scholarly journals Studies of some aspects of rodent ecology in the four districts of the gangetic plain of West Bengal, India

1970 ◽  
Vol 27 ◽  
pp. 85-90 ◽  
Author(s):  
Lalyan Brata Santra ◽  
Chanchal Kumar Manna
Keyword(s):  
West Bengal ◽  
Rattus Rattus ◽  
Winter Season ◽  
Late Winter ◽  
Gangetic Plain ◽  
Norway Rat ◽  
Clear Cut ◽  
Mole Rat ◽  
Average Litter Size ◽  
Field Rodents

This study has been conducted in four Districts (i.e., Nadia, North 24-Parganas, Hooghly and Burdwan) of the Gangetic plain of West Bengal, India. The results of the present study indicate that these Districts are badly infested by various types of rodents. Among them wild Indian house rat (Rattus rattus) is quite preponderant followed by field mice (Mus musculus), Norway rat (Rattus norvegicus) and Indian mole rat (Bandicota sp). Percentage of the female individual of these species is higher than the male individual. They cause severe types of damages in the fields and houses. In the District Nadia, Hooghly, North 24-Parganas and Burdwan, paddy and potato were damaged and estimated during the study period. Other crops and vegetables such as wheat, gourd, cauliflower, cabbage and jute were also damaged by the rodents. Household properties e.g., books, clothes, utensils and electronic goods were also destroyed by the rats. Damages were maximum in the mud built houses. They build their nest and burrows in the upland, trees and periphery of the field but extensive damages were noticed in the centre of the field. Rodents breed throughout the year but peak breeding seasons are August to October and late winter season and average litter size is about 6 to 8. The present study also points out the migratory behavior, hoarding materials in the burrows, nature of damages in relation to field conditions. For the control operation of the rodents and especially the rats, it is essential to have a clear-cut idea about the species present in the area, their habit and habitat, mode of burrowing, their movements, preference of food and a detailed life history of predominant rodent species. These aspects have been thoroughly studied in the present investigation. Key words: Gangetic plain, West Bengal, rodents, Rattus rattus, paddy, burrow.    doi:10.3329/ujzru.v27i0.1961 Univ. j. zool. Rajshahi Univ. Vol. 27, 2008 pp. 85-90

scholarly journals Burrowing pattern and damage caused by the rodent pest, Indian house rat (Rattus rattus) in the Gangetic and Non Gangetic plain of West Bengal, India

1970 ◽  
Vol 28 ◽  
pp. 57-60 ◽  
Author(s):  
Debiprasad Chattopadhyay ◽  
Nithar Ranjan Madhu ◽  
Chanchal Kumar Manna
Keyword(s):  
Key Words ◽  
West Bengal ◽  
Rattus Rattus ◽  
Gangetic Plain

Key words: Burrowing pattern; hoarding materials; Gangetic and non Gangetic plain; laterite; alluvial.DOI: 10.3329/ujzru.v28i0.5288Univ. j. zool. Rajshahi Univ. Vol. 28, 2010 pp. 57-60

scholarly journals Butterfly diversity in heterogeneous habitat of Bankura, West Bengal, India

2020 ◽  
Vol 12 (8) ◽  
pp. 15804-15816
Author(s):  
Kalyan Mukherjee ◽  
Ayan Mondal
Keyword(s):  
West Bengal ◽  
Diversity Indices ◽  
Species Number ◽  
Butterfly Species ◽  
Gangetic Plain ◽  
Butterfly Diversity ◽  
Heterogeneous Habitats ◽  
Heterogeneous Habitat ◽  
Chotanagpur Plateau ◽  
Bankura District

