Archive for July, 2012
But mountain cattle don’t. I am surprised that people are still driving around with this misguided sticker attached to their cars. Mind you most of the cars I see them on look like the closest they have come to the high country are the Mt. Buller ski fields. Equally misguided and erroneous is the sticker that states, “Alpine Grazing Reduces Blazing,” especially in light of a CSIRO study that found grazed areas are just as likely to burn as non-grazed ones (http://www.csiro.au/Outcomes/Environment/Australian-Landscapes/AlpineGrazingAndFire.aspx#adoes).
It’s about time people faced the facts that cattle do nothing but damage to the high country, with their cloven hooves trampling the delicate sphagnum moss, and their huge mounds of wet steaming faeces that take months or even years to decompose (Australian dung beetles can’t cope with cattle faeces, having adapted to dealing with smaller, drier marsupial faecal pellets. See http://en.wikipedia.org/wiki/Australian_Dung_Beetle_Project).
The government is to be congratulated for finally banning cattle grazing in the high country. It’s not as if the area is an indispensable part of Australia’s beef production, as it is only used by a handful of families anyway. Surely we can set aside a few acres of national park to support an endangered species or two, and leave cattle grazing for more suitable regions? We don’t need to turn the entire country into a cattle pasture, especially when 30 million km2 (an area the size of Africa) have already been turned over to livestock production worldwide.
Dr. F. Bunny
How good is this? According to this article http://mbds.promedmail.org/direct.php?id=20120724.1213448, a water based house paint has been developed that contains microcapsules of pesticide and insect growth regulator. The paint has been used on adobe houses in Bolivia to reduce infestations of kissing bugs, which transmit the parasite that causes Chagas disease. Its application has reduced infestation rates as high as 90% down to nearly zero, and works for up to two years. The paint is called Inesfly and was developed by a Spanish company (http://www.pilarmateo.com/).
Trials are also under way to assess its effectiveness against mosquitoes, in an attempt to reduce malaria rates. A promising study from Benin found that Inesfly applied to cement huts had a 100% kill rate for three months, and was still 90 to 93% effective after nine months.
It does have some drawbacks as it can’t be used on thatched walls and, if the bugs are resistant to the pesticides, it is ineffective. Still it looms as an extremely promising tool that can help control multiple vector borne diseases.
Dr. F. Bunny
For those not familiar with it, The Gruen Transfer is a regular program shown on the ABC that looks at ads, advertising and the various techniques used to sell products. Each episode features a segment called, “The Pitch” where two advertising companies compete against each other to create an ad designed to sell an unsellable product. Some of these have included bottled air, lowering the national drinking age to 16, and convincing people that Facebook is uncool. My favourite, however, is the pitch designed to convince us that banning all religions is a good idea. Mind you, it didn’t take much to convince me. Both ads are very clever and thought provoking and well worth a look. The whole thing takes less than five minutes to watch and can be found at: http://www.abc.net.au/tv/gruentransfer/poll4/vote/past.htm. Pitch 6 is the one you’re after. I can only hope and “pray” that one day we will see these ads for real.
Dr. F. Bunny
Last year the Dutch banned religious slaughter of animals. Now Germany is to be congratulated for banning circumcision (http://in.reuters.com/article/2012/06/27/germany-circumcision-idINDEE85Q0GN20120627). Predictably all the same religious groups that complained about not being allowed to cause unnecessary pain to animals are now affronted that they can no longer cause pain to small boys. They conveniently see it as another attack on their religious freedoms and ignore the real reason for the ban: infants cannot decide for themselves whether or not they want pieces of themselves cut off as part of an arcane, outmoded ritual. There are no medical reasons to cut off a foreskin. While Herodotus suggested over two thousand years ago that circumcision was done for the sake of cleanliness I believe that, in the twenty-first century, we are not only able to wash behind our ears, but behind our foreskins as well. If an adult voluntarily consents to have things snipped off that is different but to subject an infant to this practice is unacceptable. Perhaps we should bring back witch burning and human sacrifice? Female circumcision was outlawed in the US in 1996. Why should male circumcision be any different?
