How to tell if your aphid is done reproducing.

If you want to know if a parthenogenetic pea aphid is all done reproducing, look at her abdomen. If there are eyespots, she still has embryos in her. If not, she's done. If she is post-reproductive, she's likely to move to the edge of the colony, where risk of predator attack is highest. Details are here, in a paper written with some very talented undergraduates at Bates College.

Computer bugs

We now have enough ladybugs in our window plants that the aphids and white-flies won't last long. However keeping the predators concentrated in the little ecosystem for that long requires some doing. We find these little red happy pills wandering all over the apartment, and occasionally find them congregating in some warm dark niche. They like to be in groups, as their defensive chemicals and colors work better that way. This morning I found them assembling a conclave on and in the wireless router. Warm. Dark. Dry. Connected. Perhaps it is time to supply some hidey-holes in the planters under the plants.


P.S. Yes, I know that they are actually beetles, not bugs, but who has ever heard of computer beetles?

The dead blackbird thing.

Much has been made of the news that 5000 dead blackbirds fell from the sky onto a small Arkansas town at the turning of the year. ~11:30PM on New Year's Eve. Conspiracy theories and omens abound, but I will propose my own theory: a conspiracy between fireworks and the migratory behavior of blackbirds.

There are several species of blackbirds in North America (e.g. Red-winged Blackbirds, Grackles, Starlings), that tend to migrate in large mix-species flocks. And when I say large, I mean blot out the sun, river in the sky, ornithophobe's nightmare large. Frequently in the hundreds of thousands, not rarely in the millions of birds. I was working at the Long Point Bird Observatory (in southern Ontario) one day in late November when one of these blackbird flocks went by, too thickly to count, for an hour and a half. As soon as we saw them we rushed out and closed the mist-nets we had put up to catch birds. While these nets work well for catching a flock of a dozen chickadees (which we would then measure, band and release), a thousand blackbirds hitting the nets all at once will collapse them, potentially killing large numbers of the birds. Many of the nets had several dozen blackbirds in them within the first minute, and it was a struggle to free them faster than new birds got caught. We couldn't close the nets until they were empty, and we couldn't stop catching them without closing the nets, so thick and fast they came, despite the fact that the main stream of birds was far above our heads, and despite each bird tending to avoid places where humans were standing. We put brightly colored cloths in the nets to make them more visible, but still we couldn't keep up. The nets began to sag under the weight of birds, each of which weighed only a few ounces. Only when the course of the avian river shifted significantly to one side were we able to empty and close the nets, and then stand and gape at the immensity of the flock. That night they all settled in a nearby wetland, densely and within a surprisingly small area.

Now by New Years Eve, these flocks would not be in Ontario, but in places more like Arkansas. It is reported that a wooded area in Beebe was being used as a nighttime roost for several hundred thousand blackbirds. My guess is that somebody was setting off fireworks near that wood, and scared the bejesus out of at least half a million blackbirds. Fireworks are used in agriculture to scare blackbirds out of fields, and to uninitiated birds, they are quite terrifying. So this river of blackbirds leaps into the air whirl around and around as the rockets and fountains go up. Now blackbirds, like most songbirds, have very poor night vision, and frequently smack into things if startled up at night. So maybe one in a thousand in the whirling disoriented mass smacked into a lamp, a sign, a building, each other. They go quite fast enough to kill themselves crashing headlong into hard objects, and can rebound several feet. The birds seemed to have died of blunt trauma, as from a crash.

Or it could be a sign of the end times.

Lovers in the snow

The UnterWarnow is frozen, and snow is building up on the ice. Sunset will come 7 hours and 45 minutes after sunrise today. The crows and blackbirds are digging in the snow looking for food, and the birds that usually haunt the harbor all winter are gone, perhaps to the south, perhaps out to the Baltic where the water isn’t solid.

But in the tree in front of my office window, two magpies are carrying fresh twigs into a crook between three branches. There is only one reason I know of why they would be doing this: they are building a nest. Most birds, including magpies, only build nests to lay eggs in, and now is not the time to lay eggs. It is too cold for the eggs to develop (even with mom sitting on them), and if they did hatch , there would be nothing to feed them. Any nest built now isn’t even likely to still be in good enough shape to use come spring. The spot where they are putting the twigs is near the top of the tree, on the branch closest to the river, and shakes whenever the wind blows, which it does frequently.

