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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. SavvyExacta is a lifelong animal enthusiast with more than 20 years of experience with horses. Freckles (an English setter) is a frequent topic on the blog. Other CR4 bloggers occasionally add great posts.

Parasitoid Wasps Are Walking Horror Stories

Posted October 27, 2015 1:24 PM by Jonathan Fuller
Pathfinder Tags: ichneumon wasp parasite wasp

Love it or hate it, Halloween's upon us, and so is the proliferation of horror movies on many of your 800 cable channels. Most everyone seems to have a favorite horror genre, whether it's the slasher, psychological thriller, or classic monster movie. The boon of horror fiction is, of course, that you can turn off the movie or close the book if it gets too scary. Nature, however, has written a terrifying story we can't turn off at will, and it stars the parasitoid wasp.

Wasps of the Ichneumonidae family are parasitoids, meaning that unlike your run-of-the-mill parasites, their behavior often results in the sterilization or death of their host. Many ichneumonid species measure about a centimeter in length, so they often go unnoticed by humans. Despite their diminutive size, these creatures could be the inspiration behind a sci-fi or medical thriller flick.

First, many parasitoid wasps are parthenogenetic, meaning their species are entirely female and essentially clone themselves using unfertilized eggs. After a female's eggs develop, she uses her long stinger-like ovipositor to inject the eggs and a soupy substance into a caterpillar, insect, spider, or other suitable host. The eggs hatch into larvae, which infest the host and feed on its blood, internal tissues, and non-essential organs in order to keep the host alive long enough to ensure their successful growth. The larvae then cut through the host's body and exit, typically causing the host's eventual death.

The egg solution injected into the host also contains a polydnavirus-possibly developed from the wasp's genes-that hijacks the host's neurological functions while it's being slowly consumed. A virus' function seems to vary based on the wasp species. At the most basic level, the virus breaks down a host's immune system until the larvae have hatched and gained enough strength to overpower the immune system on their own. Some viruses compel a mortally wounded caterpillar to spin a protective web around the just-hatched larvae to grant an added level of protection. Wasp viruses injected into spiders force them to spin a web high above a forest floor; when the web is complete a wasp larva hatches, kills the spider, drains it of its blood, and spins its own pupa in the spider's web, protected from any threats on the ground below. (If you have a half hour or so, this presentation goes over a whole bunch of wasp virus scenarios as well as other strange parasites. Plus, who wouldn't want this guy's "I <3 Parasites" shirt!?)

The icing on this story is that parasitoid wasps are also hyperparasitic, meaning they are prone to parasitizing their own eggs or larvae. So, when Ichneumonid larvae build pupae to protect themselves while morphing into an adult wasp, they're really trying to protect themselves from being parasitized themselves as much as against predators.

Thankfully, all of this micro-activity goes on outside the scope of our normal days, but scientists have been fascinated by parasitoid wasps for centuries. Darwin was troubled by Ichneumonids and said their behavior dramatically shook his faith in a supposedly benevolent creator. Ichneumonids are also beneficial in many areas of the world and control the populations of crop pests like tobacco hornworm and tomato hornworm caterpillars.

I think we can all agree with the words of an annoying internet meme: Damn nature, you scary!

Image credits: Alex Popovkin / CC BY 2.0 | Christoph Rupprecht / CC BY-SA 2.0

1 comments; last comment on 10/28/2015
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More Photos from My Trail Camera

Posted September 22, 2015 12:40 PM by SavvyExacta
Pathfinder Tags: ANIMAL SCIENCE trail cam

Here's another batch of deer photos from my trail cam. I'm sharing these because my first post about the camera seemed to be popular. (You can check out that post for the specs of the camera.)

Toward the end of August I relocated the camera to an area beneath a pair of apple trees. The deer spend a lot of time feeding. I eventually shifted to another angle in the same spot.

As you'll see in the nighttime photos, the 12 IR emitters really seem to attract the attention of the deer. Some of the deer even look like they are taking "selfies!"

Some of the other highlights (not shown here) include a rabbit, a bat, and a neighbor's dogs having a fun romp through the yard. There's also an unidentified critter (probably a raccoon) shown wandering the woods at night. Unfortunately, a full view of it was obscured by some weeds. Placement of the camera takes a lot of thought!