Butterfly diversity was observed in different habitats of Bankura District, West Bengal, India.  This district is located at the junction of Chotanagpur plateau and Gangetic plain; it contains a variety of transitional habitats.  We found 117 butterfly species from our covered survey area.  The highest species recorded in the present study belonged to family Lycaenidae (30.76%) and Nymphalidae (29.91%) followed by Hesperiidae (16.23%), Pieridae (13.67%), Papilionidae (8.54%), and Riodinidae (0.85%), respectively.  Based on sighting we found that 12.82% of all the butterflies recorded were abundant in nature while 21.36% were very common, 41.88% were frequent, and 23.93% were rare. Cluster analysis and other diversity indices gives us an overall idea about environmental health.  The pattern of diversity change from plain to plateau gradient gives important insight about ecological edge effect.  High species number in relation with low individual numbers were found in forest habitat.  This preliminary study showed that heterogeneous habitats could harbour many butterflies and need proper conservation efforts to sustain it. 

Owl survey of the Peel–Harvey Estuary in south-western Australia

2017 ◽  
Vol 65 (2) ◽  
pp. 71 ◽  
Author(s):  
Graham R. Fulton
Keyword(s):  
Western Australia ◽  
Oryctolagus Cuniculus ◽  
Rattus Rattus ◽  
Late Winter ◽  
Red Foxes ◽  
Black Rat ◽  
South West ◽  
Eastern Australia ◽  
Ringtail Possum ◽  
Flying Fox

Little is known of owls in south-western Australia compared with the owls of southern and eastern Australia. Surveys of forest owls in the south-west are almost completely lacking. This study sought to determine the abundance and detectability of owls immediately around the Peel–Harvey Estuary in south-western Australia. The southern boobook (Ninox boobook) and the masked owl (Tyto novaehollandiae) were the only owls detected (n = 23 and n = 1 respectively), although the nocturnal tawny frogmouth (Podargus strigoides) was detected from unelicited calls on three occasions. Southern boobooks were found to be common in this area though they are reported to be in decline in south-eastern and inland Australia. Their detectability was significantly greater in August (late winter) than at other times through unelicited calls; otherwise, there were no detections in winter. A variety of small mammals were detected during the surveys, including: a little red flying-fox (Pteropus scapulatus), a western ringtail possum (Pseudocheirus occidentalis), 19 southern brown bandicoots (Isoodon obesulus), 4 common brushtail possums (Trichosurus vulpecula), 21 rabbits (Oryctolagus cuniculus), a black rat (Rattus rattus), 2 red foxes (Vulpes vulpes) and 22 microbats.

scholarly journals Land Situation and Sowing Date Effects Growth and Yield of Crops in the Rice-Pulse Based Cropping Systems of Coastal India

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 152
Author(s):  
Koushik Brahmachari ◽  
Sukamal Sarkar ◽  
Donald S. Gaydon ◽  
Manoj Kumar Nanda ◽  
Argha Ghosh ◽  
...  
Keyword(s):  
West Bengal ◽  
Cropping Systems ◽  
Winter Season ◽  
Cropping System ◽  
Sowing Date ◽  
Growth And Yield ◽  
Limited Area ◽  
Pulse Crops ◽  
Stover Yield ◽  
Saline Zone

The costal saline zone of West Bengal in India is the home for millions of the world’s poorest and most vulnerable people. Due to gradual increase in salt accumulation on soils of the costal saline zone of West Bengal in India from winter to summer days, cultivation of the second crop in winter season becomes possible in a limited area. To address this issue, field experiment was conducted both in rainy and winter seasons of 2016–2017 and 2017–2018 in this zone to study the feasibility of incorporating different winter pulses (lentil and grass pea) in the rice based cropping system. The experiment was conducted in strip plot design having two factors namely, Factor I: Six dates of sowing of rice at an interval of one week (2nd week of June to 3rd week of July) and Factor II: Two land situations (Medium-upland and Medium-lowland). Date of sowing significantly influenced dry matter and macro-nutrients (NPK) partitioning in rice. Irrespective of land situation, crop sown on 1st and 2nd dates recorded significantly higher grain yield and macro-nutrient uptake by rice. Date of sowing of rice and land situation also significantly influenced the seed and stover yield of different pulse crops. Pulse crops sown on 1st and 2nd dates recorded significantly higher seed yield in coastal saline ecology of West Bengal, India.