This raises the question of why? When other birds in the neighborhood are struggling just to keep from freezing or starving, why are the magpies wasting their time and exposing themselves to the cold building a nest they can’t use? Perhaps the cold has driven them mad? Maybe they are pulling food out of the dumpster of the near by grocery store, and having plenty of food, think it is time to breed? A genetic disorder?

There may be some perfectly good reason for this (pair-bonding activity?) but I’m not sure I buy that.

When my colleagues and I were writing a paper on the definition of behavior, many of previously published definitions we came across specified that behavior is adaptive, that it will tend to increase the fitness of the individual performing the behavior. We omitted this from our definition, because there are so many behaviors whose adaptive significance is uncertain, or which seem maladaptive. It is certainly true that most behaviors are adaptive, some, like building a nest in a snow storm, probably are not.

Crazy like a crow

I've seen a lot of birds doing a lot of bizarre things. But I couldn't figure out what the heck this crow was doing. Yesterday afternoon, as I was leaving work, I saw a hooded crow (one of the common urban birds hereabouts) flying in the most bizarre bouncy way. Flap hard to climb, drop sharply, pull up, flap upward, attempt to hover, sliding from side to side, drop sharply and repeat. It weaved and bobbed 30 meters above a road full of moving cars. All I could think was that it was playing (which was surprising because crows usually play when there are other crows around to impress, and this was the only one in my line of sight). Then I noticed it had something in its beak. A small ball on a string, or something such. It repeatedly, and obviously intentionally dropped it, only to dive downward and catch it again, then regain altitude for another drop. Several times I thought the what-ever-it-was would fall on one of the moving cars, but the crow always caught it before it could fall that far. After a couple of minutes of this, the crow changed position, flying high over the broad and mostly empty sidewalk on which I stood. After a couple of false starts it dropped its cargo, which plummeted to crash in the middle of the sidewalk, in a clear area with little leaf debris and no people within 20m . As the crow came in to land, I ran over to see what the thing was. It watched me, keeping maybe 5m back, but obviously not ready to take off. The something it had carried, dropped and broken was a large chestnut, now cleanly cracked in half, with the meat easily accessible through the shattered shell.

I backed off and let the crow enjoy its well-earned meal.

Something's doing at the zoo

I can think of nothing that divides the opinions of animal lovers more than zoos. To some they are horrid spectacles where wild animals are locked in little cement boxes for the public to gawk at. To others they are a way to educate the public about wildlife while adding to our knowledge of each species and contributing meaningfully to conservation efforts. Some view zoo animals as living short boring lives of confinement, while others view zoos as predator, poacher and disease free shelters for species rapidly declining in the wild. Both groups are passionate in their support of animal welfare, and both are partly right about zoos. Zoos for a very long time were, and to some extent and in some places still are, places where animals are kept in very unnatural conditions for the gawking pleasure of humans. Zoological gardens originally cared little about the welfare of the animals, beyond the expense of replacing them. When most modern zoos were opened, animals usually were kept in small hard cages with no natural elements and nothing to do. It is still possible to find many zoos like this, and many cages like this even in the more modernized zoos. But many zoos, including most I have been to in the US, are actively and intentionally reforming themselves, and have been gradually improving for some decades. Rapid improvement is difficult while one has a large group of animals to keep. You can't simply bull-doze the whole place and start anew. Rather you must find what open space you have and build a new tiger habitat, then move the tigers there and rip up their old cages to build a large outdoor space (with winter quarters underneath) for the baboons. When that is done, and the baboons are safely outside, the monkey house can be rebuilt, and so on. In a few decades when all the old cages are gone, you will realize that the tiger habitat you built really isn't big enough for tigers, and you can start the cycle again. So changing from a bad old zoological garden to a new fancy new wildlife conservation and education center takes decades.

I recently had the pleasure of visiting one of the most advanced and impressive zoo I've been to, the Copenhagen Zoo. In overall appearance and plan it reminded me very much of the Bronx Zoo, where I worked for a short time. In fact it was so similar I have no doubt many of the same people were involved in planning the individual habitats in the two zoos. The two are so similar that I could say to my wife, "this looks just like the place in the Bronx Zoo where they have the crocodiles and river turtles," only to turn the corner and find the crocodiles and river turtles in nearly identical enclosures.

