(posted in Birds)

Hi Jerry,

How nice that you have a returning pair of mourning doves in your garden! I love their sad calls...

Don't worry, contrary to popular belief, most birds can't smell very well, and in any case, your pair are probably quite used to people. However, a visible disturbance in the nest itself might make them choose a different location.

You can still help them by leaving soft twigs, grass stems and pine needles where they can see them. They'll pick the ones they like.

An idea: Would be an interesting project to start a photo record of this season's nesting and chick rearing?

All the best,

Carlos.

Hi Martin,


There is an easy way for us humans to understand how a cat's retractable claw works:

Imagine your hand is a cat's front paw. The claw would be attached to the very last bone of your finger. When the claw is retracted, it's this last little bone that's pulled back by a tendon. The toe-tip points straight up, and the claw doesn't touch the ground and disappears into a fold of skin. This keeps it sharp. |

The cat walks on the bottom of this last knuckle of each finger, these are the four little pads you can feel on the bottom of a cat's paw.
   
Hope this helps, please contact me again if you have any questions,


Carlos.

Hi Chris,

It looks like a dragonfly larva. Dragonflies start their lives in water, feeding on smaller creatures up to the size of tadpoles.

When it's ready, it'll crawl out on a twig, and, like a catterpillar turns into a butterfly, it too will turn into a flying adult: The dragonfly.

Hope this helps!

Carlos.

Hi Bob,

I'm not an expert in insects, but I did show your pic to a few entomologists I know, and they all agreed your bug is Anthocomus equestris, the soft-winged flower beetle.

As their name suggests, they live on flowers, so he probably got into your house by accident.

Hope this helps!

Carlos.

Hi Martin,

You're absolutely right in that respect: Your digestive system won't be able to tell the difference between GM foods and any other kind (your tastebuds might though, more on that later).

GM foods directly harming humans is just the stuff of sensationalist headlines, and is certainly not the reason why many biologists are suspicious of GM crops.

One of the many points they bring up is that plants hybridize naturally much easier than animals, and pollen from a crop genetically modified to be resistant to a herbicide or a pesticide, for example, might cross with a wild weed. The results would be unpredictable and could be catastrophic for the environment.

There are several more objections which I won't go into detail here. Not all of them are so gloomy, though: For some people, these GM crops just taste bland compared to traditional varieties!

By the way, for the sake of fairness I have to say that we have been indirectly modifying our food plants and animals since agriculture began, through selecting the best and most productive to breed for us. This is why the modern potato or milk cow, for example, looks nothing like its primitive wild ancestor and produces much more food.

What's being debated currently is is the direct manipulation of an organism's genome using biotechnology, because the results (and the consequences, good or bad) of this new modification technique happen much quicker and can be more widespread than those obtained through more traditional means.

It's a very intricate topic, and there are a lot of positives to consider as well, such as producing crops that are less reliance on chemical pesticides or that can produce medicines for us more efficiently...

Hope this helps!

Carlos.

Hi Pranit,

The quickest answer to this question is that birds inherited their excretory system from the group of animals we commonly call reptiles. Specifically, birds descended from the branch called Archosaurs,which also includes dinosaurs and crocodiles.

This awesome lineage had already evolved an efficient way of getting rid of nitrogenous waste by passing it out in the form of uric acid (the white paste you see in bird poop).

All animals need to eliminate nitrogenous waste, but there are several ways to do this. In mammals, this is done by producing urea, which is slightly poisonous but very soluble in water. This has led to the evolution of a structure, the urinary bladder, which dissolves this urea safely in a large amount of water before excretion.

Uric acid is solid (more or less), and also non-toxic. In consequence, the evolution of a urinary bladder has never been favoured by natural selection in birds, so they don't have one.
Hope this helped!

Carlos.

Hi Louis,

Bearded Dragons are great to get started on reptile keeping! They are amongst the friendliest and least-demanding of lizards.

However, they do have specific requirements that you need to be aware of before you get one. You've done the right thing, asking and reading before you get your new pet. You'd be surprised how many pet owners get the animal first and the knowledge after, often with very bad results for the pet.