scholarly journals Snow Thickness Estimation on First-Year Sea Ice from Late Winter Spaceborne Scatterometer Backscatter Variance

2019 ◽  
Vol 11 (4) ◽  
pp. 417 ◽  
Author(s):  
John Yackel ◽  
Torsten Geldsetzer ◽  
Mallik Mahmud ◽  
Vishnu Nandan ◽  
Stephen Howell ◽  
...  
Keyword(s):  
Sea Ice ◽  
Snow Cover ◽  
Winter Season ◽  
Late Winter ◽  
First Year ◽  
Snow Layer ◽  
Independent Case ◽  
Brine Volume ◽  
Snow Thickness

Ku- and C-band spaceborne scatterometer sigma nought (σ°) backscatter data of snow covered landfast first-year sea ice from the Canadian Arctic Archipelago are acquired during the winter season with coincident in situ snow-thickness observations. Our objective is to describe a methodological framework for estimating relative snow thickness on first-year sea ice based on the variance in σ° from daily time series ASCAT and QuikSCAT scatterometer measurements during the late winter season prior to melt onset. We first describe our theoretical basis for this approach, including assumptions and conditions under which the method is ideally suited and then present observational evidence from four independent case studies to support our hypothesis. Results suggest that the approach can provide a relative measure of snow thickness prior to σ° detected melt onset at both Ku- and C-band frequencies. We observe that, during the late winter season, a thinner snow cover displays a larger variance in daily σ° compared to a thicker snow cover on first-year sea ice. This is because for a given increase in air temperature, a thinner snow cover manifests a larger increase in basal snow layer brine volume owing to its higher thermal conductivity, a larger increase in the dielectric constant and a larger increase in σ° at both Ku- and C bands. The approach does not apply when snow thickness distributions on first-year sea ice being compared are statistically similar, indicating that similar late winter σ° variances likely indicate regions of similar snow thickness.

scholarly journals Absence of Ship Rat Rattus rattus, and Norway Rat Rattus norvegicus, on Ouvea (Loyalty Islands, New Caledonia): consequences for conservation

1995 ◽  
Vol 2 (4) ◽  
pp. 390 ◽  
Author(s):  
Olivier Robinet ◽  
Michel Salas
Keyword(s):  
Success Rate ◽  
New Caledonia ◽  
Action Plan ◽  
Rattus Rattus ◽  
Indirect Evidence ◽  
Barn Owl ◽  
Norway Rat ◽  
Crop Fields ◽  
The Pacific ◽  
Ship Rat

A rat trapping campaign was conducted from July to December 1994 on Ouvea in the Loyalty Islands, New Caledonia. Locations of rat traps took into account different geographic sectors (North, Centre, South and Islets) and different habitats (forest, crop fields, coconut plantations, houses). The campaign encompassed a total of 1 363 trap nights and autopsy data were collected on rodents that were captured. Vertebrate remains from Barn Owl roosts were also collected and examined to determine which rat species were present. For the whole campaign the corrected trap success rate was 9.5 rodents per 100 trap nights. No significant variations in the trap success rate were observed in relation to geographic sector or habitat. Ninety-eight rodents were captured and 64 identified: six Mus musculus and 58 Rattus exulans. No Rattus rattus and no R. norvegicus were caught. Similarly, the only species identified from material found in Barn Owl roosts were M. musculus and R. exulans. Observation of the fauna and environment on Ouvea provided some indirect evidence to confirm the absence of both R. rattusand R. norvegicus. The history and geographical characteristics of Ouvea, and certainly chance, could explain the fact that these two species never reached the island. With regard to rat species, Ouvea's situation is remarkable and unique in the Pacific for inhabited islands of comparable size and level of development. Considering the dramatic and well known effects resulting from the introduction of rat species such as R. rattus and R. norvegicus on small Pacific Island environments, the authors have alerted local authorities and the population of Ouvea, and have proposed initial measures as part of an action plan.

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