Almost all of the enclosures were state of the art, made to look and feel as much as possible like habitat, with places the animals can go to get out of the weather, and out of the view of tourists, or where they lay in the sun if they so choose. They had a large display (in Danish, so I couldn't read any of it) on the bad old way of doing thing, set up so that the viewers actually walk through a series of cold cement cages with giant steel bars where rhinos and hippos used to be kept. But what impressed me most was the attention paid to making sure the animals had something to do. The anteater ate not from a trough, but from a rotten log with numerous holes drilled in it and food stuffed into each hole. This gave it something to do with its improbably long tongue and impressive curved claws. Rather than laying around looking bored, it spent its time ripping open logs and licking food out from inside them.


Inside the impressive new elephant house the elephant also has to work for its food. I spent half an hour watching an elephant attempting to extract its food from a large barrel hung 5 meters off the ground. The barrel hangs from a rope, such that the elephant can barely reach it with its trunk. By repeatedly whacking the barrel with the tip of its trunk it can make it swing enough that eventually some of the food inside spills out on the ground. The elephant then eats this and goes back to whacking the barrel. By the time the meal was over, the elephant looked honestly tired, a rare and precious thing for a zoo animal.


The bears spent enough time digging in their enclosures (with enough magpies and starlings closely following them) that I can only assume there was food buried somewhere in there, with the location changing from day to day. Over and over throughout the zoo we saw animals doing something.



The term in the zoo community for this is behavioral enrichment, and it turns out to be incredibly important not only for the animal's mental state, but for their overall health, their longevity and the satisfaction and education of the viewing public. Crowds these days don't just want to see an elephant standing there, they want the elephant to be happy, and they want it to be doing something. In the Copenhagen Zoo, the animals are doing something, and usually it is something similar to an actual behavior observed from the wild. Wild elephants really do whack and grab overhead food with their trunks. Anteaters really do tear open rotten logs. Behavioral enrichment takes a lot more thought, and a lot more work, than dumping food in a trough, but it makes for a wonderful zoo. (A recent episode of the NPR show Radio Lab focuses on Zoos, and talks a lot about the importance of behavioral enrichment.)

We spent about eight hours walking around the Copenhagen Zoo, and saw most but not all of it. I strongly recommend it to anyone who loves animals, whether or not you love zoos. I took about 500 pictures that day, 60 of the better ones are linked to below.

Copenhagen Zoo

Ego boost of science.

There is a very flattering article in tomorrow's New York Times science section, by Natalie Angier, about our article on the definition of behavior. (There is also an online quiz associated with it.) It has, to be honest, many fewer errors than I generally expect from science journalism. The main one that will jump out at most of my peers is her statement that, "neither that textbook nor any other reference he consulted bothered to" define behavior precisely. We found lots of definitions, they just didn't agree with each other, or with what we or other biologists thought the word meant. That said, I think this NYTimes article is much better than most science reporting on the accuracy front. And of course, it is nice to have one's work described as "provocative and crisply written" in a large circulation newspaper.

She did neglect mention my two favorite things about the article; the title is, "Behavioral biologists do not agree on what constitutes behavior," and; in a biological article in a peer reviewed journal, we quote both Supreme Court Justice Potter Stewart's opinion on pornography and Conan-Doyle's Sherlock Holmes mystery of the dog that did nothing in the nighttime. I amuse myself heartily.

Behavio(u)r defined.

Published in this month's Animal Behaviour. British spelling.

Behavioural biologists do not agree on what constitutes behaviour

Daniel A. Levitis, William Z. Lidicker Jr. and Glenn Freund

"Behavioural biology is a major discipline within biology, centred on the key concept of ‘behaviour’. But how is ‘behaviour’ defined, and how should it be defined? We outline what characteristics we believe a scientific definition should have, and why we think it is important that a definition have these traits. We then examine the range of available published definitions for behaviour. Finding no consensus, we present survey responses from 174 members of three behaviour-focused scientific societies as to their understanding of the term. Here again, we find surprisingly widespread disagreement as to what qualifies as behaviour. Respondents contradict themselves, each other and published definitions, indicating that they are using individually variable intuitive, rather than codified, meanings of ‘behaviour’. We offer a new definition, based largely on survey responses:

Behaviour is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal and/or external stimuli, excluding responses more easily understood as developmental changes.

Finally, we discuss the usage, meanings and limitations of this definition."

Forthcoming paper

The paper I wrote with two colleagues on how biologists define the word behavior should be coming out in Animal Behaviour in June or July. I am guessing it is the first article to appear in that journal to reference both a supreme court decision and a Sherlock Holmes mystery. I am certain it is the first one to tell behavioral biologists that they don't agree on what they mean by 'behavior.' I am very curious to see how it will be received.