Your questions cover a lot of territory, too much for this site. I recommend you get a specialized book or two, read magazines that cater to the herp hobbyist and find a good online forum, such as this one:

http://www.practicalreptilekeeping.co.u … hp?nav=qas

Good luck and hope this helps!

Carlos.

(posted in Fossils)

Hi Trevor,

This is a very interesting question. How can we know if Basilosaurus' head was rounded like an orca, or not?

Mammalian bones tend to not give away too much about what the animal looked like in life. For example, it's pretty hard to tell what the living animal looked like from a rabbit skull (if you open these links in separate tabs (right-click) you can compare them as you read):

http://etc.usf.edu/clipart/48100/48121/ … _skull.htm

On the other hand, there's no mystery about what these guys looked like when they were alive!:

http://www.azdrybones.com/crocodylia.htm


Back to orcas. If you look at the top of this orca skull:

http://www.dreamstime.com/stock-photos- … age4519413

You'll see it has two ridges running along the top of the snout, and ending in a cup at the forehead. This supports the "melon", which is a ball of fatty tissue right in front of the whale's skull. This is what gives whales and dolphins their rounded heads. What the melon does, by the way, is not completely understood, but it seems to be like an acoustic lens, to focus the whale's sonar.


If you look at the top of Basilosaurus' skull:

http://whalesandmarinefauna.wordpress.c … ed-skulls/

it doesn't seem to show these ridges, or the cup at the forehead. So, chances are, it probably didn't have a "melon", so its head would have looked pointy in life.

About the fossils, sorry, no idea what they might be, or even if they are fossils!

Hope this helped!

Carlos Grau.

Hi Ewan,

Reptiles, like geckos, snakes, chameleons (but not turtles) don't pee as a liquid. Instead, their "pee" is  that white chalky sludge next to their poop.

This white stuff is called Uric acid. The stuff in our pee is Urea, which is a different thing that most reptiles can't produce. Turtles can though, and they do pee in liquid form (sometimes when you're picking them up, disgusting).

Hope this helps, and happy reptile keeping! It's a brilliant hobby, you learn lots by reading up on your pets.

Carlos.

Hi Carnivora (cool nickname, BTW!),

Good question, and one that allows us to show how palaeontologists make their educated guesses.

A lot of what we'd like to know about dinosaurs, like what colour most of them were, or what their skin was like, can't be seen in the fossil record. This is either because we haven't found it or because it just can't be fossilized. So we need to guess. Some guesses are stronger than others: It's unlikely that T-rex was bright purple, for example, because a predator that isn't camouflaged would probably not survive...

It's likely that keratin was the covering of Triceratops's horns and beak, because the feathers of birds and the scales of crocodiles (both of which are the closest living relatives of dinosaurs) are made of keratin.

Hope this helps,

Carlos.

(posted in Birds)

Hi Anna,

This is just a guess of course, but what you describe sounds a lot like mobbing behaviour. Many birds do this, especially social ones like seagulls. If they spot a predator, they will fly around it, vocalizing and generally annoying it, until the predator goes away. They were probably chasing off a cat!

Hope this helps!

Carlos.

Hi Rachel,

Fish do sleep, in fact! If you have a tropical aquarium, you'll notice them going pale silvery and quite still amongst the plants. Parrot fish in the coral reef make a 'sleeping bag' out of mucus (apparently, it prevents their scent from wafting and attracting predators) and go to sleep in it. Dolphins also sleep, but because they need to be conscious to breathe (unlike us), they can't completely shut down their brains, as they must regularly pop to the surface.

Deep, comfortable sleep like we're used to is actually not all that frequent in the animal world. Many animals only sleep for a few minutes at a time, or not at all.

Big predators that are very safe in the wild, like lions, and small mammals that can tuck themselves safely in a burrow, like rodents, are champion sleepers!

C.

(posted in Mammals)

Hi Yustine,

Hyenas do look very dog-like, with their running legs and feet and their pack organization. In fact, they are more closely related to cats.

Together with mongooses (not "mongeese"!), cats, civets and a few others, hyenas are in the Feliforma group, one of the major divisions of the carnivores.

Amongst other things, Feliforms all have four carnassial teeth in the front of the jaw and similarities in their ear bones.

Hope this helps,

Carlos.

