Blue Grouse Research Articles

Classification of Sex in Young Blue Grouse

age and sex of dusky blue grouse. J. Wildl. Manage. 41:662-666. CASWELL, E. B. 1954. A method for sexing blue grouse. J. Wildl. Manage. 18:139. HELMINEN, M. 1963. Composition of the Finnish populations of capercaillie, Tetrao urogallus, and black grouse, Lyrurus tetrix, in the autumns of 1952-1961, as revealed by a study of wings. Finn. Pap. Game Res. 23. 124pp. HICKEY, J. J. 1955. Some American population research on gallinaceous birds. Pages 326-396 in A. Wolfson, ed. Recent studies in avaian biology. Univ. Illinois Press, Urbana. 479pp. HOFFMAN, R. W. 1981. Volunteer collection station use for obtaining grouse wing samples. Wildl. Soc. Bull. 9:180-184. LEOPOLD, A. 1933. Game management. Charles Scribner's Sons, New York, N.Y. 481pp. MUSSEHL, T. W., AND T. H. LEIK. 1963. Sexing wings of adult blue grouse. J. Wildl. Manage. 27:102-106. REDFIELD, J. A., AND F. C. ZWICKEL. 1976. Determining the age of young blue grouse: a correction for bias. J. Wildl. Manage. 40:349-351. VAN ROSSEM, A. J. 1925. Flight feathers as age ind cators in Dendragapus. Ibis 1:417-422. ZWICKEL, F. C. 1982. Demographic composition of hunter-harvested blue grouse in east-central Vancouver Island, British Columbia. J. Wildl. Manage. 46:1057-1061.

Sex Classification of Juvenile Blue Grouse from Wing Characteristics

Knowledge about the structure of wildlife populations is vital for their proper management (Leopold 1933). Such knowledge concerning upland game birds is commonly obtained by the collection and subsequent analysis of wings (Hickey 1955, Helminen 1963). Although harvest data may not exactly reflect the characteristics of the population from which they were collected (Hickey 1955), it has been demonstrated that data of this nature have

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

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.

REPRODUCTIVE ISOLATION IN SONORAN DESERT DROSOPHILA.

of enzyme polymorphisms in relation to environmental variability. Amer. Natur. 108:1-19. 1976. A comment on the role of environmental variation in maintaining polymorphisms in natural populations. Evolution 30:188-189. CHAISSON, R. E., L. A. SERUNIAN, AND T. J. M. SCHOPF. 1976. Allozyme variation between two marshes and possible heterozygote superiority within a marsh in the bivalve Modiolus demissus. Biol. Bull. 151:404. FRANKEL, D. H., AND M. E. SOULE. 1981. Conservation and Evolution. Cambridge Univ. Press, Cambridge. FRELINGER, J. A. 1972. The maintenance of transferrin polymorphism in pigeons. Proc. Nat. Acad. Sci. USA 69:326-329. GILLESPIE, J. H., AND C. H. LANGLEY. 1974. A general model to account for enzyme variation in natural populations. Genetics 76:837-848. MILKMAN, R. 1978. Selection differentials and selection coefficients. Genetics 88:391-403. MITTON, J. B., AND M. C. GRANT. 1980. Observations on the ecology and evolution of quaking aspen, Populus tremuloides, in the Colorado Front Range. Amer. J. Bot. 67:202-209. REDFIELD, J. A. 1974. Genetics and selection at the Ng locus in blue grouse (Dendragapus obscurus). Heredity 33:69-78. SAMOLLOW, P. B. 1978. Dynamics of enzyme polymorphism in a natural population of the Boreal toad, Bufo boreas boreas Baird and Girard: evidence of natural selection via differential mortality in early life history stages. Ph.D. thesis. Oregon State Univ., Corvallis. 1980. Selective mortality and reproduction in a natural population of Bufo boreas. Evolution 34:18-39. SASSAMAN, C. 1978. Dynamics of a lactate dehydrogenase polymorphism in the wood louse Porcellio scaber Latr.: evidence for partial assortative mating and heterosis in natural populations. Genetics 88:591-609. SINGH, S. M., AND E. ZOUROS. 1978. Genetic variation associated with growth rate in the American oyster (Crassostrea virginica). Evolution 32:342-353. SNEDECOR, G. W., AND W. G. COCHRAN. 1980. Statistical Methods, 7th ed. Iowa State Univ. Press, Ames. SOKAL, R. R., AND F. J. SONLEITNER. 1968. The ecology of selection in hybrid populations of Tribolium castaneum. Ecol. Monogr. 38:345-379. SOULE, M. E. 1980. Thresholds for survival: maintaining fitness and evolutionary potential, p. 151-169. In M. E. Soule and B. A. Wilcox (eds.), Conservation Biology: An Evolutionary-Ecological Perspective. Sinauer Associates, Sunderland. WATT, W. B. 1977. Adaptation at specific loci. I. Natural selection on phosphoglucose isomerase of Colias butterflies: biochemical and population aspects. Genetics 87:177-194. WILLS, C. 1978. Rank-order selection is capable of maintaining all genetic polymorphisms. Genetics 89:403-417. 1981. Genetic Variability. Oxford Univ. Press, Oxford. ZOUROS, E., S. M. SINGH, AND H. E. MILES. 1980. Growth rate in oysters: an overdominant phenotype and its possible explanations. Evolution 34:856-867.

