THE DISTRIBUTION AND LIFE HISTORIES OF THE CADDIS FLIES OF WASKESIU LAKE, SASKATCHEWAN

1943 ◽  
Vol 75 (10) ◽  
pp. 191-198 ◽  
Author(s):  
D. J. Milne

A study of the caddis flies of Waskesiu Lake was carried out during the summer of 1940 as part of the general program of limnological investigations which have been conducted in Prince Albert National Park, Saskatchewan, since 1928. The importance of caddis flies in the ecology of the lake had been recognized since they provide much food for fish in the near shore reginn.

Author(s):  
Richard K.F. Unsworth ◽  
James J. Bell ◽  
David J. Smith

The present study considered the influence of the tide on shallow water fish assemblages within the Wakatobi Marine National Park, Indonesia. Timed underwater visual observations were made across a gradient of intertidal to subtidal habitats from near-shore to reef crest at different tidal heights. Transient fish were found to dominate shallow water fish assemblages and the assemblage composition varied with tidal state. Fish assemblages were more diverse and abundant at higher tides in both coral and sea grass habitats, however, this was more pronounced within sea grass habitats. A tidal reduction from ≈2.0m to ≈0.8m (above chart datum) corresponded to a 30% reduction in fish abundance, while species richness also significantly decreased from 13.5 to 10.8 species per standardized timed observation. Fifty fish groups were reported from sea grass habitats with the most abundant being from the Engraulidae family and Lethrinus harak, which form important local subsistence fisheries. This research confirms the importance of tidal changes in structuring the fish fauna of Indonesian sea grass habitats and underlines the connectivity that exists between these habitats and nearby coral reefs.


2013 ◽  
Vol 127 (1) ◽  
pp. 50 ◽  
Author(s):  
Digit D. Guedo ◽  
Eric G. Lamb

Encroachment into grassland by woody species is a global ecological phenomenon, and it is of particular concern in remnant fescue (Festuca) prairie at the aspen parkland–boreal forest ecotone. Fire suppression is thought to encourage encroachment; however, prescribed burning as a means of controlling encroachment and restoring system structure, function, and composition has had variable success. The objective of this study was to determine the effects of different season of burn, number of annual burns, and number of years after burning treatments on Trembling Aspen (Populus tremuloides) encroachment into the fescue grasslands within Prince Albert National Park, Saskatchewan. Temporal changes in density and cover of Trembling Aspen in grassland and grassland–forest transition plant communities were evaluated using data from a prescribed burn study conducted in Prince Albert National Park from 1975 to 2010. The effect of year (indicating varying amounts of time relative to prescribed burning) and the interaction between spring burning and year reflect a stimulatory effect of burning on Trembling Aspen suckering. Increased Trembling Aspen cover in the forest transition community with more annual burns, burning in the fall, and the interaction between year and number of annual burns and increased Trembling Aspen cover in the grassland community with year indicate that none of the treatments had lasting control of Trembling Aspen encroachment. Ongoing Trembling Aspen encroachment despite prescribed burning may be due to important missing interactions between fire and grazing. A change in the use and expectation of prescribed burning is needed when attempting to suppress Trembling Aspen encroachment into the fescue grasslands.


2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Justin R Shave ◽  
Andrew E Derocher ◽  
Seth G Cherry ◽  
Gregory W Thiemann

