). These nocturnal animals were studied in captivity under both natural climatic (outdoor) and controlled artificial (indoor) environmental conditions. Over a sixteen month period, 1285 observations were made under all kinds of weather upon the time at which flying squirrels became active. The average "awakening" time was 35.4 minutes after sunset. Spontaneous locomotor activity, of both individual and groups of flying squirrels, were recorded under natural climatic conditions by means of activity wheels, a treadle-board activity recorder, and an electronic vibration amplifier. Under these outside conditions an inverse relationship exists between the level of activity and the intensity of the nocturnal illumination. Locomotor activity was at a high level between the last and first quarter phases of the moon and declined markedly at full moon, or just afterwards. The relationship appeared to be unaltered by temperature, vapor pressure, the season, or the sex of the animal. The internal physiological "clock" governing this activity cycle persisted even after nine months under constant environmental conditions in which only the light was manipulated to produce 2-3 month periods of continuous light, continuous darkness, or light-dark periods in normal or reversed sequences. In later experiments manipulation of artificial moonlight was used to produce in the animals cycles of activity corresponding to lunar cycles of normal duration and lengthened cycles of 40-days duration or shortened cycles as brief as 7-days in duration. Under 8-hours light and 8-hours darkness (a 16-hour day instead of a 24-hour day), responsiveness differed markedly from the previous experiments i. e. the animals became almost as active under illumination as under darkness. Only after two months under these conditions did daylight activity begin to decline. Whether or not the animals could eventually adapt to a 16-hour day was not determined. This study reveals a series of inherent physiological controls within the animal which govern the level of the spontaneous activity under varying natural climatic conditions and under controlled artificial experimental conditions. The flying squirrel is sensitive to slight changes in light intensity during the dark periods. By observing the responses to varying environmental photoperiods, an attempt was made to understand the inherent rhythms of activity of this species--whether these should be neural, endocrinological, or both. Most nocturnal animals respond mainly to olfactory stimuli. The activity of the flying squirrel is shown by this study to be intimately determined by illumination. / Science, Faculty of / Zoology, Department of / Graduate

Although scale is consistently identified as the central problem in ecology, empirical examinations of its importance in ecological research are rare and fundamental concepts remain either largely misunderstood or incorrectly applied. Due to the mobile and wide-ranging nature of wildlife populations, species-habitat modeling is a field in which much proliferation of multi-scale studies has occurred, and thus provides a good arena within which to test both scale theory and its application. Insufficient examination of a relevant breadth of the scale continuum could be an important constraint in all multi-scale investigations, limiting our understanding of scalar concepts overall. Here I examine several concepts of ecological scale by studying free-ranging populations of northern flying squirrels (Glaucomys sabrinus), purported to be a keystone species in northern forests. Coarse-grain digital forest coverage revealed that flying squirrels in the boreal and foothills of Alberta were not conifer specialists, rather forest generalists regarding stand type and age. Lack of coarse-grain scale effects led me to examine fine-grain data, including an assessment of scale domains using a novel continuum approach. Fine-grain data revealed important scale-related biases of trapping versus telemetry, namely that, at fine-grain scales, different habitat associations could be generated from the same data set based on methods alone. Then, focusing on spatial extent, I develop a true multi-scalar approach examining scale domains. First, I quantify only forest attributes across multiple extents, and demonstrate unpredictable scale effects on independent variables often used in species-habitat models. Second, including both independent (habitat) and dependent (squirrel telemetry) variables in the same approach, I demonstrate that the relative ranking and strength-of-evidence among different species-habitat models change based on scale, and this effect is different between genders and among life-history stage (i.e., males, females, and dispersing juveniles). I term this the “continuum approach”, the results of which question the validity of many published species-habitat models. Lastly, I attempt to clarify why existing models should be scrutinized by reviewing common rationales used in scale choice (almost always arbitrary), outlining differences between “observational scale” and the commonly cited “orders of resource selection”, and making a clear distinction between multi-scale versus multi-design ecological studies. / Graduate