Factors affecting the return of young blue grouse to breeding range

From 1969 to 1976, 1958 juvenile blue grouse, Dendragapus obscurus fuliginosus, were marked with patagial wing tags and(or) leg bands in east-central Vancouver Island. Return and(or) recovery records from these birds in their 2nd year of life or greater indicate no significant differences among annual cohorts, between sexes, by time of hatch, by body weight at hatch, or by age of maternal parent (yearling or adult). However, a difference in the returns of smaller and larger chicks at time of hatch approached significance (smaller, least). There was a constant and significant increase in rate of return of chicks first marked at from 1 to 10 weeks of age.

Dispersal and site fidelity in Blue Grouse

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.

Renesting in adult and yearling blue grouse

Eight of 31 radio-tagged female blue grouse (Dendragapus obscurus) that had first nests terminated before hatch produced second clutches. Significantly more adult than yearling hens renested. All yearling hens that produced a second clutch had first nests terminated during laying or early incubation; but most yearlings did not renest. Adult females renested independently of the stage of incubation when nests were terminated. Average size of second clutches of adults are likely larger than those of yearlings and average size of second clutches of all females are likely smaller than those of first clutches. Most prenesting home ranges used during second nesting attempts were in the same general areas and of the same sizes as those used during initial nesting attempts.

Foods selected by blue grouse (Dendragapus obscurus fuliginosus)

The spring and summer diet was determined from 811 blue grouse crops collected from 1957 through 1966 near the town of Campbell River on Vancouver Island. Main foods eaten were conifer needles, broad-leaved vegetation, flowers, fruits, and invertebrates. More than 80% of the plant diet was from nine species. Most foods were selected and selection varied with season, sex, and age. In the spring, females apparently ate more broad-leaved plants than did males, and chicks up to approximately 3 weeks of age fed largely on invertebrates, mainly ants (Formicidae). We attempt to explain selection by relating known nutrients in plants and animals to their use as food. Selection may be partly explained by availability, nutrients, and the nutritional requirements of grouse. Nutrients apparently selected most frequently were ash and nitrogen. The diet of females in May and June seemed richer than that of males in ash, nitrogen, and magnesium. In June, chicks had a diet likely higher in nitrogen, phosphorus, and potassium but lower in carbohydrate, fat, and calcium when compared with adults. The diet of blue grouse compared with that recommended for some other grouse was possibly deficient in ash, phosphorus, and calcium. We postulate food on the summer range might limit populations of blue grouse by the amount of nitrogen and minerals, especially calcium, available to hens in spring and by a range of nutrients available to very young chicks.

