Monday, July 30, 2012

Our Tiny Garden Terrors

A few weeks ago, my family and I woke up on what we thought would be a normal day. My mom was making breakfast, I was reading a book, my dad was trimming our trees, and my sister was playing with her dog. After a little while, my dad came inside and told us to come outside to see something. I thought it was going to be something uninteresting at first, but I went along anyway. He took us to the big Ficus tree in our front yard, and what do you know, we found out we had some guests.

We were very surprised! The little teacup nest was right among the branches carefully concealed. The little protruding beaks from the nest told us we were dealing with Hummingbirds, or members of the Trochilidae family, if you want to be scientific about it. We've had Mourning Doves and Sparrows nest in the eaves of our house before, but Hummingbirds were a first for us.

The nest they were in was woven out of many different kinds of materials. The mother probably wove it out of spiderwebs, animal hair, lichen, and other materials. The two hatchings probably came into the world a few days apart, as suggested by the size difference between the two (one was definitely bigger than the other). They were hidden underneath the branches and surrounded by leaves on all sides, making it hard for any predators to get to them.  The mother did very well protecting them.

Speaking of the mother, my dad said he had seen a hummingbird flying around the tree a few days earlier, and said it had a brown stomach and a green back. Not much to go by, but we thought it was an Anna's Hummingbird (Calypte anna), as they're common where I live and we'd seen them before feeding on our neighbor's Hummingbird feeder.

My mom, however, was mostly worried about their safety. While trimming the trees, my dad had accidentally exposed a bit of the nest from underneath, which could've made them a potential target for predators. The Mourning Doves we had before had their babies eaten by a small gang of crows, and she was also worried since our new neighbor's cat kept on coming into our driveway. In fact, in some places pet cats are decimating to local bird species, but that's a different story altogether.

I was also concerned, so we decided to help the mother out and watch the youngsters grow, which was very fast. We swear that on some days the hatchlings almost doubled in size within 24 hours, and  after a few days they were getting too big for the nest.

This was when they started to look more like Anna's Hummingbirds. Hummingbirds are fed on a mixture of nectar from different kinds of flowers and crushed up insects (since nectar alone doesn't provide enough protein for growth). We hadn't seen the mother very much.  We caught a few glimpses of her flying by, but we never saw her on or near the nest. However, by the health and growth rate of the hatchlings, we knew they were being fed well, probably when we weren't looking. Smart mom, she didn't want to give them away.

In most bird species, however, both the mother and father would help raise offspring. Hummingbirds are different in that only the mom takes care of the young. This is likely due to both the father's interest in mating with other Hummingbirds and the fact that Hummingbirds are more territorial than other birds.

WHAT? Cute little innocent birds are territorial? That doesn't sound right...

I normally get that remark when talking to people about hummingbirds, as you typically see them traveling around the countryside, flitting from garden to garden.  Hummingbirds are very territorial, especially the brightly colored males (as you can see below). A few species are less territorial than others, but many won't tolerate one another and will lay claim to areas of land. Sometimes up to 30 houses and gardens can be a single male's territory, and when you look at these animal's diets, it's easy to see why.
Male Anna's Hummingbird
Female Anna's Hummingbird

Nectar is very precious to Hummingbirds, and their high energy diet is the only thing that allows them to do what no other bird can: hover, and fly backwards. This is because Hummingbirds are the only birds able to flap their wings in a figure 8, and they flap in that pattern more then 80 times per second, both of which allows for more control in flight. Only Hummingbirds can access this mode of flight because of the energy provided from nectar. Without nectar, they won't have enough energy to fly, and if they can't fly, they will die. That's why their their food is worth fighting for, and why they create territories to protect it. If you have ever seen two Hummingbirds at the same feeder, they'll normally fight over it, making loud noises, dive bombing each other, and even clawing each other if it goes on too long.

