Thursday, July 29, 2010

The Jacana

well, I'll tell you what, I went to Les Grands Tetons avec my family and friend for vacation last week.

and i'll tell you what else, it was beyond beautiful.

[follow standard magic eye procedure and you'll see me. i'm on the right!]

i was really frustrated at first when we got there, because the birds were not iowa natives. i could not recognize hardly any of them! it was so annoying to see this guy:

and not have a clue as to who he was! i felt like such an ornithological fraud. don't worry, i didn't go into a state of depressed self re-evaluation wherein i decided to completely give up birding.

i just got a book for species ID!

turns out that black and white dude is a magpie. the bird on the front of the book is a male western tanager, which i saw flitting around camp more than once. his colors are so wild!

also at camp was a fellow birder! she works for hawkwatch,and it was great to hang around and geek out about birds with her. she had a sibley guide, which made me jealous. naturally, i had to get one so i didn't have to keep coveting hers! [and one about behavior. thanks mom and dad!]

my dad totally got mad at me for my instant gratification reflex. i blame society and say it's a symptom of not only me but my whole generation to want things RIGHT NOW. so gimme dat book!

i figure it is now up to me to:
a) wolf down the information in these books as fast as i can and then
b) relay it back in fun and easily digestible blog-o-form to you, the reader!

weird, it's kind of like when a mother bird regurgitates food into her young's gullets. happy analogy! but kinda gross!

while i was perusing these new books of mine for information about grouse mating rituals, i stumbled upon these guys:

jacanas! not grouse, but not bad! they're in a family known as jacanidae, and in the same order as killdeer [charadriformes].

the family is comprised of six species, all of which are characterized by what first caught my eye: the foot morphology.

jacanas, being shorebirds, have "amazingly long toes" adapted for smooth commute on top of floating vegetation.

holy phalanges, that thing can walk on lily pads!

my favorite, aesthetically speaking, is the comb crested jacana. also known as lilytrotters, comb crested jacanas are cool because they have those weird bright red combs on their foreheads; it's almost as if walking on water hyacinth wasn't impressive enough.

one might think: well, the comb must be for the males to attract the ladies. TyPiCaL~*

and one would be right! kind of!

BUT jacanas are an interesting set of birds: they are polyandrous.

as you may have guessed from the above stock photo, polyandrous implies "a lot of guys serving one girl." but i can break it down even further for you with my rudimentary understanding of greek! as i understand it, polygamy is multiple partners; polygyny multiple females to one male.

poly = many
gamy = any reproductively active bits
andry = male reproductively active bits
gyny = female reproductively active bits

polyandry, then, must be the opposite of polygyny!

with jacanas, the females mate with a male, lay the eggs, and leave the male to take care of the fertilized eggs. the female then mates with a different male and pulls the same stunt: she lays and leaves. no time for actually tending to the young--leave that to the male.

hey honey, can you take care of the nest? i'm going to be late tonight.

see yuhh

jacana females are, on average, much larger than the males, and seem to be the dominant [in the territorial sense] sex. according to the PBS online library, the reason behind the jacana's polyandry may be due to the high amount of egg predation the species of the jacanidae family has historically experienced. due to predatory conditions, if the females lay more eggs, the species has a higher survival rate. jacana females have evolved to become "egg laying machines"

and i mean, let's be honest, those eggs look SWEET. i would totally prey on those babies. [pun fully intended]

Tuesday, July 13, 2010


Warning: I want to address a theory on the evolution of feathers, but I have to reach Way-Back-In-The-Good-Days-Before-Even-Dad-Was-Born to do so. Don't worry, dinos rule!

Check it:

This is a Dromeosaur. It is a dinosaur from the clade [dur] Dromaeosauridae. Dromaeosauridae is a sister clade to Aves, and the way I understand the relationship between a dromeosaur and its bird contemporary is comparable to the relationships between chimpanzees and their human contemporaries.

[It's not a perfectly analogous fit, so don't quote me on that one.]

what I wanted to point out on this dromeosaur are the filamentous protofeathers. The dromeosaur's feathers:
a) were used for insulation
b) did not make dromeosaurs capable of flight
and c)are [were] derived from scales!

shall we investigate point (c)?

well, okay! heEeErE we go!

reptiles have scales, some of which are classified as scutes. we know almost certainly that dinosaurs had scutes from ample evidence in the fossil record:

uh okay that looks like an old rock.

reptiles like crocodiles and turtles have them, as well as really old fish like sturgeons. it's basically a bony plate that a lot of different organisms have, like

this weird catfish

dig the ridges! like ruffles, except not a delicious salty chip!

