July 20, 2008 Lionfish decimating tropical fish populations, threaten coral reefs
(Lionfish being studied by Mark Albins at Oregon State University).
CORVALLIS, Ore. – The invasion of predatory lionfish in the Caribbean region poses yet another major threat there to coral reef ecosystems – a new study has found that within a short period after the entry of lionfish into an area, the survival of other reef fishes is slashed by about 80 percent.
Aside from the rapid and immediate mortality of marine life, the loss o... more >>
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Product Description
Expanded and updated to include an additional 44 species, this is a handy guide to those fishes that are likely to be observed by anybody visiting or diving on the coral reefs of the Caribbean, the Indian Ocean, and the Pacific to a depth of sixty meters. Accessible to amateur marine life enthusiasts, this book is the first comprehensive guide of its kind. It enables the reader to quickly identify 2,118 species of fish and includes over 2,500 color illustrations depicting the major forms of each species--male, female, immature, or geographical varieties. The text proceeds according to region, depicting each species and its varieties, and offering information on its geographic range and where on the coral reef itself the fish may be found. Important identification characteristics are highlighted on every color plate.
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WHAT THIS PORTAL IS ABOUT
(Spotted hyena arising from a nap in the Masaii-Mara Reserve, Kenya. Photo taken by DrTom).
UNDERSTAND, LOVE, PROTECT!
I have always liked this adage by Baba Dioum, the Senegalese environmentalist: "In the end we will conserve only what we love. We love only what we understand. We will understand only what we are taught."
So understanding, at least at some level, is essential. For nearly 30 years, I have taught university students in the classroom. I estimate that I have instructed about 2,000 students during this phase of my life. Some have become biologists, policy makers, environmental lawyers, veterinarians, or professors, and some have become dance instructors, models, and actors. I know that many of them have been enriched by the small-group interactions we shared in the classroom and in the field; certainly, I benefited as much as they.
But the internet empowers us to reach a greater number of people than ever before. There are millions of people who will never attend an Ivy League university, or perhaps any type of higher education, who would benefit from learning more about the world around them. All they need is internet access, encouragement, and guidance. In time, they could provide a focused point of view on the health of the environment in the place they know best--where they live. But before this army of local experts can be mustered, the citizenry must become informed and involved. That is my mission.
I am a conservationist who teaches and conducts research. I have studied birds, lizards, and frogs in Costa Rican rainforests, bobolinks in New York meadows, white-tailed deer along the Columbia River in the Pacific Northwest, ground squirrels in Idaho sagebrush, and wildlife in Arizona. But it always comes back to the same two values for me—the natural history of organisms is fascinating, and I care about conserving our natural heritage. I also believe that human well-being is at stake, which is most evident for people who live "close to the land". The earth and her people need our help, and they need it now!
The content here conveys what I and many others have learned about the natural world. We will explore the scientific method as a way of knowing, but learning is a two-way street. I urge you to share your knowledge and observations from across the globe. Get outside and peer inside a flower, listen to a bird sing (really listen), or follow an ant through the forest. Or figure out a clever way to reduce your carbon footprint. Or listen to an elder tell a story from his youth. Then, return here and tell us about it.
Singing of male songbirds increased during the past week. This is correlated with an increase in hormones that signal reproductive readiness. During the past few days, I have witnessed the fledging of black-capped chickadee, American robin, and Eastern phoebe nests. This evening I saw a chestnut-sided warbler feeding a fledging in the aspen grove in my forest. Singing of all these species, as well as tufted titmice, brown creeper, ovenbirds, dark-eyed juncoes, and veery, has increased noticeably. The males, at least, are ready for round two.
In April I wrote here about the return of the phoebes from their wintering grounds in Latin America. The pair near my house usually nests on the light fixture next to the front door. However, this year they nested on the ledge above a basement window on the back of the house. A few days ago, they fledged five young from that nest. I know this because I was checking the contents of the nest almost daily. When I walked past the nest last week, the babies, which were now over-sized for the diameter of the cup nest, exploded in flight in all directions into the woods. The adults followed them immediately and I am sure they have been feeding them ever since. Within a day, the male was singing again, new eggs started to appear in that same nest, and today a female was incubating four eggs. Second clutches are almost always smaller than the first clutch of the season. Remember that starting today, day length begins to shorten. Winter is right around the corner (well, you know what I mean), so adults need to get those young fledged and grown. The big question is whether the female phoebe is the same female that raised the first clutch. Without having marked birds, I can not be sure, but I have to assume she is the same. Phoebes are a bit atypical in reusing the same nest during the breeding season.
And so it goes. Produce as many young as you can. The forest is noisy again, with the singing of adult males, and the baby-like begging of fledglings of a half dozen species. I measure the season of the year by this never-ending cycle that keeps me alert for the cues that signal where the earth is in its orbit around the sun. And it keeps me going outside to look and to listen.
(Abb. Der nachtaktive Kakapo - einer von neun untersuchten Vogelarten - erkennt vermutlich bestimmte Früchte am Geruch. Das Gleiche gilt auch für den Streifenkiwi aus Neuseeland. Bild: Don Merton).
