Tag / lek

by Roslyn

Life imitates [filmmaking] art

Congratulations to Myra Burrell – her peacockumentary has been short-listed for the Animal Behavior Society’s film festival!

Myra, a veteran of the natural history film program at the University of Otago in New Zealand, traveled to California with me in 2010. She helped with peacock field work, capturing more females than anyone thought possible. Somehow, in the meantime, she made a movie about the birds. It’s a short film that gives you an idea about what happens on a peacock lek, from the hen’s point of view.

It’s quite an honour to be among the 6 films selected for festival screening, since they must get on the order of ~100 applicants. If Myra wins, it would be oddly fitting: a wildlife film straight out of a park that moonlights as a real Hollywood set.

You can watch “Hen’s Quest” here.

The best parts? I love the music and Myra’s cinematography. I contributed writing (including the title!) and did the artwork; Brian McGirr turned my map drawing into a fantastic animation. Good luck, Myra!

by Roslyn

How I learned to respect the peahen

Written for the Los Angeles Arboretum.

Meep meep? More like “Honk honk!”

Arboretum regulars will no doubt recognize the call of a startled peahen, but you may not be aware of the clever ways they use it. Not that they try to boast or taunt the enemy, necessarily, but I’m starting to think that the birds at the Arboretum owe a lot to their version of the Road Runner’s call.

How do I know? Some background is in order here: I’m the tall blond woman who has been hanging around the Arboretum morning and night for the past few years, overdressed and hauling a camera, a pair of binoculars, some peanuts and, if I was lucky, a peacock. Working at the park each spring, I often wished I had more time to chat with visitors. But I was preoccupied, and the life of an ornithologist can sometimes feel like that of Wile E. Coyote on a bad day.

For the past four years, I’ve been chasing peafowl across the continent – from Arcadia in February to Winnipeg, Toronto and New York in May and June. Incidentally, the Bronx Zoo is the only place in North America that even comes close to the Arboretum in sheer number of peafowl. Three years into my PhD in biology, and I’ve spent literally hundreds of hours watching these birds.

You may be wondering what got me into this mess.

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by Roslyn

Furious about eyespots

I think I flubbed an interview this week. My supervisor Bob and I just published a paper that is getting some press, because it addresses a recent controversy about the peacock’s train1. Eager for the interview with Nature News, I wasn’t exactly prepared with good lines for the reporter to go on – and I wonder if that’s why he had to pump up our story as a “furious debate”2.

In truth, most of the “debate” played out in a flurry of news articles back in 2008. That was when Mariko Takahashi and her colleagues in Tokyo and Kanagawa published the fruits of their exhaustive 7-year study of the peafowl at the Izu Cactus Park in Shizuoka, Japan3. I’ve never met Takahashi, although I did meet her supervisor and one other player in this story at a conference back then, and all were quite friendly. But the title of Takahashi’s 2008 paper, “Peahens do not prefer peacocks with more elaborate trains” was a direct jab at an earlier one, “Peahens prefer peacocks with more elaborate trains”, by Marion Petrie in the UK4. Takahashi and her coauthors had the difficult task of proving a negative – and they did it pretty convincingly, with the aid of a much more extensive data set than anyone had gathered before with this species. The upshot? For a peacock in Japan, having a bigger train ornament doesn’t necessarily win you any favours with the ladies.

Bigger in terms of the number of eyespots visible in the ornament during courtship, that is; males have about 150 on average, each on the end of a single feather. The results of the Japanese study were in direct contradiction to Marion Petrie’s earlier work as well as some recent studies of peafowl in France suggesting that eyespot number is often correlated with male mating success4,5. What’s more, in the 1990s Petrie had confirmed the causal effect of eyespots by showing that you could alter a male’s fate just by removing about 20 of them6.

Peacock in flight

Taken at the Los Angeles Arboretum in 2009. Photo by Roslyn Dakin.

