A STUDY OF THE BLUE GROUSE (DENDRAGAPUS OBSCURUS (SAY)) ON VANCOUVER ISLAND, BRITISH COLUMBIA

1960 ◽  
Vol 38 (4) ◽  
pp. 701-713 ◽  
Author(s):  
C. David Fowle
Keyword(s):  
British Columbia ◽  
Feeding Habits ◽  
Free Water ◽  
Breeding Cycle ◽  
Adult Males ◽  
Seasonal Movements ◽  
Second Growth ◽  
Dendragapus Obscurus ◽  
In Captivity ◽  
Main Item

A study was made of the summer habitat, seasonal movements, fluctuations in populations, population density, breeding cycle, and summer feeding habits of Dendragapus obscurus fuliginosus (Ridgway). During the summer the grouse were found mainly in the early stages of the developing second-growth forests following fire or logging. The birds descended to the lowlands in late March and early April. Most of the adult males returned to the uplands by the end of July, The females and broods left the lowlands by the end of September. There is evidence of several well-marked fluctuations in the numbers of blue grouse in British Columbia since 1904. A density of about.2 adults per acre was recorded in late June and early July. Nesting took place in May and the first young appeared early in June. After the first of July it was not uncommon to see two females with their intermingled broods feeding together. The summer foods of both adults and young were almost entirely vegetable. Grit was the main item in gizzards from birds collected before the middle of July but later it was largely replaced by hard seeds. The grouse were not observed to drink free water except in captivity. There is a rough parallelism between frequency of occurrence of the main items of food in the environment and the proportion of each occurring in the diet.

Spatial Patterns of Yearling Male Blue Grouse and Their Relation to Recruitment into the Breeding Population

The Auk ◽  
1983 ◽  
Vol 100 (3) ◽  
pp. 653-657 ◽  
Author(s):  
Ian G. Jamieson ◽  
Fred C. Zwickel
Keyword(s):  
British Columbia ◽  
Spatial Patterns ◽  
Radio Telemetry ◽  
Breeding Population ◽  
Adult Males ◽  
Costs And Benefits ◽  
Breeding Range ◽  
Dendragapus Obscurus ◽  
Different Types ◽  
Occupied Territories

Abstract Movements of yearling male Blue Grouse (Dendragapus obscurus) were monitored by radio telemetry during the springs of 1980 and 1981, on Hardwicke Island, British Columbia. The locations of the birds were clumped around territories of adult males. Most birds were associated with a few occupied territories, others settled near vacant sites that had been used as territories in previous years, and a few moved widely over the breeding range. Some territories attracted more yearlings than others. Presumed costs and benefits that may be associated with different types of spatial patterns of yearling males are discussed.

scholarly journals Relative feeding specialization may depress ontogenetic, seasonal, and sexual variations in diet: the endemic lizard Cnemidophorus littoralis (Teiidae)

2003 ◽  
Vol 63 (2) ◽  
pp. 321-328 ◽  
Author(s):  
P. F. Teixeira-Filho ◽  
C. F. D. Rocha ◽  
S. C. Ribas
Keyword(s):  
Sexual Dimorphism ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Analysis Of Covariance ◽  
Head Size ◽  
Head Width ◽  
Adult Males ◽  
Important Prey ◽  
Relative Contribution ◽  
Main Item

