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Animal Science

The Animal Science Blog is the place for conversation and discussion about scientific and technological topics related to pets, livestock, and other animals. See how cutting-edge advances help – or hinder – species around the world. The blog's owner, Laura Sicley, is a lifelong animal enthusiast who received an AS in Equine Studies before switching to a "more practical" college major. She currently has two beagles, two horses, a cat, and a tank full of tropical fish.

Woolly Bears as Winter Indicators - True or False?

Posted November 18, 2009 12:01 AM by SavvyExacta

When I lived in a rural area, I tried to count the many woolly bear caterpillars I saw each autumn. One season my tally reached over a hundred before I gave up! Now that I live in a small city, I have yet to see a single woolly bear. What will I use to predict the winter – and should I have even used woolly bears in the first place?

From Bears to Tigers – Oh My!

Found in North America, the banded woolly bear caterpillar is the larva of the Isabella tiger moth. We see them "scampering" around in the fall because they have recently emerged from eggs. Woolly bears eat plants and prefer low vegetation, which is probably why I haven't seen them in the city – despite living near a wooded bike path and "forever wild" area.

Over the winter, they hide under leaves and create their own protection from the freezing weather; it's called cryoprotectant and it actually prevents them from freezing! Glycols are commonly used in preventing ice formation. Similar stuff is also used in food – ever wonder why your ice cream isn't ice?

In the spring, woolly bears warm up, eat, pupate, emerge from their cocoons, and turn into Isabelle tiger moths.

Folklore or Weathermen?

Where I'm from, kids grow up trying to predict the weather based on the length of the brown middle section of a woolly bear. Folklore says, the longer the mid-section, the shorter the winter and vice versa.

From 1948 to 1956, American Museum of Natural History insect curator, Dr. C. H. Curran, studied woolly bears in Bear Mountain State Park, New York. He found that Woolly bears have 13 band segments in a black-brown- black pattern. During this time period, the caterpillars averaged 5.3 to 5.6 segments of brown bands – more than a third of their body length. The winters during the same period happened to be milder than average.

According to almost all of the other sources I reviewed, this theory is untrue. Band length can vary based upon a number of factors, including but not limited to:

  • Age – the black outer bands decrease as the caterpillar matures
  • Color variation – even larvae from the same clutch can have different brown band length from the start

Still, the woolly bear is important to many people. Take, for example:

  • The Woollybear Festival in Vermillion, Ohio, which includes a costume contest.
  • The Woolly Worm Festival in Beattyville, Kentucky – including a human vs. woolly bear race.
  • The Woolly Worm Festival in Banner Elk, North Carolina – the caterpillar that wins the featured race predicts the upcoming winter.
  • Oil City, Pennsylvania's "Oil Valley Vick" is hoping to predict the nation's winter just like Punxatawney Phil predicts springtime.
  • Hagerstown, Maryland holds an annual contest to find the cutest and cuddliest, as well as the biggest and woolliest caterpillars.

Resources:

http://en.wikipedia.org/wiki/Pyrrharctia_isabella

http://en.wikipedia.org/wiki/Cryoprotectant

http://www.almanac.com/content/woolly-bear-caterpillars-weather-predictors

http://www.cirrusimage.com/woolly_Bear_Caterpillar.htm

http://www3.islandtelecom.com/~oehlkew/indexarc.htm

http://www.enature.com/fieldguides/detail.asp?recnum=BU0165

http://www.herald-mail.com/?cmd=displaystory&story_id=232155&format=html&autoreload=true

http://blogs.woodtv.com/files/2008/10/terri-woolly-caterpillar.jpg

3 comments; last comment on 11/18/2009
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Feral Pigs – Fact or Fiction? (Part 2)

Posted November 11, 2009 12:01 AM by SavvyExacta

Imagine walking through a wooded area on a crisp fall day, enjoying the brilliant foliage. Suddenly you hear a squeal, followed by the thundering sound of a huge animal galloping up behind you! You turn to look – it's a huge pig with giant tusks, bigger than you could've imagined! If you survive, your friends will never believe this story.

Or will they? Giant feral pigs have been in the news for several years. The photograph above depicts an Australian farmer and his catch – a feral pig said to weigh 440 pounds. Supposedly, the farmer was checking the windmills on his farm and saw and shot the pig. Part 1 of this story explains the differences between feral and domestic pigs.

Catching Big Pigs

eHow.com explains how to catch a feral pig – although the article only achieved a rating of 2/5 stars. The basic steps were the following, with warnings that although dogs could be helpful in finding the scent, they could easily be hurt or killed by feral pigs:

  1. Find nesting ground and determine feeding patterns
  2. Set up pig feeders
  3. Set up pig traps
  4. Place feeders in traps
  5. Use online resources for domestication info

Most of the exceptionally large feral pigs on record have simply been shot on sight.

Hogzilla

In 2005, the remains of a feral pig were dug up and studied for a documentary. The pig had been shot and killed in Georgia in 2004. At the time of its death "Hogzilla" was supposedly over 12 feet long and 1,000 pounds.

