No description available.

Thesis (M.S.) -- University of Montana, 2008. / Title from author supplied metadata. Description based on contents viewed on May 15. Author supplied keywords: habitat selection, porcupine. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Abstracted in Dissertation abstracts, v. 16 (1956) no. 11, p. 1994-1995. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 155-157).

The emission of the telemetry signal is required over minimum two different antennas to keep the telemetry link available during a maneuver of a flying object. If nothing is made at the transmitter side, the telemetry link can be fully lost as both signals may have an opposite phase. This is the well-known “2-antennas problem”, also known as the “porcupine effect”. In 2016, Zodiac Data Systems (ZDS) presented a pragmatic and cost effective concept named eXtended Time Diversity (XTD) which is dedicated to combat the porcupine effect. The efficiency of this concept was demonstrated through lab tests, as well as its robustness in presence of multipath. The goal of this paper is to present the performance of the Extended Time Diversity in real conditions, after a series of flight tests.

The study, extending over two summers a and one uni­versity year, was an endeavour 1) to determine the existence and nature of an innate activity pattern in porcupines under laboratory conditions, 2) to determine the behaviour of por­cupines in their natural habitat, 3) to compare field and laboratory data on the behaviour of the porcupine and 4) to determine the home range of the porcupine. / Thesis / Master of Science (MS)

Several aspects of kokanee (Onchorhynchus nerka) ecology were studied in the fluctuating, 80ha Porcupine Reservoir, Utah in order to determine optimum management strategies. In 1981, escapement was enumerated and estimates of egg deposition were made . An estimate of the resulting fry recruitment was also attempted and was successful up to the arrival of spring runoff. In 1982, escapement was enumerated and estimates of egg deposition were made, with subsequent estimates of egg deposition and percent survival to the advanced eyed stage. Age and growth rates were determined and survival rates estimated. Escapement for 1981 and 1982 was 5,463 and 7,113 kokanee, respectively, depositing an estimated 1,843,955 and 2,393,757 eggs, respectively._ The estimated fry recruitment to the reservoir for the 1981 spawning run was 57,000 fish up to the arrival of spring runoff and appeared to be only a fraction of the total number of fry in the river. From the 1982 spawning run, an estimated 2,265,507 eggs were actually deposited, of these an estimated 64.2% or 1,457,599 eggs were fertilized and survived to the advanced eyed stage. Kokanee growth rates were good. Fish mature and spawn at 34 months of age at an average total length of 364mm. Twelve month old kokanee average 124mm and 24 month old fish 257mm. The kokanee population continues to grow but at a decreasing rate and survival rates are declining. For every kokanee that estimated 8.2 progeny survived to spawn spawned in 1972, an in 1975 and for every spawning kokanee in 1979 an estimated 3.0 progeny survived to spawn in 1982. The kokanee is presently underharvested and appears to be at or near the carrying capacity of the reservoir. In order to acheive an optimum sustainable yield the spawning population should be reduced and maintained at approximately 2,000 fish ( 1,000 redds).

No description available.

A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.

A 4-year study was conducted on the Missouri Coteau in the Mixed Grassland Ecoregion of Saskatchewan to determine the effects of mowing to a 7.5 cm stubble height on the growth of <i>Festuca hallii</i> (Vasey) Piper and <i>Stipa curtiseta</i> (A.S. Hitch.) Barkworth. Green standing crop (GSC), dead standing crop (DSC) and above ground net primary production (ANPP) were compared to an unmowed control after a single mowing in April, May, June, July, August, September, October or November on 5 landforms including north aspect-concave-slope, north aspect-convex-slope, south aspect-concave-slope, south aspect-convex-slope and level upland. Mowing reduced GSC, DSC and ANPP with reductions varying among months of mowing and among landforms. Green standing crop, DSC and ANPP of <i>F. hallii</i> were greatest on the north aspects and least on south aspect-convex slope and ranged from 2 to 122 g m-2, 3 to 121 g m-2, and 8 to 122 g m-2, respectively. Mowing reduced GSC of <i>F. hallii</i> for 1 to 11 growing season months and DSC for 1 to >11 growing season months. Mowing in May or November reduced ANPP of <i>F. hallii</i> for 1 growing season, while mowing in other months reduced ANPP for 2 growing seasons. Green standing crop of <i>S. curtiseta</i>, ranging from 3 g m-2 to 55 g m-2, was least on the north aspects and greatest on the south aspect-convex slope and was reduced 1 to 5 growing season months following mowing. Mowing after June reduced DSC of <i>S. curtiseta</i>(5 to 58 g m-2) for 1 to 10 growing season months, and ANPP (6 to 64 g m-2) for 1 growing season. Generally, mowing reduced GSC, DSC and ANPP of <i>F. hallii</i> longer than <i>S. curtiseta</i>. Production of <i>F. hallii</i>- and <i>S. curtiseta</i>-dominated plant communities in the Northern Mixed Prairie will be maintained by providing rest periods between defoliation events based on the number of growing season months for <i>F. hallii</i> to recover production.

Hierarchical habitat selection was studied in the North American porcupine (Erethizon dorsatum) in Parc National du Bic, Quebec, Canada. To establish the study population, 150 porcupines were captured and immobilized using a mixture of ketamine and xylazine. Different drug doses and injection techniques were tested. Best results were obtained by injecting in the tail muscles, which allowed a 50% reduction in dose relative to reported dosage. Hierarchical analysis of habitat selection revealed that although porcupines are generalists at the landscape scale, they display habitat selection at the home range and individual tree scales. Human-used land and conifer forests were least preferred features of home ranges. Trembling aspen was found to be preferred over other deciduous trees, except for fruit-producing trees, which came out as being even more preferred at the tree scale. This study shows the importance of a multi-scale approach that includes fine-scale selection.