<p>Red spruce forests, one of the most critically endangered ecosystems in the United States</p>provides critical habitat for several endemic species or subspecies of the Appalachian Mountains, including the Virginia northern flying squirrel. Once listed as threatened under the Endangered Species Act, the Virginia northern flying squirrel was delisted in 2013. Managers are currently focusing their efforts on projects that increase the extent and connectivity of the squirrel’s habitat through red spruce restoration. At present, there is a paucity of available data to assess the implications of the silvicultural activities associated with red spruce restoration on the movement and occupancy of the Virginia northern flying squirrel. In order to inform management activities, I measured home range, fine-scale habitat use, and estimated detection and occupancy for northern flying squirrels across a gradient of red spruce stands in the Monongahela National Forest. I concluded that home ranges for northern flying squirrels within this region are comprised primarily of red spruce and that northern flying squirrels were selecting larger diameter trees compared to the nearest available neighbor. Additionally, I found that microhabitat characteristics alone did not sufficiently predict northern flying squirrel occupancy and that acoustic methods for surveying northern flying squirrels will require further refinement. Future research efforts should focus on a combination of landscape-level and microhabitat covariates to best predict occupancy of this species across the landscape. Future red spruce management should be approached with caution regarding the potential impact on northern flying squirrel habitat in the short-term. I recommended using spatially-explicit modeling to assess the long-term effects of proposed red spruce restoration projects on northern flying squirrel population demographics, dispersal, and metapopulation connectivity prior to the implementation of silvicultural treatments.

The Virginia northern flying squirrel (Glaucomys sabrinus fuscus) and the Carolina northern flying squirrel (G. s. coloratus) are geographically isolated subspecies of the northern flying squirrel found in montane conifer-northern hardwood forests the Appalachian Mountains of the eastern United States. Both subspecies were listed under the Endangered Species Act in 1985 as endangered, and accordingly, the Virginia northern flying squirrel and the Carolina northern flying squirrel are considered high conservation priorities by state and federal agencies. Although the listing prompted work to determine the broad distribution and habitat associations of both subspecies, numerous data gaps remain, particularly with regard to habitat management and development of efficient monitoring techniques. Regional interest in restoration of red spruce (Picea rubens) forests in the central and southern Appalachian Mountains, considered to be the flying squirrels' primary habitat, increases the importance of understanding habitat selection and managers' ability to detect squirrels at multiple spatial and temporal scales. I compared two novel survey techniques (ultrasonic acoustics and camera trapping) to a traditional technique (live trapping) to determine which method had higher probability of detection (POD) and lower latency to detection (LTD, number of survey nights to initial detection) of northern flying squirrels in the region. Both novel techniques performed better than the traditional techniques with higher POD and lower LTD. I found that ultrasonic acoustics and camera trapping had similar POD, whereas LTD was significantly lower with ultrasonic acoustics versus camera trapping. Additionally, the ability to distinguish between northern flying squirrels and the parapatric southern flying squirrel (G. volans) also is possible with ultrasonic acoustics, but not with camera trapping. This ultimately makes ultrasonic acoustics the most effective and efficient method to obtain detection/non-detection data. To better inform management decisions and activities (i.e., red spruce restoration), this method should be used in conjunction with existing traditional monitoring techniques that provide demographic data such as nest boxes. I assessed habitat selection of radio-collared Virginia and Carolina northern flying squirrels at multiple spatial scales with use-availability techniques. I analyzed field data from paired telemetry and random points and determined Virginia northern flying squirrels microhabitat (within-stand habitat) selection showed preference for conifer-dominant stands with deep organic horizons, a factor that might be directly linked to food (hypogeal fungi) availability. Similar to previous studies on the Virginia northern flying squirrel on the landscape- and stand-level using Euclidean distance based analysis, Carolina northern flying squirrels also selectively preferred montane conifer forests in greater proportion than their availability on the landscape. Additionally, Carolina northern flying squirrels did not select for or against northern hardwood forests regardless of availability on the landscape. Habitat preference of both subspecies indicates that red spruce restoration activities may be important for the persistence of Appalachian northern flying squirrels into an uncertain future, as anthropogenic climate change may cause further reduction of the quality and extent of high-elevation montane conifer forests in the region. / Ph. D.