Ist der Geruchssinn bei Vögeln besser ausgeprägt als als bislang gedacht?
Vögel sehen und hören nicht nur gut, auch ihr Geruchssinn ist wahrscheinlich stark ausgeprägt, wie Max-Planck-Ornithologen jetzt herausgefunden haben
Augen und Gehör sind die wichtigsten Sinnesorgane bei Vögeln, so die gängige wissenschaftliche Meinung. Doch auch der Geruchssinn hilft vielen Vögeln dabei, sich zu orientieren, Nahrung zu finden oder sich gegenseitig zu erkennen. Wissenschaftler vom Max-Planck-Institut für Ornithologie in Seewiesen und ein Kollege vom Cawthron Institute in Neuseeland haben jetzt nachgewiesen, dass Vögel über sehr viele Geruchsrezeptor-Gene verfügen. (Proceedings of the Royal Society B, 16.07.2008).
Der Geruchsinn bei Vögeln verfügt über ein ähnlich großes Potential und eine vergleichbare Bandbreite wie bei Fischen und Säugetieren, ergab eine Studie von Silke Steiger vom Max-Planck-Institut für Ornithologie und ihrer Kollegen. Im Vergleich zu anderen Tierarten wurde der Geruchssinn bei Vögeln allerdings bisher als niedrig eingestuft, obwohl Verhaltensstudien gezeigt haben, dass einige Vogelarten durchaus ihren Geruchsinn zur Orientierung, Nahrungssuche, oder auch zur Unterscheidung von Individuen einsetzen.
Silke Steiger und ihre Kollegen haben für ihre Studie einen genetischen Ansatz gewählt, um den Geruchssinn bei Vögeln zu erforschen. Sie untersuchten Geruchsrezeptor-Gene, welche die molekulare Basis des Geruchssinns bilden. Die Geruchsrezeptoren werden in den Neuronen der Riechschleimhaut ausgebildet und dienen dazu, verschiedene Duftstoffe wahrzunehmen. Solche genetische Studien über den Vogel-Geruchssinn gab es bisher nur von Hühnern.
Die Wissenschaftler verglichen neben dem Huhn acht weitere Vogelarten, die nicht oder nur entfernt miteinander verwandt sind. Dazu kalkulierten sie jeweils die Gesamtzahl der Geruchsrezeptor-Gene im Genom jeder Art mit einer Methode aus der Ökologie, die dort für die Berechnung von Artenreichtum verwendet wird - und fanden große Unterschiede zwischen den Arten. Der Streifenkiwi aus Neuseeland hat zum Beispiel fast sechsmal so viele Geruchsrezeptor-Gene wie ein Kanarienvogel oder eine Blaumeise.
"Vergleicht man die relative Größe der Riechkolben im Gehirn, in denen die olfaktorische Information verarbeitet wird, finden sich ebenfalls große Unterschiede zwischen den Arten", sagt Steiger. "Es ist wahrscheinlich, dass die Anzahl der Geruchsrezeptor-Gene widerspiegelt, wie viele verschiedene Gerüche wahrgenommen und unterschieden werden können. So hat es uns nicht gewundert, dass die Anzahl der Gene eng gekoppelt ist an die Größe des Riechkolbens im Gehirn."
Große Schwankungen in der Anzahl von Geruchsrezeptor-Genen und Größen von Riechkolben wurden auch bei Säugetieren gefunden. Dies deutet darauf hin, dass die ökologische Nische einer Tierart das Repertoire der Geruchsrezeptor-Gene beeinflusst. Die hohe Rezeptoranzahl des Streifenkiwis erklären sich die Forscher zum Beispiel als Anpassung an dessen Nachtaktivität. Als einzige Vogelart hat er seine Nasenlöcher an der Spitze des Schnabels und nicht an seiner Basis, und gibt bei der Nahrungssuche in Dunkelheit sogar Schnüffelgeräusche von sich.
Neben der Gesamtzahl an Geruchsrezeptor-Genen kalkulierten die Forscher auch das Verhältnis an Genen, die tatsächlich funktionsfähig sind und als Geruchsrezeptor ausgeprägt sind. Denn nicht alle Gene, die in einem Genom zu finden sind, kommen auch zum Einsatz. Gene unterliegen Mutationen und können dadurch ihre Funktion verlieren. Ist der Geruchssinn für ein Tier nicht wichtig, lässt der Selektionsdruck auf die Geruchsrezeptor-Gene nach und Mutationen können sich anhäufen. Funktionslos geworden, vererben sich die Gene trotzdem weiter. Beim Menschen zum Beispiel wird geschätzt, dass nur ca. 40 Prozent der Geruchsrezeptor-Gene funktionsfähig sind. Bei den untersuchten Tierarten fanden die Wissenschaftler jedoch weit mehr funktionsfähige Gene als für Vögel erwartet wurde. Auch dies spricht dafür, dass der Geruchssinn bei Vögeln viel wichtiger ist als bisher gedacht.
