Observations on the intrinsic innervation of the islets of Langerhans of Rattus rattus rufescens (Indian black rat)

1975 ◽  
Vol 92 (1) ◽  
pp. 8-13 ◽  
Author(s):  
R.S. Purwar
Keyword(s):  
Islets Of Langerhans ◽  
Rattus Rattus ◽  
Black Rat ◽  
Intrinsic Innervation

MODULATION OF TRIGLYCERIDES IN FEMALE RATTUS RATTUS WITH STEROID CONTRACEPTIVE ALGESTONE ACETOPHENIDE (DHPA)

2019 ◽  
Vol 25 (1) ◽  
Author(s):  
ASHOK KUMAR ◽  
ALPANA PARMAR ◽  
ANAND KUMAR BAJPEYEE
Keyword(s):  
Mixed Type ◽  
Rattus Rattus ◽  
Young Female ◽  
Female Rats ◽  
Control Group ◽  
Black Rat ◽  
Long Acting ◽  
Steroid Contraceptive

Young female Black rat (Rattus rattus), were administered monthly long acting steroid contraceptive to induce hypertriglyceridemia. It was observed that by 3 weeks of the second injection of estrogen containing mixed type of contraceptive, female rats developed consistent and frank hyperglyceridemia . TG in the treated rats was 195.8 ± 7.44 mg /100 ml as compared to 91.5 ± 6.27 mg/100ml in plasma of the control group.

Late-Holocene asynchronous extinction of endemic mammals on the eastern Canary Islands

The Holocene ◽  
2011 ◽  
Vol 22 (7) ◽  
pp. 801-808 ◽  
Author(s):  
Juan Carlos Rando ◽  
Josep Antoni Alcover ◽  
Jacques Michaux ◽  
Rainer Hutterer ◽  
Juan Francisco Navarro
Keyword(s):  
Canary Islands ◽  
Late Holocene ◽  
Middle Age ◽  
Rattus Rattus ◽  
Tyto Alba ◽  
Isolated Populations ◽  
European Contact ◽  
Black Rat ◽  
Local Extinctions ◽  
Ams Dating

The Lava mouse ( Malpaisomys insularis), and the Canarian shrew ( Crocidura canariensis) are endemic of the Eastern Canary Islands and islets. The former is extinct while Canarian shrew survives in the two main islands and two islets. In order to provide insights regarding causes and processes contributing to the extinction of these endemic mammals: (i) we established last occurrence dates for Lava mouse, and first records for two exotic species – House mouse ( Mus musculus) and Black rat ( Rattus rattus) – through direct 14C AMS dating of collagen from bones; (ii) we analysed recent material from Barn owl ( Tyto alba gracilirostris) roosting sites to evaluate its impact on Canarian shrew in the presence of introduced rodents. The new data strongly suggest that the extinction of Lava mouse was the result of an accumulative process of independent disappearances (or ‘local extinctions’) affecting the isolated populations. The timing of the introduction of the Black rat on the main islands (before Middle Age European contact in Lanzarote and after Middle Age European contact in Fuerteventura) matches with the last occurrence dates for the presence of Lava mouse on these islands, and are very probably their cause. The losses of these Lava mouse populations occurred in an asynchronous way, spreading across at least six centuries. On small islands, hyperpredation emerges as the most plausible process to explain the disappearance of the Lava mouse in the absence of rat populations, although stochastic processes can not be definitively excluded.

Introduced predators and cavity-nesting seabirds: unexpected low level of interaction at breeding sites

2008 ◽  
Vol 86 (9) ◽  
pp. 1068-1073 ◽  
Author(s):  
L. Ruffino ◽  
K. Bourgeois ◽  
E. Vidal ◽  
J. Icard ◽  
F. Torre ◽  
...  
Keyword(s):  
Rattus Rattus ◽  
Breeding Cycle ◽  
Mediterranean Islands ◽  
Breeding Sites ◽  
Low Level ◽  
Black Rat ◽  
Cavity Nesting ◽  
Introduced Predators ◽  
Puffinus Yelkouan ◽  
First Time

The mechanisms by which introduced predators and long-lived seabirds interact and even coexist are still poorly known. Here, the interactions between the widely introduced black rat ( Rattus rattus (L., 1758)) and an endemic Mediterranean cavity-nesting seabird, the yelkouan shearwater ( Puffinus yelkouan (Acerbi, 1827)), were for the first time investigated for a set of 60 suitable breeding cavities throughout the entire breeding cycle of this seabird. Our results pointed out that rat visits to cavities were significantly higher when shearwaters had left the colony for their interbreeding exodus. Among the set of suitable breeding cavities, yelkouan shearwaters preferentially selected the deepest and the most winding cavities for breeding. Very few rat visits were recorded at the shearwater-occupied cavities and no predation event was recorded. These intriguing results reveal a low level of interaction between introduced black rats and yelkouan shearwaters, which may have facilitated their long-term coexistence for thousands of years on some Mediterranean islands.

