Reproductive Output, Population Structure and Cyclic Dynamics in Capercaillie, Black Grouse and Hazel Grouse

1997 ◽  
Vol 28 (1) ◽  
pp. 1 ◽  
Author(s):  
Jan Lindstrom ◽  
Esa Ranta ◽  
Mats Linden ◽  
Harto Linden
Keyword(s):  
Population Structure ◽  
Reproductive Output ◽  
Black Grouse ◽  
Hazel Grouse ◽  
Cyclic Dynamics

The effect of population structure on growth patterns in the woody goldenrod Solidago pauciflosculosa

1983 ◽  
Vol 61 (7) ◽  
pp. 1955-1958 ◽  
Author(s):  
Marvin P. Pritts ◽  
James F. Hancock
Keyword(s):  
Population Structure ◽  
Seedling Establishment ◽  
Reproductive Output ◽  
Plant Biomass ◽  
Growth Patterns ◽  
Dispersion Pattern ◽  
Allocation Patterns ◽  
Total Plant Biomass ◽  
Total Plant ◽  
Two Populations

The population structure and growth patterns of two populations of Solidago pauciflosculosa, a woody goldenrod, were investigated. Populations consisted of even-aged contagious patches of individuals, a dispersion pattern likely caused by the periodic appearance of microsites suitable for seedling establishment. The density of individuals within the even-aged clumps varied considerably and was correlated with total plant biomass and reproductive output. Density was not correlated with either reproductive or nonreproductive allocation patterns.

On Leucocytozoon in Swedish Capercaillie, Black Grouse and Hazel Grouse

1954 ◽  
Vol 18 (1) ◽  
pp. 142
Author(s):  
Arnold B. Erickson ◽  
Karl Borg
Keyword(s):  
Black Grouse ◽  
Hazel Grouse

Population structure and reproductive performance in the sea anemone associated shrimp Ancylocaris brevicarpalis (Caridea: Palaemonidae)

2021 ◽  
Vol 101 (1) ◽  
pp. 109-116
Author(s):  
Sanjeevi Prakash ◽  
Ampuli Muthu ◽  
Amit Kumar
Keyword(s):  
Population Structure ◽  
Tamil Nadu ◽  
Reproductive Output ◽  
Early Stage ◽  
Monsoon Season ◽  
Gulf Of Mannar ◽  
Sea Anemones ◽  
Individual Level ◽  
Obligate Symbiont ◽  
Post Monsoon Season

AbstractThe peacock-tail shrimp Ancylocaris brevicarpalis Schenkel, 1902, is an obligate symbiont of sea anemones and well known for its remarkable colouration. Yet, very little information is available about its population structure and life-history traits, including reproductive parameters (fecundity, embryo volume and reproductive output). A total of 574 individuals were collected from the Gulf of Mannar, Tamil Nadu, India between February 2017 and July 2018, out of which 214 were males (37.28%), 355 were females (61.84%), and 5 (0.87%) juveniles. The highest percentage of individuals were observed in the post-monsoon season (38.10%) followed by monsoon (34.85%), pre-monsoon (15.02%), and summer seasons (12.01%). The overall sex ratio was skewed towards female individuals (0.55 male: 1 female). Fecundity was higher in females carrying early-stage embryos and embryo volume did increase, but not statistically significantly from early to late stages. The reproductive output was negatively allometric to the mean female body weight. The present study provides first-of-its-kind information on the population as well as individual-level reproductive characteristics of A. brevicarpalis.

scholarly journals Inference of hazel grouse population structure using multilocus data: a landscape genetic approach

Heredity ◽  
2008 ◽  
Vol 101 (6) ◽  
pp. 475-482 ◽  
Author(s):  
J Sahlsten ◽  
H Thörngren ◽  
J Höglund
Keyword(s):  
Population Structure ◽  
Genetic Approach ◽  
Hazel Grouse ◽  
Landscape Genetic

scholarly journals Species structure of small game hunting in the Kirov region at the beginning of the XXI century

2021 ◽  
Vol 22 (4) ◽  
pp. 597-607
Author(s):  
Boris E. Zarubin ◽  
Vyacheslav V. Kolesnikov ◽  
Anna V. Kozlova ◽  
Maria S. Shevnina ◽  
Alexander V. Economov
Keyword(s):  
Species Structure ◽  
Total Production ◽  
Black Grouse ◽  
European Hare ◽  
Hunting Season ◽  
Small Game ◽  
Hazel Grouse ◽  
Bean Goose ◽  
Species Groups ◽  
Game Hunting

An assessment of the species structure and size of small game prey for the spring and autumn-winter hunting seasons on the territory of the Kirov region was made, using a questionnaire survey based on the analysis of the prey of 3220 individuals. Small game includes such species (groups of species) as mallard, Northern shoveler, pintail, teal-whistle, teal cracker (Garganey), Eurasian wigeon, diving ducks, white-fronted goose, bean goose, wood grouse, black grouse, hazel grouse, woodcock, double snipe, snipe, corncrake, wood pigeon, turtle doves, white hare, European hare. The average index of production by species and groups of species per 1 hunter, who went hunting in the spring and autumn-winter seasons, has been calculated. The size of game catch during the spring hunting was 135.8 thousand individuals, in the autumn-winter hunting season -470 thousand individuals. The summation of the results obtained made it possible to estimate the volume of the total (annual) catch of small game in the amount of almost 606 thousand individuals. The main species are the mallard, hazel grouse, white hare, woodcock, black grouse, Eurasian wigeon, teal cracker (Garganey), Northern shoveler, wood grouse, white-fronted goose, bean goose, teal-whistle, their total share is 94.88% of the annual production of small game. The first five species can be assessed as the most massive in production (or popular), the share of each of them is over 10% of the total production, and in total they amount to 70.4%.