The Japanese team proposed a rather bold new hypothesis. Perhaps the cumbersome, ridiculous train ornament is obsolete – a relic of sexual selection past, no longer used by females in quite the same way as it was when it first evolved3.

This was taken up with gusto by the news media. Check out the headlines: “Peacock feathers: That’s so last year”, “Have peacock tails lost their sexual allure?”, “Peacock feathers fail to impress the ladies”. Amusingly, this last article was also published with the title, “Female peacocks not impressed by male feathers” by Discovery News7-10. Males could probably be forgiven for striking out with those elusive female peacocks, since they don’t actually exist.

Headlines aside, Takahashi’s interpretation is somewhat of a concern. Here’s why: creationists picked up on this story too11.

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by Roslyn

A case of mistaken celebrity

They all look the same to us. Celebrities, that is. And by us, I mean academics.

The proof starts with peacocks. Last fall, I was working on some measurements I took of the crest ornament in these birds. Peafowl have this funky little fan of feathers on top of their heads, and though it’s not that small in the grand scheme of fancy bird plumage ornaments, the peacock’s five centimetre crest looks a bit ridiculous next to the metre-and-a-half long train.

Why bother having a crest when you also have a big train? And why do females wear crests too? In this species, the crest appears to be the only plumage ornament shared by both sexes. Here are some of my pictures from the field, taken on the cusp of the breeding season:

Crest ornaments of male and female peafowl

Crests of (a) male and (b-c) female peafowl. Scale bars are 10 cm. Photos by Roslyn Dakin.

Over the years, I’ve measured the crests of close to 150 birds. These data lend some support to the idea that the crest is a signal of health in both males and females, although it might work in slightly different ways for the two sexes1. As you can see from the picture above, there is a lot of variation in how the crests look – and it’s mostly on the female side of the equation. Almost all adult males have tidy looking crests like the one shown in (a), but females often have crests with a lot of new feathers growing in (c). It turns out that males in better condition tend to have fuller, wider crests. The healthiest females, on the other hand, have crests that look most like those of males, with all feathers grown out to the top level (b).

The extreme variability among females leads to an additional hypothesis, and it’s one that I can’t rule out at this time. Perhaps the crest is a signal of individual identity that the birds use to sort out who’s who in their social groups – just as faces do for us. A clue that this could potentially work for peahens is that my field assistants and I can do it. Once you spend enough time hanging around with these birds, you find yourself recognizing certain females that haven’t been captured yet (and that therefore lack identifying leg bands). Your first clue? Usually a unique pattern of crest feathers.

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by Roslyn

Reaching the other side, in synchrony

It’s a familiar site on campus here during the first week of class: packs of jaywalkers moving in tight co-ordination, in sync with the flow of oncoming cars. From traffic lights and power grids to stereo sound and cinema, synchrony is so common in our environment that we usually only notice it when it fails. Not so with nature: the examples of synchrony in living things tend to be much more surprising to people studying animal behaviour.

Group courtship displays are a classic example. Think of chorusing songbirds in the morning or calling frogs gathered around a pool of water at night. Readers of my blog on peacock field work might be familiar with lek-mating birds gathered around a clearing to wait for females. Peacock train displays also tend to happen in sync. One traditional explanation for these co-ordinated displays is that, by synchronizing their most conspicuous behaviour, animals might gain some protection from predation1. Another possibility is constructive interference: co-ordinated timing might allow a pair of animals to spread the message farther than either one could on its own2. Two innovative new studies on animal courtship have added to this list. The first, on firefly displays, shows that synchrony might help insects recognize members of their own species by getting rid of visual clutter.

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by Roslyn

Masters of illusion

It can be easy to see intelligence in the animals we spend a lot of time with. Everyone has their pet example, one of the most common being dogs who can anticipate the precise time of their owners’ return. But what does this really say about the mental life of dogs? Some birds are capable of even more impressive mental stunts – only they often go unnoticed in the wild. Two recent field studies in Africa and Australia provide a nice illustration. The results challenge our notion of limited animal intelligence, but as we will see, the way we interpret them might say more about our own minds than it does about the birds.