Our baby birds were likely to become powerful garden terrorists in the future, that is, if they'd survive past fledgling, which is the time they are at their most vulnerable. One day, we came outside to see that one of our little birds was starting to exit the nest (sorry I don't have a pic). My sister and mom were panicking that it might fall, but it made it back in rather easily. We came back later and found that the two hatchlings were gone. My sister was sad that we couldn't find them, and we were somewhat worried that, since they vanished, they might have been eaten by the neighbor's cat.

Later that day, however, when I was preparing for dinner I heard a loud metallic chirp outside my window where the Ficus tree grows. It was loud and sounded like metal scraping against metal. My sister said she had been hearing it all day, and thought it was my Dad's rock tumbler at work (he's always up to something). He then came in and told us he had finished tumbling his stones yesterday. We were confused for awhile about the source of the sound, but when I looked out the window, voila!, there one was of the youngsters.

The youngster was perched on a branch outside the window, looking in at us. We watched him ruffle his feathers up a few times when we saw the mother come down to feed him (I don't have any pictures sadly). Before she fed it, however, the youngster made a loud metallic noise that sounded like scratching metal. Two mysteries solved.

It turns, and I only learned this later, baby Anna's Hummingbirds are unique in the fact that they don't chirp while in the nest to ask for food. This is thought to be a protective behavior to not reveal the location of the nest when the young are vulnerable. However, when the young leave the nest to learn how to fly, as our baby did, they begin chirping so the mother can locate them, as they aren't yet accomplished fliers, nor can they feed themselves. It's a neat survival trick, and I'm surprised it's unique to Anna's.

We went outside later to find the other one in another part of the Ficus tree. Both were safe, and the mom was hovering nearby. Since it was very windy that night, my sister was worried the two could be blown out of the tree. Luckily the next morning, although we couldn't find them very easily, we could hear them chirping just fine.

It was around the time when I was writing my Sciurumimus post when we found them again, this time perched outside my bedroom window being fed and given flying lessons by their mom.

The two were staring in at me while I was writing the post. We were happy to see them both together again, something we hadn't seen since they were in the nest, but it got even better. One time, the mother joined the two in a little bit of family bonding:

The two stayed up their for 2 days, but on the third, we had seen that they had moved to the telephone lines along our street, venturing back to the Ficus tree only occasionally. They obviously flew there, but all we ever saw in the air was their mother, and a few sparrows near our neighbor's bird feeder. That, however, was the last we saw of them. We haven't seen the family since, and it's likely that they moved on to bigger gardens and greener bushes for the young to start families of their own. I have to admit I'm sad that I probably won't see them again, or even know if they are still alive, but there is hope. Apparently, some hummingbirds like to use the same nesting tree year after year, so I'm hoping to see another brood in the future.

So there you have it... my summer surprise. Anything interesting happen to you? Feel free to share in the coments below. My next post is hopefully going to be on Mesozoic Plants, as I've been reading an article about some new research into it. Either that or it's going to be on the feeding adaptations and skulls of Sauropod dinosaur. After that, I'm hoping that I'll be able to publish a post I've had a request to write a for awhile by Mr. Gorsh (just so he knows, I've been working on it). I haven't had the proper notes and guides to help me out with it until now.

Untill next time, stay sharp!

Tuesday, July 3, 2012

Otto, the baby feathered Megalosaur

An image of Otto's beautifully preserved skeleton. It's no wonder that he's considered the most well-preserved theropod in Europe.

If any of you have been reading any of the news articles from yesterday, you will be excited to find that a new dinosaur discovery has finally been announced! One that the scientific community has been waiting for years and years to find. The announcement of the new theropod species Sciurumimus albersdoerferi. You have probably actually seen him before, for about a year now images of this little fella have been seen all over the Internet.

Before he was scientifically described though, the researchers studying him simply called him Otto. Otto was uncovered in the Solnhofen Formation a few years back (the same place we found Archeopteryx and Compsognathus), and was sold to a private collector. However, this collector realized the importance of this little fella, and happily allowed Otto to be studied by scientists (I guess all collectors aren't bad).