Abstract Chronic stress and poor body condition can cause adverse physiological and behavioural responses and may make animals more vulnerable to predation. We examined hair cortisol concentration (HCC) and marrow lipid content, as bioindicators of chronic stress and body condition, respectively, of bison (Bison bison bison), moose (Alces alces) and white-tailed deer (Odocoileus virginianus) killed by wolves (Canis lupus) in Prince Albert National Park (PANP), Saskatchewan, Canada. The Sturgeon River plains bison population in PANP is one of only a few wild populations of plains bison in their historical range in Canada and has experienced a decline of around 50% since 2005. We expected wolf-killed bison to have elevated HCC compared to human-harvested bison and that there would be a negative relationship between HCC and marrow lipids among wolf-killed animals. We compared HCC between different mortality sources for bison (wolf-killed n = 20 or human-harvested n = 23) and found that HCC was significantly elevated in wolf-killed bison (̄ = 7.56 ± 1.35 pg/mg). We found that HCC, species, sex and snow depth were all significant predictor variables of marrow lipid content of bison (n = 14), moose (n = 11) and deer (n = 27). Bison displayed the strongest negative correlation between HCC and marrow lipid content (r2 = 0.31). Our results suggest that chronic stress and poor body condition make prey more vulnerable to predation by wolves. HCC and marrow lipid content can provide reliable indicators of the physiological response of animals to stressors and may provide information on expected predator success that can be used to predict predator population dynamics.


Oryx ◽  
2000 ◽  
Vol 34 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Anna. M. Whitehouse ◽  
Anthony. J. Hall-Martin

AbstractThe history of the Addo elephant population in South Africa, from the creation of the Addo Elephant National Park (AENP) in 1931 to the present (every elephant currently living within the park is known), was reconstructed. Photographic records were used as a primary source of historical evidence, in conjunction with all documentation on the population. Elephants can be identified in photographs taken throughout their life by study of the facial wrinkle patterns and blood vessel patterns in their ears. These characteristics are unique for each elephant and do not change during the individual's life. The life histories of individual elephants were traced: dates of birth and death were estimated and, wherever possible, the identity of the individual's mother was ascertained. An annual register of elephants living within the population, from 1931 to the present, was compiled, and maternal family trees constructed. Preliminary demographic analyses for the period 1976–98 are presented. The quantity and quality of photographs taken during these years enabled thorough investigation of the life histories of all elephants. Prior to 1976, insufficient photographs were available to provide reliable data on the exact birth dates and mothers' identities for every calf born. However, data on annual recruitment and mortality are considered sufficiently reliable for use in analyses of the population's growth and recovery.


Blue Jay ◽  
1971 ◽  
Vol 29 (3) ◽  
Author(s):  
J. A. Wedgwood ◽  
M. Belcher

2009 ◽  
Vol 87 (7) ◽  
pp. 642-647 ◽  
Author(s):  
Tina M.J. Giroux ◽  
Douglas P. Chivers ◽  
Michael J. Fitzsimmons ◽  
Neil B. Chilton

Genetic diversity of the remnant population of lake trout ( Salvelinus namaycush (Walbaum in Artedi, 1792)) in Crean Lake was compared with that for two other populations in the Prince Albert National Park (PANP) using single-strand conformation polymorphism (SSCP) and DNA sequencing analyses of two mtDNA genes. Although there was no sequence variation among individuals for nad5, six different nad2 haplotypes were detected. The Crean Lake population had the least number of haplotypes and lowest nucleotide variation. Also, one common nad2 haplotype in Crean Lake was not detected in the other populations. The results suggest that introductions of lake trout from Wassegam Lake into Crean Lake were unsuccessful with respect to the establishment and (or) reproduction of the stocked fish. Conservation of the remnant population of lake trout in Crean Lake is important because it is genetically distinct from other populations within PANP and in adjacent areas.


2013 ◽  
Vol 89 (05) ◽  
pp. 664-674 ◽  
Author(s):  
Åsa Almstedt ◽  
Maureen G. Reed

Planning for and managing disturbances in protected areas requires governance arrangements that are both adaptive to changing conditions and effective in dealing with multiple challenges. This paper presents a framework composed of principles and criteria of good and adaptive governance that pays attention to inclusiveness, responsibility, fairness, strategic vision, performance orientation, and adaptiveness. The framework was empirically tested on fire management planning in Prince Albert National Park, Saskatchewan, Canada, involving interactions between Parks Canada and Saskatchewan Environment. Our results suggest that while the principle of performance orientation was upheld, principles such as inclusiveness and adaptiveness were only partially supported. Additional testing beyond fire management planning can help determine the utility of the framework for other environmental management situations.


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