Hypotensive Effects of an Aqueous Extract of Bambusa vulgaris (Poaceae) Leaves in Rabbit Oryctolagus cuniculus

Plant of Bambusa vulgaris is used in traditional medicine practice for the management of many pathologies including hypertension. The effect of the aqueous extract of the leaves of Bambusa vulgaris on blood pressure was evaluated in normotensive male rabbits. Blood pressure was measured by the invasive method. Thus, aqueous extract of Bambusa vulgaris leaves had been injected intravenously at doses ranging from 1 mg/kg to 30 mg/kg in rabbits anesthetized with thiopental. The effects of this extract on blood pressure were also evaluated in rabbits having previously received different doses of atropine. The aqueous extract of Bambusa vulgaris leaves induced a dose-dependent hypotension which is not canceled in the presence of atropine. The results obtained show that the extract has blood pressure lowering effect which may be mediated by muscarinic-type cholinergic receptors.

Teratogenicity Studies of a New Potent Tetanus Vaccine in Rabbit (Oryctolagus cuniculus)

Glaxo Laboratories, Bombay, have prepared a potent tetanus vaccine of 250 Lf as a substitute of the previous 5 Lf tetanus vaccine. The safety evaluation of the vaccine has been reported, but the teratogenic potential was not studied. In the experiment reported herein we have studied the teratogenic action of the vaccine in the progeny of rabbits. No congenital anomalies were observed.

Successful eradication of the European rabbit(Oryctolagus cuniculus)and house mouse(Mus musculus)from the island of Selvagem Grande(Macaronesian archipelago),in the Eastern Atlantic

The Portuguese island of Selvagem Grande(Great Salvage)in Macaronesia is an important seabird breeding station in the eastern Atlantic.Significant populations of Cory’s shearwater Calonectris diomedea(Scopoli,1769),Bulwer’s petrel Bulweria bulweria(Jardine&Selby,1828)and little shearwater Puffinus assimilis baroli(Bonaparte,1857)are present,and white-faced storm-petrel Pelagodroma marina(Latham,1790)and Madeiran storm-petrel Oceanodroma castro(Harcourt,1851)populations are of global significance.Selvagem Grande also provides diverse habitats for an extensive flora,including 11 endemic species.The 270-ha island was also inhabited by two alien invasive mammals:the European rabbit Oryctolagus cuniculus(Linnaeus,1758)and the house mouse Mus musculus(Linnaeus,1758).Both are known to have had adverse impacts on breeding seabirds and island vegetation.In 2002,the Natural Park of Madeira conducted a program using brodifacoum bait formulations aimed at rabbit and mouse eradication.Approximately 17000 individual baiting points were established on a 12.5×12.5 m grid.Baits were also applied by hand“seeding”on steep slopes and cliffs where bait stations could not be placed.Rabbits were removed after a month.However,mice persisted for considerably longer and strategic bait applications against them continued for a further six months.Subsequent assessments by trapping,bait takes and systematic observa-tion of signs over three years,has confirmed the removal of both alien invasive species.This paper presents information on these operations,on measures adopted to mitigate adverse impacts of the eradication program on important vertebrate non-target species,including Berthelot’s pipit Anthus berthelotii Bolle,1862 and a species of gecko Tarentola bischoffi Joger,1984 and on the initial response of the island’s ecosystem to the eradication of rabbits and mice.

Forage offering and seasonal intake comparisons to evaluate European rabbit threat in Nothofagus forests of southern Patagonia

Background:The European rabbit(Oryctolagus cuniculus L.1758)was introduced into different regions of the world,generating significant trade‑offs that critically impacted native vegetation.Here,we evaluate the rabbit’s forage intakes in three vegetation types(forests,shrublands,and grasslands)along the four seasons in a temperate forest landscape in Southern Patagonia and discuss the potential threats over native vegetation.We formulated the following questions:(i)what is the forage offer at each vegetation type?(ii)what is the rabbit’s forage intake and how it varied across the seasons along the year?and(iii)which vegetation types and plant life forms were more used according to the rabbit’s forage intakes?Methods:We censused understory vegetation to characterize the forage offer at each vegetation type and determined seasonal dietary intakes using microhistological analysis of pellets.The plant species identified in the field were grouped according to life form classes(tree regeneration,shrubs,forbs,graminoids,orchids,ferns,bryophytes,and hemiparasites).Data were analysed through uni‑and multi‑variate analyses,determining relationships between forage offer and the rabbit’s forage intakes.Results:Forage intakes revealed changes in plant life form consumption across vegetation types,where intake pressure was considerably different for tree regeneration(p=0.001),graminoids(p=0.001),and hemiparasites(p=0.001).Besides,significant changes in consumption among seasons were detected for shrubs(p=0.001),ferns(p=0.030),and hemiparasites(p=0.002).Although many species play an important role in the rabbit’s forage intake networks(e.g.,Chiliotrichum diffusum,Holcus lanatus),the strongest intake linkages were found in exotic grasses(e.g.,Poa pratensis and Festuca sp.),native hemiparasites(e.g.,Misodendrum sp.),native shrubs(e.g.,Empetrum rubrum),and native trees(e.g.,Nothofagus sp.).The summer and autumn seasons presented higher intake compared to the winter and spring seasons.Furthermore,hemiparasites intake(e.g.,Misodendrum sp.)suggests that rabbits utilize different forage sources depending on the vegetation types.Conclusions:Rabbits regularly inhabit the forest,even though it is not their preferred vegetation type to live.Rabbit management entails isolating regions that are more favourable to intake and emphasizing the year’s season for rabbit control efforts.

Trophic niche changes associated with the eradication of invasive mammals in an insular lizard: an assessment using isotopes

Invasive species are a major threat to island biodiversity,and their eradications have substantially contributed to the conservation of island endemics.However,the consequences of eradications on the trophic ecology of native taxa are largely unexplored.Here,we used the eradication of invasive black rats Rattus rattus and European rabbits Oryctolagus cuniculus from the Berlenga Island,in the western coast of Portugal,as a whole-ecosystem experiment to investigate the effects of the eradication of invasive mammals on the trophic niche and body dimensions of the island-restricted Berlenga wall lizard Podarcis carbonelli berlengensis over a 2-year period.Our results suggest an expansion of the isotopic niche and an intensification of the sexual dimorphism of the lizard following mammal eradication.Additionally,we found considerable variability in isotopic niche across the island and detected evidence of sex-specific and season-modulated nutritional requirements of this threatened reptile.Our findings support that the eradication of 2 of the planets most problematic invasive vertebrates led to changes in the lizard trophic niche and sexual dimorphism in just 2 years.This suggests that the ecological pressuresfor example,prey availability and habitat structureto which lizards are exposed have substantially changed post-eradication.Our study emphasizes the scientific value of island eradications as experiments to address a wide range of ecological questions and adds to the increasing body of evidence supporting substantial conservation gains associated with these restoration interventions.