A third way of seeing things

The paper I'm writing now is on sex-biased longevity in primates. I'm trying to understand why in some species the males live longer, and in others the females live longer. The story I'm trying to test goes like this:

The largest investment in primates' offspring is in the form of care, not eggs or sperm or pregnancy. In species where females provide all of the care, males need not stay with a single mate, so the operational sex ratio is male biased (i.e. lots of males are out looking for a mate, while most of the females are pregnant or nursing and therefore not looking to mate), reproductive skew is high for males (some males will father lots of offspring, others none), and the fitness rewards to successful male competitors are great. Larger males are more likely to win these competitions, resulting in an increase in optimal male size. These large belligerent males risk increased mortality through conflict, and through diversion of physiological and developmental resources away from longevity and into competitiveness. Simultaneously, selection for longevity in females may be increased by the need to stay alive until their young become independent (and in the case of humans, to care for grandkids). This leads to males who, relative to females, are non-caring, short-lived, large and conflict prone.

I have data (gleaned from the literature) for a bunch of primate species on how long males and females live, how much care the fathers provide in each species, how big males and females are and how frequently and intensely males fight with each other. Depending on how I analyze these data, I get two very different answers. If I treat each species as an independent sample, and look at the correlations between these variables, the data completely support the story. The species range along a continuum having short-lived belligerent large, uncaring males at one end and long-lived caring low-conflict small males at the other.

But most evolutionary biologists would say that is not the right way to analyze the data. I need to take into account the relationships among the species. Two traits might seem to be correlated not because the one makes the other selectively advantageous, but because a group related species all have the one and all have the second. Take the example of feathers and laying eggs. All birds have feathers and all birds lay eggs. Is this because something about feathers requires egg-laying (probably not) or because all birds are descendents of some ancestral birds that laid eggs and had feathers, and ever since no bird has arisen that didn't do both those things. That all birds have eggs and feathers is an example of what biologists call evolutionary inertia.

The question this poses for me in writing my paper on primates is whether the correspondence between sex-biased longevity and these other variables is because of the adaptive story I told you, or because of evolutionary inertia. So I look at the data a second way, and see that there is a great deal of evolutionary inertia in these traits. Most primate species are somewhere near the middle of that continuum I described. Ever species at one end is from one group of related monkeys. Every species at the other end of the continuum is either a great ape or from a different family of monkeys. Plugging my data into software designed to test for evolutionary inertia, I find that closely related species are very likely to have similar values for all the traits I am measuring, and that inertia is fully sufficient to explain the correlations between these traits. It is like eggs and feathers in bird.

As I am trying to write the paper to present all of this in a scientifically rigorous way, I am struggling with what to say about it. The easiest, and least interesting, conclusion would be to simply say that the correlations are purely illusions conjured by evolutionary inertia. What I'm attempting to find a way to argue it that it could just be inertia, but that the inertia might be because of selective effects. In other words, that both the inertia story and the selective story could simultaneously be true, and closely related species are similar not because they can't change, but because what was adaptive for their common ancestor is still adaptive for them. If a male from a very belligerent species was to grow in a way that made him not a good competitor, but able to live a long time and provide care to his young, this wouldn't fit with the way his species lives, so he wouldn't pass on his novel trait, and his species would stay like their ancestors had been. It is evolutionary inertia caused by adaptive mechanisms. I think my next step is to find out who has already written about adaptive evolutionary inertia, and what they said.

Finallly!

We have submitted our paper on the meaning of the word behavior (or, since the journal is British, behaviour). It took much longer to get it to the point where we could all agree on it than I expected, and there are still a few stylistic points I am not fully satisfied with, but overall I think it is a good paper, and has a good chance of being accepted. I am sure none of the reviewers will entirely agree with out conclusions, but the point of the paper is that we don't agree, so I think that is okay.

So many data, so little time.

I first met Jerram Brown in 1999, when I was a senior at Bennington College. My adviser, Betsy Sherman, had been his student many years earlier. I was about to graduate from college and he was about to retire from a very long and extremely successful career in exactly the part of biology I was interested in. For the previous 30 some years he had been studying the behavior, ecology, demography and so forth of the Mexican Jay. I asked him about the possibility of working for him, but I was too late, his retirement plans were gathering momentum. He officially retired in 2002.
When I graduated, I went to work for Glen Woolfenden, who had an almost as long-term study of a very closely related bird, the Florida Scrub-Jay. Glen and Jerram, for reasons I don't know, had some sort of tension between them, and I had no further contact with Dr. Brown's group.

