(Press-News.org) An invading species of shrew first discovered in Ireland in the pellets of barn owls and kestrels in 2007 is spreading across the landscape at a rate of more than five kilometres a year, according to findings published in the scientific journal PLOS ONE.
University College Dublin scientists who conducted the study say that the invading species, the greater white-toothed shrew (Crocidura russula) is capable of colonizing the entire island by 2050. This, they say, is leading to the disappearance of the pygmy shrew (Sorex minutus) from Ireland, one of the world's smallest mammals, which has been on the island for thousands of years.
"The invading population of the greater white-toothed shrew currently covers an area of 7,600 km2 and is found in Counties Tipperary, Limerick, Cork, Waterford, Kilkenny, Offaly and Laois," says Dr Allan McDevitt, UCD School of Biology and Environmental Science, University College Dublin, the lead author of the paper.
"Small satellite populations have also been found in Cork city and more recently in Mullingar, but according to our data they have not yet crossed the Shannon," he adds.
"Species can live together after invasions occur, but in this case there may not be sufficient landscape complexity in Ireland to allow niche partitioning between these two species of shrew."
"The displacement of the pygmy shrew will continue in Ireland as the greater white-toothed shrew carries on spreading rapidly, with the invader only being temporarily hindered by rivers and other barriers," adds Dr Jon Yearsley, a co-author on the PLOS ONE paper, who is also based at University College Dublin.
"Our findings suggest that at the present expansion rate, the greater white-toothed shrew is capable of colonizing the whole island of Ireland by 2050," he says.
"The sheer speed of the invasion of the greater white-toothed shrew and its competitive superiority in eating large insect prey could have severe negative impacts on the population of Irish pygmy shrews, and even lead to its local extinction."
"The greater white-toothed shrew needs to be recognized as an invasive species that has the potential to have a large negative impact on the Irish ecosystem", says Dr Allan McDevitt.
"With these findings, we appeal to the appropriate authorities in both the Republic of Ireland and Northern Ireland to address the issue of invasive species causing severe ecological impacts across the island."
According to Professor Ian Montgomery of Queen's University Belfast, who recently published in the journal Biological Invasions on the impact of invasive small mammals on Ireland's resident small mammal populations, ensuring bigger hedgerows and more deciduous woodland may enable the protection of species against invaders.
The pygmy shrew is one of the world's smallest mammals. Adults weigh between 3 and 6g. They have iron deposits at the tip of their teeth which give them a red colour. They have brownish hair on upper surface and whitish grey on the belly. Their tails are thick, hairy and long relative to its body size.
The greater white-toothed shrew can weigh between 8 and 14g, or about three times the size of the pygmy shrew. As their name suggests, they have distinctive white teeth. They are bicoloured, with greyish brown hair on upper surface and yellowish grey lower belly. They have prominent ears and long, white hairs on their tail.
Pygmy shrew population in Ireland threatened by invasion of greater white-toothed shrew
ELSE PRESS RELEASES FROM THIS DATE:
Women sometimes benefit more from cardiac resynchronization therapy than men
Bottom Line: Cardiac resynchronization therapy plus defibrillator implantation (CRT-D) sometimes helps women with heart failure more than men, although women are less likely to receive CRT-D than men. Author: Robbert Zusterzeel, M.D., and colleagues at the Center for Devices and Radiological Health at the U.S. Food and Drug Administration, Silver Spring, Md. Background: Women are underrepresented in CRT trials for heart failure, making up only about 20 percent of participants. In selected heart failure patients CRT, or biventricular pacing, is used to help improve ...
Examining lifetime intellectual enrichment and cognitive decline in older patients
Bottom Line: Higher scores that gauged education (years of school completed) and occupation (based on attributes, complexities of a job), as well as higher levels of mid/late-life cognitive activity (e.g., reading books, participating in social activities and doing computer activities at least three times per week) were linked to better cognition in older patients. Author: Prashanthi Vemuri, Ph.D., of the Mayo Clinic and Foundation, Rochester, Minn., and colleagues. Background: Previous research has linked intellectual enrichment with possible protection against ...
