Preliminary Investigation into the Population Size and Habitat Characteristics of Triplophysa erythraea in the Dalong Cave, Huayuan County, Xiangxi Prefecture, China

2019 ◽  
Vol 08 (04) ◽  
pp. 278-282
Author(s):  
思思 严
Keyword(s):  
Population Size ◽  
Preliminary Investigation ◽  
Habitat Characteristics

A PRELIMINARY INVESTIGATION OF THE FACTORS REGULATING POPULATION SIZE IN THE WOODPIGEON COLUMBA PALUMBUS

Ibis ◽  
1964 ◽  
Vol 106 (4) ◽  
pp. 482-507 ◽  
Author(s):  
R. K. Murton ◽  
N. J. Westwood ◽  
A. J. Isaacson
Keyword(s):  
Population Size ◽  
Preliminary Investigation

Population Size and Habitat Characteristics of the Indo-Pacific Humpback Dolphin (Sousa chinensis) Off Donsak, Surat Thani, Thailand

2015 ◽  
Vol 41 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Suwat Jutapruet ◽  
Shiang-Lin Huang ◽  
Songhai Li ◽  
Mingli Lin ◽  
Kongkiat Kittiwattanawong ◽  
...  
Keyword(s):  
Population Size ◽  
Habitat Characteristics ◽  
Sousa Chinensis

Habitat Characteristics, Population Size, and Home Range of the Bog Turtle, Clemmys muhlenbergii, in Maryland

1989 ◽  
Vol 23 (4) ◽  
pp. 356 ◽  
Author(s):  
Janis Davis Chase ◽  
Kenneth R. Dixon ◽  
J. Edward Gates ◽  
Dan Jacobs ◽  
Gary J. Taylor
Keyword(s):  
Home Range ◽  
Population Size ◽  
Habitat Characteristics ◽  
Bog Turtle ◽  
Clemmys Muhlenbergii

scholarly journals Distribution, Population Size, and Habitat Characteristics of the Endangered European Ground Squirrel (Spermophilus citellus, Rodentia, Mammalia) in Its Southernmost Range

2021 ◽  
Vol 13 (15) ◽  
pp. 8411
Author(s):  
Dimitra-Lida Rammou ◽  
Dimitris Kavroudakis ◽  
Dionisios Youlatos
Keyword(s):  
Population Size ◽  
Ground Squirrel ◽  
Agricultural Land ◽  
Land Use Changes ◽  
Population Decline ◽  
Habitat Characteristics ◽  
System Productivity ◽  
Agroecological Zones ◽  
Conservation Actions ◽  
Spermophilus Citellus

The European ground squirrel (Spermophilus citellus) is an endangered species, endemic to Central and Southeastern Europe, inhabiting burrow colonies in grassland and agricultural ecosystems. In recent years, agricultural land-use changes and increased urbanization have largely contributed to a severe population decline across its range, particularly in its southernmost edge. Assessing the population and habitat status of this species is essential for prioritizing appropriate conservation actions. The present study aims to track population size changes and identify habitat characteristics of the species in Greece via a literature search, questionnaires, and fieldwork for assessing trends in population size as well as spatial K-means analysis for estimating its relation to specific habitat attributes. We found that both distribution size (grid number) and colony numbers of the species decreased in the last decades (by 62.4% and 74.6%, respectively). The remaining colonies are isolated and characterized by low density (mean = 7.4 ± 8.6 ind/ha) and low number of animals (mean = 13 ± 16 individuals). Most of the colonies are situated in lowlands and did not relate to specific habitat attributes. Habitat aspect and system productivity (NDVI) were the main factors contributing mostly to the clustering of the existing colonies. These results demonstrate that the species is confined to small, isolated anthropogenic habitats. Specific conservation actions such as population reinforcement, habitat improvement, and specific common agricultural policy measures could effectively improve agroecological zones that are suitable for the maintenance and protection of existing and potential habitats for populations of the species.

scholarly journals Habitat differentiation and population traits variation between the rare Meconopsis napaulensis and the common congener M. paniculata: Implications for rare plant management

1970 ◽  
Vol 8 ◽  
pp. 57-69 ◽  
Author(s):  
Mukti Ram Poudeyal ◽  
Suresh Kumar Ghimire
Keyword(s):  
Population Size ◽  
Habitat Characteristics ◽  
Plant Management ◽  
Habitat Specificity ◽  
Habitat Features ◽  
Topographic Features ◽  
Area Of Occupancy ◽  
Habitat Differentiation ◽  
Rocky Habitats ◽  
The Impact

