the red queen

okay, when i say parasite, what comes to mind?

ticks?

conjoined parasite twin?

caterpillar hijackers?

scott disick of i-got-kourtney-kardashian-pregnant fame?

well i'll tell you what, when i hear the word parasite, i think of this:

wow, something bird related. weird!

look closely at the above picture, and you'll notice that the bigger bird is getting fed by the smaller bird. what's up with that?

well, this is no episode of "maury: my 10 month old baby is one hundred pounds" or whatever.

yeah that's really not the case here.

instead, something way cooler is happening: brood parasitism! in the above picture, what is portrayed is a young brown-headed cowbird being fed by a yellow warbler.

brown-headed cowbirds are birds in the blackbird family (Icteridae) that live in the great plains of north america, and though they lay their own eggs, they sure as hell don't want to take care of their babies.

i wouldn't either; baby cowbirds are seriously ugly and seriously altricial.

(what's altrical?!)

i guess taking care of babies takes a LOT of energy, because you have to provide everything for them, like:

-food

-shelter

-rides to their friends' houses

to save on energy, brood parasites [like cowbirds] have evolved a simple behavior that solves the problem of actually having to raise their own young:

[forced] adoption!

actually, forced adoption is a really nice term for what brood parasites do. Essentially, parasites, like the common cuckoo,

greater honeyguide,

and brown-headed cowbird,

lay their eggs in other species' nests.

this behavior usually translates into some pretty bad things for the host species, including, but not limited to:

1. their own babies dying

but aubrie, why do the host species babies die? can't the introduced young [cowbird, i.e.] and the host young live together happily?

well, simply put...NO

that would be a brown-headed cowbird hogging the bed AND the sheets.

generally, a brood parasites' young hatch earlier and grow at a faster rate than the host's young, and end up out-competing the host babies for food and room in the host nest.

great deal for the baby parasite, bad deal for the host baby.[bad deal like starvation and death]

way short straw deal

the thing about parasite eggs is that they are often hard for hosts to identify as parasite eggs. a lot of the time, birds figure: "well, it's in my nest, musta laid it!" and go on with their lives as if the egg was their own.

and when it hatches, i mean, you have to love your kids no matter what, right?

so, okay, birds aren't going to get rid of eggs they think are their own. and if the parasitic eggs "come to term" as it were, then they're going to get fed and thrive instead of the host species babies.

in fact, to really get the upper hand, the parasites might even get rid of the host eggs themselves:

what lies! what trickery! how treacherous! dang!

yet, there is hope for the hosts.

unfortunately, this hope comes via more baby and egg killin'

as parasites have developed behaviors to lay their eggs in other species' nests, some species have evolved counter-parasite protection plans. for example, the yellow warbler:

when the yellow warbler recognizes there is a foreign egg in its nest, it just builds a new nest to lay eggs in on TOP of the old one.

other birds, like catbirds, just get really angry and throw the eggs outta the nest. sometimes, in their fervor, they actually eject their own eggs out of the nest, too. whoops!

though it provides protection against the invaders, egg recognition and ejection is not the end of this evolutionary battle.

in fact, it is just the beginning.

to prevent host species from recognizing their eggs, cuckoos have developed the ability to lay eggs that look extremely similar to the host's eggs. check it:

the bottom eggs are the impostors. WOW!! that will make it hard to tell.

but aubrie, let's get real. birds can't do stuff like they're in some sort of technological war! they don't even have thumbs or laptop computers.

WRONG! [well, right about the thumbs and laptops bit, maybe] to illustrate and expand your brain, let's have a little evolutionary theory with a side of humiliTEA.

the phenomenon i've been describing to you has often been called an evolutionary arms race, because no matter what one species does to either:

take advantage of [parasite]

-or-

defend themselves [host]

the other will respond [evolutionarily] to keep the status quo.

it's called the red queen effect, after a quote by louis carroll in alice in wonderland.

relatively, though there is evolutionary change in the species, there is no net gain of one species over the other in the given interaction.

woah, thanks leigh van valen! (also, if you're really interested, read this)

graphically, the interactions of host-parasite can be represented with a simple population frequency/generations graph:

more individuals of the host in one generation causes greater success of the next generation of parasites. eloquent!

otherwise, the red queen effect can be represented in terms of fitness.

okay, don't get scared like i do when i see graphs [especially when they're small and black and white. b0ring, i like a little more PiZaZz.]

anyway, all the graph is demonstrating is that:

1. as the adaptiveness of the prey goes up

2. the exploitation of the prey by the predator goes down

basically, it's harder to be a predator when your prey knows all your tricks!

so, the predators eventually learn new tricks.

not quite

for our birds in evolutionary terms:

parasite learns to lay eggs in host nest to save energy--> host bird learns to recognize and eject parasite eggs to save babies --> parasite young ejects host eggs instinctually to out-compete host babies--> ?

looks like it's the host's move to defend...wonder where they'll move the red queen next?!

