Wednesday, 21 November 2012

Brazilian Horses

A Mangalarga Marchador

Horses have played a huge part in Brazilian history, and every one was descended from an imported horse, there being no natural equines in South America. Over time, many local breeds have developed, often based on Portuguese types such as the Lusitano and Alter Real imported with Portuguese colonisers. The Lusitano was specifically bred for the bull fighting ring, and they tend to be intelligent and highly manoeuvrable, whilst the Alter Real were originally high grade carriage horses.

Incidentally, horses are traditionally measured to their shoulders, not the top of their heads, and they are measured in "hands", one hand being 4 inches.

Baixadeiro  - an old breed developed in the marshlands, they are tough, with hard wearing feet able to withstand long immersion in water. Perhaps surprisingly for such an environment they are small, with short legs, and only abut 14 hands high.

Brazilian pony - bred for use with children using bloodlines including Scottish ponies and the Argentine Falabella, they are of course small (8.3 to 9.8 hands), but docile and popular.

Brasileiro de Hipismo (Brazilian Sport Horse) - a fairly recent and very successful breed developed in the 70s for competition and they have already competed at the Olympics. They are tall (over 16 hands) and lively, but not temperamental.

Campeiro - basically "field horse" the origins of this breed go right back to the horses brought with the Portuguese to southern Brazil in the 1540s. Over the years the breed has been improved with Thoroughbred and Arabian bloodlines and they now make good riding and ranch horses.

 A Campolina

Campolina - developed in the 1860s and 70s in Minas Gerais from a mixture of many bloodlines including Andalusian and Clydesdale (!), it is one of the larger breeds at 15-16.2 hands and used for riding and driving

Corajosa - "courageous", this pony is not only hardy, but also apparently gentle and kind. They were bred not for children, but for riding and draft work in areas with little grassland.

Crioulo - a cross of African and European breeds they are found in the south, where they make good ranch horses for the cowboys and gauchos.13-15 hands high.

 A Crioulo and Gaucho rider

Mangalarga Marchador (see photo at start of the blog) - originally developed in the 1700s and one of the most popular breeds in Brazil today. They are comfortable and easy to ride, with lots of stamina, and so make good trekking or ranch horses. The breed includes bloodlines from various Spanish lines, and they may be the closest living connection to the medieval Spanish Jennet. 

Mangalarga Paulista - basically an attempt to upgrade the Mangalarga Marchador by crossing with English Thoroughbreds or Anglo-Arabians, the Mangalarga Paulistas  are attractive, but apparently not so comfortable to ride over long distances.

Nordestino - a fairly small (13 hands), but extremely rugged and sturdy horse, probably derived from North African breeds, the Nordestino was developed in the harsh and hot north east of Brazil. They were popular in the military as being easy to train and with great endurance, but they are less common these days.

Pampa - apparently derived from feral horse populations that were caught and trained by various indigenous tribes in Brazil. They are well adapted to local conditions and characteristically have hard, tough, hooves as they would not have been shod. They also generally have "pinto" markings, which means large white splodges somewhere on their body

Pantaneiro - a breed from the Pantanal, a huge marshy area in the state of Mato Grosso. As they were not developed as such, with the deliberate introduction of blood lines, but were rather just bred from those horses that survived the harsh terrain, they are extremely hardy, with excellent disease resistance. They are mostly used as ranch horses.
 Pantaneiros

Piquira - a fairly recent development for children, mostly derived from crossing Crioulos with, bizarrely, Shetland ponies. They aren´t tiny, but are on the small side (12-13 hands) and apparently docile and calm

Many of the breeds above are now quite rare, as either their original function no longer exists, or they´ve been replaced by imported breeds. This applies especially to the Baixadeiro, the Campeiro and the Pantaneiro. Because of this the Brazilian Agricultural Research Assocation (Embrapa) encourages breeding programs, as well as storing seman and DNA samples, and even frozen embryoes, so the breeds are not lost.

More details on these breeds, and many others, can be found at the Equinest web site at http://www.theequinest.com

Friday, 2 November 2012

Very small red dots

Panonychus ulmi (Dept Agriculture UK)

This is the European red spider mite (Panonychus ulmi), ("ácaro vermelho europeu"), but it has emigrated. It is now found all over the world, where it is something of a nuisance. It feeds on plants, and unlike many invertebrates, it`s not fussy. Add a very high reproductive rate and you have a pest.

