Survival of embryos, tadpoles, and adults of the frogs Rana aurora aurora and Rana pretiosa pretiosa sympatric in southwestern British Columbia

1974 ◽  
Vol 52 (5) ◽  
pp. 613-627 ◽  
Author(s):  
Lawrence E. Licht

Field survival of embryos, tadpoles, and adults of Rana aurora and Rana pretiosa sympatric in marshes near Vancouver, British Columbia, was studied.Embryonic survival for R. aurora was 90% and better, whereas for R. pretiosa it was about 70%. As well, in dry periods during breeding, R. pretiosa embryos face the danger of desiccation and extensive or complete mortality.Survival of tadpoles of both species in a pond breeding site studied was less than 1% in 1968. By the end of the season of transformation, there was about 5% survival of young-of-the-year frogs of both species from the initial number of eggs deposited in river breeding sites.After the end of the first full year of life (1969), there was a minimal survival of 2.5% for R. aurora and 3.5% for R. pretiosa from the eggs laid the year before. By the end of 1969, there was a 52% survival of R. aurora and 67% of R. pretiosa which metamorphosed in 1968.For R. pretiosa adults, there was a 64% survival between 1968 and 1969; males suffered higher mortality than females. The survival of adult R. aurora was 69% between 1968 and 1969.Factors influencing mortality are discussed, and the conclusion is reached that predation (and chance climatic events for R. pretiosa embryos) on all life-history forms is the strongest factor limiting frog population numbers.

1975 ◽  
Vol 53 (9) ◽  
pp. 1254-1257 ◽  
Author(s):  
Lawrence E. Licht

Comparisons are made of life history features of the western spotted frog, Rana pretiosa pretiosa, living at 70 m in southwestern British Columbia, and 2600 m in Yellowstone Park, Wyoming.Lowland tadpoles remain longer as larvae and transform at twice the body size as highland tadpoles.Growth rates of juveniles and adults are rapid in the lowland population and the same amount of growth achieved by them in 2–3 years takes 8–10 years for highland frogs.Body size at sexual maturity is the same for frogs from both populations, but B.C. frogs breed at half the age of Wyoming frogs. Female fecundity, the number of eggs at spawning, is the same, but lowland females breed annually, while high-elevation females breed only every 2 or 3 years.Various explanations are put forth to account for observed differences.


1969 ◽  
Vol 47 (6) ◽  
pp. 1287-1299 ◽  
Author(s):  
Lawrence E. Licht

The breeding behavior of Rana aurora aurora and R. pretiosa pretiosa from an area of sympatry in southwestern British Columbia is described and compared. A 7-ac field near White Rock, B.C., was closely observed during the 1968 and 1969 breeding seasons.Both species arrived at breeding sites and began breeding activities within 2 weeks after emergence from hibernation in February and March. They both used the same temporary pond and slow-moving stream, and breeding occurred simultaneously.Male pretiosa gather into small groups with individuals vocalizing within inches of each other. The mating call is given in air as the frogs float on the surface of water only a few inches deep at the margins of the pond and river. Male aurora call several feet apart while completely submerged in 2 ft or more of water, and 3 ft or more from the pond and river edges. Descriptions of the mating calls of both species, as well as a call peculiar to amplectic male aurora, are given.Female pretiosa spawn mainly during daylight and the eggs are placed on top of, or immediately adjacent to, the first mass present. As many as 26 separate masses were laid on top of one another in the same place, unattached to vegetation in only a few inches of water. Female aurora spawn only at night and deposit their eggs attached to submerged vegetation in a minimum of 12 in. of water, and at least 3 ft from the pond and river shore; masses are several feet apart. The eggs of both species are laid in those areas where conspecific males vocalize.Peculiar aspects of both species' breeding behaviors are discussed, as well as those factors leading to successful reproductive isolation. Observations of breeding aurora in allopatry indicate no major differences from those on aurora sympatric with pretiosa.


1978 ◽  
Vol 56 (9) ◽  
pp. 1198-1205 ◽  
Author(s):  
D. K. Gordon ◽  
R. E. DE Wreede

Egregia menziesii (Turner) Areschoug is a common component of the algal flora along the west coast of Vancouver Island, Queen Charlotte Strait, and the Strait of Juan de Fuca but is absent from the Strait of Georgia in British Columbia, Canada. This distribution pattern was found to be correlated with temperature and salinity in that E. menziesii is not present in areas where there are seasonal periods of low salinity and high temperature. To test this correlation, field transplants of sporophytes and laboratory experiments with sporophytes and culture work were carried out. The results suggest that the distribution of E. menziesii is limited by specific combinations of salinity and temperature; it requires high salinities and temperatures less than 15 °C for its survival.