Understanding the causes of rarity has become increasingly important for the conservation and management of plant species. In this study, we compared spatial distribution, habitat characteristics, and population size and structure of two closely related species of poppy occurring in the Himalaya, the rare and endemic Meconopsis napaulensis and the widespread common congener M. paniculata in order to explain the causes of rarity of the former species. This study was carried out in Langtang National Park, north-central Nepal covering six populations of M. napaulensis and four populations of M. paniculata. Analysis of the habitat features revealed greater tendency of M. napaulensis to exhibit high habitat specificity. It was restricted to nutrient-poor, open and rocky habitats at >3700 m asl. Sites where M. paniculata were sampled showed high variability in terms of edaphic and topographic features. Mean ‘area of occupancy’ tended to be high for M. paniculata compared to M. napaulensis. M. paniculata showed larger population size and greater abundance as compared to M. napaulensis. The poor representation of younger life stages in M. napaulensis despite high proportion of reproductive adults indicated lower recruitment potential. The present study has illustrated that the rarity of M. napaulensis is strongly related to a combination of ecological and geographical constraints, which prevent reproduction, dispersal and colonization. It further demonstrates that the maintenance of population size of rare species largely depends on the survival and abundance of plants of younger stages. Thus, management directed towards reducing the impact on plants of young stages and protecting reproductive individuals from flower and fruit harvesting would help to maintain population size. Finally, development of action plans and guidelines incorporating scientific findings and accommodating local peoples’ socio-economic and cultural factors associated with the extinction risks is imperative for the conservation of rare and endemic species.doi: http://dx.doi.org/10.3126/botor.v8i0.5959 Botanica Orientalis – Journal of Plant Science (2011) 8: 57-69

scholarly journals Population size and habitat relationships of Black-bellied Sandgrouse Pterocles orientalis in the Canary Islands, Spain

2009 ◽  
Vol 20 (2) ◽  
pp. 161-175 ◽  
Author(s):  
JAVIER SEOANE ◽  
LUIS M. CARRASCAL ◽  
DAVID PALOMINO ◽  
C. LUIS ALONSO
Keyword(s):  
Population Size ◽  
Canary Islands ◽  
Distance Sampling ◽  
Breeding Population ◽  
Absolute Number ◽  
Habitat Characteristics ◽  
Ndvi Index ◽  
Rock Cover ◽  
Birds Directive ◽  
Special Protection Areas

SummaryWe estimated the breeding population size and assess the habitat relationships of Black-bellied Sandgrouse in the Eastern Canary Islands (Fuerteventura, Lanzarote and La Graciosa, Spain) by means of a survey based on 1,787 0.5-km line transects and distance sampling done in 2005 and 2006. The population comprised 2,906 individuals (90% CI: 2,363–3,562), which is much higher than the numbers estimated in previous reports based on partial surveys, and constitutes 20% of the total Spanish population. Sandgrouse in the Canaries are currently restricted to Fuerteventura, where 70% of the population gathers in four areas that encompass just 16.7 % of the island and are largely within Special Protection Areas classified under the EU Birds Directive (except the area of Tefia-Ampuyenta, first in absolute number of individuals). The environmental characteristics that maximize the probability of occurrence of the sandgrouse in Fuerteventura (probability = 0.196) are: treeless non-cultivated areas of sandy soils without bare bedrock, with a rock cover less than 44%, located in non-coastal areas with an average terrain slope less than 27.5%, at more than 400 m from the nearest urban area, with less than 795 m of dirt roads per 20 ha, with at least 0.9% of shrub cover and a NDVI index higher than 53. Sandgrouse were closer to human settlements in midsummer than in March, perhaps being attracted to artificial pools surrounding villages. Similar habitat characteristics exist in nearby Lanzarote, where the species could hypothetically reach densities as high as 4–5 birds km−2. Possible reasons for the absence of sandgrouse in this island are discussed.

Effects of tourism disturbance on habitat quality and population size of the Chinese giant salamander (Andrias davidianus)

2018 ◽  
Vol 45 (5) ◽  
pp. 411 ◽  
Author(s):  
Qinghua Luo ◽  
Yingjie Song ◽  
Xiao Hu ◽  
Shenhai Zhu ◽  
Han Wang ◽  
...  
Keyword(s):  
Population Size ◽  
Habitat Quality ◽  
Habitat Characteristics ◽  
Negative Effects ◽  
Coordinated Development ◽  
Andrias Davidianus ◽  
Animal Protection ◽  
Aquatic Microbes ◽  
Chinese Giant Salamander ◽  
Pathogenic Microbes