We investigated the feeding habits of the teiid lizard Cnemidophorus littoralis in the markedly seasonal habitat of Restinga da Barra de Maricá (22º57'S, 43º50'W), Rio de Janeiro State, Brazil, to evaluate to what extent its diet is ontogenetically, sexually, and/or seasonally conservative. Lizard stomach contents were analyzed, identified, counted, estimated for volume (in mm³), and grouped in four classes (active, sedentary, and clumped preys, and plant material). The relative contribution of each food class to the total prey volume consumed by adult males and females and juveniles was compared in three ways: between juveniles and adults, sexes, and seasons (wet and dry). Sexual dimorphism in head size was tested by comparing head width and jaw length using analysis of covariance (ANCOVA). Isopterans were the most important prey item, occurring in 93% of the lizard stomachs examined and corresponding to 96.4% of total prey content and 69.7% of total prey volume. They occurred in high frequencies in the stomachs of C. littoralis throughout all study months. We found no sexual, ontogenetic, or seasonal differences in C. littoralis diet although the sexes differed significantly in head width. We concluded that isopterans are the main item in the diet of C. littoralis in Restinga da Barra de Maricá, both for juveniles and adults. The lack of seasonal, sexual, or ontogenetic variation in its diet results from the massive consumption of these insects. Isopterans are small, occur in clumps, and are available year-round, and thus are an advantageous food item for the active forager C. littoralis. We also found sexual dimorphism in the head size of C. littoralis: males have wider heads than females. This dimorphism, however, does not seem to be related with the diet of the species, and is probably a result of sexual selection.

scholarly journals An infanticide attempt by a free-roaming feral stallion ( Equus caballus )

2008 ◽  
Vol 5 (1) ◽  
pp. 23-25 ◽  
Author(s):  
Meeghan E Gray
Keyword(s):  
Sexual Selection ◽  
Genetic Analysis ◽  
Equus Caballus ◽  
Adult Males ◽  
Free Living ◽  
Feral Horses ◽  
Selection Hypothesis ◽  
Sexual Selection Hypothesis ◽  
In Captivity

Infanticide by adult males occurs in a variety of species. While infanticidal attacks have been documented in several equid species in captivity, it has never been witnessed in free-roaming feral horses. I report an infanticide attempt by a free-living feral stallion on a recently born female foal. The stallion picked up the foal by the shoulders, tossed it around twice and bit in on the neck several times. The dam of the foal charged the stallion and successfully protected her foal from additional attacks. The foal survived the attack and later weaned successfully. The stallion recently took over the band and was excluded as the sire through genetic analysis. While this type of attack is rare, this case lends support to the sexual selection hypothesis and further demonstrates that equids have evolved with the risk of infanticide. Furthermore, it shows that maternal protectiveness can be successful against attacks by infanticidal males.

Macrofungi from six habitats over five years in Clayoquot Sound, Vancouver Island

2004 ◽  
Vol 82 (10) ◽  
pp. 1518-1538 ◽  
Author(s):  
Christine Roberts ◽  
Oluna Ceska ◽  
Paul Kroeger ◽  
Bryce Kendrick
Keyword(s):  
British Columbia ◽  
Rare Species ◽  
Vancouver Island ◽  
The Other ◽  
Forest Types ◽  
Natural Ecosystems ◽  
Old Growth ◽  
Second Growth ◽  
Clayoquot Sound

Over 5 years, macrofungi from six habitats in Clayoquot Sound, Vancouver Island, British Columbia, were documented. Habitats were categorized as dune, spruce fringe, old-growth rainforest, second-growth forest, bog, or estuarine. All but the second-growth forest are natural ecosystems. A total of 551 taxa of macrofungi were recorded. Between 17% and 36% of the species in any one habitat were found only in that habitat. The most frequently encountered and ubiquitous species was Craterellus tubaeformis (Fr.) Quel., found in all years, habitats, and sites. Of the 551 taxa, only 28 were found every year, and 308 were found in only 1 year. Rare species that were recorded include Cordyceps ravenelii Berkeley & Curtis, Hygrophorus inocybiformis Smith, and Tricholoma apium Schaeffer in the dunes and Stereopsis humphreyi (Burt) Redhead in the spruce fringe. Similarities between habitats based on taxa in common showed that bog and estuarine habitats had only 9%–17% in common with each other and the other habitats, whereas dune, spruce fringe, and the two forest types shared 21%–31% of their species. Old-growth rainforest yielded approximately 4 times as many species as bog and estuarine habitats, and approximately 1.5 times as many as the other three habitats.Key words: Clayoquot Sound, Vancouver Island, macrofungi, habitats, biodiversity.