Studies showed that Hogzilla was half feral pig and half domestic swine. National Geographic experts believe the animal actually weighed 800 pounds and was really about eight feet long. The length discrepancy comes from the fact that the hunter measured Hogzilla while the animal was suspended by its hind feet. The tusks of the carcass measured 28 inches in length!

It was determined that this type of large pig is either a domestic pig, obese from captivity, or a huge feral pig (or in this case, a combination).

Bigger than Hogzilla?

There is a story floating around that in 2007, a boy from Alabama killed a feral pig that weighed in at 1,051 pounds – trumping Hogzilla's record. This pig was "only" 9 feet, four inches in length. The 11-year-old boy shot the animal eight times and had to follow it through the woods for three hours before finishing it off. The animal generated an estimated 500-to-700 pounds of sausage and a mounted head with a circumference of 54 inches.

Entelodonts – Hell Pigs / Terminator Pigs

Entelodonts are an extinct family of omnivores that were around for about 20.9 million years during the Eocene and Miocene epochs. They are distantly related to modern pigs and stood about 6.9 feet at the shoulder – with brains the size of an orange. Weight was estimated to be about 9,300 pounds. These guys obviously put today's giant pigs to shame!

Largest Captive Pig

All of this research on wild pigs had me wondering if there was a record for the largest pig in captivity. Obviously, this would be "cheating" to some extent, because the animal would not forage for its food and probably wouldn't receive any exercise either.

According to Syracuse.com, Big Norm, the world's largest pig weighed in at 1,600 pounds and passed away on August 17, 2008. He was seven years old.

Resources:

http://www.hoax-slayer.com/giant-feral-pig.html

http://www.ehow.com/how_2248177_catch-feral-pigs.html

http://en.wikipedia.org/wiki/Hogzilla

http://www.foxnews.com/story/0,2933,275524,00.html

http://en.wikipedia.org/wiki/Entelodont

http://www.syracuse.com/news/index.ssf/2008/09/big_norm_the_worlds_largest_bi.html

http://cr4.globalspec.com/blogentry/10534

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Feral Pigs – Fact or Fiction? (Part 1)

Posted November 04, 2009 12:01 AM by SavvyExacta

Does the fear of giant feral pigs keep you up at night? As if people don't have enough to worry about! This two-part series will first explain what feral pigs are, and then get into some of the stories (both myths and factual) about giant feral pigs.

What is a feral pig?

Wild boar, razorback, wild hog – these are all aliases for feral pigs, which look quite similar to their domestic counterparts. Sows (females) weigh an average of 110 pounds, but can range from 75-to-330; boars (males) weigh an average of 130 pounds, but can weigh as much as 440. Some unusually large specimens have been measured to be up to three feet tall, six feet in length, and 500 pounds.

The main physical differences between feral and domestic pigs are:

  • Tail – wild pigs have straight tails; domestic pigs usually have curly tails
  • Feet – similar to deer hooves, making distinguishing tracks challenging to novices
  • Tusks – feral pigs have sharp tusks that don't stop growing

Feral pigs are native to Eurasia. They were introduced to the U.S. in the 1500s when they were released as a food source. In theory, it was a sensible idea – a walking food source that virtually took care of itself. However, the pigs became overpopulated and began to damage native plants and crops.

Oh Give Me a Home…

Feral pigs are wild and are certainly not pets, but they do claim a territory. Most call about 10 square miles home, but if food is scarce, they have been known to range over larger distances of up to 50 miles. Their capability to travel at speeds of up to 30 miles per hour makes covering their territory relatively easy.

Because of their relatively poor eyesight, feral pigs rely on scent to find their food, mostly roots and small animals. Smaller feral pigs feed on roots, berries, and mice; larger ones have been known to eat lambs, calves, and other small livestock.

Feral Pig Sightings

Where are feral pigs located? In the U.S., they have been found in quite a few places. According to the Department of Natural Resources of the State of Wisconsin, feral pigs are known to be located in the states on the map to the right.

Read Part 2 of this series to learn about some giant pigs!

Resources:

http://www.dnr.state.wi.us/org/land/wildlife/publ/wlnotebook/pig.htm

http://www.invasivespeciesinfo.gov/animals/wildboar.shtml

http://cr4.globalspec.com/blogentry/9040/Aliens-Focus-of-International-Day-for-Biological-Diversity

16 comments; last comment on 11/09/2009
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Is the Chupacabra South America’s Vampire?

Posted October 28, 2009 12:01 AM by SavvyExacta

Have you heard of the chupacabra? Its Spanish name means "goat sucker". The chupacabra was named for the reported attacking and blood-drinking of livestock. Most curious are the reports of the screech of the chupacabra, at which time its eyes glow a shade of red that causes witnesses to become nauseated.

I had never heard of the chupacabra until a recent CR4 bloggers' meeting. This creature is legendary in Puerto Rico, but has allegedly been sighted as far north as Maine in the United States and as far south as Chile in South America. Because I will be visiting Puerto Rico in December, I decided to do some research.

What is a Chupacabra?

