anonymous said:

WHY DO CATS DO THE BUTT WIGGLE

For traction in their rear paws. Cats do the wiggle right before they pounce, which as we know is a forward leap. They don’t want to slip when they’re pushing off with their hind legs, so they dig their rear claws into the dirt (or whatever surface they are on) to get a solid grip.

Or, in shorter words, cats do the butt wiggle so that this doesn’t happen:

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anonymous said:

why wolf eat berry

Wolf eat berry because wolf not obligate carnivore. Wolf have more to diet than just big prey animal even though big prey animal make up most of what wolf eats. Wolf also like berry, insect, fishy, nice fruits.

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Wolf not only canid that like berry. All but three canid species occasionally eat plant matter, with some like the maned wolf eating nearly 50% plant matter. Only species that may be 100% meat eaters are bush dog, African wild dog, and dhole. This theory is based mainly on modified shearing carnassial in these 3 species.

Source: Canid species accounts

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This is definitely a really interesting topic to me, and I’ll try to answer to the best of my ability. Keep in mind that I’m coming at this from a psychology/biology background, not an anthropological one- I’d love to hear people from that field weigh in on the topic.

I’d also like to note that some of the things in this article aren’t based on scientific research but my own observations and opinion.

My reply got pretty long so I put it behind a cut, but here’s what I go over:

  • Why people keep animals, and the types of relationships people have with animals
  • Domestic vs tamed animals
  • Conditions that allow humans to keep pets
  • Animal-animal relationships that resemble human pet keeping

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thespineanditstingle said:

Any chance you'll show us pictures of your axolotls? Please please please please?

I mean OKAY but I don’t have any good recent pictures of them so you can have some old ones. but yeah here are my three children

so there’s mama Wooper (i was so fucking original)

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she’s so majestic

and here’s papa Moony (i almost named him Padfoot b/c of his black foot but Moony suited him better)

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he’s a fussybutt and he always spits out his food

and finally here’s baby Nano

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this is an old picture, she is enormous now

okay more behind this cut so it doesn’t get too obnoxious (literally don’t ever ask me for pictures of my pets I CAN’T STOP)

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anonymous said:

Are you for or against raw diet?

I’m… neither?

Ok, fine, I wouldn’t put any of my pets on a raw diet because there isn’t sufficient scientific evidence that raw diets are any healthier than commercial pet foods (and raw diets have a couple of risks that commercial pet food doesn’t).

I know a lot of people are REALLY SUPER FOR raw diets and again, all I think is that they’re neither awful nor revolutionary. If you have your pet on a raw diet, it’s probably going to do perfectly fine so long as you are careful and consistent.

The problem I have with raw diets is more the way they are talked up by their advocates. With flat-out lies that sound convincing but have no actual scientific basis. That’s what angers me.

The research into pets fed raw diets (and indeed, vegan diets) is limited, and what studies there are out there have small sample sizes, so it’s hard to give definitive answers one way or another. A lot of raw diet enthusiasts claim that this is because of an inherent bias in the way that the research is carried out, that commercial pet food companies are the ones funding it. It is certainly possible. (Though I think it’s more likely that the movement just isn’t big enough to garner sufficient interest.)

Either way, a lack of evidence saying something has negative effects doesn’t automatically mean it has positive effects.

Here are some claims I see commonly repeated on raw food websites:

Anatomy shows that cats and dogs are carnivores!

Gosh, these people love to go on about dentition and musculature and all that. That’s great. It doesn’t actually provide evidence as to whether a dog can digest plant-derived carbs or cooked food. Yes, carnivores usually have certain types of dentition. But anatomical observations don’t substitute for actual scientific studies.

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Just look at the canines on this maned wolf skull! You’d almost never know that their diet in the wild can be up to 50% plant matter!

Do I think that cats are obligate carnivores? Yes. Do I think that a healthy diet for dogs includes a large proportion of meat? Yes. I’m simply pointing out that the anatomy argument is largely a distraction.

Dogs and cats can’t process dietary carbs!

Yes, dogs can. (In fact, genetic evidence suggests they evolved to eat a diet much richer in starch than their wolf ancestors.) Yes, cats can, though they don’t need to, and they certainly can’t survive without a diet rich in proteins derived from meat. Still, the claim that cats are more likely to be obese when fed a diet rich in carbs has no actual evidence to back it. Same for the claim that more carbs are more likely to lead to diabetes in cats.