Bei den molekularen Forschungen an Hühnern wurde eine ganz neue Klasse von Geruchsrezeptor-Genen gefunden. Nun haben Silke Steiger und ihre Kollegen nachgewiesen, dass diese Gene bei allen untersuchten Vogelarten ausgeprägt waren, nicht aber bei anderen Tieren wie Fischen, Säugetieren oder den mit Vögeln nah verwandten Reptilien. Die Funktion dieser vogelspezifischen Geruchsrezeptoren ist allerdings noch gänzlich unbekannt.
[SP/BA]
Originalveröffentlichung:
Silke S. Steiger, Andrew E. Fidler, Mihai Valcu & Bart Kempenaers
Avian olfactory receptor gene repertoires: evidence for a well-developed sense of smell in birds?
Proceedings of the Royal Society B, veröffentlicht am 16.07.2008, doi:10.1098/rspb.2008.0607
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CONVERSATIONS ABOUT THE ENVIRONMENT: James Gustave Speth
Capitalism, the Environment, and Crossing from Crisis to Sustainability James Gustave Speth, Dean of the School of Forestry and Environmental Studies, Yale University Recorded April 2, 2008 Conversations host Harry Kreisler welcomes Yale Professor James Gustav Speth for a discussion of his career in the environmental movement. Professor Speth traces his changing perspective on the appropriate response to the environmental crisis. Concluding that only a radical transformation of capitalism will save the planet for future generations, he outlines the changes in consciousness and in the political agenda that will be required.
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BOOK REVIEWS
If you would like to submit a short review of any book on the natural history of any organism, or on the environment, please send me a message. I only need 2-3 paragraphs. Thanks.
DrTom
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FEATURED BIOLOGICAL STATION (scientists, tourists, and students)
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The Edward J. Meeman Biological Station consists of two sites: The Meeman site (623 acres; 252 ha) is located about 25 miles north of Memphis and 2 miles east of the Mississippi River on a Chickasaw Bluff. This site is in the narrow transition zone between the Mississippi River Valley and West Tennessee Coastal Plain physiographic regions. The Station and surrounding areas are characterized by low plains and fertile valleys which are drained by the Mississippi River and several tributaries. The Station has a modest conference/administrative center, large laboratory building with classrooms, research and teaching labs, dormitory room, and a kitchen. The Brunswick site (367 acres; 149 ha) is located adjacent to the Loosahatchie River about 20 miles east of the Meeman Site. This is a bottomland site with sluggish streams, cypress swamps, and numerous old fields surrounded by private lands.
The Station is available to graduate students and qualified investigators throughout the year. Faculty from The University of Memphis and several other institutions in the Mid-South utilize the facility for research purposes. Ongoing research programs include river and wetland ecology, wildlife ecology, plant community ecology, population ecology, evolutionary ecology, ecological genetics, and others.
Courses in ecology, botany, field techniques, and related disciplines are offered during the summer.
Click the Green Search button to find thousands of links to environmental problems and solutions, legislation, endangered species, alternative fuels, zoos, invasive species, and much more.
Four weeks ago, we launched the 350 Challenge to help bloggers like yourself raise awareness for the fight against global warming.
You quickly rose to the challenge. Today we're proud to announce that not only did we hit our goal, but we blew right past it. As of this morning, over 400 bloggers are participating in the challenge.
Thanks to you, Brighter Planet will now offset 140,000 pounds of CO2 on behalf of everyone who participated. Soon, you will receive an offset certificate to commemorate your involvement.
Since we've hit our goal, we'll stop pestering you for help, but due to the campaign's success, we've decided to leave it open for now. We'll continue to offset 350 pounds of CO2 for each new blogger who joins the fight.
We're now working on some new, creative ways to continue raising awareness. Please join our facebook fan page to stay current. If you have any suggestions, we'd love to hear them.
There are about 40 species of dolphins, which are distinct from porpoises and whales. All dolphins are in the family Delphinidae. The Killer Whale is a dolphin. Click on link below to see the entire list of species.
pundits on television keep asking why the price of oil is going up. Most estimates indicate we have already used up 50% of all the oil that was ever on earth, and we are now working on the remaining 50%. There are 6.4 billion people on earth, and we are adding an additional 80 million per year. The two most populous nations, India and China, have a rapidly growing middle class who want to own cars and drive. The whole world wants to consume like Americans, if they can.
I never even took an economics course in college, but the supply/demand curve here is a no-brainer. I predict that in my lifetime (and I'm 61), I will see the day when we remember how cheap oil was in the good ole days at $100 a barrel. (February 2008)
Remember that you have the option of building a profile for yourself that can be a sort of online resume. Check out "Deer" for his recent upgrade. Do not be bashful about selling yourself. In my opinion, it is absolutely necessary to publicize who you are and what you can do to create opportunities for yourself.
Also realize that when you are in your profile page, you make changes in Admin mode. You can, however, toggle to the view that the rest of us see when you want to check its appearance.
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Where did the .tv internet domain (as in drtom.tv) originate?