Fork-tailed drongos are masters of deception. These small, glossy black birds from southern Africa are known for their ability to mimic the calls of other bird species – much like the mockingbirds found throughout the US and parts of southern Canada. Most of the time, drongos forage alone hunting insects, but occasionally they get other animals to do the hard work for them. Drongos will follow groups of meerkats and pied-babblers – mammals and birds known for their highly social lifestyles – and steal their food, a process known as kleptoparasitism. It might not be a complete loss for the victims, either. Drongo thieves give plenty of alarm calls along the way, and these may help the meerkat and babbler groups avoid predation1.

Perhaps not surprising for an accomplished mimic, the fork-tailed drongo has a diverse alarm call repertoire that includes its own unique warning “chink” as well as the calls of several other bird species. On the savannahs of the Kalahari Desert, birdwatchers noticed that drongos often seem to use these mimicked calls during kleptoparasitism, swooping in to steal food from pied-babblers immediately after sounding a false alarm1. For Tom Flower at the University of Cambridge, this was fascinating anecdotal evidence, so he set out to test whether these alarm calls are used by the drongos in a deceptive way2.

The first thing Flower needed to do was eliminate the possibility that the drongo false alarms are coincidental. If the drongos are truly deceptive, the calls should only occur when the birds are attempting to steal food. Flower also had to establish that the drongos sound the same, regardless of whether they are using their alarm calls in an honest or deceptive context. Finally, he had to show that the meerkats and babblers respond similarly in both cases.

Fork-tailed drongo

Fork-tailed drongo.

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by Roslyn

Deep archives: Sex “pests” get more practice

Juvenile male peafowl practice their displays

Having finished my field work this year, I thought I’d keep up with this blog by writing about interesting things that other people have seen animals do.

To start: this BBC science news report on the discovery of a “sex pest” seal that attempted to mate with a penguin, brought to my attention by Rob Ewart (the original paper can be found here but you will need a subscription to the journal to read the whole thing).

Apart from the entertainment factor – the abstract to the scientific paper concludes, “we report a case of interspecific sexual harassment bridging the rank of vertebrate class” – there are a few interesting issues here. The first being, why on earth would the seal do this? The authors provide a few possible answers. Apparently these fur seals sometimes eat king penguins, so perhaps by some strange mis-wiring, predatory arousal translated into sexual arousal in this case. Alternatively, the seal may have been too young to find a real mate, desperation leading it astray. Or, intriguingly, the young seal could have been play mating, a form of practice for the real thing later on.

The second issue: why on earth would a scientific journal publish something like this? Is it really that unusual for hormonally-charged animals to make the occasional mistake? This year alone I witnessed a peacock give chase to a human female (with the characteristic “hoot” of excitement that accompanies all mating attempts), and I’ve seen several peacocks attempt the same with guinea fowl and squirrels. All of these events happened with males that were displaying intently but that hadn’t had any peahen visitors in quite some time. Is this paper really such a novel finding, or are the authors just as desperate as the seal?

On reflection, it’s probably important to document these unusual behaviours somewhere, since it would be an interesting outcome if they turned out not to be mistakes after all. Young peacocks, for example, will frequently display their undeveloped train feathers to each other (pictured above). This male-male display may seem futile, but I wouldn’t be surprised if the kind of dancing skill required later in life demands some practice. Similarly, in Costa Rica I remember hearing juvenile long-tailed manakins displaying long after the real mating season had ended, no doubt honing their skills for next year. There is even some evidence that the reason male manakins pair up for their co-ordinated display dances, even though only the dominant member of the pair will get to mate, is for the practice.