25 comments; last comment on 10/06/2015
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The Summer of the Shark

Posted July 15, 2015 3:47 PM by HUSH
Pathfinder Tags: beach protection shark technology

It's that time of the year where people are more interested in getting out of their office or home and to the pool. Or if you live in a coastal area, the beach. Are there few things better than a day of beer, beach bocce and bikinis? Of course I haven't even mentioned the whole reason people flock to the beach in the first place: to swim.

Shark attacks seem to leave lasting impressions on beachgoers (and movie-goers…dunah-dunah-dunah), but the swimming never ceases. Even after an unprecedented 11 shark attacks along the Carolina coastlines in the past several weeks (yearly average is 6), beach traffic remains high through the East Coast. There has been a lot of discussion about how to reduce or eliminate the number of shark attacks. Pine Knolls Shores, N.C., has prevented fishermen and swimmers from co-mingling. Emerald Isla, N.C., has eliminated shark fishing until September. Both responses are meant to reduce sharks brought closer to shore by anglers.

A more active response-culling-incites mixed emotions. Great white sharks have earned some human empathy in recent years, often being called "misunderstood." What's to understand? The killing machine kills. Culling also has mixed results. Western Australia has implemented a $20+ million policy that attaches baited hooks to buoys 1 km from popular beaches. Sharks that are caught and over 3 m are killed. Hooks are preferable to shark nets because of the large number of dolphins, whales and fish that also get caught in the nets. Ultimately WA decided to abandon this program because of its uncertain long term effect on shark populations and shark attacks, the cost of each shark killed was over $25,000, and, oh, it didn't catch a single great white. Culling is more about improving publicity than stopping real attacks.

Despite recent dips in attack numbers, the volume of shark attacks is much higher than in previous decades. Attacks are likely swelling due to increased beach tourism and shore residents resulting in more encounters. According to a one study in Frontiers in Ecology and the Environment journal, all the increased beach visitors greatly dispels the probability of getting bit by a shark, simply because a shark has more targets. To this effect, the probability of getting bit by a shark in California waters is down 91% from 1950.

Those same researchers believe that based on their analysis, one day predicting shark attacks could be possible. For example, in Florida the most likely spot to get attacked by a shark is in the waters of New Smyrna Beach, in September, between 2-3 p.m. In California, the deadliest time is during fall evenings, while the safest times are in March. Like how beachgoers check the weather and surf forecasts, they might need to one day check the shark forecast.

Or seaside communities could opt for one of many growing shark sonar technologies. The first is Clever Buoy, a Google-backed sonar device that detects shark-sized objects. Previously this technology had many issues, such as false alarms. By analyzing the wake as well as the shape of the animal, Clever Buoy can distinguish sharks like no other technology. The other is Shark Shield, an antenna that radiates low-range, low-frequency electrical fields in the water. It causes enough discomfort in the snout of the shark to repel it. Unfortunately neither of these technologies is prepared to be deployed this year, but they well could be a solution in coming summers.

Until a comprehensive shark strategy is in place, wading into the ocean is always going to carry some risk. You're much more likely to step on glass or catch something from gross coastal run-off, both man-made hazards, than to be bit by a shark. But the glory and gory image of the shark will live on and overshadow more dangerous summer threats.

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Spotted on My Trail Camera

Posted June 20, 2015 12:00 AM by SavvyExacta
Pathfinder Tags: ANIMAL SCIENCE trial cam

Last month I set up a trail camera in a wooded part of my property. It's caught family members, a guy we don't know, and a few animals. I thought I'd share the photos here for fun.

First, a little bit about the camera. It's a Stealth Cam P12 Scouting Camera. It has a 50 foot range and can shoot photos up to 6 megapixels. It can also do video! I have it set to take 6 photos a second apart once it's been activated.

The camera takes eight AA batteries. I put rechargeable batteries in and it's holding up fine. It also uses an SD card. I usually take a small digital camera out into the woods and put the SD card into that in order to see if there are any new photos.

There was one little hiccup a few weeks after I attached the camera to a tree. The motion sensor was being activated because the leaves came out on the tree after I placed the camera. More than 2,500 photos of a leaf! I moved it to a new spot.




The best picture since this batch is a deer ear! I backed up the camera by about 10 feet and we'll see if we can get him to fill the frame.