Looking through the program of the Animal Behavior Society Meeting I just attended, I was very excited to see that Jerram Brown would be momentarily be coming out of retirement to accept a distinguished researcher award and deliver a plenary address on his work. That talk was the last morning of the conference, and it turned out far more interesting than even I had suspected.

His data set on the Mexican Jays is shockingly extensive. In addition to the multi-decade highly detailed demographic data, he has an enormous number of ancillary data sets, many of which he had never gotten around to publishing, because he had not found any theoretically important question they could be used to answer. But as he heaped data upon data, I came to realize something. These data he had gathered because he could, rather than because he had a particular question in mind, were potentially exactly the data one of my advisors, Ron Lee, needed to test some of his hypotheses on the importance of intergenerational transfers of resources (in this case food) to the evolution of longevity and sociality. Dr. Brown had records of >26,000 individual food transfers, including who was transferring, to whom, how old each one of them was and how they were related to each other. My heart started thumping. I had to get Jerram's data and Ron's theoretical framework and analytical prowess together. But most scientists jealously guard the data sets they spent their lives gathering. And Ron is already terribly busy with far too many projects, would he even be interested?

Then Dr. Brown said, as part of his planned talk, something I have never heard any scientist say before, even though we probably should all say it sooner or later, "I will gladly turn over my entire dataset to anyone who can make good use of the data." There was a loud gasp. It was me, but not only me, several people gasped. He may as well have said, "I will turn over all this gold ore I have spent my life mining to anyone who can smelt it."

Immediately after his talk, I went up to speak to him. I shook his hand, told him that I was a former student of his former student (in case it helped) and began to tell him about Ron and his work. Another fellow, a Dr. Ha, came up and said that he would like to apply for NSF funds to hire a post-doc to work with Dr. Brown to make sure the data set is preserved and made available. He said that if Ron were involved, this would increase the chances of getting the funding, as NSF would want to know the data would be put to good use.

With some trepidation, I emailed Ron and told him all this. He wrote back almost instantly saying it sounded like a great opportunity, and he would love to join this collaboration, but would want, "some more junior researcher with more years of research ahead of him/her" to be involved, and suggested that I was the "leading candidate."

So this all raises the very real possibility that I may be spending a couple of years immediately after my doctorate applying Jerram Brown's data to Ron's hypotheses (and perhaps a few hypotheses of my own). I haven't yet figured out if this is something I actually want to do, and would be able to accomplish, but the prospect is very exciting all the same.

Chimp Politics

It is 8:30 AM on the second full day of the conference and I have already lost my name-tag. Things are going well. There are five people (with at least four PhDs among them) trying to deduce why the projector for the Keynote Address isn't working.
There are about 300 conference participants here, half of the usual ABS meeting. The reason, other than the scheduling conflict, seems to be that they are having it at the Snowbird Ski and Summer Resort. The problems with this are two. First, they had their meeting here in 2006, and a significant part of why many people decide to go to conferences is to have an excuse to visit a new and exciting place. The second problem is that the Resort is an industrial scale conspicuous consumption machine, meaning that it is overbuilt, overdone and overpriced. I have to admit that it is in a beautiful place, and I will be posting pictures of a moose and some marmots some time soon.

Looks like the projector is working, John Mitani is a well known expert on primate behavior, and has performed fieldwork on all five species of non-human apes. He is giving the Keynote Address, and I will try to convey in non-technical terms my understanding of his understanding of what he says (Or at least that part of it based on previously published work. I don't actually know, but I suspect it would be very rude to distribute the parts of his talk that he had not yet published.)

He has been studying the social behavior of the chimps of southwest Uganda for the last 14 years. Male chimps are more social than the females, form more lasting bonds, move more broadly over a group territory and more often cooperate in coalitions. Male coalitions seem to serve the function of supporting their members in conflicts with other males. The male with the most coalition support rises to the top of the social status, even if he is not the smartest, strongest etc. (A slide of Bush and Cheney somehow appeared in his talk.) The alpha male gets most of the mating opportunities, but in times of coalitional uncertainty, will cede those opportunities to other males whose coalitional support they need.