Context Tourism is becoming one of the largest and fastest growing industries in many countries. Increasing tourism exerts serious impacts on the habitats of wildlife in nature reserves. Aims To ascertain how tourism affects the habitat of the Chinese giant salamander (Andrias davidianus), especially water quality and population size. Method An experiment was conducted to investigate the influences of different tourism disturbance intensities on the habitat quality and population size of the Chinese giant salamander in the Hunan Zhangjiajie Chinese Giant Salamander National Nature Reserve. Habitat characteristics, water physicochemical properties and microbial abundance were analysed, and population size estimated. Key results The results showed that high levels of tourism disturbance (>100 000 visitors per year) had negative effects on habitat quality. These effects included increased noise and abundance of aquatic microbes, increased concentration of total nitrogen (TN) and total phosphorus (TP) and a reduction of dissolved oxygen (DO) in water. The abundance of Escherichia coli could be regarded as an indicator of tourism disturbance on Chinese giant salamander. Conclusions It is concluded that: (1) the habitats were much noisier with increasing numbers of tourists, which might directly reduce the population size; (2) tourism indirectly disturbs the salamander population by increasing TN and TP, and reducing DO in the water; and (3) tourism might take in pathogenic microbes to the water habitats, which could cause disease for the salamander population. Implications Although tourism development might reduce local poverty, such efforts must consider the deterioration of habitats for wildlife, especially for this endangered animal species. Moreover, the intensity of tourism disturbance needs be reduced (by controlling the number of tourists) to achieve the coordinated development of tourism and wild animal protection.

A preliminary investigation into the potential impacts of fire on a forest dependent burrowing frog species

2006 ◽  
Vol 12 (1) ◽  
pp. 78 ◽  
Author(s):  
T. D. Penman ◽  
F. L. Lemckert ◽  
M. J. Mahony
Keyword(s):  
Population Size ◽  
Negative Impact ◽  
Preliminary Investigation ◽  
Management Issue ◽  
Frog Species ◽  
The Impact

The impact of fire on anurans is generally poorly understood and the response appears to vary between species, habitats and regions (Pilliod et al. 2003). Studies monitoring population size following fires have observed populations increasing (Kirkland et al. 1996; Roberts et al. 1999), remaining stable (Bamford 1992; deMaynadier and Hunter 1995; Lemckert et al. 2004) and decreasing (Bamford 1992; Driscoll and Roberts 1999; Papp and Papp 2000), with one study observing a localized extinction (Lemckert 2000). Therefore, when fire has a negative impact, it can be severe and present a serious management issue.

Habitat characteristics and population size of Iranocypris typhlops, the Iran cave barb

2016 ◽  
Vol 99 (2-3) ◽  
pp. 179-185
Author(s):  
M. Bagheri ◽  
F. Goudarzi ◽  
A. H. Zalaghi ◽  
M. Savabieasfahani
Keyword(s):  
Population Size ◽  
Habitat Characteristics

Surface ultrastructure of danazol treated rat endometrium: A SEM study

1983 ◽  
Vol 41 ◽  
pp. 556-557
Author(s):  
R.P. Apkarian ◽  
J.S. Sanfilippo
Keyword(s):  
Cross Sections ◽  
Reproductive Tract ◽  
Preliminary Investigation ◽  
Breast Disease ◽  
Distal Segment ◽  
Uterine Horn ◽  
Female Reproductive Tract ◽  
Ultrastructural Changes ◽  
Cycle Phase ◽  
Sprague Dawley

The synthetic androgen danazol, is an isoxazol derivative of ethisterone. It is utilized in the treatment of endometriosis, fibrocystic breast disease, and has a potential use as a contraceptive. A study was designed to evaluate the ultrastructural changes associated with danazol therapy in a rat model. The preliminary investigation of the distal segment of the rat uterine horn was undertaken as part of a larger study intended to elucidate the effects of danazol on the female reproductive tract.Cross-sections (2-3 mm in length) of the distal segment of the uterine horn from sixteen Sprague-Dawley rats were prepared for SEM. Ten rats in estrus served as controls and six danazol treated rats were noted to have alterations of the estrus cycle i.e. a lag in cycle phase or noncycling patterns. Specimens were fixed in 3% glutaraldehyde in 0.05M phosphate buffer containing CaCl2 at pH 7.0-7.4 and chilled to 4°C. After a brief wash in distilled water, specimens were passed through a graded series of ethanol, critical point dryed in CO2 from absolute ethanol, and coated with 6nm Au. Observations were made with an IS1-40 SEM operated at 15kV.

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