Intervention appears to help teen drivers get more, better practice
Bottom Line: A web-based program for teen drivers appears to improve driving performance and quality supervised practice time before teens are licensed. Author: Jessica H. Mirman, Ph.D., of The Children's Hospital of Philadelphia, and colleagues. Background: During the learner phase of driver education, most states have requirements for supervisors and practice content. However, parent supervisors can vary in their interest, ability and approach to driving supervision. Inexperience is a contributing factor in car crashes involving novice drivers. How the Study ...
Mammals defend against viruses differently than invertebrates
Biologists have long wondered if mammals share the elegant system used by insects, bacteria and other invertebrates to defend against viral infection. Two back-to-back studies in the journal Science last year said the answer is yes, but a study just published in Cell Reports by researchers at the Icahn School of Medicine at Mount Sinai found the opposite. In the Mount Sinai study, the results found that the defense system used by invertebrates — RNA interferences or RNAi — is not used by mammals as some had argued. RNAi are small molecules that attach to molecular scissors ...
Many ER patients test positive for HIV while in most infectious stage
WASHINGTON — Human Immunodeficiency Virus (HIV) screening for emergency patients at an institution with a large number of ethnic minority, underinsured and uninsured people reveals few are HIV positive, but of those who are, nearly one-quarter are in the acute phase and more than one-quarter have infections that have already advanced to Acquired Immune Deficiency Syndrome (AIDS). The results of the study were reported online yesterday in Annals of Emergency Medicine ("Identification of Acute HIV Infection Using Fourth Generation Testing in an Opt-Out Emergency Department ...
Fatal cellular malfunction identified in Huntington's disease
Researchers believe they have learned how mutations in the gene that causes Huntington's disease kill brain cells, a finding that could open new opportunities for treating the fatal disorder. Scientists first linked the gene to the inherited disease more than 20 years ago. Huntington's disease affects five to seven people out of every 100,000. Symptoms, which typically begin in middle age, include involuntary jerking movements, disrupted coordination and cognitive problems such as dementia. Drugs cannot slow or stop the progressive decline caused by the disorder, which ...
Cocoa extract may counter specific mechanisms of Alzheimer's disease
(NEW YORK – June 23) A specific preparation of cocoa-extract called Lavado may reduce damage to nerve pathways seen in Alzheimer's disease patients' brains long before they develop symptoms, according to a study conducted at the Icahn School of Medicine at Mount Sinai and published June 20 in the Journal of Alzheimer's Disease (JAD). Specifically, the study results, using mice genetically engineered to mimic Alzheimer's disease, suggest that Lavado cocoa extract prevents the protein β-amyloid- (Aβ) from gradually forming sticky clumps in the brain, which ...
'Tom Sawyer' regulatory protein initiates gene transcription in a hit-and-run mechanism
A team of genome scientists has identified a "hit-and-run" mechanism that allows regulatory proteins in the nucleus to adopt a "Tom Sawyer" behavior when it comes to the work of initiating gene activation. Their research, which appears in the Proceedings of the National Academy of Sciences, focuses on transcription factors—proteins that orchestrate the flow of genetic information from DNA to messenger RNA (mRNA). Their results show how transcription factors (TFs) activate mRNA synthesis of a gene, and leave the scene – in a model termed "hit-and-run" transcription. "Much ...
Treading into a gray area along the spectrum of wood decay fungi
One of the most basic rules for playing the game "Twenty Questions" is that all of the questions must be definitively answered by either "yes" or "no." The exchange of information allows the players to correctly guess the item in question. Fungal researchers have been using a variation of Twenty Questions to determine if wood-decaying fungi fall under one of two general classes. If a fungus can break down all the components – cellulose, hemicellulose and lignin – of plant cell walls it is considered a white rot fungus. If a fungus can only break down cellulose and hemicellulose ...
Emergence of bacterial vortex explained
VIDEO: When confined in a water droplet, B. subtilis bacteria collectively and spontaneously form a swirling vortex, with some bacteria moving in one direction and others moving the opposite way. Researchers... Click here for more information. PROVIDENCE, R.I. [Brown University] — When a bunch of B. subtilis bacteria are confined within a droplet of water, a very strange thing happens. The chaotic motion of all those individual swimmers spontaneously organizes into a swirling ...