and turtles

what a ridiculous image--there is no way somebody could simultaneously hold the full time jobs of doctor AND mailman. gEt ReAl

so scutes are found in fish and reptiles, and i'll bet you have guessed by now that scutes are also found in birds! they're the bony gross part found on birds' feet.

the reason we can call all of these structures found on all of these different animals "scutes" is because they are chemically and structurally composed in the same way:

"The β-keratins in feathers, beaks and claws — and the claws, scales and shells of reptiles — are composed of protein strands hydrogen-bonded into β-pleated sheets, which are then further twisted and crosslinked by disulfide bridges into structures even tougher than the α-keratins of mammalian hair, horns and hoof"

[thanks for wording it for me, wikipedia!]

okokokokok so... what?!

essentially, the proteins that make up the keratinized structures we know as scales and scutes have the same structure as feathers and claws! the specific protein is known as beta-keratin.

oh baby do i love molecular structures.

the "beta" in beta-keratin is just referring to the way the molecules bond to form the 3-D structure of the protein. if it is a beta protein, the structure is sheet-like, and the sheets line up in opposite directions and then bond further to ultimately form a very strong material.

so: scutes [to a point] [[that could be a weak pun]] have the same molecular makeup as feathers.

but how do we get from a hardened bony structure such as a scute to a soft pretty feather that aids in flight?

i mean, scutes are not velly cute, you know?


no competish, thing with feathers is way cuter. i swear i'm not even biased!

to determine the relation between scutes and feathers, a guy named Alan Brush conducted a study in which an inhibitor virus was introduced to bird embryos that targeted scute development. when the birds hatched, they consistently had [some] feathers and/or filaments in place of where the scutes should have developed!

woah, so scutes are just hardened feathers? how exciting!

portrayal of the brush experiment. probably accurate!

chout and watch me work, i'm going to draw a conclusion:

over time, certain scales of reptiles [scutes] developed into the filamental protofeathers of early avian ancestors like dromeaosuars. initially they were used for warmth and protection, but these feathers started to serve for a means of locomotion, and hey! it worked out. avian feathers are derived from reptilian scales.

edit: an earlier version of this post incorrectly labelled an experiment as conducted by Alan Burns. Alan Brush conducted the experiment. Alan Burns was my simpsons-filled imagination running away with me. sorry!

Saturday, May 15, 2010


so before i start talking about introduced species: school's out! i can go bird watching without feeling guilty for not doing homework! yahoo!

pardon the double negative.

i haven't actually gone bird watching yet this summer for extended periods of time; i tried to go to a wetlands, but i fell out of a tree into a stream and couldn't explore as much as i would have liked. wet socks are really uncomfortable! other than that, it's been sitting on the porch with binoculars.

[if anyone wants to go bird lookin' with me someday, just let me know? here are some of the cool guys i've seen:

...and more! it's really exciting seeing birds in action.]

but on to the topic at hand-- introduced species!

the term "introduced species" isn't used exclusively with birds. an introduced species is just a species that has [for whatever reason] been taken from its native habitat and placed in a non-native habitat. introduced species generally get a pretty bad rap: you've got your asian lady beetles, your zebra mussels, your kudzu...

these examples are known as invasive introduced species, and probably do deserve the poor connotation that comes with the "introduced species" label. asian lady beetles and kudzu were both introduced in north america to fix certain biotic problems, but what ended up happening is they did a little too well in their introduced environments and "took over," as it were.

the introduction of zebra mussels was an accident, whoops!

that shopping cart is covered in a colony of zebra mussels. they're apparently native to eastern europe, but someone [not naming names] [mostly because i don't know who] didn't czech their boat before coming into north america after boating abroad. i guess these mussels were attached, and as it turns out, they love it here! so now they're out-competing native species in lacustrine ecosystems.

like i say, whoops!

introduced bird species in north america are not hard to come by-- in fact, on a day to day basis, introduced species are what i see most often. one example of this is the house sparrow. if i had a quarter for every time i saw a house sparrow, i could probably get unlimited sandwiches for myself and five of my closest friends!

another example of an introduced avian species: the european starling

the european starling's history in the united states is actually kind of cool. well, kind of cool and kind of pretentious. in the late 1800s, a group called the American Acclimatization Society thought it a good idea to introduce every species of bird ever referenced in the published works of shakespeare. considering his proliferousness [that's probably a word?], its not surprising they ended up introducing over six hundred species to the united states. the starling was one of them. introduced in new york from 1890-1891, the european starling could be found almost anywhere in the contiguous united states by 1950. holy smokes!