In Brazil it is mainly found in the south, where like many European migrants it finds the climate more congenial.  There it is a major pest of apples, pears, peaches and vines, overwintering as eggs on the tree trunks.  In the spring the eggs hatch and nymphs  start crawling over the plant. Now, these mites are very very small, about 0.7 mm, so you wouldn´t think it would matter much, but there are a LOT of mites. Each female only lives about 2-3 weeks, but can lay up to 50 eggs. Gradually the leaves become spotted, then bronzed and they fall off. Infested flowers often produce no fruit.

Incidentally, mites are NOT insects, they´ve got eight legs and they are distantly related to spiders. Including the ability to spin webs.
 Neoseiulus californicus

The main predators of mites are other mites, predatory mites.  Since 1992 hundreds of thousands of Neoseiulus californicus have been reared in huge plastic greenhouses in Brazil and released into orchards. They don´t eat all the mites, which is a good thing as then they themselves would starve. They just kill enough to leave the tress healthy. With luck you get a balance.

Saturday, 27 October 2012

Brazilian Dogs

Everybody likes dogs, and most parts of the world have dogs developed for the local conditions, from Labrador to Chihuahua. It`s surprising therefore that a country as large as Brazil has only two,  the Brazilian terrier, and the Fila Brasileiro. It`s not that there aren`t dogs around, there are thousands of miniature poodles and Yorkshire terriers keeping people company in the apartments of Rio and Sao Paulo, even Gisele Bunchen had until recently a Yorkie called Vida. And there are innumerable "Vira latas" (mongrels) in the favellas and fazendas. But of specifically Brazilian purebred breeds, there are only two.

The Brazilian Terrier, or Fox Paulistano

 The exact ancestry of the Brazilian terrier is unknown, but they are basically descended from Fox Terriers, with some Jack Russell, Miniature Pinschers and Chihuahuas thrown in. They resemble a large Jack Russel, and are said to have a similar temperament, friendly, intelligent and energetic. They were bred for farm work, active all day and they make excellent ratters. A group will even combine to attack larger prey, attacking from each side until it`s worn down.

 Although fairly small they are NOT apartment dogs, they need lots of exercise and stimulation, otherwise they get bored and a bit destructive. They also have a very strong hunting instinct, strongest of all the terriers, and so leaving one with a cat all day is probably not a good idea.

The Fila Brasileiro or Brazilian Mastiff

The Fila Brasileiro is another animal entirely, large (about 50 Kg) and very powerful. They were bred as working dogs on plantations or cattle ranches, probably from a combination of Mastiffs, Bulldogs and Bloodhounds, but unlike some large breeds they are normally alert and active.

 Life as a working dog on a Brazilian farm meant driving off predators such as jaguars, and running down stray cattle, and slaves. The bloodhound ancestry made them good trackers, and they were trained not to kill their prey, but to grab the animal or slave by the neck until the farmer arrived. Puppies still show this instinct in play today.

Although affectionate to their owners and families, it goes without saying that Filas are utterly and completely unsuited to be apartment dogs! Infact, in many countries such as the UK, Denmark and New Zealand you cannot own one at all. In the past Filas were often trained to be "Ojeriza" or distrustful of strangers, and with their very strong protective instinct this made them sometimes dangerous to anyone outside of their "pack". But this was the fault of stupid owners rather than the dogs themselves, and with proper training and socialisation from an early age they are calm and safe with strangers, even if not especially friendly.

Filas still make good farm dogs, and they might be branching out. They are reportedly used by the Israeli army and some American police forces, where they have the advantage as tracker dogs that, if necessary, they are fiercely defensive of their handlers once the quarry is found.

A five year study by the Brazilian army compared Filas, Dobermans and Alsatians in jungle conditions, looking at intelligence, aggressiveness, sensibility, temperament, energy, resistance, and strength. The Alsatians were smarter, the Dobermans more aggressive, but Filas won every other category.

Monday, 8 October 2012

Natural Resources

Brazil is blessed with natural resources, a huge and fertile country exporting vast quantities of food around the world. There is even oil under the rolling South Atlantic, but it doesn´t stop there.

