SubscribeNovember 9th, 2011
gender games
Male birds who dress like females:
Some male harriers are colored almost exactly like females, with mainly brown plumage and white heads and shoulders, instead of the overall gray of adult males. It’s not because they are immature, as is the case in many bird species, but because they spend their life in drag, a type of permanent mimicry known in only one other species of bird.
The abstract from the originating article:
Permanent female mimicry, in which adult males express a female phenotype, is known only from two bird species. A likely benefit of female mimicry is reduced intrasexual competition, allowing female-like males to access breeding resources while avoiding costly fights with typical territorial males. We tested this hypothesis in a population of marsh harriers Circus aeruginosus in which approximately 40 per cent of sexually mature males exhibit a permanent, i.e. lifelong, female plumage phenotype. Using simulated territorial intrusions, we measured aggressive responses of breeding males towards conspecific decoys of females, female-like males and typical males. We show that aggressive responses varied with both the type of decoys and the type of defending male. Typical males were aggressive towards typical male decoys more than they were towards female-like male decoys; female-like male decoys were attacked at a rate similar to that of female decoys. By contrast, female-like males tolerated male decoys (both typical and female-like) and directed their aggression towards female decoys. Thus, agonistic responses were intrasexual in typical males but intersexual in female-like males, indicating that the latter not only look like females but also behave like them when defending breeding resources. When intrasexual aggression is high, permanent female mimicry is arguably adaptive and could be seen as a permanent ‘non-aggression pact’ with other males.
It makes me remember a woman I once knew who was rather violently opposed to homosexuality (her son was a closet gay applying to belong to the Catholic priesthood). Her reasoning was that homosexuality wasn’t normal biologically. She said to me “bucks always go with does.” Silly woman. For someone whose set of values was centered around the natural world and the power of animals, she sure didn’t know much about them.
November 3rd, 2011
imagining the place where you are in the past
and not just in the human past, but the far, far past when birds like this flew over head.
For example, Aiolornis incredibilis is a bird that lived up to the end of the Pleistocene. It had a wingspan of 5.0-5.5 m (and it was not the biggest of the Teratorns). It weighed something around 23kg and was a predator. Holy frakking shit man. That would have been like a SUV with wings and nasty-assed beak flying over head.
These guys live in the Americas and there were people there at the time. It’s no wonder we have stories of thunderbirds.
One of the places where fossil remains of this bird have been found is in California (the Anza-Borrego Desert). If you hunt around on the net you’ll find lots of regional sites with pictures of remaining pictographs and petroglyphs. Of course most of these far post-date the end of the Pleistocene.
During the late Pleistocene the Anza-Borrego Desert was probably very different than it is today from the point of view of the kinds of plants and animals you find there.
From: Isotopic Records From Herbivore Teeth
To compare, the mean annual precipitation in Barstow today is about 111 mm, but the place was covered in grass lands. The mean annual temperature today is 18.7 °C. Horses, camels, mammoths, lynx, bison, antelope, deer, Capromeryx, Platygonus, Nothrotheriops, Paramylodon, Smildon, oh and so many more. And were today you’ll find desert scrub, you’d find then pinyon-juniper woodlands, and where there are woodlands today, you’d find mixed-conifer and boreal communities of plants. I mean there were evergreen oaks (Quercus spp.) growing in what today is the Chihuahuan Desert. But the big plant deal, according to Connin, were the C4 plants.
A C4 plant is better adapted than a C3 plant in an environment with high daytime temperatures, intense sunlight, drought, or nitrogen or CO2 limitation. Most C4 plants have a special leaf anatomy (called Kranz anatomy) in which the vascular bundles are surrounded by bundle sheath cells. Upon fixation of CO2into a 4-carbon compound in the mesophyll cells, this compound is transported to the bundle sheath cells in which it is decarboxylated and the CO2is re-fixed via the C3 pathway. The enzyme involved in this process is PEP carboxylase. In this mechanism, the tendency of rubisco (the first enzyme in the Calvin cycle) to photorespire, or waste energy by using oxygen to break down carbon compounds to CO2, is minimized.
Examples of C4 plants include sugarcane, maize, sorghum, amaranth, etc.
It’s these plants that supported the large numbers of animal species that lived in the south west then.
The thing is that because of the placement of the ice sheet, jet streams and high and low pressure zones would have changed as well. You change one element, the others adjust. It’s one big system and what may seem like a little change to us can have big consequences. So in the south west they would have probably had more winter rain than today, more seasonal differences than today, i.e. cooler summers. One of the things this could have meant is that there was more effective moisture than today, even though there was not much difference in the amount of rain that fell over the whole year. There were, for example, great pluvial lakes throughout the Great Basin and the desert areas of the south west.
And there were huge flying predatory birds, camels, mammoths, sabre toothed cats and people. On what today is a desert. Awesome.
September 6th, 2011
sex and pair bonding are not the same thing and why is this a surprise?
Browsing today and saw this article (Same-Sex Finch Couples Form Strong Bonds) mentioned over at Lilian’s blog.
If you look at what the study examines and then read the first paragraph of the report (then the comments) it becomes clear that some people confuse the two concepts “homosexuality” and “male-male pair bonding”.
I’m sure this pains the people who take offense at the true-life tale And Tango Makes Three, but heterosexuality is not the rule in the animal world. There are hundreds of species, from bison to bunnies to beetles, that pair off in same-sex couples. (And then there are bonobos.) Birds often pair off this way, too. And now a study of zebra finches, published in Behavioural Ecology and Sociobiology, has found that the bonds between same-sex couples can be just as strong as those in heterosexual birds.