Author(s):  
Patrick Uthe ◽  
Robert Al-Chokhachy

The Upper Snake River represents one of the largest remaining strongholds of Yellowstone cutthroat across its native range. Understanding the effects of restoration activities and the diversity of life-history patterns and factors influencing such patterns remains paramount for long-term conservation strategies. In 2011, we initiated a project to quantify the success of the removal of a historic barrier on Spread Creek and to evaluate the relative influence of different climate attributes on native Yellowstone cutthroat trout and non-native brook trout behavior and fitness. Our results to date have demonstrated the partial success of the dam removal with large, fluvial Yellowstone cutthroat trout migrating up Spread Creek to spawn, thus reconnecting this population to the greater Snake River metapopulation. Early indications from mark-recapture data demonstrate considerable differences in life-history and demographic patterns across tributaries within the Spread Creek drainage. Our results highlight the diversity of life-history patterns of resident and fluvial Yellowstone cutthroat trout with considerable differences in seasonal and annual growth rates and behavior across populations. Continuing to understand the factors influencing such patterns will provide a template for prioritizing restoration activities in the context of future challenges to conservation (e.g., climate change).


1958 ◽  
Vol 90 (10) ◽  
pp. 627-631 ◽  
Author(s):  
Peter Harris

Ocnerostoma piniariella Zell. is an unimportant pest of Scots pine, Pinus sylvestris L., in Europe. A variety, copiosella Frey, is found in the Swiss Alps attacking a white pine, Pinus cembra L., and sometimes occurs in sufficient numbers to reduce growth. Both European forms have a life-history similar to that described here for British Columbia.In North America, specimens identified as O. piniariella were collected in 1882 at Ithaca, New York (Forbes, 1924). The first Canadian record was for 1922 at Abbotsford, British Columbia, from white pine (Felt, 1922). The species has since been found in British Columbia at Vancouver, Victoria, Langley, and Aldergrove. Dr. T. N. Freeman (in litt.), Entomology Division, Ottawa, has collected it at Constance Bay, South March, Ottawa, and Bells Corners, Ontario.


1973 ◽  
Vol 105 (4) ◽  
pp. 605-612 ◽  
Author(s):  
David Evans

AbstractErannis vancouverensis Hulst occurs from northern British Columbia to central California, and has been occasionally reported at infestation levels. The larvae feed on young leaves of several species of deciduous trees; winter is passed in the egg or sometimes in the pupal stage; adults emerge during late autumn or occasionally during winter or early spring; females are wingless. The life stages, including larval instars, are described here in detail. Virus disease and parasitism by tachinid flies help control the species.


1945 ◽  
Vol 23d (3) ◽  
pp. 17-103 ◽  
Author(s):  
J. A. Munro

The interior plateau of British Columbia between the 51st and 53rd parallels of latitude and the 120th and 126th degrees of west longitude constitute a definite biotic area designated as the Cariboo Parklands. Composite forests of lodgepole pine and aspen, grasslands, and shallow valleys containing numerous lakes, ponds, and marshes of various types are the principal physiographical features. Ten vertebrate habitats, each with a characteristic biota, are recognized. The region is an important migration route for waterfowl and constitutes the principal, and for some species the most northerly, nesting ground in the province. Nesting grounds are in units that vary greatly in size, in type of cover, and in their food potentials. They are subject to contraction in space, and consequent reduction in productivity, because of periodic seasons of drought. The biota is in rapid process of modification as a result of various human activities. Agricultural developments permanently impaired waterfowl habitat in some places but in other places, where the outlets of ponds have been dammed in order to store water for irrigation purposes, nesting grounds have been improved. The summer land bird population is derived mainly from the south and it includes several species that here reach the northern periphery of their range. The population also contains species of eastern origin that are not known to nest further south in the province. A total of 212 species and subspecies of birds are recorded for the region. Observations of the life history and behaviour of certain species are presented in detail.


2016 ◽  
Vol 145 (2) ◽  
pp. 348-362 ◽  
Author(s):  
Richard J. Beamish ◽  
Chrys M. Neville ◽  
Ruston M. Sweeting ◽  
Terry D. Beacham ◽  
Joy Wade ◽  
...  

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