I look forward to moving the camera around and seeing what else I can find.

If you have a trail camera, please feel free to share some photos of the animals you've "captured."

34 comments; last comment on 06/23/2015
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Analysis of a Champion: American Pharoah

Posted June 09, 2015 10:33 AM by SavvyExacta
Pathfinder Tags: horse racing

American Pharoah has won the Triple Crown! This headline has been shouted at us since he became the first horse in 37 years to accomplish the feat.

What makes a Triple Crown champion? There is a lot of statistical analysis from many sports fans about how this can happen. There are also a lot of naysayers who claim American Pharoah isn't all that great. In this post I'll take a look at some theories from both sides, taking a scientific approach to analyze some of the facts.

Marks of a Champion

American Pharoah's pedigree contains fast horses; winners that were able to sustain long distances. 43 Triple Crown race winners are descended from Northern Dancer, Buckpasser, and Mr. Prospecter - all visible in American Pharoah's pedigree. His grandsire Unbridled won the Kentucky Derby and Breeder's Cup Classic in 1990. Another grandsire, Empire Maker, won the Belmont Stakes in 2003. A family tree full of all the right names doesn't make a champion, however. Of the thousands of thoroughbred foals that are born each year, very few go on to win top races.

Three other factors may have contributed to American Pharoah's success: his stride, his running style, and his temperament. Some might even add a fourth factor-his tail!

  • Stride - American Pharoah has a long, fluid stride. He simply covers more ground with each step. Although many trainers have commented on the length of his stride, I've been unable to find a measurement. I'm sure this is something we'll see analyzed in the days to come! (For comparison, Secretariat's stride measured 25 feet and Man O' War's 30 feet. The average thoroughbred's galloping stride length is 20-24 feet.
  • Running Style - Seven of the previous 11 Triple Crown winners led from wire to wire in the Belmont. American Pharoah was likewise sent right to the lead. This is his preferred place to be (although he did win the Derby from slightly off the pace). He was able to set his own cruising speed with enough left in the tank to pull away from the others in the stretch run. And his time for the last quarter-mile in the Belmont was faster than Secretariat's time over the same part of the race.
  • Temperament - American Pharoah has matured into an easygoing, friendly horse. His trainer, Bob Baffert, commented that many top horses tend to be "mean." Some equate this as focus, a will to win. American Pharoah has mellowed out since his time as a fidgety 2-year-old. His ear plugs help him focus on the task at hand. He doesn't waste precious energy with distractions.

For the moment, American Pharoah's tail is a little shorter than average. Nobody knows for sure what happened, but it's thought that a stablemate chewed it off. According to a blog post on the website America's Best Racing, this short tail might be helping American Pharoah. Peter Caruso, a physicist who works with aerospace engineers, said: "The faster a horse runs, the aerodynamic drag increases. And the back of a horse, that's where all the downforce happens. The slipstream that moves over the horse will eventually meet up again in the back, right at the tail."

The Negatives - Why American Pharoah Might be "Just Average"

Few will argue there is a greater American racehorse than Secretariat. (Some argue that the only horse that might top him is Man O'War.) Secretariat's owner, Penny Chenery, weighed in with her opinion prior to the Belmont Stakes. She acknowledged that American Pharoah had a chance at the Triple Crown based on his physical appearance and stride length.

However, she didn't believe American Pharoah was of the same caliber as Secretariat based on the times for his races in the Kentucky Derby and Preakness Stakes. The times were slow (although the Preakness Stakes was run during a torrential downpour); Secretariat holds the records for all three events.

Secretariat (1973)

American Pharoah (2015)

Kentucky Derby

Distance 1 1/4 miles 1 1/4 miles
Time 1:59.4 2:03:02
Condition Fast Fast
# Entries 13 18

Preakness Stakes

Distance 1 3/16 miles 1 3/16 miles
Time 1:53 1:58:46
Condition Fast Sloppy
Entries 6 8

Belmont Stakes

Distance 1 1/2 miles 1 1/2 miles
Time 2:24 2:26:65
Condition Fast Fast
Entries 5 8

Watch a very cool side-by-side replay of American Pharoah's Belmont and Secretariat's Belmont.