Otto is officially the most well preserved theropod fossil yet found in Europe, being over 98% complete, something scientists would normally dream about finding. In fact, a close examination of Otto under UV light has shown that he had feathers, and quite surprisingly, a long bushy tail like a squirrel, hence his genus name meaning "squirrel mimic." Many have been pleased by Otto's discovery, not just because he is so well preserved, but because he rewrites the history books on Dinosaur feather evolution. Unlike all other feathered dinosaurs found so far, a scientific analysis suggests that Otto isn't a member of the Celurosauria, the branch of theropods that all feathered dinosaurs have been found on. He is instead thought to be part of an older branch of theropods, the Megalosaurs.
A close-up of Otto's curious little skull.
I've been wondering whether or not the bone beneath his jaw is actually part of him or another animal, such as a "last meal." If anyone has an answer I would be grateful if you could tell me.

Megalosaurs were mostly 20-25 ft predatory Tenurans that lived during the Jurassic, and apparently died out due to competition with more successful theropods like members of the Carnosauria. However, during their time on earth they were very powerful predators, and one species called Torvosaurus apparently reached and even exceeded the size of some specimens of T-rex.

Now Otto isn't an adult megalosaur (if he was, he'd definitely be the smallest one we know of), he is only a baby, possibly only a few hours out of the egg and roughly 28 inches from nose to tail, and on par with Scipionyx for the youngest theropod we know of, but he is monumental in the fact he is the most well preserved megalosaur ever found. Almost all megalosaurs that have been found are known from only fragmentary remains, which is one reason why Otto is such a monumental find. We have already learned so much from his remains, including finally solving the riddle of how many fingers megalosaurs had, and roughly how long the tail was.

But the monumental find is, of course, the feathers. Otto provides the first piece of evidence of feathers on another theropod branch outside the coelurosaurs. (If, of course, Concaventator's bumps aren't quill knobs and Yutyrannus is 100% a tyrannosauroid) Being a megalosaur, the origins of feathers in theropods would have to be pushed back to the base of the Tenurans at least, and with fluffy ornithischians like Tianyulong and Psittacosaurus, it really does seem like all dinosaurs have a fluffy ancestry. So we may need to start portraying our more primitive giant theropods like Allosaurus, Giganotosaurus, and more primitive forms like Dilophosaurus and Crylophosaurus with fluffy coats.

Before the discovery of Otto, Juravenator was
the most well preserved Theropod in Europe,
 and is considered a Coelurosaur.
I've gotten a lot of sass with this subject, as I've heard a number of people complain that we are lacking the evidence of making such assumptions. However, absence of evidence is not evidence of absence. We don't have any skin impressions of primitive and basal dinosaurs from the early Jurassic and Triassic, and of what we do have does seem to suggest the idea of feathers. One fossil of a Dilophosaurus(?) that was sitting down in a resting position have shown evidence of fibers around the stomach, legs, and pelvice, suggesting possible filament-like feathers. However, this impression has been greatly criticized, and many think that these traces might simply be plant debris that was dragged along by the dinosaur. The discovery of Otto might help people lean towards the fluffy side of things.

So with the discovery of Sciurumimus we're going to have to start drawing some fuzzy Allosaurus, and I do hope that in the new Jurassic Park expected to come out in 2015 we'll have some fuzzy dinosaurs. The fossil record right now is screaming at us "DINOSAURS ARE FLUFFY, STOP ANIMATING NAKED T-REXES!" that we should really start listening. I've also gotten some sass as above with all dinosaur having a feathers about how if we start animating our dinosaur as fuzzy, they'll become less scary and less apealing to audiences and the general public in things like horror films. Well, I swear that if you were being attacked by a lion, you wouldn't be standing there thinking "Awwwww, it's so fluffy!"

So there you have it, if anybody has any more questions feel free to ask me. I'm going to make a post soon about some Dinosaur decendents I found in the tree in front of my house, and one of which was watching me through my window as I typed this article. I'm not giving away what they are, but I'll tell you they're very cute, and very fast.