The ecological impacts of commensal species: black rats, Rattus rattus, at the urban–bushland interface

2015 ◽  
Vol 42 (2) ◽  
pp. 86 ◽  
Author(s):  
Peter B. Banks ◽  
Helen M. Smith
Keyword(s):  
Exotic Species ◽  
Urban Areas ◽  
Rattus Rattus ◽  
Research Priorities ◽  
Ecological Impacts ◽  
Black Rat ◽  
Urban Impacts ◽  
Commensal Species ◽  
Commensal Rodents ◽  
Black Rats

Exotic species have had devastating impacts worldwide and are a major threat to native wildlife. Human commensal species (hereafter commensals) are a special class of exotic species that live largely off the resources associated with human activity. The encroachment of commensals from an urban area into surrounding bushland has been frequently overlooked as an important component of urban impacts, even though human-commensals are common to many urban regions globally. In this review, we present theoretical and empirical evidence for the processes and outcomes occurring when exotic commensal species encroach into native bushland. Specifically we ask when, how and why exotic commensal species encroach into bushland, what determines whether they establish, and what are the ecological consequences. We focus on the black rat, Rattus rattus, arguably the archetypal commensal species with a cosmopolitan distribution and the greatest potential for ecological damage of all the commensal rodents. We expect that the processes that we outline apply to other commensal species more broadly. We argue that commensals are in fact natives of the urban milieu and only become alien when they encroach into peri-urban bushland. We propose that the mechanisms of this encroachment will be different from those of other, non-commensal exotic species because urban areas act as dispersal hubs to overcome many of the barriers of invasion that other exotic species face. We suggest that resource supplementation by urban areas creates a great potential for promoting encroachment, invasion as well as impact. However, biotic and abiotic barriers to invasion are still relevant for commensals, highlighting the need to maintain the integrity of ecosystems and wildlife populations in urban edges so as to prevent commensal incursion. We examine how commensal black rats affect wildlife via three fundamental mechanisms, namely, predation, disease transfer and competition for resources, and also consider their possible positive impacts acting as functional replacements for lost natives. We conclude the review with an outline of research priorities and future directions that are essential for progressing our understanding of the ecology of commensal species.

scholarly journals Seasonal demography of different black rat (Rattus rattus) populations under contrasting natural habitats in Guadeloupe (Lesser Antilles, Caribbean)

2020 ◽  
Vol 65 (4) ◽  
pp. 793-804
Author(s):  
Jean Goedert ◽  
David Cochard ◽  
Arnaud Lenoble ◽  
Olivier Lorvelec ◽  
Benoît Pisanu ◽  
...  
Keyword(s):  
Rattus Rattus ◽  
Lesser Antilles ◽  
Natural Habitats ◽  
Black Rat

scholarly journals Genetic structure of black rat populations in a rural plague focus in Madagascar

2007 ◽  
Vol 85 (9) ◽  
pp. 965-972 ◽  
Author(s):  
A. Gilabert ◽  
A. Loiseau ◽  
J.-M. Duplantier ◽  
S. Rahelinirina ◽  
L. Rahalison ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Rattus Rattus ◽  
Geographic Distance ◽  
Distribution Area ◽  
Clear Correlation ◽  
Habitat Segregation ◽  
Fine Spatial Scale ◽  
Natural Systems ◽  
Black Rat ◽  
Indoor And Outdoor

The genetic structure of reservoir populations is a key characteristic in understanding the persistence of infectious diseases in natural systems. In the Highlands of Madagascar, where plague has persisted since 1920, the black rat, Rattus rattus (L., 1758), is the sole species acting as a reservoir of the disease. Ecological surveys have shown a clear correlation between the locations of the plague-persistence area in Madagascar (above 800 m elevation) and the distribution area of one endemic plague vector, the flea Synopsyllus fonquerniei , which is found exclusively on rats living outdoors. This clear habitat segregation has led to the suggestion that R. rattus populations in the central highlands are divided into indoor- and outdoor-dwelling populations. Using eight microsatellite markers, we analysed the genetic structure of R. rattus populations living within a human plague focus in relation to habitat and geographic distance. We found that habitat by itself was not a structuring factor, unlike geographic distance. Nevertheless, the significant genotypic differentiation of R. rattus populations that was found at a fine spatial scale might relate to differences in population dynamics between rats in indoor and outdoor habitats.

Keeping Australia’s islands free of introduced rodents: the Barrow Island example

2013 ◽  
Vol 19 (4) ◽  
pp. 284 ◽  
Author(s):  
Penelope Greenslade ◽  
Andrew A Burbidge ◽  
A Jasmyn ◽  
J Lynch
Keyword(s):  
Rattus Rattus ◽  
Cost Effective ◽  
Processing Plant ◽  
Gas Processing ◽  
Black Rat ◽  
On This Island ◽  
Threatened Taxa ◽  
Eradication Costs ◽  
Economic Considerations ◽  
Black Rats

Islands are important reservoirs of endemic and threatened species, but anthropogenic influences have impacted their biotas. Australia has over 8000 islands, both continental and oceanic, but because of considerably increased traffic, both tourist and commercial, many of these islands have been and are subject to increased threats from invasive species. The invasive Black Rat Rattus rattus is of particular concern as it can negatively impact mammal, bird, reptile, invertebrate and plant populations. Barrow Island, in northwest Western Australia, is an island requiring particular protection from Black Rats as it is a Class A nature reserve with many unique and threatened taxa that is subject to major disturbances from activities associated with oil extraction and a large liquefied natural gas processing plant. Strict quarantine is currently imposed on all materials and persons being sent to the island and there is an intense on-island surveillance programme. So far the protocols used have prevented Black Rats establishing on this island, but such a level of biosecurity is clearly impossible for all islands. In this paper we discuss the effectiveness of quarantine inspections and surveillance together and alone in protecting high-risk, high-value Australian islands against introduced rodents and we document eradication costs for other islands. World-wide, it has only been possible so far to eradicate rats from relatively small islands, mostly with no non-target indigenous mammals and larger islands only where there are no non-target indigenous mammals. Models based largely on economic considerations have suggested it is more cost effective to use surveillance alone without quarantine for Black Rats on Barrow Island and that if rats become widespread (an estimated 4% risk), it may be more cost effective not to attempt eradication. Such models provide useful guidance for managers where biodiversity values are relatively low or where there are no non-target species, but for Barrow island we argue for continuation of quarantine as well as surveillance and an increased level of quarantine controls at the point of departure on all people, vessels and aircraft visiting other vulnerable Australian islands.

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.

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