Others argue that this year's crop of 3-year-old thoroughbreds is a weak one. (This is a common theory when there aren't a number of apparent standouts.) People that stick to this opinion say that even though he won, it doesn't matter because there wasn't much competition. Even so, there have been other "weak" years, and in the past 37 nobody has been able to win all three races.

Still, Secretariat raced against fewer horses than American Pharoah. Sham was Secretariat's main competitor. He finished second in both the Derby and Preakness; he was last in the Belmont where he had tried to keep a fast early pace with Secretariat. Our Native was third in the Derby and Preakness; he did not enter the Belmont.

American Pharoah faced more entries in each race than Secretariat did. The Derby alone is enough to rattle any horse; the cavalry charge from the gate can easily set any horse up for a bad trip.

To wrap up, here's a reason that I think makes him average while at the same time leading to his victory: American Pharoah is lightly raced for his age. He raced just three times as a 2-year-old before injury caused him to sit out the rest of the season. He didn't head to the races again until March of this year, a few months after most 3-year-olds started prepping for the Derby. His light race record is not as impressive as the dozens of races horses of decades past used to compete in. But trainer Bob Baffert timed it right; the horse peaked at the opportune moment.

Time will tell if American Pharoah continues to be successful. No matter what, he is still a horse racing legend, accomplishing a feat that only 11 others have been able to claim.


Yahoo! Sports | Secretariat's owner: American Pharoah doesn't measure up to all-time greats

Sporting News | Where does American Pharoah rank among Triple Crown champions? Look no further than Seattle Slew

Blood-Horse | Pharoah Fits Profile of Triple Crown Winner

America's Best Racing | The Aerodynamic Advantage of American Pharoah's Short Tail

Wikipedia | Kentucky Derby

Wikipedia | Preakness Stakes

Wikipedia | Belmont Stakes

Wikipedia | American Pharoah

Zayat Stables | American Pharoah

image credit Gary Jones | Fox Sports

image credit Belmont Stakes History | Triple Crown Winners

5 comments; last comment on 06/09/2015
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Brontosaurus vs Apatosaurus

Posted April 24, 2015 12:00 AM by Chelsey H

When I was little one of my favorite movies was "We're Back: A Dinosaur Story". It's a ridiculous cartoon about dinosaurs showing up in a big city. Now, the Brontosaurus can say "I'm back"!

For many years paleontologists have insisted that the species was incorrectly labeled and was being confused with a similar dinosaur, Apatosaurus. But now…they're back!

A team of paleontologists led by Emanuel Tschopp at the New University of Lisbon in Portugal has just completed a massive computer analysis of fossils in a group of dinosaurs called Diplodocids that includes the Brontosaurus. The group found that Brontosaurus is in a group of its own. Its fossils share distinct, incomparable bone features-enough for it to reclaim its iconic genus name. Image Credit

Although the research is well done and very convincing, many paleontologists have trouble accepting the news. The Brontosaurus holotype (the fossil to which every other fossil in that group is compared) was found in Montana in 1877. At this time naming a new dinosaur often trumped scientific scruples. But in 1903, paleontologists decided that the naming was a bit hasty and the new dino was just a smaller version of the Apatosaurus. In the 1970s paleontologists went back to the original find and discovered that it was actually a mishmash of two completely different dinosaurs with the skull from one plopped onto the skeleton from another.

But Tschopp didn't give up. His group collected a major trove of fossil data on almost all the known Diplodocid fossils. Then they ran the data through statistical programs which grouped the dino fossils based on their various bone peculiarities.

Their data matched how paleontologists currently view the evolutionary tree of these dinosaurs. But it also led them to a few surprises! According to Tschopp, there are seven specific bone differences that make the body of the original Brontosaurus its own species and genus, not just some other big dino that's been mislabeled. Image Credit

The differences are subtle. The tail vertebrae in dinosaurs related to the Brontosaurus have spiny prominences called "neural spines" and for most of these dinosaurs these spines project backwards, in the Brontosaurus they're more straight up out of the back. Brontosaurus's hips are unusual, with two bones meeting in a curious junction, and its lower leg fibula meets its ankle bones in an equally unusual manner.

Some paleontologists (and the entire dinosaur loving public) are excited that the Brontosaurus has been corralled back into the realm of science, if only because it's really become a piece of Americana.

1 comments; last comment on 04/24/2015
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