(posted in Birds)

Hi Cale

I've noticed that as well in my (sadly passed years ago) pet parrot!

No idea why they do so, but *could* be because vocalizing in this unusual way is an effort for the bird. It would be interesting to observe if this happens when the bird is calling normally (I never noticed, but then I wasn't looking for that then).

Carlos.

P.S.: Konrad Lorenz "King Solomon's Ring" has a very nice reference to keeping pet starlings.

Hi Jake,

There are quite a few migratory butterflies and moths (Lepidoptera is the term for them). Some species - like the Monarch - are famous for spectacular journeys, but many species move from valleys to mountain meadows in temperate climates, or follow the monsoon rains in the tropics.

Depending on the species, they can use the sun, the moon and stars or even the Earth's magnetic field, or a combination of these. They also follow the coastline, rivers and even roads!

Hope this helps,

Carlos.

Hi,

You're probably looking for a more specific term, like "ornithologist" refers to someone who studies birds, but not every speciality in biology has a particular name, I'm afraid! The reason why you get a word like "ornithologist" is because there are quite a lot of people out there specialized in the study of birds. In contrast, not very many scientists work with predators. I would use "zoologist" to describe them.

The second part of your question is more complicated... From an academic point of view, you could study zoology and go on to specialize in conservation. Or, you could work in one of the rescue centres in Africa, or volunteer with a conservation organization. There are many possible paths, but they all involve lots of hard work. All the best of luck!

Carlos.

(posted in Mammals)

Hi Esme,

That is exactly how it works! Both narwhals and babirusas (and anything else horned/tusked) are born without any pointy things... This certainly makes birthing easier on the mother. Also, tusks and horns are often a sign of maturity, and as such appear later in the animal's life. In many mammals, only the males have these structures.

In babirusas, the tusks do protrude out of the skin, and don't seem to cause the animal any discomfort at all... However, sometimes in very old males the tusks are so long they curve back into the skull, and that might be a problem for them.

Hope this helps!

Carlos.

(posted in Birds)

Quick answer is: Probably! Budgies have shown great variation in a single species, as far as colour and size goes, with some domestic breeds being very different from the wild colour.

In contrast, cockatiels breeds show different patterns of the same general soft greys and whites that can be seen in the wild.

This has to do, in part, with the number of generations that a species has been in captivity, and the budgie has been domesticated for slightly longer than the cockatiel. It also has to do with how plastic a species is. For example, it's well known that dogs breeds are much more varied than cat breeds.

Domestic animal breeds usually come about because an alert breeder notices a mutation (called a "sport" in bird breeding) and tries to establish it as a strain. So, as soon as a white-faced budgie shows up in a breeder's flock, it's highly likely it'll become the start of a new breed!

Hope this helps,

Carlos.

Hi Matt,

Endothermy is a brilliant strategy, but it's expensive! In fact, a very big chunk of the daily calorie intake of a warm-blooded animal is spent just keeping everything at the right temperature...

So it makes sense to try an conserve as much energy as possible. As you correctly pointed out, endotherms of all sorts, from birds to mammals to hawkmoths, have developed some sort of covering to keep heat from escaping the body. One of the 'cheapest' ways to do this is using filaments, fur or feathery down. Fat is also used in many cases, as in marine mammals.

For most animals, the main concern is not to get too cold. This is especially true for small animals, which tend to be the "furriest". Large endotherms tend to have the opposite problem, that of overheating. Unfortunately, fur is almost too good an insulator, and although raising it allows some heat to escape, most of that underfur can't really move, so air can't really reach the skin very well.

So, there are several alternatives to reduce temperature. Horses and humans sweat, dogs pant, and the biggest endotherms, like elephants and rhinos, have just done away with hair altogether. Incidentally, big mammals like elephants have some sort of 'radiator' to further get rid of heat. In elephants it's the ears, in big cattle it's the horns and the dewlap.

Hope this helps!

Carlos.

(posted in Mammals)

Hi Megan,

Skin in albino animals does indeed look pink because the blood vessels underneath can be seen through the lack of dark pigments. The lack of melanin, particularly, makes albino animals (and people) very sensitive to sunburn.