The full citation for the seal paper:

De Bruyn PJN et al. 2008 Journal of Ethology 26:295-297.

And two on long-tailed manakin displays:

Trainer et al. 2002 Behavioral Ecology 13: 65-69.

Trainer and McDonald 1995 Behavioral Ecology and Sociobiology 37:249-254.

by Roslyn

Deep archives: Lek perspective

Scene from a lek at the Bronx Zoo

Males display in the “Wild Asia” exhibit at the Bronx Zoo, which can only be seen by riding the zoo monorail. The structure behind the birds is the monorail track.

I’ve had some success on this trip after all. The weather was perfect for my model experiments yesterday (sunny, warm, not too much wind), and although I wasn’t able to fit in quite as many trials as I was hoping for, the ones that I was able to accomplish worked perfectly. Of 16 successful trials (i.e. ones where the male danced for the model), 6 ended in a copulation attempt. In California, 3 of 22 trials ended in such an attempt. This apparent geographical difference in Penelope’s popularity is a bit of a mystery (it could be because a number of my California trials were at the end of the breeding season, when males were somewhat less motivated and harder to trick). Nevertheless, it’s safe to say that overall she was a hit.

One reason I didn’t get as many trials as I could have was that the Bronx peacocks were the most skittish ones I’ve encountered so far. When I stepped into the nyala enclosure at 7 am yesterday, I had about 2 hours to collect as much data as I could (as many as 20 five-minute trials, I figured). But it took a long time for the males to get used to me being in there. I spent the first hour waiting quietly (and nervously) for one of them to make a move, while they did the same – watching me carefully and no doubt waiting for me to leave. This stand-off shouldn’t be too surprising, though, since the Bronx Zoo birds have enough space to live their entire lives away from people.

This morning, I moved across the Bronx River to work in “Wild Asia”, and the birds there were even more difficult. Happily, though, I was able to get a video of a male reacting positively to Penelope, which will be excellent for illustrating exactly how she worked.

I also made a trip to the “World of Birds” exhibit. They have some pretty amazing animals there – here is a picture of another lek-breeding bird, the lesser bird of paradise:

Juvenile male lesser bird of paradise

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by Roslyn

Deep archives: The Californians, in pictures

Although I’m very happy to be back in Canada (having decided that Los Angeles is a terrible place to live, mostly because of all the driving), I have to admit that the people of California were quite friendly. I found the peafowl to be equally amenable. Since mating activity was finished during my last week in Los Angeles I decided to take some photographs of them (and other birds at the Arboretum, including the hummingbird in the border above). Here are a few of my favourites…

A peacock on the lawn: the male below manages to guard his territory while simultaneously resting in the shade. These birds can be surprisingly camouflaged at times.

Peacock on the lawn at the Los Angeles Arboretum

Other times, this is not the case:

Peacock perching among some pink flowers

A peahen on a nest: one of the first females to lay chose to do so in the sink of the men’s bathroom. This one appears to be more fortunate, but I wasn’t around long enough to see any peachicks.

Finding a nest

A female with Penelope: the model drew a lot of negative attention from the ladies. This picture was taken when I had Penelope stashed away in some bushes; after a lengthy inspection, the real female (on the left) started pecking at her aggressively.

I’ve been meaning to photograph peafowl in flight for at least a year, now, and I sat under a roosting tree for nearly two hours to get these last pictures. First, a peahen:

Peahen in flight

And, my favourite from the same morning: peacocks do it too!

Peacock in flight

by Roslyn

Deep archives: A working strategy

I am very excited to report that Penelope has finally lived up to her name!