Chimps are also group hunters, especially of young monkeys. Most of the hunters are adult males. A large group of male chimps will surround a troop of monkeys, and are extremely frequently successful, even if the amount of food per hunter is very small. But group hunters are not necessarily cooperative hunters. If 50 guys all go for the same prey, they may successfully grab it, but that doesn't necessarily mean they are intentionally helping each other. Each individual may be trying to be the one who grabs the meat.

But the chimp who catches the monkey is likely to share it with others. Why? Males are the primary hunters, and hunt mostly when there are a bunch of other males around. It is suggested they may go hunting for male-bonding purposes. The meat seems to be used as a political tool. Males use meat to buy coalition support from other males.

Male coalitions will also make territorial patrols and raids into the territory of neighboring groups. They defend their own territories and grab more land, not infrequently resulting in serious injury or occasionally death. The larger the group patrolling together, the less the risk from any rival group encountered. Dr. Mitani's study group has killed 18 rival males in 10 years, because they are the largest group around. He wants to show us a video of chimps attacking each other, but is having technical difficulties. Now we see another video of a gang of male chimps beating another to death. The room is very still.

Female chimps disperse to other groups, males do not. So males are potentially living in groups of close relatives. And it turns out that males do preferentially help their maternally related brothers. It is easy to know if you have the same mother as another chimp. It is much harder in a non-monogamous species to know if you have the same father, and males don't preferentially help paternally related brothers.

He is finished telling us about the chimps in particular, and is going on to discuss the differences between those who study the behavior of primates and the broader animal behavior community. He says that primatologists can be overly focused on the primates, but that the broader behavioral biological community can be overly resistant to viewing the primates as relevant to their own work. This is apparently one shot in an arguement I was not aware of, and it seems odd to raise it here. One of the biologists sitting near me mutters that he regularly references primate papers, while he never sees primatologists reference the frog literature.

The address is over, time for bagels, juice and schmoozing. Then I'll try to take pictures of the marmot that hangs around on the hotel lawn, and find my name tag.

What I'll be talking about at ABS.

The concept of "behavior" is central to the activities of the Animal Behavior Society and its members, but do we know what we mean by this term? Most published sources either do not include a definition of the word "behavior", or have definitions that both contradict each other or are either too broad or too narrow to be applied operationally.

We examined the range of available definitions, and finding no consensus, polled members of ABS as to their understanding of the term. Here again, we found surprisingly widespread disagreement as to what qualifies as behavior. This paper highlights the areas of agreement and disagreement, and proposes a definition intended to be operational and as free as possible of taxonomic bias.

Dueling Conferences

Most scientific societies have a conference every year or two. A chance to meet other scientists with similar research interests, hype your work, hear them hype their work, network and generally schmooze. This year the two big meetings most likely to draw American behavorists, the International Society for BehaviorAL Ecology, and the Animal Behavior Society, are almost overlapping. ISBE is, as the name implies, international, and have their meetings only every other year. Now they are having their meeting in Ithaca, at Cornell too good a chance for most American behaviorists to pass up. ABS is having their meeting a few days later at an overpriced resort in the mountains above Salt Lake City. A beautiful spot, to be sure, but not enough to convince many people who have just sat through a week of behavior talks to fly west and sit for another week. ISBE will have about three times as many attendants as ABS.

I am going to ABS, rather than ISBE, because it is easier to get to from here, because ISBE had their deadline for submission of abstracts before I got my act together, and because ABS is supposed to be more student friendly. I'm staying at a very affordable campsite some thousands of feet above the resort, and giving what I suspect will be the only philosophical talk of the meeting. I am not sure whether the ABS meeting will be more fun or less for being so much smaller than ISBE, but I shall try to liveblog the whole thing.

Catnip -> Olfaction -> Happy

My Friend Terry Johnson is a lecturer in Bioengeneering at UC Berkeley. He also writes the Ask a Biogeek column for io9.com. Now he is one of the judges for their Mad Science Contest: Build a Lifeform. And, in investigating my idea for an artificial organism, I came across this abstract:

Hart BL, Leedy MG.1985. Analysis of the catnip reaction: mediation by olfactory system, not vomeronasal organ. Behav Neural Biol. 44(1):38-46.