Dr. F. Bunny
Culling of eastern grey kangaroos has always been contentious. Since white settlement their numbers have increased dramatically thanks to improved pasture, the provision of dams and waterholes for livestock, and the removal of any possible predators. In many areas they are now at the point where they need to be culled to prevent them destroying their own habitat. The situation is worse when they are confined to fenced reserves where they breed unchecked with no opportunity for youngsters to disperse. I suppose we could just leave them be, which would more closely mimic their natural boom and bust cycle. In this scenario numbers build up until they get beyond the carrying capacity of the land. The population then crashes with large numbers of animals dying from starvation, malnutrition and diseases such as lumpy jaw and hookworm infection. As a veterinarian that does not sound particularly humane to me and it also impacts, not just the vegetation, but all the other animals that share their environment with the kangaroos. This occurred some years ago when a reserve in Victoria was denied culling permission. The vegetation suffered badly and all the eastern barred bandicoots, an endangered species that had been introduced to the reserve, perished as a result.
While culling is not a particularly pleasant option it is surely better than letting them starve to death. All fenced reserves need to develop a comprehensive management plan that involves reducing numbers to their optimum stocking density followed by reproductive manipulation through castration, vasectomies and contraceptive implants. In this way culling would not be used as an ongoing management tool but only to deal with a problem that has been allowed to get out of hand.
I am convinced that much of the opposition to culling is because kangaroos, like their arboreal brethren the koalas, are cute. Many years ago koalas were introduced to Kangaroo Island. Given that an island is similar to a fenced reserve with no predators and no opportunity for dispersal the koalas ate themselves out of house and home. Culling would have solved the problem caused by this introduced species destroying its environment, but they were far too cute for that. If the island had been overrun by tiger snakes instead I’m sure no one would have raised so much as a whisper at the suggestion of culling.
The greatest tragedy, however, is that when a kangaroo cull is approved the shot animals must be buried and cannot be used for human or even animal consumption. While over 90% of Australia’s woodlands have been cleared, mostly for cattle and sheep production, a readily available resource is squandered. Not only is kangaroo meat lean and healthy but the animals themselves have a much smaller environmental impact than their cloven hooved brethren, with their methane breath and destructive feet. Why not use the resource that is already there, instead of importing thousands of ferals to further abuse an already damaged environment?
Dr. F. Bunny
This time we are talking about flu, not cute primates with upturned noses. It’s that time of year again, at least in the southern hemisphere, and there are a few simple precautions you can take to help you through.
As previously mentioned in Vaccination 101 there are lots of different flu viruses that, unlike leopards, do change their spots regularly. This makes it impossible to control all of them with a single vaccine. However, each year the World Health Organisation recommends which three flu strains to stick in the current year’s vaccine, and I certainly recommend getting it. It stops you feeling miserable and may even save your life. If work places displayed any common sense they would vaccinate all their employees for free. The savings in sick leave taken would surely compensate for the cost of the vaccination. But you don’t have to be vaccinated if you don’t want to. Your plane won’t be shot down, you won’t be rounded up and forcibly jabbed and you won’t be stopped from travelling and infecting other people.
The trouble with flu viruses is they get around, fast. It is estimated that, if a new flu strain emerged in Europe, it would hit Australia in four to eight weeks, despite our relative isolation from the rest of the world. While the H1N1 flu turned out to be relatively benign (only killing 0.03% of the people it infected) it did hit 70 million people. The H5N1 flu has killed 60% of its victims but has only infected 600 people (http://www.who.int/influenza/human_animal_interface/EN_GIP_20120607CumulativeNumberH5N1cases.pdf). Because it targets receptors in the lower respiratory tract it is harder to spread but more deadly. Unfortunately it would not take many mutations for H5N1 to start spreading like H1N1. Then we’ll see who thinks vaccination is a waste of time.
Apart from receiving a needle the best form of prevention has been discussed previously. Boring though it sounds, here it is: wash your hands, with soap, regularly. Flu viruses survive in the air for up to an hour, on hands for five minutes, on soft cushions for 20 minutes and on hard surfaces for 24 hours. So, every time your flu sufferer touches anything they will also be applying a liberal dose of virus. When you then touch the same surface, or shake that hand, you also receive a helping of virus. Alternatively use alcohol wipes on your hands. Monk wasn’t nearly as crazy as he was made out to be in his TV series.