There are three main descriptions of the chupacabra:

  • As a reptile-like creature with scaly green-gray skin.; scales or spines reportedly run down its back. The height of the animal is estimated to be three-to-four feet tall and said to travel in a hopping motion similar to a kangaroo – as far as 20 feet. It has a nose like a dog or panther and a forked tongue with fangs. It smells like sulfur and hisses and screeches with red eyes.
  • As a wallaby-like creature with coarse, gray fur. It has a dog-like head, large with large teeth. This version also stands and hops like a kangaroo.
  • Or as a dog-like creature the size of a small bear; hairless with a pronounced spinal ridge, fangs, and claws.

The chupacabra preys on livestock and other animals and drains blood and organs through two holes in the body.

New Species or Urban Legend?

Despite an appearance in an animated film, the chupacabra does not appear in many scientific resources. In fact, apart from alleged sightings on websites, the only "evidence" appears to be puncture wounds in the necks of the animals' prey. (Sounds like it could also be vampires, right?)

A woman discovered what she thought could be a chupacabra head near her Texas ranch in 2007. She planned to have its DNA tested to confirm it was not just a dog or coyote, but perhaps a hybrid of sorts, and maybe part chupacabra. In November 2007, a month after the discovery of the carcass, biologists at Texas State University announced the DNA sequence was just about the same as a coyote.

What about the more than 2,000 reported cases of animal mutilations in Puerto Rico that have been blamed on chupacabras? Authorities blame stray dogs or a panther, which could have been illegally introduced to the island. Panthers would also explain the screeching and screaming – something less likely attributed to a dog.

As far as the images I saw in my research, they did look like hybrid dog-coyote crosses or mutated coyotes. The cartoon caricatures were far more frightening than the actual photographs! Fearful people are likely to believe anything. I've also learned that the longer you look at something, the more likely you can turn it into just about whatever you'd like to believe.

What do you think about the chupacabra?

Resources:

http://en.wikipedia.org/wiki/Chupacabra

http://www.imdb.com/title/tt0369903/

http://www.crystalinks.com/chupacabras.html

http://www.foxnews.com/story/0,2933,295481,00.html

http://www.msnbc.msn.com/id/21595838/

http://www.skepdic.com/chupa.html

http://www.thesun.co.uk/sol/homepage/news/expats/expats_news/2039508/Panther-in-Puerto-Rico.html

http://animal.discovery.com/tv/lost-tapes/chupacabra/history/

http://www.kcra.com/irresistible/20661717/detail.html

14 comments; last comment on 10/30/2009
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Things That Go BOO!

Posted October 21, 2009 12:01 AM by SavvyExacta

Animals like bats and foxes are nocturnal animals – those primarily active at night. Many of these animals can be scary, because we can't get a good view and they tend to swoop by in the darkness. Even when seen during the day, like the red fox that trotted past my office window at 11:00 AM recently, they are not only startling, but can raise a few questions. (The image to the left is a weasel my cat caught in the early 90s.)

Why Are Some Animals Nocturnal?

Most humans are diurnal – they stay up during the day and sleep at night. But, some humans are nocturnal too – ever hear of a "night owl"? Their reasoning can help figure out why some animals are nocturnal.

  • Work schedule – some jobs are only available at night
  • Weather – if it's too hot out during the day, it might be best to sleep in the AC and come out during the cooler hours later on
  • Crowd control – errands are much quicker during the off-peak times

Let's match up human reasoning with animal instinct:

  • Work schedule – bats hunt best at night, so this time makes for the ideal feeding condition
  • Weather – desert animals sleep during the day when it's the hottest to avoid losing water
  • Crowd control – turtles breed at night to avoid falling prey to predators that may be around when it's light out

What Are Some Common Nocturnal Species?

You may be surprised at some of the animals that are considered to be nocturnal. Among the list are bats, foxes, catfish, cockroaches, hamsters, mice, mink, opossums, owls, scorpions, and tarantulas. Also making the list are cats and dogs. I believe these (and some others) are probably metaturnal animals, those that function both during the day and at night – especially because of domestication.

Why Would These Animals Come Out During the Day?

There are quite a few reasons for animals to step outside their normal behavioral patterns:

  1. Disease – Illnesses, most importantly rabies, can cause animals to depart from how they usually act. Sick animals typically appear to be in ill health (remember, wild animals are not pets; they usually never look perfectly groomed) and often act strangely.
  2. Food – Hungry animals will do just about anything for food and this includes staying up "late".
  3. Weather/Seasons – Some animals store food or eat more to prepare for winter; others are hungry when spring comes. A recent storm may have made it challenging to find food for several nights.

What Should You Do If You See This Behavior?

Remove potential food sources such as open trash, pet food, and bird feeders. Keep your pets restrained and make sure they are up-to-date on pertinent immunizations like rabies and other diseases local to your area. Contact a local environmental or wildlife organization to help observe, contain, or test the animal – particularly if you or a pet have come in contact with it.

Resources:

http://uk.encarta.msn.com/encnet/Features/Lists/?article=Animalnocturnal

http://en.wikipedia.org/wiki/Nocturnality

http://en.wikipedia.org/wiki/List_of_nocturnal_animals

http://www.utexas.edu/safety/ehs/animalmakesafe/faq.html#day

10 comments; last comment on 10/23/2009
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