New medicines, new drugs, are often based on chemicals found naturally in nature and few countries have more nature than Brazil. That flower deep in the Amazon may hold the cure for any number of diseases, just as aspirin came from willows, digitalin from foxgloves, and the common anti-cancer drug Vincristine from the Madagascar periwinkle.

Cayenne Ticks, as shown in a Globo News report on amblyomin-X

It´s not a rule of nature that something has to be beautiful to be useful. Few animals are uglier or more unpleasant than the Cayenne Tick, Amblyomma cajennense, which lives to suck blood from any animal it can find, including man. Not only that, but it can transmit disease, including Sao Paulo fever, or Rocky Mountain spotted fever. If you see one biting you, don´t just flick it away, you might leave the head still biting you, or at least cause the tick to regurgitate it's infected saliva into your wound (what you should do is use forceps to grasp it as close to your skin as possible, and gently pull straight back, then disinfect the wound).

So how is this tick a good thing? Well, researchers at the Butantan Institute in Sao Paulo have isolated a compound from that saliva called amblyomin-X. It´s not quite clear how, but amblyomin-X persuades cancer cells to self-destruct, whilst leaving healthy cells alone. Even better, it stops angiogenesis, which is now tumours get their own blood supply - so the tumour cannot grow, cannot spread around the body, and basically "starves".

 Harvesting tick saliva (Globo News)

Amblyomin-X works very well on rats, and next year should enter human trials. If these are successful it would be historic, because it would be the very first medicine developed from discovery to industrial production in Brazil.

Sunday, 16 September 2012

Me, Me, ME!!

There is an election coming up in Brazil, the most obvious manifestation of which is the use of vans playing annoying, repetitive, jingles, very very loudly. As with most things, there is a natural equivalent.


The master of "political" advertising is the male Screaming Piha (Lipaugus vociferans), a grey thrush-size bird that lives in the tree canopy in northern Brazil and Amazonia. The call is not unpleasant the first time you hear it, but you tend to hear it a lot, and he is one of the loudest birds on Earth! The Piha's call reaches 111.5 decibels, whilst for comparison, an electric drill is 98 dB, and a power saw 110 dB. The aim of course, like that of the advertising vans, is to draw attention, although in this case he is after mates, and is presumably more positively received.

http://www.freesound.org/people/felix.blume/sounds/140623/

The Screaming Piha works on the "lek" system, which is basically like an election, all the candidates in the same place screaming for attention. Apparently there is little difference in content in each lek, just in volume, but the calls change a little over the years.  Perhaps we have more in common with birds than we think.

Monday, 20 August 2012

Like fire-walking over flaming charcoal with a 3-inch rusty nail grinding into your heel

As probably you know, the sting of a wasp is more painful than the the bite of a mosquito (though not necessarily more dangerous!). If you wanted, you could rank the stings of all insects in order, from the mildest to the most painful, but don´t worry, you don´t have to, for the Hymenoptera (bees, wasps and ants) it has already been done - the Schmidt Pain Index.

So who is the winner?, the most painful possible sting, described as......

"immediate, excruciating pain and numbness to pencil-point pressure, as well as trembling in the form of a totally uncontrollable urge to shake the affected part"
"Pure, intense, brilliant pain. Like fire-walking over flaming charcoal with a 3-inch rusty nail grinding into your heel."

Not a wasp, but an ant, the Bullet ant (Paraponera clavata), and guess where they live? Yes, as well as piranhas, anacondas and parasites that enter your private parts when swimming, Brazil also has Bullet ants! Mainly in the Amazon, but they´ve also been reported in the Cerrado, the hot dry savanna in the north of Brazil.

The Life of Bullet ants

Paraponera clavata (Wikipiedia)

Bullet ants live in colonies several hundred strong, mostly built in the soil at the base of trees, and ruled by a queen. And they are big, about an inch long, and jet black. Although they are omnivorous, and will chop up any insects they come across, their main food seems to be nectar, each day they climb up into the forest canopy and bring back nectar from the flowers there. But don´t imagine gentle giants, colonies can be quite close to each other and a state of war is more or less continuous. Injured ants give off a scent which attracts parasitic wasps, sort of ant Valkyries, who feed off the ants and lay their eggs there.