The pink dolphin in this picture is more than likely Pinky, a very rare albino bottlenose dolphin living in Calcasieu Lake, Louisiana. Pinky was first sighted in 2007 and has been very popular with visitors since, although conservationists are worried that the attention is not good for him (or her)...

The Amazon River dolphin Inia geoffrensis is a beautiful large freshwater dolphin that is often pink without being an albino.

Hope this helps!

Carlos.

Hi Josh,

You might not see them very often at your local supermarket, but there certainly are some blue veg out there! For example, some of the oldest known varieties of potato are blue. There are also blue carrots and blue corn.

Why don't we see them when we go shopping? The varieties of vegetables we find in supermarkets are usually those that most consumers want, or those varieties that do best in industrial production. So, a lot of interesting veg can only be found in local markets...


Hope this helps!

Carlos.

Hello,

The animals pictured look like they could be does (females) of the Sambar, an Asian species. They could also be European Red Deer. Both species have been introduced by man from their native range into several areas around the world, and both are larger than either the Whitetail or the Axis. The Sambar has a longer skull, so it might be the likelier option...

Hope this helps!

Carlos Grau.

(posted in Birds)

Hi Megan,

Like so often happens with good questions, there isn't a simple answer to yours...

First, tail feathers (properly called rectrices, from the Latin for helmsman - the guy who steers a boat) are most of what we see as a bird's "tail", the actual, flesh-and-bone tail is a very short little stump (have a look next time you have a roast chicken dinner!).

These feathers vary greatly in shape, number and size in different species, and it does affect flight dynamics a great deal, mainly because the tail is used for steering in flight (thus the name above) and braking. Look for a fanned-out tail next time you spot a pigeon landing.

Now for your actual question: No hard and fast answer, but here are some very general ideas...

Birds that do most of their flying by gliding and soaring, like swifts and albatross, tend to have very short tails and very long wings. Living in the wide open sky, they don't usually need to steer suddenly...

Birds that do most of their flying by zipping in and out through thick forest cover, like many songbirds and the sparrowhawks that fly after them, tend to have long tails and short rounded wings. This makes them highly maneuverable.

Hope this helps!

Carlos.

P.S.: Macaws and Conures are just as much a " true parrot" as all the other Psittacidae. The other groups of parrots are the Cockatoos and the New Zealand parrots... However, this grouping may change, as new evidence surfaces.

(posted in Birds)

Hi Jim,

What you've seen is called mobbing, and it is, like you said, an anti-predator behaviour, and it is seen also in many mammals and even in some fish.

Even though the prey species are smaller and weaker, their effectiveness is due to numbers: there's always one annoying the backside of the predator whichever way it turns, making it impossible for the hawk to strike at any one individual. The result is that the predator flees to somewhere more peaceful!

Hope this helped, and sorry for the delay!

Carlos Grau.

(posted in Birds)

Hi Joe,

Crows have so many legends around them. They are wonderfully intelligent birds, with very interesting behaviour, which I'm afraid don't include a legal system like the one you describe...

Corvus: A Life With Birds, by Esther Woolfson, is a brilliant book about crow behaviour from someone who rescued birds.

Hope this helps!

Carlos.

Hi Luke,

Another well-known example of asymmetry in tetrapods is the lung in snakes, in which the left lung is functional and the right lung vestigial...

Hope this helps!

Carlos.

(posted in Mammals)

Hi Luke,


Maybe dogs do 'smile'!

We have a long relationship with dogs, and as species we have developed a deep understanding of each other's behaviours. There is no doubt that many behavioural and physical characters that we see in dogs today have been selected by humans through this long association, whether intentionally or not.
Maybe the 'smile' is a modification of a previously existing 'puppy' or appeasement behaviour (e.g.: licking their owner's face is thought to have derived from a very similar behaviour in wolf cubs, in which they lick their adult's muzzle to beg for regurgitated food). It could also be a completely 'new' behaviour, one that evolved in dogs and not in wolves, as barking is thought to be.

Animal behaviourist Konrad Lorenz understood dogs very well, and his books King Solomon's Ring and Man Meets Dog are great reading if you're interested in this subject.

Hope this helps!

Carlos.

Hi Joey,

This is a very deep question.