Pet owners and behavioral scientists alike are fascinated by unique behavioral reactions that cats show in the presence of catnip. These experiments explored the possibility that the catnip reaction might be triggered by chemosensory stimulation of the vomeronasal organ. In the chewing and mouthing of the catnip source, substances might be dissolved in saliva and transported to the vomeronasal organ. The rolling and rubbing during a catnip reaction might be a sexual response activated by the accessory olfactory system since the system projects to parts of the brain involved in mediation of sexual behavior. However, removal of the vomeronasal organ did not attenuate any of the behavioral reactions to catnip. Olfactory bulbectomy immediately eliminated catnip responding, revealing that the chemosensory stimulus evoking the catnip reaction is undoubtedly mediated through the main olfactory system. Catnip activates behavioral elements associated with several species-specific behaviors, including sniffing and chewing as associated with oral appetitive behavior, rolling and rubbing characteristic of female sexual behavior, batting the catnip source characteristic of play behavior, and a type of kicking associated with predatory behavior. These behavioral reactions occur randomly and intermittently.

The moral of the story seems to be that:
A. Cats respond to catnip through their olfaction, the type of smelling that humans do fairly well, rather than through the vomeronasal organ, the part of smelling that humans don't seem to do at all.
B. Catnip elicits from cats behaviors associated with almost every active things cats enjoy (eating, playing, sex and hunting). Catnip does not elicit the calming and resting behaviors such as self-grooming and napping that cats also enjoy. Catnip also does not elict behavior associated with things cats don't enjoy (fighting, danger, housechoirs).

Based on this, and my own observations, it seems likely that catnip is a quick-acting stimulant, extremely pleasant to the cat and absorbed through the olfactory epithelium.

Stefanie Schwartz, in her book "Psychoactive Herbs in Veterinary Medicine" list some other useful facts. Catnip response is not associated with any know histological or physiological effect, (meaning that while it certainly does something in the body, it is something subtle) catnip is not toxic even at relatively high doses, and the physiological and psychological effects are very different in cats than in humans. In humans, catnip is mild sedative, and smoked catnip is said to have similar psychtrophic effects to smoke marijiana. In cats, it is clearly a stimulant. In neither species does it have any known side effects.

Nepetalactone, the active ingredient, is also aparrently a powerful insect repellant, driving off both lice and cockroaches many times more powerfully than does DEET.

Plant Behavior

There is a scientific society dedicated to the study of almost anything. But until recently (2005) there was no society dedicated to the study of the behaviors of plants. Enter The Society of Plant Neurobiology. which states on its website:

"Plant Neurobiology describes a newly named, but also old and fascinating field in plant biology addressing the physiological basis of adaptive behavior in plants. Perhaps this field could be called "Sensory Biology in Plants" or something similar. However, these names don't quite cover topics like plant cytology and anatomy, adaptive plant behavior, signaling and communication in symbiosis and pathogenesis, or newly emerging topics like for instance plant immunity, plant memory and learning, plant-plant communication, as well as plant intelligence."

This is very convenient for me, as I am currently writing a paper on, among other things, taxonomic bias in definitions of the word 'behavior.' Having gotten input from member of the Animal Behavior Society and the International Society for Applied Ethology, I am thrilled to be able to get the viewpoints of botanists interested in behavior. I emailed the chair of their steering committee, asking her to forward a link to my "what is behavior?" survey to their membership. If she is sympathetic, this could be really cool.

I learned of the existence of SPNb through this article on NYTImes.com. Check out the video of the parasitic plant sniffing for prey and pouncing on the unsuspecting tomato vine.

Dying for Sex

One of the projects I am working on currently is an analysis, using data from primates, of what life history factors are correlated with sex-biased longevity. To put that plainly, I want to know why in some species the females live longer, in some the males live longer, and in some they live equally long. One of the dozens of hypotheses out there explaining why females live longer, in species where they do, is the 'risky male behavior' hypothesis' which says that males don't live as long because they take risks while out looking for sexual partners.

There has been limited support for this hypothesis, and most of the others, because so many hypotheses make the same predictions that one can rarely conclude that a particular factor is at play unless one ignores all the other possibilities (which seems to be the standard practice.)

This paper from Proc.Roy.Soc.B. takes an interesting new tack, looking not at whether males that are shorter lived than their mates are taking more risks, but rather at whether their short-livedness can be explained by increased mortality during the season of risk taking.