here's a map of relative densities of where starlings are found presently:

remember when i talked about ecological niches? []

well, invasive introduced species [like starlings] fit into native species' niches really well. as it turns out, they fit into a lot of different species' niches because they're just so gall dern robust!
bird watchers especially hate this, because starlings out-compete better looking native birds like kestrels and flycatchers.

my dad got free return address stickers with vermillion flycatchers [pictured] on them from the audubon society. me not recieving those is a perfect example of ageism. don't they know that being an AARP member does not automatically make you a birder?!? i should have gotten those!

so jealous.


one might think that introduced species are a totally bad thing, but i don't necessarily agree. globalization and the world becoming flatter has increased the spread of native species to non-native environments, and humans are notorious for messing around with what animals go where. with all the technology those damn neighbor kids have for transporting goods [like animals], the introduction and subsequent "take over" of certain robust species is preeeeetty much inevitable.

i don't like that native species are getting out-competed. i do, however, see that it's nature acting naturally under unnatural human-created conditions. take from that what you will.

i mean, it's really all about the competition:

[looks like the kestrel came out on top that time]

Friday, January 15, 2010


coloration is one of the most appealing aspects about the avian clade. for example, the parrot's colors are what makes it one of the most charismatic birds in the animal kingdom. well, that and the whole talking thing.

one might say that coloration a hue-ge aspect in the daily lives of birds.[oh gee, i wish i was a shade better at pun-making.]

colors are expressed in the feather of the bird, rather than in the skin, as in humans. that is why if you see a bird without feathers, it will be effectively colorless. i know, you probably don't see a lot of featherless birds. well, you're in luck! here's this:

different colors are produced by different means, and the way they are expressed depends on these means. i think i'll start out with talking about a pigment we all know and love, melanin:

melanin is a really common pigment found in all types of animals, including humans! it's what is responsible for browns, deep purples, grays, and blacks. melanins, though they are kind of boring looking, have a bonus effect: they strengthen the substrate they are embedded in, which reinforces structure! for example, the hair in bears is really wiry and thick due in part to melanin.

wow, bears are weird looking.

incidentally, an inability to produce the melanin pigment results in albinism.

melanin explains brown, but let's be honest here, brown should be called BORE-own, am i right? whattabout the fun colors like ........Oranges Yellows and Reds? Blues? Greens?

i'll be addressing them in that order.

oranges, yellows, and some reds are produced by nifty pigments called carotenoids. carotenoids were first discovered in...carrots! [botanists are some of the most apt namers in the biz. --oh, you found a compound in a carrot? call it a carotenoid!]

carotenoids are found in a lot of fruits and vegetables, and interestingly enough cannot be synthesized by birds. thus, in order to express these pigments, they must be ingested.

this is a really really really really close look at a group of red pepper cells. the red dots are called chromoplasts, which are organelles that synthesize and house carotenoids.

flamingos are pink because of the carotenoids in their diet of shrimp and red algae. this dead one is not pink because it hasn't been eating carotenoid containing food for a while. i don't think it's been doing much of anything else, either.

tough break!

blues are my favorite type of coloring in birds. the thing about blue is, it isn't really a pigment. instead, blue is emitted from a feather due to the structure of the feather itself.

what happens is light [usually white] hits the surface of the feather, whose surface physical properties are altered in such a manner that they reflect blue light waves. this principle is also used in human technologies, cool!

blue jays and indigo buntings, both native to iowa, are good examples of the rich blues that can be found in feathers.

bright greens occur when a feather has both carotenoids and physical structure that allows the feather to emit blue. these two properties work in tandem, et voila, on a des plumes vertes.

wow, what a picture! people who own birds are such oddballs.

the exciting coloration found across bird species is generally limited to the males, which seems like kind of a rip for the females. i mean, comon, look at the wood duck drake vs. the wood duck hen:

the brown boring ones are females.

though it may seem like a total rip for the female, the reason behind the disparity in flamboyant coloration in males and pretty drab colors in females is called sexual dimorphism, and can be attributed to a phenomenon known as sexual selection.

females run the show when it comes to makin' babies. generally speaking, it is the females who house the eggs in their body, lay the eggs, and then raise their progeny. the whole point of having babies is to further propagate the species, and the best way to do this is to make sure the babies survive to adulthood, where they in turn will go on propagating the species. birds cannot analyze genotype (all the genes an organism has), and so must base their decision for a mate on phenotype (what genes are expressed, or what the organism looks like physically). essentially, the females are going to select the best looking dude available.

because the males who look the best are the ones passing on their DNA, the male offspring will probably look just as good. as time progresses, females are essentially choosing mates from the creme de la creme, and as a result, we get REALLY COOL LOOKIN' birds.