Uncooked meat is what cats and dogs evolved to eat! Therefore, it’s natural, which means it’s better!

Yes, dogs and cats originally ate uncooked meat. So did we. There is a reason humans started cooking their food: a) it kills off dangerous bacteria and b) it makes food more digestible, increases potential energy obtained, and actually makes certain nutrients more available to use. The idea that because something is “natural” means that it is automatically better is inherently flawed. You know what happens a lot in nature? Animals die.

All modern veterinary diseases are caused by the consumption of cooked food!

I swear to god. Do I actually have to refute this? The fact that we know about more diseases in cats and dogs than we used to does not mean that these diseases never previously existed. And the fact is that dogs are actually living much longer now than they used to thanks to modern veterinary medicine.

There is no actual evidence that feeding your dog kibble is going increase the likelihood of cancer, diabetes, obesity, GI tract issues, etc., etc., etc. Or dental disease. (In fact, raw diets may raise the risk of getting a dental disease.)

The chances of bacterial contamination of raw meat and/or getting injuries from eating bones are negligibly low/nonexistent.

Not true. And there is a human health risk both from preparing raw meat and from pets that may shed bacteria.

And finally: Raw fed pets are much healthier than pets fed commercial pet food!

While there isn’t a whole lot of evidence either way, what does exist points to one thing: pets on properly balanced, carefully regulated raw diets show no measurable health benefits compared to pets fed raw diets. This is true for both cats and dogs.

These are the facts as I understand them. It may well be that eventually, some research comes out to prove that raw diets are indeed much better for your pet than commercial cooked food. In that case, I’d probably change my opinion on raw diets. However, as long as the proponents of these diets continue to tout fallacious claims about what these diets can do, I am going to treat them the way they deserve to be treated: as crock.

Please don’t send me anecdotes about how well your pets are doing on raw diets. Anecdotes are not and will never be any grounds to refute published studies.

For further reading: here’s the full text of a lit review of a collection of papers published about raw feeding.

anonymous said:

Hi. I dont want to sound like a jerk I just was wondering... I read somewhere that axolotls are near extinction...

It’s a valid question, and you’re not a jerk, haha. Axolotls are indeed near extinction- so close that it was wonderful news to hear that two had been spotted in the wild this February. That’s the knife’s edge the species is currently on.

There is a large population of axolotls in the pet industry right now, as well as decent populations in both labs and zoos. All of these populations face issues of inbreeding- the pet and lab populations in particular. Both those populations have also been interbred with tiger salamanders as well, to introduce that coveted leucistic look.

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This is not how axolotls look in the wild. This is a color mutation.

The zoo population and perhaps a small portion of the lab population might someday be returnable to the wild if suitable habitat is recovered, but now the fear is that this would cause the introduction of chytrid fungus to the already-failing wild population.

I understand the concerns about keeping axolotls as pets when the wild situation is so dire, but no wild axolotls have really been taken into the industry for the last 3-4 decades; it’s a species that breeds readily in captivity. And to be honest, many more people are interested in the unusual colors than in the original wild-type.

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This is how axolotls look in the wild.

Because of how easy it is to satisfy the species’ needs in captivity and because it is not hurting the wild population, I don’t really have qualms about people having them as pets.

But, if it puts your mind at ease, I did not buy my axolotls from a pet store or breeder. They are former lab animals that were down to be culled before I adopted them.

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Which is why Moony has one jazz hand (it was grown on him from the cells of another axolotl).

carryonmywaywardstirrup said:

I just watched an episode of QI and they said if you inject axolotl with iodine, they turn into salamanders! Is that true?

An iodine injection, applied along with other things, might cause an axolotl to metamorphose. It is much more likely to kill the axolotl.

If you weren’t aware, axolotls are neotonized salamanders, aka they never leave the larval stage. (Just like frogs, salamanders undergo metamorphosis.)

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Here’s a normal (neotonized) adult leucistic axolotl.

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And here’s an artificially metamorphosed adult axolotl.