There aren´t many other things which eat Bullet ants, not surprisingly. But why exactly is the venom so powerful.

Why so painful?

Bullet ants sting through a syringe-like spike at the tip of their abdomen. The consequent horrendous pain can last until the next day, and meanwhile you will have nausea, trembling and probably paralysis. It takes a lot of stings to actually kill you, about 30 per Kg of your weight, though after just one, death probably feels like a good alternative

Like most venoms, the Bullet ant sting is a cocktail of bad things, but most of the effect comes from poneratoxin. This blocks nerve transmission and causes long lasting contraction of smooth muscle fibres, which translates as pain and trembling. One sting contains only 1 ug of poneratoxin, a tiny, tiny, quantity, but enough.

What are they good for?

Various Indian tribes of the Amazon have utilised Bullet ants for years. The sting is a treatment for rheumatism, presumably as the pain takes your mind of it. More productively, the mandibles at the other end can be used as a form of suture, they clamp shut on a wound even when the head of the ant is twisted off, and ant saliva causes the patients wound to swell, closing it.

The Satere-Mawe tribe have found another use. Hundreds of ants are sedated and then woven into a leaf to form a sort of glove. Wearing this glove for 10 minutes, and surviving, is an initiation rite for boys of the tribe. The Satere-Mawe were also the first people to domesticate the stimulant producing Guarana plant (Paullinia cupana), the product of which is now found in a hugely popular soft drink in Brazil. All of which suggests that the Satere-Mawe have a rather "innovative" approach to biology.

Reference

A very good guide to poneratoxin by Vivienne Baillie Gerritsen can be found at
ttp://web.expasy.org/spotlight/back_issues/2001/09/princess_balas.shtml

Friday, 17 August 2012

Pity the poor mosquito!

You are probably, dear reader, a little prejudiced against mosquitoes. Take Aedes scapularis. Whilst it´s true that it is a vector for yellow fever, and  human and Venezuelan equine encephalitis, poor A. scapularis has a hard life. In 2002, Casanova and do Prado studied them in the pastureland around a farm near Campinas, in Sao Paulo state, Brazil.

During the hot rainy season (October to March) muddy puddles form all over the land, and the drought resistant eggs of Aedes scapularis hatch, little larvae swimming off hopefully into the water. It seems a good life in a hot bath full of rich organic matter, but little scapularis does not realise the horrors ahead.


For a start, it might rain, it might not, it might rain a LOT. Aedes only needs 9 days from hatching to adulthood, but even that might be too long. Of the 58 populations studied by Casanova and do Prado, 27 were wiped out by their ponds drying up, and 15 were washed away by floods, they never stood a chance.

Life in the 16 remaining pools was better, but not by much. The good news was that starvation was almost unknown, the bad news that all those mosquitoes ensured that starvation was unknown for their predators too. Estimates of total mortality from tiny larvae to emerging adults varied from 68 to a massive 96% per pool!

Predators included........

Giant water bugs "Baratas d' aqua" (Belostomatidae), aggressively predaceous insects who feed on, well, anything, injecting a digestive saliva and sucking out the remains. One of the most painful bites of any insects to us, let alone to a little mosquito.

Giant Water Bug larva (Wikipedia)

Water scorpions (Nepidae) - actually another type of insect

Diving beetles (Dytiscidae) -  you can eat these, if you want to,  in Mexico the adults are roasted and salted and added to tacos

Dragonfly larvae - there are, incredibly, at least 267 species of dragon- and damsel-fly in Sao Paulo state alone, and many of these eat mosquitoes

Last, but not least, larvae of a predatory mosquito, Psorophora ciliata. Don´t start to feel too grateful to this one, they feed on us as well, and infact are the largest blood feeding species found in the USA.

So, the little larva hatching into a warm, muddy, pool will almost certainly desiccate, be swept away, or be eaten. No wonder they are so angry!

Reference
Key-factor analysis of immature stages of Aedes scapularis (Diptera: Culicidae) populations in southeastern Brazil byC. Casanova and A.P. do Prado (Bull. Entomol. Res. 92, 271-7)