Depending on your level of paranoia you could also avoid crowded areas such as public transport, classrooms and offices, as these all have lots of possibly contagious people and minimal air movement. Stay away from small children and keep at least two metres between yourself and your infected colleagues.
Unfortunately the time when people are most contagious and shedding the most virus is a day or two before they develop symptoms. They will remain contagious for about another four days after symptoms start, so do yourselves, and the rest of the world, a favour. Stay home and finish that book, win that Playstation Stanley Cup or watch all those episodes of Get Smart you always promised yourself you would. And, in the words of Sergeant Phil Esterhaus from Hillstreet Blues, “Let’s be careful out there.”
Dr. F. Bunny
And if you’re still not convinced see: http://www.sbs.com.au/news/article/1667868/Deadly-flu-season-hits-Australia-hard
We are always very happy to construct evolutionary pyramids beginning with the basic single celled life forms at the bottom and culminating with us at the apex, the very peak of intelligence. However, were we to construct a pyramid of cunning and manipulation we would almost certainly be nowhere near the top, while those life forms we consign to the depths of the intelligence pyramid would do very well when it comes to being crafty and underhanded. But then, if you can’t use intelligence to survive, you need to find other ways to make a living. Here are a few of the more wily members of the animal kingdom.
1) Gordius. This is a large parasitic worm that lives in water. The eggs and/or larvae it produces are inadvertently drunk by a spider (or other invertebrate). They then develop to maturity within the spider’s body. At this point Gordius convinces the spider that it is in desperate need of a drink and sends it scuttling to the nearest puddle. Once there Gordius bursts forth from the spider’s body, in true Alien style, and re-enters the water to continue its life cycle. These large worms are frequently found by zoo keepers in animal water bowls. They do not affect the zoo’s regular inmates and are completely harmless, unless you happen to be a spider.
2) Clistobothrium carcharodoni. This mouthful is a tapeworm that lives in the gut of great white sharks. Tapeworms produce eggs that develop into larvae which encyst in an intermediate host. This host is then consumed by the definitive host, thus completing the life cycle. In this instance the intermediate host is the dolphin. The larvae preferentially encyst in the muscles of the dolphin’s belly, as these are the particularly tasty ones targeted by sharks when they attack. In this way the shark not only gets a mouth full of Flipper but a mouth full of Clistobothrium as well.
3) Euhaplorchis californiensis. This is a parasite of birds that uses killifish as its intermediate host. It gets into the fish’s brain and, in order to increase its chances of being eaten by the bird encourages the fish to swim conspicuously near the surface of the water, advertising its tastiness.
4) Leucochloridium paradoxum. This flatworm employs a similar strategy when it gets into snails. The larvae enter the snail’s eye stalks and then wriggle about to look like little caterpillars that once again attract the bird definitive host.
5) Toxoplasma gondii. This parasite has its home in the cat intestine but uses rats, among others, as an intermediate host. It gets into the rat’s brain, removing its innate fear of cat urine, replacing it with a deep desire to seek it out instead. You can guess the outcome.
6) Guinea worm. In case you thought we were immune from this kind of manipulation, think again. The guinea worm begins life as a larva tiny enough to fit inside the common water flea. The flea is accidentally drunk by a thirsty human. Not being adequately equipped to survive the harsh environment of the human stomach, the water flea is dissolved away, leaving the guinea worm larva behind. It finds a soft, fleshy cavity to burrow into and starts growing. About a year after infection, the full sized guinea worm measures two to three feet long and decides it’s time to get out. It does this by burrowing to the surface of the skin and creating a blister. This causes a burning sensation, which makes the infected human want to dunk it in water. The rear end of the worm emerges from the blister and releases hundreds of thousands of larvae. They are eaten by water fleas and the whole thing starts all over again. Fortunately or unfortunately, depending on where you are currently living, the guinea worm is only endemic to Sudan, Ghana, Mali and Ethiopia.
You may have noticed the one thing all these characters have in common is that they are parasites. If you make your living by manipulation and stealing someone else’s resources and livelihood I guess you need to be cunning to survive. Perhaps humans are not so low on the cunning pyramid after all, as we’ve spent thousands of years doing just that to the Earth.
Dr. F. Bunny