Intraspecific Interactions and Parasitism in an Association of Rhizocarpon lecanorinum and R. Geographicum

1997 ◽  
Vol 29 (6) ◽  
pp. 533-545 ◽  
Author(s):  
Stephen R. Clayden
Keyword(s):  
Population Structure ◽  
Reproductive Output ◽  
Intraspecific Interactions ◽  
Clonal Population ◽  
Somatic Incompatibility ◽  
Mycelial Interactions ◽  
North Wales ◽  
Mixed Populations ◽  
Clonal Population Structure

AbstractIntraspecific thallus interactions in mixed populations of Rhizocarpon lecanorinum and R. geographicum in North Wales are described. In contrast to the most commonly occurring morphotype of R. geographicum, which forms mosaics comprised of sharply delimited individual thalli, R. lecanorinum thalli consistently merge with one another at intraspecific contacts, leaving no visible trace of their initial boundaries. On the analogy of mycelial interactions in populations of wood-rotting and other non-lichen-forming fungi, it is postulated that these differences are the outcome, in R. geographicum, of somatic incompatibility between distinct genotypes, and in R. lecanorinum of somatic compatibility among genetically identical or very closely related thalli. Possible mechanisms for the evolution of clonal population structure in R. lecanorinum and links between somatic interactions and reproductive output in these species are discussed. Facultative parasitism of R. lecanorinum by Schaereria fuscocinerea, and resistance to such parasitism by cooccurring R. geographicum, are also documented.

Population structure effect on reproduction of a rare plant: beyond population size effect

2006 ◽  
Vol 84 (9) ◽  
pp. 1371-1379 ◽  
Author(s):  
Arantzazu L. Luzuriaga ◽  
Adrián Escudero ◽  
María José Albert ◽  
Luis Giménez-Benavides
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Reproductive Output ◽  
Seed Set ◽  
Plant Density ◽  
Size Structure ◽  
Seed Mass ◽  
Plant Size ◽  
Aggregation Index ◽  
Negative Effect

Several studies have evaluated the effect of population size on plant reproductive output, but there are few studies concerning the effect of other population structure variables on plant reproduction. In this study, we went beyond population size effect and we tested the effect of some population spatial variables such as plant density, plant aggregation, population structure, and population identity on plant reproductive success and fitness in large populations (>1000 individuals) of Centaurea hyssopifolia Vahl., an endemic species of central Spain. We analysed the reproductive output (capitula, flowers, and seeds) and another two components of plant fitness (seed mass and germinability) in 350 individuals from seven populations in 2002 and 2003. All populations were similar in size but differed in other population spatial characteristics (density, plant aggregation pattern, population plant size structure). We used Morisita’s aggregation index to characterize the level of plant aggregation within populations. Population plant size structure variable determined the proportion of different sized plants in a population. We used generalized linear mixed models to model the contribution of these population spatial variables to several reproductive parameters. Our results showed that whereas the aggregation index exerted a positive control on plant seed set, plant density had a negative effect, and plant population size structure did not significantly influence any response variable. Density only exerted a negative effect on seed set. On the contrary, plant aggregation had a positive effect. Seed mass was also larger in more aggregated populations, although no differences in seed germinability were observed. We detected the effect of population attributes on reproduction in terms of seed set, but we did not detect any effect on other overall reproductive variables measured at plant level. To sum up, our results showed that if population fragments were large enough, spatial population attributes became crucial factors for plant reproductive output and fitness. These easily measurable population variables may improve the conservation management of rare plant species.

scholarly journals Declining reproductive output in capercaillie and black grouse – 16 countries and 80 years

2016 ◽  
Vol 66 (3-4) ◽  
pp. 363-400 ◽  
Author(s):  
Torfinn Jahren ◽  
Torstein Storaas ◽  
Tomas Willebrand ◽  
Pål Fossland Moa ◽  
Bjørn-Roar Hagen
Keyword(s):  
Land Use ◽  
Reproductive Success ◽  
Boreal Forests ◽  
Reproductive Output ◽  
Temporal Trends ◽  
Adult Survival ◽  
Generalist Predator ◽  
Black Grouse ◽  
Proximate Cause ◽  
Underlying Mechanisms

Declines in populations of capercaillie (Tetrao urogallus) and black grouse (Lyrurus tetrix) have been reported from both Central Europe and the continuous boreal forests of Fennoscandia. While intensified land-use is assumed to be the underlying cause of these declines, the mechanisms are not yet understood. Predation is the proximate cause of mortality of eggs, chicks and adults throughout capercaillie and black grouse ranges, but the link between predation and habitat and/or climate change remains unclear. To investigate temporal trends in reproductive output of woodland grouse, we collated previously published and unpublished data of reproduction in capercaillie and black grouse throughout their ranges from 1930 to 2012. We show that, overall, reproductive success has decreased and stabilized at low levels in most regions whilst capercaillie reproductive output in Scotland is still declining. With today’s net reproduction, capercaillie and black grouse adult survival is too low to compensate for reproduction declines. Consequently, populations are expected to further decline unless reproductive performances improve. We put our findings in the context of changes in land use, climate and generalist predator numbers. By critically reviewing how these factors limit reproductive success in capercaillie and black grouse, we hope to shed light on the underlying mechanisms causing the decline. Our results imply that measures should be undertaken to reduce mortality of capercaillie and black grouse chicks and eggs. We suggest that future studies should aim to better understand which predators limit capercaillie and black grouse populations and how predation rates are mediated by continuously changing habitat and climate.

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