The simplest (please note: and very incomplete) answer is that evolution takes time. Although mammals have been around since the Mesozoic, they didn't diversify until after the dinosaurs became extinct, about 65 million years ago. That's not a long time, in biological terms. Compare that with, for example, birds: They started all the way back in the Jurassic! Archaeopteryx, widely considered the first bird, is about 150 million years old...

Hope this helps,

Carlos.

Hi Wood,

Sorry for taking so long to reply!

Apparently, an octopus' arm won't grow back, but squid and cuttlefish regeneration seems to be more documented.

Hope this helps,

Carlos.

Hi Danielle,


You're both right, in a way! Cats do tend to fare better out in the wild, mainly because their hunting instinct seems to 'switch on' more easily, and because, as small animals, they don't need a lot of food and can shelter in small places. Dogs tend to be scavengers when living wild, and as such don't usually stray too far from human villages and their garbage tips....

There is a large population of cats that have gone back to the wild in Australia, and unfortunately they are killing off many small native animals. When animals revert to the wild they are known as 'feral' (see http://www.askabiologist.org.uk/answers … id=4244 ).

This applies to cats and dogs as species. Individuals of course are different, and the fact is that most of the time, abandoned cats and dogs don't survive for long if they're not rescued.

Hope this helps!

Carlos.

Hi David,

My vote would go to the Saltwater Crocodyle Crocodylus porosus from Northern Australia and neighbouring areas. 

This bad boy is the biggest of the reptiles, and certainly among the most dangerous, with one or two documented attacks on humans each year.

Hope this helps!

Carlos.

Hi Wendy,

There are many amateur geological/palaeontological societies in the Uk that can help. A good place to look is the Natural History Museum's list:

http://www.nhm.ac.uk/jdsml/research-cur … rd=geology

Hope this helps, and happy holidays!

Carlos.

It actually could be the spine from the pectoral fin of a catfish, they look very similar, so good guess...

It's not that big Dave, the red and black seeds are the size of a chickpea....

Carlos.

Hi Pamela,
 
It's the "sting" from the South American freshwater stingray Potamotrygon.

I often found them along the riverbank while fishing back home in Venezuela. They are very hard, made of enamel, unlike the rest of the skeleton, which is cartilage, so they survive in the mud after the rest of the animal has disappeared. The serrations along the sides make a nasty wound if you are unlucky enough to step on the ray.

The seeds in the rest of the necklace are also characteristic of the souvenirs made by the local Pemon Amerindian people. 

Additional random fact: The pretty black-and-red seeds are called Peonia, and are supposed to protect you against the 'Evil Eye'...

Hope this helps,


Carlos.

(posted in Fossils)

Hi Vincent,

Nice find! Ammonites are hugely diverse, and only an expert could tell you with certainty what yours is.

A better bet is to source the Us Geological Survey map of your area. There you will find the formation in which you found your ammonite, and how old it is.

Hope this helps!

Carlos.

Hi Sean,

My personal fave is the Aquatic Ape Hypothesis, which suggests that our ancestors spent some evolutionary time as coastal or riverbank waders/swimmers/divers. Thus, hairlessness would have been favoured by Natural Selection for our ancestors just as it was for other mammals that share that habitat. We share other traits with coastal mammals, such as the layer of subcutaneous fat with which we are born, or the mammalian diving reflex (a series of complex responses to sudden inmersion in cold water).  

It's - as far as I know - pretty much untestable, and has its critics, but I like it...


Carlos.

Hi Kyle,

Interesting idea... Difficult, but not impossible.

You'd have to research a lot, starting with how to set up an ant colony, as that's likely to be your trickiest step! Not many ant species would survive on a diet of duckweed alone, and you would probably have to obtain a queen, which tends to live quite deep down. Then there's a trick to keeping them inside their intended container (lots of Vaseline smeared on any boundaries, have a look at the 'bug house' at your local zoo), but some will always escape...

It might be easier to set up a self-contained ecosystem using purely aquatic animals - like insect larvae and water fleas - sourced from a local pond... Be careful when pond dipping, make sure you're aware of all dangers, from irate landowners to irate snapping turtles!

Whatever you choose in the end, it's always better to have the plants well established in the aquarium and a healthy algae growth before introducing any animals to the set-up.

Good luck, and do keep us posted!

Carlos.