GIFSoup

Flowers and Dead Hummingbirds

ok guys, so i found a hummingbird about...oh, four months ago outside of the dining center i frequent on campus. unfortunately, she was dead. the body is currently in my freezer, only venturing out for the occasional party trick and/or webcam photoshoot.

exhibit a:

using my highly developed forensic skills, i have attributed the death to an incident with a window.

my support:

1) i found it in front of a very large, un-smudged window

i don't think you can see it in the photo, but the little tongue is sticking out of its mouth! typical.

okay the picture of the sleeping sloth may or may not be completely unnecessary. i thought things usually died with their tongues out? guess not.

[incidentally, if you are looking for something to do, google image search "dead with tongue out." my safe search is on moderate, and there's still some pretty weird stuff coming up! exciting! [also to note: i do not condone nor condemn turning safe search OFF. i just...know my boundaries.]]

so i couldn't just leave this ickle dead hummingbird with its ickle tongue sticking out on the ground for some janitor or homeless guy to pick up and do lawd knows what with! so, i prepared my forensic kit and carried the body home in my backpack.

here were the contents of my my forensic kit:

1) a napkin from the dining center

2) hand sanitizer

i'm a natural!

my main plan was to dissect ze petit oiseau, but that plan has been put on ice, as school has been in the way of me doing any proper dissections. [pun fully intended, did you catch it? come on i dropped it in your lap. frozen bird? plan on ice?]

plus, apparently, people think it's "weird" and "gross" when you opportunistically dissect animals that are already dead but otherwise in perfect condition.

that's my sister and me with a squirrel that was tragically involved in a hit and run on our street. caught a lot of flack for dissecting that one.

... back to the hummingbird.

so, i had been continuing on with life with a very small, neglected, and dead apodiform in my freezer up until THIS was brought to my attention:

okay, you can't read the caption BUT my friend erin has a hummingbird nesting in her ficus tree! totally exciting! [more about eggs/nests here]

and so my interest in my ickle dead hummingbird with its ickle tongue sticking out has been reinvigorated! thanks erin!

the specific species my hummingbird-cicle is, as you might have guessed, the ruby-throated hummingbird, so named for its...ruby colored throat.

male

female [more about dimorphism here]

i say "as you might have guessed" because the ruby-throated is the only hummingbird native to iowa.

also, i'm going to venture to guess that the hummingbird in erin's ficus tree is an anna's hummingbird:

they're pretty common in SoCal.

as you may have noticed, all of these hummingbirds seem to be hanging out around flowers. lemme tell ya, it's not just because they're both pretty. the birds feed on the sugary substance known as nectar that is produced by the flowers!

i just think it's so perfect that something as cute as a hummingbird would feed on not only sugar, but sugar from flowers. how aesthetically considerate of both parties!

nectar is also popular among other cute animals like butterflies and bumblebees.

the garden above portrays what is known as "buffet-style dining" for nectar enthusiasts.

nectar isn't just sugar water, either, guys. depending on the plant, it can have other essential things for life, such as

1. amino acids [building blocks of proteins]

2. vitamins

3. metal ions [!]

4. proteins

wow! forget acai berries, nectar should be the next big thing!

the only problem is that nectar is rly rly hard to obtain. unless, that is, you have The Proper Equipment!

no, not THAT kind of equipment! speaking of google image search...proper equipment. might want to turn safesearch on for that one.

the nectaries, or the things that actually produce the nectar in a plant, are found at the velly bottom of the flower:

[to note when looking at this diagram:

1. anthers are the parts that produce pollen, pollen being the male bits needed to produce viable seeds [think sperm]

2. pollen from one flower needs to be carried to a different flower's stigma to get to the ovule, the ovule being the female bit needed to produce a viable seed [think egg]]

a probable reason these flowers have their nectaries at the bottom is so hummingbirds and bees and butterflies [and i guess some bats too] have to get all up in the flower to get to the nectar. in the process, these so-called pollinators get covered in pollen, which is then conveniently transported along to the next flower.

comin' atcha!

it follows that the next flower's stigma will get pollen attached to it from the hummingbird, bee, butterfly, et cetera and hopefully an ovule will be fertilized and become a seed!

it's really a win-win situation! i like to think of it as support for the idea of co-evolution.

so, uh, why do we care about flowers? this is supposed to be about birds.

WELL, flowers with nectar at the bottom have determined the morphology of our ickle dead red ruby throated friend, ESPECIALLY with regard to her ickle sticky-outy tongue!

though i speak from limited experience, it's really probably much easier to get to the nectaries at the bottom of a flower if you have a long skinny bill with a loooong skinny tongue.

and guess who has those features?

woodpeckers! ha, gotcha!

the above is actually a diagram of a woodpecker, but hummingbird tongue morphology follows the same principles.

to reach flowar nectaries, birds can't have a short bill with a short tongue muscle attaching at the base of the trachea. that would be like, i don't know, you trying to drink out of a bud vase. [tongue use only, no cheating!]


don't be foolish, al!

so, hummingbirds [like woodpeckers] have specialized structural features of their skull that allow for housing a long tongue. here's a picture of the skull:


see that forked thingy? that's the tongue tract that eventually leads to the throat. it also just so happens to be The Proper Equipment to get dat nectar, allowing for the win-win interactions of flowers and hummingbirds. unless, of course, they're dead.


mmm, sugar water.

Introduced

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? [http://bird-log.blogspot.com/2009/12/finches_29.html]

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.

anyway!

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]