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Axolotls became permanently neotonized when an ancestor was born with a defect in its hormonal system. Metamorphosis in salamanders is triggered by a hormonal pathway involving the thyroid- axolotls lost the ability to produce one of the first hormones in this sequence, thyroid stimulating hormone, which triggers the thyroid to release thyroxine (T4) to start metamorphosis.

In the 20s it was found that injections of iodine as well as “thyroid extract” could trigger metamorphosis in the axolotl. Iodine is used by the thyroid to manufacture thyroxine, so this was likely why. Later scientists directly used thyroxine to get the axolotl to metamorphose. The process is delicate even under laboratory conditions, with many individuals not fully metamorphosing and/or dying.

There are reports of pet axolotls spontaneously undergoing metamorphosis without the injection, but these are likely individuals that have hybridized with the closely related tiger salamanders (or are tiger salamander larvae that have been sold as axolotls). I’ve also read that there may be some differences in the way that wild-caught versus captive bred axolotls respond to different metamorphosing techniques, but wild axolotls haven’t been brought into the captive breeding pool for decades, and are now so rare in their natural habitat that it’s highly unlikely any ever will again.

Ok, so if you are an axolotl owner, this may sound cool and exciting. But recall that axolotls have evolved to stay in the larval stage. Even if they survive, the forced metamorphosis is very bad for them and most only live a year or so past it (versus their normal 10-15 year lifespan). So please, please do not attempt to metamorphose your axolotl with some method you found on the internet- it likely won’t work anyway and will severely stress out or possibly kill your pet.

Source:

Rosenkilde & Ussing, 1996. What mechanisms control neotony and regulate induced metamorphosis in urodeles? Int J Dev Bio 40(4):665-73.

anonymous said:

Um, can I ask why purebred dogs have so many problems? Or is there already a post on the subject?

The concept of purebred dogs is not a bad one; it’s just the state of many purebred dogs (and other animals) is awful right now.

Theoretically, having a purebred dog would be a way of determining size, looks, and approximate temperament of the animal you are hoping to get. And that is generally a good thing; some owners live in apartments and some live on farms, some want working dogs and some want lapdogs. It’s good for both the owner and the animal if they match up.

Where breeding can go wrong is when the looks and price of an animal matter more than the quality of life that its genes will cause it to have.

The two main issues affecting purebred animals can be summarized to inbreeding depression and overbreeding, both of which I’ll discuss in detail (and with science) below.

Read More

anonymous said:

What are those holes in the snake's head, like along its bottom lip?

Those are sensory organs called pits. You can also see them in this carpet python.

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(Source.)

Pit organs are specialized for detecting infrared light- i.e., heat. And it isn’t as if the pits simply get warm and tell the snake that there’s something hot nearby. The pits actually connect to the snake’s optic nerve, allowing it to view a very blurry heat picture.

This image is overlaid over the snake’s normal vision, though it does provide them a way to see- to a limited extent- even in places without visible light.

A common misconception many people have is that the snakes use these organs primarily to detect and strike prey. While the pits may be used in this manner, they require a lot of contrast: a hot mouse on very cool ground would be visible via thermoreception, but not a warm mouse on warm ground.

The pit organs function essentially like pinhole cameras (and like some of the earliest forms of eyes did). The smaller the hole, the sharper the image. As you can see, the size of the apertures of the pits are quite large, meaning the image the snake receives is quite blurry. There’s some evidence to suggest that the picture is sharpened in the snake’s brain before it reaches the optic nerve, but no one yet knows to what extent this is.

In this case, being infralabial pits (on the lower jaw) they are angled slightly towards the ground. These pits may actually serve a defensive, rather than offensive purpose- they may help the snake find cooler areas on the ground that are shaded and protected. (And, as stated before, the snake can use higher temperature contrast to have better thermal vision to seek prey with.)

Not all snakes have pits; in fact, it’s only evolved in a limited number of groups: pit vipers, pythons, and some boids. In each case, the pit organs seem to have evolved independently, leading to two different types of structures. In boas and pythons, like the snake pictured above, there are multiple simple pit organs along the upper and sometimes lower jaw. In pit vipers, there is single, complex pair of pits located near the nostrils.

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(The grouchiest pit viper.) (Source.)