(posted in Birds)

Hi Allen,
I'll have a look next time I dine on albatross! Just kidding, it's actually a very interesting question...

Your prediction sounds like it might work: Domestic ducks  have red meat on the breast, probably because, while they don't fly much, they are descended from the Mallard, a fast-flying migratory animal.

Hope this helps,

Carlos.

(posted in Mammals)

Hi Ambulocetus,

You always have the most interesting questions! I don't know the answer to this one, but a strong guess would be: By smell, like most every aspect of a mole's life...

Hope this helps,

Carlos.

Hi Eric,

Sorry for taking so long to answer your question...

The fact that it's been hanging around unanswered all this time should give you a clue: Nobody knows the answer for certain!

Most tropical birds, fish, reptiles and even mammals do tend to be more colorful than their temperate cousins... I can venture a guess for one case:

Animal coloration is generally a consequence of natural selection. This can take many forms, like camouflage that hides the animal from predators or prey. This color pattern is probably the 'industry standard' in nature, the default option.

But color can also be brought about by the natural selection of display, to mates or enemies, and that can be a very powerful selective force that can override the selective pressure to hide from predators.

Konrad Lorenz, in his book On Aggression, describes how many coral fish are extremely territorial, and their varied color patterns serve as banners to tell friend from foe in the very diverse, bright and populous neighbourhood of the reef.

Maybe, gray temperate rocky coasts aren't that busy as backgrounds, and the selective pressure to defend their territory can be satisfied with a small bright patch (look carefully for these next time you're at an aquarium), or with behaviour. The standard pressure to hide from predators would result in a drab grey color (matching the grey background) for the rest of the body.

This is, of course, all conjecture!

Hope this helps,

Carlos.

Hi Klaus,
I like your 'Cognition versus genetics' idea! Maybe that's why I'm under the impression that most cats are tabbies like mine. It makes sense, we do notice things more if we're looking for them.

Cat colour is of course determined by genes, some of which are dominant and some recessive (complicated and fascinating, and nearly not enough room to discuss here!). The frequency of a particular colour varies regionally, either by selection from humans or by accident. Natural selection might play a part in feral populations as well. Maybe tux cats were historically preferred in your area.

There is some evidence that tabbies had been selected for in Britain and Western Europe soon after their introduction, and they do seem to be a very abundant type in the present (I am biased, though!).


Hope this helps,

Carlos.

Hi Robin,

There is a wide range of shades between 'full-time solitary' (like a male tiger) in which the animal makes an active effort to not come into contact with others of its species; and 'full-time social' (like a chimpanzee), in which the animal not only lives in a group but actually needs to live within a heirarchy.

For example, there is the 'anonymity of the flock' in which an animal, like sardines, live in a large group without acknowledging each other very much. This definition was first put across by the seminal ethologist Konrad Lorenz, which leads me neatly into your next question (his book, King Solomon's Ring, is a brilliant introduction to animal behaviour in captivity).

According to Lorenz, there's no way of telling which species would be best suited for domestication. Closely related species, like the wolf and the fox, can be very different in how easily the can accept being tamed. It helps if it is a social species, but some solitary animals are quite tameable. An example of this is the European Genet, an beautiful creature which used to be tamed in ancient times, and one which we could have in our living rooms today had the Romans not fallen in love with the cat!

This last bit also links to your question: The animals we now know as domestic have been so not only because they are tameable, but also because, for historical reasons,  we have chosen to keep them instead of many others that could be equally well suited for the job.

For example, there are a couple of South East Asian domestic cattle species that are only kept in localized areas, whereas the common cow is kept in huge numbers worldwide because the people who first domesticated the Aurochs (the original wild cow) then traded with other people. 


Hope this helps,

Carlos.

Hi Bryan,

I don't personally know of any reptile species with 'eyelashes', but there certainly is no reason why fine hair-like structures can't arise from reptile integument: just look at the tiny setae on the soles of gecko's feet, they are even finer than eyelashes (you have to look at tree-living geckos, the leopard gecko that is a popular pet does not have them).

The answer, as with most biology questions, must lie in natural selection: if there is an advantage for a reptile to have eyelashes, natural selection would favour those that do.

