Orkney's seabirds and coastal otters

1985 ◽  
Vol 87 (1-2) ◽  
pp. 83-93
Author(s):  
Peter Reynolds
Keyword(s):  
Population Size ◽  
Size Distribution ◽  
Highland Region ◽  
Distribution And Ecology

SynopsisThe size and distribution of Orkney's breeding seabird populations are relatively well known, with cliff-nesting species having been monitored annually since 1976. Conditions for these monitored species appear to be less favourable now than they were at the beginning of the study.Nationally significant populations of seaducks and waders winter in Orkney. With exceptions, the population size, distribution and ecology of these birds is only poorly understood.Otters appear to be widespread; however, spraint surveys suggest that these animals may not be as numerous in Orkney as they are in Shetland, the Western Isles and Highland Region.

The white-chinned petrel (Procellaria aequinoctialis) on South Georgia: population size, distribution and global significance

Polar Biology ◽  
2009 ◽  
Vol 32 (4) ◽  
pp. 655-661 ◽  
Author(s):  
A. R. Martin ◽  
S. Poncet ◽  
C. Barbraud ◽  
E. Foster ◽  
P. Fretwell ◽  
...  
Keyword(s):  
Population Size ◽  
Size Distribution ◽  
South Georgia ◽  
Procellaria Aequinoctialis ◽  
Georgia Population

Flood disturbance and shade stress shape the population structure of açaí palm Euterpe precatoria, the most abundant Amazon species

Botany ◽  
2020 ◽  
Vol 98 (3) ◽  
pp. 147-160
Author(s):  
Heloisa Dantas Brum ◽  
Alexandre F. Souza
Keyword(s):  
Population Structure ◽  
Population Size ◽  
Size Distribution ◽  
Amazon Basin ◽  
Habitat Type ◽  
Forest Products ◽  
Life Stages ◽  
Disturbance Regime ◽  
Human Settlements ◽  
Human Management

Euterpe precatoria Mart. is the most abundant plant species in the Amazon basin, and one of the main non-timber forest products on the continent. A thorough understanding of the ecology of this species is needed to support sustainable management initiatives. Resource availability, disturbance regime, and human management are some of the main factors influencing population structure. We described the species’ life stages, evaluated its allometric relationships, and assessed the effects of habitat type (floodplain and upland) and proximity to human settlements on population size distribution in the Central Amazon near the Purus River. The height:diameter ratio increased from Seedlings to Juvenile 2, but decreased from Juvenile 2 to Reproductive 2, indicating changing height investment for any given diameter along these life stages. There was a marked habitat dependency in both the density and population size distribution, with populations in upland forests dominated by juveniles, whereas populations in the floodplains were dominated by reproductive palms. Proximity to human settlements was not related to population structure parameters. Our results suggest that the disturbance regime may have opposite meanings in várzea forests, where it limits recruitment under increased light levels, and in terra firme forests, where it may stimulate recruitment under limited light conditions.

Brachioteuthis beanii Verrill, 1881 (Cephalopoda: Brachioteuthidae) in the northwest Atlantic

2020 ◽  
Vol 96 (2) ◽  
pp. 309-322
Author(s):  
Elizabeth K Shea ◽  
Judy Stadler ◽  
Annie Lindgren
Keyword(s):  
Nova Scotia ◽  
Food Web ◽  
Population Size ◽  
Size Distribution ◽  
Protected Area ◽  
Marine Protected Area ◽  
Measurement Data ◽  
Spawning Aggregation ◽  
Males And Females ◽  
External Ornamentation

Four research cruises to the Gully Marine Protected Area (known as "the Gully") off Nova Scotia, Canada (2007–2010) collected 1454 specimens of the oegopsid squid family Brachioteuthidae. All specimens were identified as Brachioteuthis beanii, and the 842 individuals collected in 2007 were used to describe the morphology and ecology of the species. A subset of 565 specimens were measured for population size distribution, and over 200 of these individuals (21–117 mm ML) were fixed, vouchered, measured, dissected, and sexed to examine the internal and external characters of juveniles, males, and females. Specimens <40 mm ML were almost entirely juveniles. Specimens 40–49 mm ML were a mix of juveniles, males, and females. The smallest specimens, where the spermatophoric complex and nidamental glands could be identified, were approximately 39 mm ML in both males and females, suggesting that maturation begins at roughly the same size in both sexes. Specimens >50 mm ML could be sexed based solely on the color and texture of the mantle. Male mantles were fusiform in shape with few small, widely spaced chromatophores and a reticulated net on the mantle that developed concurrent with the internal spermatophoric complex. Females had a flaccid mantle with larger and denser chromatophores on the mantle and head and no external ornamentation (i.e., ridges or nodules). Measurement data showed that males had slightly larger arms and wider fins than females. The high abundance of B. beanii at the Gully in August/September may be a spawning aggregation and suggests that this small squid is an important component of the canyon food web.

scholarly journals Reconsidering Zipf’s law for regional development: The case of settlements and cities in Croatia

2018 ◽  
Vol 22 (1) ◽  
pp. 22-30
Author(s):  
Hrvoje Josic ◽  
Maja Bašić
Keyword(s):  
Regional Development ◽  
Population Size ◽  
Size Distribution ◽  
Population Survey ◽  
Urban Economics ◽  
Urban Agglomeration ◽  
Zipf’S Law ◽  
Statistical Relationship ◽  
Zipf's Law ◽  
Urban Agglomerations

Abstract Zipf’s law is a striking regularity in the field of urban economics that states that the sizes of cities should follow the rank-size distribution. Rank-size distribution, or the rank-size rule, is a commonly observed statistical relationship between the population size and population rank of a nations’ cities. The goal of this paper is to test Zipf’s law as applied to data for settlements and cities in Croatia using the Census of Population Survey for the year 2011. The results of the analysis have shown that Zipf’s law for settlements in Croatia holds true for the majority of the settlement sizes. However, the rank-size distribution does not hold true for extremely small and extremely large settlement sizes. When city proper and urban agglomeration of 127 Croatian cities were examined, Zipf’s law was found to hold true only for urban agglomerations. The results of the study are discussed in terms of regional development.

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