Demographic Composition of Hunter-Harvested Blue Grouse in East Central Vancouver Island, British Columbia

Demographic Composition of Hunter-Harvested Blue Grouse in East Central Vancouver Island, British Columbia

Survival and delayed breeding in male blue grouse

We present an analysis of survival of male blue grouse (Dendragapus obscurus) using known-aged individuals and examine the results in terms of the evolution of delayed breeding. Males had low rates of mortality and, among 2-year-olds, mortality rates of territorial and nonterritorial birds were the same. Up to 6 years of age, males had life expectancies of at least 2 years. Males that postponed breeding and survived had a 40–45% chance of eventually obtaining a high-quality site for a territory. If males had not delayed breeding they likely would have had to settle on areas where opportunities for breeding appear to be low. Thus, survival patterns of males are consistent with the hypothesis that it is advantageous for some males to delay breeding if high-quality sites cannot be obtained.

Mortality of nestling Blue Grouse owing to inclement weather

Mortality of nestling Blue Grouse owing to inclement weather

Postovulatory Follicles as Indicators of Egg Production in Blue Grouse

Postovulatory follicles (POF's) of birds are the ovarian remains of mature follicles that have ovulated. In many avian species total regression of a POF is complete within a month after ovulation (Davis 1942; Payne 1965, 1966, 1973; Erpino 1969). However, in ring-necked pheasants (Phasianus colchicus) (Meyer et al. 1947, Kabat et al. 1948) and blue grouse (Dendragapus obscurus) (Standing 1960) pigmented remains of POF's are reported to be macroscopically identifiable for several months after ovulation. Standing (1960) stressed the value of macroscopic examination of ovaries at hunter check

Characteristics of Persistent and Transient Territorial Sites of Male Blue Grouse

Male blue grouse (Dendragapus obscurus) are promiscuous and territorial, with territories serving as areas where males can display and breed without interference from other males (Bendell and Elliott 1967). Intensive studies on Vancouver Island, British Columbia, demonstrated that areas used by males for territories had unequal frequencies of use (Lewis 1979). Some were used regularly, others intermittently. Sites used at least 9 of the 10 years studied (1969-78) were called persistent, those used 8 years or less (Lewis 1979). Although the term persistent implies use in every year, sites occupied for 9 years were included in this category because of the chance that the site actually was used in the year it was recorded as vacant, even though the presence of a male was undetected by the field techniques used. Experimental evidence indicates that males prefer persistent sites for territories (Lewis and Zwickel 1980), and males using these sites had significantly more females near them in early spring and survived significantly longer than those using transient sites (Lewis 1979). Here I examine physical and vegetative characteristics of a series of persistent and transient territorial sites to identify those features that may be important in their selection by blue grouse.

Differential Use of Territorial Sites by Male Blue Grouse

We examined the pattern of use of territorial sites occupied by male Blue Grouse on a 485-ha area over a 10-year period, 1969 to 1978. Some sites were occupied continuously while others were used only intermittently; these were called "persistent" and "transient" sites, respectively. Approximately one-half of the transient sites were vacant in any given year. Males on persistent sites survived significantly longer and had significantly more females near their territories during the breeding season than those on transient sites. Thus, males on persistent sites may have better opportunities for breeding than males on transient sites. These results help to explain why yearling males delay breeding, despite being physiologically able to do so, and they also provide new insights into how breeding densities of males are regulated.