A pit viper’s pit contains a membrane stretched across the hole. This membrane contains all the heat-sensing thermoreceptors, while in boas and pythons the thermoreceptors are simply inside the pit. In both cases, the area around the pit is surrounded by blood vessels so that the thermoreceptors can be quickly cooled down. This prevents the snake from seeing heat aftermirages.

Studies on blind snakes have shown that pit vipers are much better at using their pits to locate prey than pythons and boas, meaning they likely are able to produce sharper images.

Probably a little more than you wanted to know, but there you go!

References

Bakken, G. S., and A. R. Krochmal. 2007. The imaging properties and sensitivity of the facial pits of pitvipers as determined by optical and heat-transfer analysis. The Journal of Experiemental Biology 210: 2801-2810.

Gorris, R. C., A. Yoshitoshi, N. Masato, H. Tatsuya, F. Kengo, and K. Tetsuo. 2003. The microvasculature of python pit organs: morphology and blood flow kinetics. Microvascular Research 65: 179-185.

Grace, M. S., O. M. Woodward, D. R. Church, and G. Calish. 2001. Prey trageting by the infrared-imaging snake Python: effects of experimental and congenital visiual deprivation. Behavioural Brain Research 119: 23-31.

Kardong, K. V., and S. P. Mackessy. 1991. The strike behavior of a congenitally blind rattlesnake. Journal of Herpetology 25: 208-211.

Krochmal, A. R., and G. S. Bakken. 2003. Thermoregulation is the pits: use of thermal radiation for retreat site selection by rattlesnakes. The Journal of Experimental Biology 206: 2539-2545.

dalektable-souffle-girl said:

I understand that you're pretty smart when it comes to animals, so I have a question that has bothered me since I was a little kid: how do cats move without making any sound? another question: why is it that small dogs usually live longer then larger ones? I had a big old dog when I was younger that died, but I also had a little dog that was the same age as the big one when she died, but lived for two or three more years.

To the first question: cats are animals that hunt by ambush- they sneak up on their prey. Compare that to animals like large canids, which generally hunt by coursing- they run down their prey until it is exhausted.

(Within the cats, cheetahs are an obvious exception to this.)

Also consider the fact that cats are on the small side, and their ancestor, the African wildcat, lived in an area with a LOT of larger predators. If you consider these two facts, you can understand why it would be beneficial for the domestic cat to evolve ways to move very quietly.

Now, as to HOW they do it, there are a number of mechanisms. First, their gait. When cats walk, they place their back foot almost directly into the same spot they put their front foot. You can see it in the doubled-up pawprints of cats walking on snow.

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Similar to the “we’re being sneaky so step where I step” trope you’ll see in books or movies, stepping in the same spot twice minimizes how much noise the cat makes when it moves.

Another anatomical adaptation is the cat’s paws. If you have ever had the pleasure of touching the underside of your cat’s paw, you may notice that the little pads are very soft- very different from a hard, calloused dog paw. Not only is the skin soft, there is soft fur growing densely around the pads.

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And here’s a dog paw for comparison.

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Soft things like cat paws make less noise than hard things when they move, because soft things spread out upon impact, muffling sound.

You’ll also notice that the dog’s paw has the blunt nails extended, while cats can retract their claws. Not only does this keep them sharp, it also keeps them from making any noise.

Cats also make a lot less noise breathing when they move than other animals- you’ll notice a cat doesn’t pant like a dog when it walks or runs. (If you see your cat panting, that is a BAD sign. Call your vet.)

But essentially, cats are generally evolutionarily engineered quietude machines.

Now, as to your second question about dog mortality… the answer is a bit more complicated. So much so that I’m going to make a separate post for it tonight when I get home from work. Stay tuned!

myskittlesexploded said:

Why do the jaguars want to kill the caiman anyway? Was it really that hungry?

Not so much a question of it being “that” hungry- caimans are part of a jaguar’s normal prey repertoire. About the only large native ungulate in South America is the tapir, so the jaguar’s diet is quite different from other big cats like the lion or tiger. (It’s the third largest feline after those two!)

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I met this gorgeous fellow, named Junior, at the Belize Zoo.

Jaguars have been recorded eating almost 90 different prey species- they are extreme generalists. They have exceptionally powerful jaws and can bite through turtle shells, so a tough-skinned caiman is absolutely no problem for them.