Here is the abstract:

Abstract

Male excess mortality is widespread among mammals and frequently interpreted as a cost of sexually selected traits that enhance male reproductive success. Sex differences in the propensity to engage in risky behaviours are often invoked to explain the sex gap in survival. Here, we aim to isolate and quantify the survival consequences of two potentially risky male behavioural strategies in a small sexually monomorphic primate, the grey mouse lemur Microcebus murinus: (i) most females hibernate during a large part of the austral winter, whereas most males remain active and (ii) during the brief annual mating season males roam widely in search of receptive females. Using a 10-year capture–mark–recapture dataset from a population of M. murinus in Kirindy Forest, western Madagascar, we statistically modelled sex-specific seasonal survival probabilities. Surprisingly, we did not find any evidence for direct survival benefits of hibernation—winter survival did not differ between males and females. By contrast, during the breeding season males survived less well than females (sex gap: 16%). Consistent with the ‘risky male behaviour’ hypothesis, the period for lowered male survival was restricted to the short mating season. Thus, sex differences in survival in a promiscuous mammal can be substantial even in the absence of sexual dimorphism.

Human Oestrus

Iris and I are reading Jared Diamond's book on the evolution of human sexuality, "Why is sex fun?" An interesting read, and in many ways a good introduction to the science of behavioral ecology, except that Diamond falls into his usual habit of making the same point many times and many ways, as if to beat you into agreeing with him. Since I generally start out agreeing with him, this gets tiring. The chapter we were reading last night was primarily his speculations on the evolutionary basis of the lack of obvious oestrus in humans. I was therefore very interested when this evening, browsing the table of contents of ProcRoySoc B, I cam across an article titled "Human Oestrus"

Here is the abstract:

For several decades, scholars of human sexuality have almost uniformly assumed that women evolutionarily lost oestrus—a phase of female sexuality occurring near ovulation and distinct from other phases of the ovarian cycle in terms of female sexual motivations and attractivity. In fact, we argue, this long-standing assumption is wrong. We review evidence that women's fertile-phase sexuality differs in a variety of ways from their sexuality during infertile phases of their cycles. In particular, when fertile in their cycles, women are particularly sexually attracted to a variety of features that likely are (or, ancestrally, were) indicators of genetic quality. As women's fertile-phase sexuality shares with other vertebrate females' fertile-phase sexuality a variety of functional and physiological features, we propose that the term oestrus appropriately applies to this phase in women. We discuss the function of women's non-fertile or extended sexuality and, based on empirical findings, suggest ways that fertile-phase sexuality in women has been shaped to partly function in the context of extra-pair mating. Men are particularly attracted to some features of fertile-phase women, but probably based on by-products of physiological changes males have been selected to detect, not because women signal their cycle-based fertility status.

Rotifers, sex and locomotion: fast males, slow females

A while back I saw a male rotifer and for the first time knew that it was a male rotifer I was seeing. Three things immediately struck me:
1. Oh! so that's what I've been seeing all this time.
2. Damn they're so tiny compared to the females
3. Golly-gee-willackers they move fast.

To give you a sense of this, observe the following Youtube video I came across. The little bizarrely fast ones are the males.



The males are short-lived, have no digestive system or foot (meaning they can't eat or anchor in one place). They hatch from an unfertilized egg, carry their mothers' genes to other females, and die.

I was discussing this with a friend of mine, who asked, "what good are the males anyway?"

"They're just swimming sperm packets." I replied. But then I thought about it more, and realized the question could be viewed another way. There are plenty of invertebrates that are hermaphroditic. A single individual has both ovaries and testes. I fertelize you while you fertilize me. No need to build a whole separate individual to deliver the sperm. So why go to all the expense of pumping out fleets of males?

Maybe, I thought, it was that speed. The smaller a rotifer is, the faster it can swim. This is the result of the fluid dynamics of how they swim. I don't know a thing about fluid dynamics, so I won't try to explain that, but the data show that swimming speed is predicted with great accuracy by size.

Having fast moving sperm deliverers could have two benefits that immediately occur to me. First, one can spread one's genes much further by producing small, fast males and sending them off in all directions, than by having one big slow female swim around. Especially considering that the female's immediate neighbors have a good chance of being clones of herself, to make sexual reproduction worthwhile, she needs to get get her sperm far away. That may require speed.

Second, maybe being fast is useful in the competition for mating. If the females are not just willing to mate with every rotifer that wanders along, perhaps being fast increases the chance of fertilizing her eggs.

These are all just hypotheses, but they are testable ones, and perhaps some day I will get to testing them.