Observations on Activity Patterns, Population and Den Characteristics of The Water Rat Hydromys chrysogaster Along Badger Creek, Victoria.

1995 ◽  
Vol 18 (1) ◽  
pp. 71
Author(s):  
J.L. Gardner ◽  
M. Serena
Keyword(s):  
Population Density ◽  
Activity Patterns ◽  
Home Ranges ◽  
Adult Males ◽  
Fish Farms ◽  
Age Classes ◽  
Irrigation Channels ◽  
In Captivity ◽  
In The Wild ◽  
Hydromys Chrysogaster

The Water Rat Hydromys chrysogaster is Australia's largest amphibious rodent, occupying freshwater rivers, lakes, and coastal and estuarine habitats throughout the continent (Watts and Aslin 1981). Little is known of the species' social organisation or use of space in the wild although Harris (1978) suggested that adults might be intrasexually aggressive. The home ranges of all sex and age classes overlap to some extent but home ranges of adults of the same sex appear to overlap less (Harris 1978). Adult males occupy the largest home ranges which overlap those of one or more females. In captivity individuals kept in groups form hierarchies in which only the dominant females usually breed successfully (Olsen 1982). Fighting occurs primarily among males, with the highest incidence of injuries observed at the beginning of the main September-March breeding season (Olsen 1980, 1982). The results of trapping studies indicate that population density may vary considerably, with the greatest numbers of animals typically occupying man-modified habitats such as irrigation channels or fish farms (McNally 1960, Watts and Aslin 1981, Smales 1984). Aggressive behaviour appears to be related to pelage colour (phenotype) and population density; the higher the density the greater the number of injured individuals (Olsen 1980).

Second Growth: Community Economic Development in Rural British Columbia

2005 ◽  
Vol 38 (4) ◽  
pp. 1067-1068
Author(s):  
Andrew Molloy
Keyword(s):  
British Columbia ◽  
Economic Development ◽  
Community Development ◽  
Small Town ◽  
Local Level ◽  
Empirical Studies ◽  
Action Learning ◽  
Small Time ◽  
Community Economic Development ◽  
Second Growth

Second Growth: Community Economic Development in Rural British Columbia, Sean Markey, John Pierce, Mark Roseland and Kelly Vodden, Vancouver: University of British Columbia Press, 2005, pp. 352.This theoretically rich, community economic development (CED) work, written by four members of the Centre for Sustainable Community Development (formerly the Community Economic Development Centre) at Simon Fraser University, is the product of a three-year participatory-action-based research project involving four “forest-based” British Columbia communities. Two Aboriginal communities and two municipalities were case studied as part of an action-learning exercise in order to gain “insight into the apparent conflict between the economic imperative and fluidity of capital versus the lived worlds of rural and small time places” (3). Through their empirical studies of the four communities, the authors argue that CED, fostered at the local level, can allow for the kind of capacity building that is needed to create diversified, sustainable economic futures for resource-based rural and small-town communities. They are careful, however, to distinguish between the use of CED as a “localized and palliative strategy” for marginalized communities caught in the throes of political and economic dependency, and the possibilities for a more robust (theoretically balanced) version of CED, which can become part and parcel of rural and small-town locally-based planning and development. While recognizing the appropriateness of CED in either situation, they argue that a host of negative economic and political factors, which are intensifying under the direction of neo-liberal ideological thinking, have resulted in a pressing need for the more robust form of community development and corresponding revitalization strategies.