The paper, actually titled “Same-sex pair-bonds are equivalent to male–female bonds in a life-long socially monogamous songbird”, emphasizes the behavioural (therefore measurable) components or markers of pair bonding. All the article is saying is that in socially monogamous songbird populations (here finches) male-male pairs exhibit the same behaviours that mark a male-female pair bond. They preen each other, they are not aggressive toward each other (as often male-male meetings can be), etc. This kind of “cuddly” behaviour is what marks a pair-bond. It happens with male-male birds as it does with female-male birds.
When human beings (or other ultra-social beings with abstract thought capability) come along this same possibility is already encoded. So we have male-male pair bonds, female-female pair bonds and male-female pair bonds. But (like the bonobo’s referenced by the article) we use sexual display and sexual pleasure for things other than reproduction. So in our pair bonds, sex is a part of the behavioural repertoire for bonding. This might not be the case in finches. (Don’t know – any finch experts that can tell me?)
The thing I find most interesting is that sexual behaviour is so much a part of our species’ pair bonding behaviour that we can’t seem to grock that it isn’t an essential part of animal pair-bonding and so confuse the point of pair bonding with the point of sex. They are not the same thing. And, btw, friendship and pair bonding are also not the same thing.
Anyway, thanks Lilian for posting the article. Interesting stuff. Now all I have to do is find a copy of the full study that won’t cost me $34 to read online.
May 31st, 2011
how does one know when one is upright
Today is a very busy day for me. The first of three appointments is now complete; the next—to have my stitches removed—is in about an hour. I am tired already.
I came home between appointment one and two in order to have a bite to eat and to browse some art sites. Both things make me feel better. Today I went to The Squirrelbasket and found this:
Squirrel has more garden bird pictures here.
This upside down blue tit seemed to be exactly right for how I am feeling recently. But then I asked myself a bunch of questions, like is it really upside down for the bird? I mean really a bird is a creature that wings life. You know when you turn your hand, twist your wrist, to pick up an orange? That’s probably how little the blue tit feels “upside down.”
If I was hanging on by my toes like that I would most definitely be upside down. This is so because I am human and have a particular attachment to certain gravity related physical orientations. Primates do. Birds just don’t have the same relationship with the ground as I do.
Having realized this, I asked myself how do you know when you are upside down and of course I meant that metaphorically because physically it has to do with the inner ear and the parts of the brain that deal with body knowledge and spatial recognition. Recognizing a “dangerous” (is that the right word?) position (and hanging upside down is a bit edgy for a primate) comes with the desire to fix the situation. But the question is about the recognition part. Does it just feel wrong? Is there a sense of impending danger? An adrenaline surge? What is is that makes one feel discombobulated?
I also wonder if (metaphorically) one can come to have a more bird-like orientation to the ground? Or, in other words, can a primate sprout wings? I wonder this because what makes the blue tit able to toe-cling with impunity is the fact that it cannot really fall. It can descend suddenly of course, but its wings mean that falling doesn’t really exist for birds with the power of flight. When you turn your wrist over so that the palm of your hand is upward you don’t get the sense that your wrist fell, nor really, that it is upside down. Nor more do birds I suspect.
Imagine life without the metaphorical fall. Something to think about.
And of course the bird question—if falling is the big primate (LOOK OUT) what is it for a bird? A space too small for the wings to spread? So what would be their Dante’s allegory? Not the descent and ascent, that is a result of primate physicality and our primary sense of body orientation to the ground. Their Dante would have written about a narrowing world and the ultimate release into interstellar space? Something else to think about.
May 29th, 2011
just because
The same person that took the eeeew photos in the earlier post took these out near Whistler yesterday. When at the camp site, he had some interesting neighbors.
February 3rd, 2011
the poetry of body from whence the poetry of words gets its start
BIRD film from Andrew Zuckerman Studio on Vimeo.
Zuckerman has a book available called Bird. Based on this video, I have ordered a copy. There is something about birds that carries beauty in and through time. Perhaps it’s their long heritage – I mean they are dinosaurs-still-wandering and how cool is that. Perhaps it’s the way they move that makes clear the origin of meaning in the body’s expression of itself in the world. I’m not sure, but I do know they captivate.
January 12th, 2011
crow highway
I went to the grocery store as civil twilight arrived. I have been deeply enervated today; I had to bribe myself with a latte to leave the house. Once I had my hot drink, I sat in the car and watched the sky. I was thinking about rush hour traffic. I’m not sure why, but I was. There is this particular incident I had in mind: a south bound highway in Calgary, about 20 km from the southern edge of the city, and still there were pulses of traffic. Red light, stop/ green light, go.
Perhaps it was the crows that made me think of it. Where the store is positioned, the parking lot is under the crow highway. Waves of birds, hundreds of them, fly in from the north west and their water-side hunting/working sites and head to their roosting tree. Every dusk: the crow commute. I wonder sometimes if there is really any fundamental difference between the minds of those who commute in cars and the ones who commute on wings.
January 6th, 2011
dead birds and word power
You have heard of the dead blackbirds I am sure. Here is the most useful coverage of it I have seen.
Are birds falling from the sky examples of pareidolia, eschatology, or something else?
Essentially the blackbirds died because fireworks frightened them out of their wits. But never mind the facts, this is a “sure sign” that Harold Camping is right. Ugh.
There is a difference between what we experience and what we think it means.
December 8th, 2010
raven dude
Love ravens. So smart and really cheeky. Cool birds. Sitting across from a greengrocer at a coffee shop I once saw a raven repeatedly steal grapes. It was hilarious. The clerk would come out and yell, wave a broom. The raven would fly off with grape in beak and sit atop the light standard waiting for the clerk to go back inside. It was a delightful coffee hour that one.
via Wimp