The ecology of blood parasites in blue grouse from Vancouver Island, British Columbia

The blood parasites in blue grouse (Dendragapus obscurus (Say, 1823)) from Vancouver Island, British Columbia were studied during the summers of 1972 through 1975. Data from 1707 birds of three age-classes indicated that infections of Leucocytozoon bonasae occurred more often (79%) than Trypanosoma avium (54%), Haemoproteus mansoni (42%), or microfilariae (37%). Concurrent associations of these taxa were more common (77%) than single species infections. Frequencies of multiple species infections did not fit expected probabilities, indicating that multiple associations are not derived independently.Young grouse acquire L. bonasae and H. mansoni by middle to late June, 2–3 weeks after hatching. Infections of T. avium and microfilariae appeared 4 and 5–9 weeks after hatch, respectively. Leucocytozoon and Haemoproteus had two transmission periods which varied seasonally among years, but which had similar within-year patterns. Simulium aureum was incriminated as a vector of L. bonasae, but attempts at experimental transmission were not made. The utilization of common species of vectors by several taxa of parasites is postulated. Competitive exclusion does not appear to exist for this species assemblage.

Migration in a Local Population of Spruce Grouse

-Migration of Spruce Grouse was observed in southwestern Alberta from 1970 to 1975 in a population of grouse that included both migratory and resident birds. Migrants comprised 39% of this population; these individuals migrated each year regardless of weather conditions. Migration occurred from mid-February to late May and from early September to midDecember. More females than males were migratory and females migrated longer distances. Distance between breeding and wintering sites ranged from 0.5 to 9.5 km. Survival and reproductive success was similar for migrant and resident grouse during the study. Migration was generally related to the dispersal history of birds as yearlings. Yearlings that dispersed in spring tended to establish migratory patterns by returning to winter sites used as juveniles. Why these birds did not remain on summer areas for the winter, as did resident Spruce Grouse, is uncertain. The quality of winter habitat may be an important factor in establishment of migration; further investigation is required to determine the qualitative aspects of the breeding and wintering habitat of Spruce Grouse. Migration has been reported for some species of the Tetraonidae, most notably Blue Grouse (Dendragapus obscurus; Anthony 1903, Marshall 1946, Wing 1947, Bendell 1955, Zwickel et al. 1968) and North American ptarmigan (Lagopus spp.; Weeden 1964, Irving et al. 1967, Hoffman and Braun 1975). Sage Grouse (Centrocercus urophasianus) undertake long seasonal movements but only in certain regions (Dalke et al. 1963, Eng and Schladweiler 1972, Wallestad 1975, Beck 1977). Sharptailed Grouse (Pedioecetes phasianellus) and Greater Prairie Chicken (Tympanuchus cupido) may travel long distances (Hamerstrom 1949, Hamerstrom and Hamerstrom 1951) although such movements occur only sporadically and have been difficult to document. Most reports suggest that changes in diet or food availability during winter may cause such movements, yet evidence is lacking. This paper is the first report of migration in Spruce Grouse (Canachites canadensis). Observations were made during studies of population size and movements of this species in southwestern Alberta (Keppie 1975, Herzog 1977). We report the proportion of a local population that was migratory, evaluate characteristics of seasonal travel, and investigate a possible relationship between the occurrence of migration and earlier dispersal of young birds. STUDY AREA AND METHODS Studies were conducted in the eastern foothills of the Rocky Mountains from May 1970 through September 1973 (Keppie 1979), April through October 1974, and February through December 1975 (Herzog and Boag 1978). The main study area encompassed 555 ha adjacent to Gorge Creek (50'39'N, 114'39'W), 27 km west of Turner Valley, Alberta. Forest cover was predominantly lodgepole pine (Pinus contorta) with scattered clumps of white spruce (Picea glauca) and poplar (Populus spp.). The study area was contiguous with habitat suitable for grouse except for a 1-km wide area along the east side. Grouse were censused regularly on the primary study area with the aid of pointing dogs. Birds were captured with extendable snare poles (Zwickel and Bendell 1967) and individually marked with colored leg bands. Essentially all birds (95%) were marked. Grouse were separated into three age-classes: juvenile (0-9 months of age; from hatching until 1 April), yearlings (9-21 months), and adults (greater than 21 months). Thus, yearlings were birds entering their first breeding season and were distinguishable from adults by tail feather patterns (Zwickel and Martinsen 1967) and shape of primaries until 14 months of age. Monthly we searched outside the main study area to obtain additional observations of migratory birds and distances they had travelled. Four migratory females were also radio-marked and monitored in 1975, using techniques described by Herzog (1979). Minimum daily movements were the distances between initial sightings on successive days. Contingency and goodness of fit chisquare tests, t-tests, G-tests and rank tests (Sokal and