There are other ways to protect eyes, most notably the nictitating membrane, a sort of third eyelid that travels sideways across the eye, rather than up and down. You can see this translucent pink membrane, if you look closely, when a bird blinks.

Hope this helps,


Carlos.

Hi Alfred,

I know next to nothing about identifying caterpillars, so I'll leave that to the experts. To answer your second question: The general rule is that if they're hairy, it's probably best to leave them alone.

A useful piece of advice I picked up from my field biology teacher is that, when it comes to suspicious-looking insects or amphibians, it's best not to handle them without gloves: Even if they're not toxic outright, you might be allergic to them, and the only way you'll find out is if you get a reaction. Definitely not worth it, especially in the field.

Hope this helps,


Carlos.

Hi Sammy,

I suppose both views would be correct in a way...

The complex arrangement of bones and organs we would know as the 'face' would certainly come from a common ancestor in tarsiers and monkeys, and so are homologous.

But, in both groups vision is also a very important sense and thus natural selection would have made them look similarly 'flat-faced', as the eyes are a more prominent feature than the nose (same thing happens in owls and cats, by the way). In lemurs, olfaction is important and so natural selection favoured a longer nose (as in dogs).

Hopes this helped,

Carlos.

Hi Kim,

Like you suggest, five does seem like a magical maximum number for digits in living vertebrates, probably because we descended from something with 5 digits. It could have turned out differently, however: Early tetrapods and 'fishapods', like Ichthyostega and Tiktaalik, had more than 5.


Ichthyostega had 8 digits, imagine what our life (and maths, and science) would be like if we had inherited that!

Hope that helps,

Carlos.

(posted in Fossils)

Hi Andyka,


That is a very good question indeed, and quite important. A fair chunk about an extinct animal's ecology and general lifestyle can be deduced by measuring aspects of well-preserved fossils, and new techniques like MRI and finite element analyis are helping palaeontologists learn more and more.

Of course, some things have to be 'guessed' at - with varying degrees of certainty - by comparison with living animals. But there is a huge amount of information that a skeleton simply can't give us at all... For example, there is probably not a whole lot in a green iguana's or a tree kangaroo's skeleton that would tell us they live in trees if we didn't already know this. And there is absolutely nothing in a zebra's skeleton that could tell us it's got stripes!

To answer your question, have a look at these pictures from the University of Texas:
http://digimorph.org/specimens/Chamaele … tus/whole/


http://digimorph.org/specimens/Chamaele … tral.phtml


In the first pic, you can sort of assume that this animal is probably not fast moving because the raised bits at the end of the arm bones are not very big, and those tell you how big the muscles are.
In the close up head pic, they've outlined the hyoid apparatus, the structure behind that strange tongue. If you found an exceptionally preserved fossil with something like that, you'd know for certain that its tongue is something special!
Hope this helps,
 
Carlos.

Hi James,

A third set of teeth has been reported in individuals a few times in medical history, so it's not impossible..

However, your idea would only work if there is a big enough market for this that would justify the investment in R&D. Who know, maybe there is!


Carlos.

(posted in Mammals)

Hi Brenda,

This is a very interesting question, I wonder if anyone's looked at it....
The only way to know for sure would be to radio-track a number of individuals to see what they get up to. Given how fragile bats are (I worked with bats during my undergrad), I see all kinds of technical difficulties for this.

My guess is that they don't go back and forth, but rather stay out eating as much as they can. Bats have a very high-energy lifestyle, and they need to eat lots to keep going.


Hope this helps,


Carlos.

(posted in Mammals)

Hi Kathryn and Sam,

The absolutely correct answer is:"By looking at its birth certificate!"... Horses bred and sold in the standard manner will have paperwork with this information and more.

Failing that, you could try the old-fashioned method of looking at a horse's teeth to tell its age: For example, a horse that's younger than three years old will have small white baby teeth (horses have baby teeth and adult teeth, just like humans). 

This isn't a very reliable method unless you have a lot of experience, and even then there can be mistakes.

If you'd like to learn more, here's a very thorough* article written by a British vet about how to tell a horse's age:

http://www.horseandhound.co.uk/horsecar … 62492.html


Hope this helps!

Carlos.


* Get it? "Thorough", as in Thoroughbred horse!