A model for predicting the value of forest stands in various market conditions in British Columbia

2009 ◽  
Vol 85 (3) ◽  
pp. 387-391
Author(s):  
Mihai Pavel ◽  
Björn O Andersson
Keyword(s):  
British Columbia ◽  
Dynamic Programming ◽  
Dynamic Programming Algorithm ◽  
Inventory Systems ◽  
Programming Algorithm ◽  
Forest Stands ◽  
Market Conditions ◽  
Second Growth ◽  
Taper Equation ◽  
Individual Trees

A model for predicting the value of forest stands was developed at FPInnovations – Feric Division. The model uses standard cruise data collected in British Columbia (BC) and company sort descriptions to predict the distribution of wood volume by species and grade sort for each proposed harvest site. The model is capable of quickly analyzing different scenarios (i.e., different sort sets) to reflect changing market conditions. Within the model, a taper equation is applied to each tree to calculate the diameters inside the bark, and quality and pathological descriptors from cruise data are used. A Dynamic Programming algorithm is used to predict the combination of logs that maximizes the value of each stem, and results are summarized and extended from individual trees to cruise plots, then to harvest blocks and/or stands. The model was successfully tested for second-growth stands with relatively few defects on Coastal BC. Improvements are being implemented to enhance its applicability to more complex stands. Key words: value of forest stands, economic operability, optimal bucking of trees, Dynamic Programming, computer model, inventory systems

Dispersal and site fidelity in Blue Grouse

1983 ◽  
Vol 61 (3) ◽  
pp. 570-573 ◽  
Author(s):  
Ian G. Jamieson ◽  
Fred C. Zwickel
Keyword(s):  
Site Fidelity ◽  
General Area ◽  
Adult Males ◽  
Same Sex ◽  
Breeding Sites ◽  
Sibling Pairs ◽  
Dendragapus Obscurus ◽  
Opposite Sex ◽  
Juvenile Males ◽  
Old Females

Ten years of banding and censusing data from Blue Grouse (Dendragapus obscurus) were analyzed with respect to dispersal of juveniles and site fidelity of yearlings and adults. Juvenile females dispersed farther than juvenile males. In sibling pairs of the same sex, brothers settled closer to one another than sisters. In sibling pairs with birds of opposite sex, females dispersed farther than males. Adult males first established territories close to where they had been sighted as yearlings, or nonterritorial adults, and most females returned in spring to the same general area where they had previously nested. Two-year-old females showed less fidelity to breeding sites they had used as yearlings than older females to sites they had used in previous years.

X.—On the Feeding Mechanism of a Mysid Crustacean, Hemimysis Lamornæ

1927 ◽  
Vol 55 (1) ◽  
pp. 219-253 ◽  
Author(s):  
H. Graham Cannon ◽  
S. M. Manton
Keyword(s):  
Digestive System ◽  
Feeding Habits ◽  
Great Length ◽  
Gastric Mill ◽  
General Biology ◽  
Feeding Mechanism ◽  
In Captivity ◽  
Fish Tanks

The general biology of the Mysids has recently been studied at great length by Blegvad (1922) at Copenhagen. His paper, containing a very complete literature list, deals with Mysis inermis, Rathke, Mysis flexuosa, Müller, and Mysis neglecta, Sars. His comments on feeding are limited, and refer chiefly to the nature of the food that the animals ate in captivity. Gelderd's work (1909) on the digestive system of the Schizopoda describes the course taken by the food through the gastric mill, the masticatory functions of this apparatus, and the method by which the masticated food and digestive juices are brought together, but does not deal with the manner in which the food reaches the stomach. An account, then, of the method by which a mysid collects its food would fill a gap in our knowledge of these forms. The only description, as far as we are aware, of the feeding habits of a mysid is that of Depdolla (1923), who worked on Praunus [Mysis] flexuosus, but his account is superficial and in our opinion very inaccurate. The following paper deals with the feeding habits of a small mysid, Hemimysis lamornœ, about 8 mm. long, which has established itself in the larger fish-tanks at the M.B.A. laboratory at Plymouth. It breeds freely all the year round, and can be obtained from the tanks in abundance, although it is stated to be only a rare visitor in the Plymouth district.

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