Removal and replacement of male blue grouse on persistent and transient territorial sites

In the springs of 1978 and 1979 we removed all male blue grouse (Dendragapus obscurus), both original occupants and subsequent replacements, from a series of persistent and transient territorial sites (those used regularly and intermittently, respectively). In both years more replacements settled on persistent than on transient sites. Most replacement males were adults, most of which likely would not have taken territories had we not made these sites available. The presence of nonterritorial adults, reported here for the first time, suggests that territorial behaviour limits breeding densities of male blue grouse. Testes of replacement adults, although smaller than those of resident males collected at comparable times, all contained mature sperm. Yearling males are seldom territorial; but of eight that took territories on removal sites all except one selected persistent sites.

Surplus yearlings and the regulation of breeding density in blue grouse

An experiment in which yearlings of both sexes of blue grouse (Dendragapus obscurus fuliginosus) were removed from breeding range showed that about two times, or more, yearlings of each sex were identified here as compared with a nearby control area, though numbers of "surplus" yearlings varied among years. The removal of large numbers of yearlings from the experimental area did not reduce breeding density, except ephemerally in 1 year. Nor did the removal of these birds affect populations in the surrounding area. These data confirm results from earlier studies with blue grouse, that surplus yearlings of both sexes are present on the breeding range. Replacement yearlings of both sexes (those taking the place of birds removed) were able to breed, but those removed sequentially (1974 to 1976) were lighter in body weight than those captured on control areas or those that settled synchronously after a near-total removal experiment in the same area. I infer from these results that some form of behaviour keeps surplus yearlings from settling on the breeding range and that this behaviour is a key mechanism involved in the regulation of breeding density. The important behaviour may involve either yearling–yearling or adult–yearling interactions.

Differences in the gonadal cycles of adult and yearling blue grouse

Gonadal cycles of adult and yearling female and male blue grouse (Dendragapus obscurus fuliginosus) collected from Vancouver Island, British Columbia, are described and compared. Reproductive organs of yearling females develop later, produce eggs at a lower oviduct weight, and regress faster to a lower oviduct weight than do those of adults. Yearling males, although most do not breed, go through the entire gonadal cycle and produce viable sperm. Testes of yearlings develop later, have a lower volume, and regress earlier than those of adults. Yearlings of both sexes appear less sexually mature than adults, but delays in or lack of breeding could be partly a result of social interaction with resident adults.

Two New Species of Coccidia, Eimeria leucuri and E. oreoecetes (Protozoa: Eimeriidae), in Grouse from Colorado

Eimeria leucuri is described from white-tailed ptarmigan (Lagopus leucurus), and E. oreoecetes from white-tailed ptarmigan and blue grouse (Dendragapus obscurus) from Colorado. Oocysts of E. leucuri are ellipsoidal, 26.6 by 17.7 micron, each bearing a micropyle, micropyle cap, up to 4 polar granules, but no oocyst residuum. The lemon-shaped sporocysts are 15.4 by 6.7 micron, and have Stieda bodies and large amounts of sporocyst residuum. The sporocyst contents are enclosed in a membrane. Oocysts of E. oreoecetes are subspherical, 26.0 by 22.6 micron, and have up to 4 polar granules. The lemon-shaped sporocysts are 14.6 by 8.8 micron, and have both Stieda bodies and substiedal bodies and a large amount of sporocyst residuum. The sporocyst contents are enclosed in a membrane. These are the first coccidia to be described from these tetraonids.