They even have a special method of killing them- normally, the jaguar uses its canines to pierce the skulls of its prey, but for caimans, which have flattened skulls, the jaguar bites them on the back of the neck to dislocate the cervical vertebrae and paralyze them.

Here’s a video of a jaguar successfully preying on a caiman!

And here’s a closer look.

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"Hey."

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"Hey."

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"Heyyyyyyy."

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"Got it."

Further reading:

Da Silveira, R., Ramalho, E. E., Thorbjarnarson, J. B., & Magnusson, W. E. (2010). Depredation by jaguars on caimans and importance of reptiles in the diet of jaguar. Journal of Herpetology, 44(3), 418-424.

Photo sources: 1/2/3/4

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I’ve lumped these together because they all converge on a similar idea.

What I will say about human behavior is this: behavioral studies apply to populations, not individuals, and that the only definitive natural thing that there is about human behavior that I have seen is that it is incredibly varied, flexible, and complex.

And let me add one more thing: just because something may seem more ‘evolutionarily salient’ does not say anything about whether or not it is morally justifiable or whether or not we have a duty to make it happen. Divorce yourself from this idea at once, please, if you hold it. We can use evolutionary theory to discuss why certain behaviors might happen, but it tells us absolutely nothing about if they should happen, nor does it mean that we have no choice in them happening it all. 

As I’ve said before, it is entirely possible to pass on your genetic material without having any of your own children by aiding your siblings and parents in raising theirs. But, in the event that you have no close immediate family, there is absolutely no reason for you to feel bad for not having children. There just isn’t. You’re not being mean to children you’ve never had, or whatever…. I can’t honestly think of a good reason to feel bad at all, as I’m trying to articulate this, haha.

No one is the sole progenitor of the human race; no one carries that burden, and even if they did- even if they were one of the last humans alive- I’d still say they had the right to choose whether or not they had children. The individual should ALWAYS have that right.

On the subject of evolutionary studies, I want you to consider a hypothetical scenario: a sample of 1,000,000 humans is given a survey of what they like better: chocolate or blueberries. The surveys come back in, and the results are that 99% of people say they like chocolate more than blueberries.

"Well, " you say, "obviously humans prefer chocolate over blueberries." But you like blueberries more than chocolate, and you wonder secretly if there isn’t something wrong with you, that you prefer blueberries to chocolate and are in that mystical 1%.

But in a sample of 1,000,000 people, 1% equals 10,000 people. 10,000 people who liked blueberries better. Furthermore, there are a hell of a lot more than one million people on the planet. Where was this sample taken- in what country, population, culture? What were the ages of these people, what were the economic backgrounds? And I’m not saying this study wouldn’t be valid- in that area among that subset of people there might really be a tendency to prefer chocolate over blueberries.

But the trend of the population tells you absolutely nothing about your snack preferences, o blueberry-loving person. You already know what they are, and they are as natural and human to you as anything else.

sylph0fl1ght said:

Do you have a favorite species of bat or do you love them all?

My god why would you even ask this this is a DIFFICULT QUESTION UGH

I mean some of my favorites are bats I’ve actually gotten to handle. Like the first bat I ever held was a big brown bat and they are so nasty and mean and loud and I love them.

(I took these pictures so they aren’t the best.)

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the grumpinest

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in a bag waiting to be weighed

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and this gal was a very upset juvenile.

And similarly I also love Eastern red bats because they are gorgeous little demons (that I got to hold).

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"haaaaate"

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"why bat god"

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Expressing rage over being banded.

And last on the list of “bats I love mainly because I got to touch them” is the hoary bat. GIANT GORGEOUS CHILD

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(This one is still a juvenile!)

But I have a lot of other secret bat loves… the wooly false vampire bat, for example.

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(Actually, I did get to touch this gal, since she was shown to us at a demonstration in Belize.)

Also a fan of pallid bats, ghost bats, and Egyptian fruit bats… lesser short-tails obviously… banana bats… vampire bats in general… tube-lipped nectar bats… jamaican fruit bats… aaaaaa this question is too hard and I hate you. I’VE NEVER MET A BAT I DIDN’T LIKE, let’s put it that way.

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