Friday, March 30, 2007
Thursday, March 29, 2007
Tuesday, March 27, 2007
So, here is the basic gist of the issue: the white tiger is a man-made phenomenon. The goal of conservation is to maintain species in as close to their natural form as possible and there is a very limited amount of money and resources to do that. Conservationists would like to see all that money go to preserving the various tiger species in their natural form. However, the white tiger is stunning! The white tiger is beautiful! The white tiger is mysterious! People love white tigers! People are much more excited about seeing a white tiger than they are with the "run-of-the-mill" orange and blacks. And, consequently, they are more likely to donate money to an institution that has white tigers. I don't have any actual figures to back it up, but just ask any zoo director or curator. They'll tell you the same story.
Monday, March 26, 2007
Today we had a very busy morning. Five African Wild Cats out at the Wildlife Safari Park needed their annual physicals and vaccinations. Blood was drawn for routine CBCs, serum chemistry along with additional blood, feces and urine for a nutrition study. Then we looked at a swift fox that had gotten into a tussle with another swift fox. She had a torn ear and some bite marks that needed to be cleaned up. After that was done, she was put on some antibiotics and pain medication for the next few days. Then we had to vaccinate 5 pelicans and a raven against the West Nile virus. So, it was a busy day!
And it is high time I talked about yet another broad lesson I’ve learned so, here we go! This will be a long post, so bear with me (if you want to, that is :p)! (link to lesson 1, as a refresher)
Lesson 2: Conservation and Population Medicine (and the revelation that money is not green, but black and white)
There are two distinct forms of medicine within veterinary medical practice: population medicine and individual medicine. In the most basic sense, population medicine deals with animals in production situations (feedlots, cow/calf, swine farms, poultry farms, etc), but it can also deal with companion situations. An example would be vaccinating a pet dog against rabies to protect the dog, but also to reduce the incidence of rabies in the area, thereby making the entire population safer. Individual medicine more classically deals with individual companion animals of all shapes and sizes, but is applicable in production schemes as well. Individual dairy and beef cows, for example, routinely get individualized care for specific conditions from milk fever to bloat. Many veterinarians go into certain areas of practice, because they either like or dislike population medicine. In zoo medicine, I have found that you can’t have one without the other.
There are two main reasons that zoos exist: animal display and animal conservation. Some institutions are more heavily involved in one side or the other, but both have a place. At the HDZ, I’ve found that the split is fairly even. Yes, there are many animals on display, but many of them are a part of intensive conservation programs for their species. And there are many animals that are here but not on display, conservation being the primary reason they are here. One example of that would be the Wyoming Toads. Declared extinct in the 90s, an isolated population was later located and captured. Now there is a growing population of these toads (which, at one time, were the most numerous vertebrate in the state of Wyoming) in a handful of conservation institutions across the country, including the HDZ.
All of the endangered and threatened species here have an SSP (Species Survival Plan). These plans look at everything from conservation of the natural habitat of these species to breeding programs that will best maintain a genetically healthy population in the future. The SSP is one of the main cornerstones on which conservation stands. It is population medicine on an individual basis.
Now enter the white tiger. The white tiger is an anomaly in the tiger world; a man-made anomaly. Many have the mistaken notion that this is a unique, highly endangered species of tiger. Others think that all white tigers are actually Siberian tigers, the white coloring helping them to blend into their snowy environment. Both beliefs are actually wrong! In fact, all white tigers alive today can be traced back to one white Bengal tiger, Mohan, who was captured in 1951.
Before I continue, I should speak briefly about the inheritance of color in tigers and give you a basic genetics review. The ‘genotype’ of an animal is the genes it has. The ‘phenotype’ is how it expresses those genes; literally what it looks like. The normal color of all species of tigers is the characteristic orange and black that most of us think of first when we think of tigers. The white and black coloring is a simply inherited recessive trait. Without getting too technical, I’ll use ‘B’ for the dominant color gene (coding for orange and black) and ‘b’ for the recessive color gene. Simple dominant-recessive expression means that an animal will need to be homozygous (having two copies of the same gene) for the recessive gene, or a ‘bb’ genotype, in this example. A tiger that is homozygous dominant (BB) or heterozygous (Bb) will look normal, phenotypically. The Bb tiger, however, may produce a bb white tiger if it is bred to another Bb tiger (or, of course, a bb tiger).
Many people are familiar with the good old Punnit square from genetics. The Punnit square is used to predict the ratio of certain genotypes in a given breeding of two parents of a known genotype (or, conversely, to identify the genotypes of the parents, given the phenotypes of the offspring). Using a Punnit square, here are the likely outcomes of tiger breeding for color:
BB x BB = 100% BB offspring = 100% orange/black
BB x Bb = 50% BB + 50% Bb offspring = 100% orange/black
BB x bb = 100% Bb offspring = 100% orange/black
Bb x Bb = 25% BB + 50% Bb + 25% bb offspring = 75% orange/black, 25% white/black
Bb x bb = 50% Bb + 50% bb offspring = 50% orange/black, 50% white/black
bb x bb = 100% bb offspring = 100% white/black
Still with me? Excellent! I’ve gotten quite long today, so you’ll need to tune in tomorrow for what this all has to do with conservation and population medicine!
Saturday, March 24, 2007
Friday, March 23, 2007
Thursday, March 22, 2007
Apparently, the Iowa State University Veterinary Diagnostic Lab has been the main instituition examing tissues from the animals that have dies due to the pet food recall. Here is some text from the website detailing some of their findings:
"Autopsy and microscopic examination of tissues from affected animals indicate acute renal toxicosis including the presence of birefringent crystals, as well as other crystal formations. The effects are consistent with exposure to ethylene glycol and derivatives, mycotoxins, ochratoxin and citrinin, some heavy metals or vitamin D toxicity. At the present time the exact cause of this problem is not yet known. Investigations are continuing."
The full report can be read here. Definately bad news for the animals, their owners and the pet food manufacturer. However, it is great that the ISU pathologists are on top of this national problem!
Tuesday, March 20, 2007
Monday, March 19, 2007
Sunday, March 18, 2007
Saturday, March 17, 2007
Thursday, March 15, 2007
And to further expand on my previous post about the lemur species that have been discovered here, the picture at right shows a wall where they have the pictures of all of the species of Sportive Lemurs that were discovered here in 2006 alone. And pictured at right is one of the mouse lemurs. Many of these species have been differentiated from other species primarily through DNA analysis.
Well, that's about enough for today. I'll continue with more "Lessons" on any upcoming days when I don't have as much to report. If any readers have any special requests regarding information/pictures and/or discussion of certain species, procedures, or topics, please let me know!
In the meantime, here is an interesting report about a new clouded leopard species that has been identifyed in the rainforests of Borneo. It's amazing to me that new species are still being discovered at the rate that they are! Here at the HDZ, they have identified a dozen new species of mouse lemurs from Madagascar in the last year alone! These species include the Simmons Mouse Lemur, among others.