Here she is right before being courted by male no. 30:

Setting up the model peahen for a displaying male

(Photo credit: Rob Ewart)

The secret to her success? You have to present her to males that are already (preemptively) inspired to display their tails. When you present her to a male that is resting on his territory, he just watches her curiously out of the corner of his eye while making himself look busy feeding and/or preening. But sometimes males will have their tails up when there aren’t any real females in the immediate area (either because they expect females to arrive very soon, or because some females have just left the area, or possibly because these males simply have the energy for it and nothing else is more pressing at the moment). Penelope’s best strategy is to target these males: when you initially approach them, they are slowly turning in circles as they keep a look out for their next female target. When you put Penelope in front of them, they enter into a pattern of dancing that is quite clearly directed towards the stuffed bird.

During one of the trials with male no. 30 (shortly after the picture above was taken), the peacock backed up alongside the model, shivered his train at her for an infinitesimal amount of time, and mounted her almost immediately for a mating attempt. Although initially shocked (and delighted) we soon remembered that we had to intervene, and certainly won’t let it happen again.

Update: Penelope was mounted two more times in California (bringing her total to three different males). I am with her now at the Bronx Zoo in New York City for some further experiments, and am determined to start writing here regularly again!

by Roslyn

Deep archives: Better than Gary Busey

They’re filming a movie on our field site right now. Apparently this isn’t out of the ordinary; one of the Jurassic Park movies and the climax from Anaconda were both shot at the Arboretum, for instance.

We’ve known this for some time, since a work crew has been gradually building a stadium on the main lawn of the Arboretum, on top of what is usually a large fountain (seems like a strange choice to me… fortunately, this area is not part of the lek so their activities won’t interfere with the peacocks). Rob found out a while ago that the stadium will be used for “a teen movie about cheerleaders”.

I learned some more details the other day. I was standing near the front gate, observing two peacocks that display on the roof of the Arboretum office building. Binoculars and notebook in hand, dressed ridiculously for the mild weather in a toque and heavy fleece, to most I would look like a crazy person taking notes about a roof. A woman approached me and struck up a conversation: apparently she was some sort of Hollywood production person on a scouting mission, and something about my appearance made her think that I was in production too. She was looking for a waterfall for a scene in an upcoming episode of Criminal Minds. She wanted to know if I was working on Fired Up, since she knew some people who were involved with it. I explained that I was actually watching the peacocks, secretly happy that I had found out the name of our cheerleading movie.

As soon as we got home, I searched for Fired Up on IMDB and learned that was a movie about “two guys who sign up for a cheerleaders’ camp in a desperate attempt to pick up girls”. And, as if this wasn’t ridiculous enough, it was billed as starring Patrick Swayze.

Our hopes of running in to the man who inspired the Patrick Swayze Express were dashed, though, a few days later. Rob had asked one of the set security guards about Swayze (and received a somewhat confused response); when we checked the IMDB site for Fired Up again, it had changed. The new site suggested that it’s most awesome (and sole recognizable) star had backed out – I think Rob’s questions might have even brought about the web update. But, as proof of how close we nearly came to Swayze, here is the old version of the site:

IMDB entry on "Fired Up"

by Roslyn

Deep archives: An instance of spite?

I have seen my first peafowl egg. Laid in the sink of the men’s bathroom, some of the Arboretum staff found it and brought it to me, unsure of what to do with it. The peafowl are overpopulated here and the staff are encouraged to find (and destroy) eggs. I ended up giving this one to Rob’s relatives from Palmdale in the hopes that they could hatch it (they keep chickens and have an incubator).

Perhaps in line with the fact that laying season is upon us, we’ve seen a few quite heated episodes involving the peahens in the last few days. Specifically, I’ve seen a couple instances of females being aggressive towards other females right in front of displaying (and preferred) males. Although this behaviour has been described before, it’s quite a paradoxical thing from the evolutionary point of view since female-female aggression over a presumably unlimited resource (mates) would be entirely spiteful.

I had seen the females in Winnipeg aggressively displaying their tails to each other in front of certain males a few times, but a recent episode here in Los Angeles has clarified the situation. This was, unmistakably, a female trying to prevent other females from mating with one of our top males. Here’s how it unfolded…

Male no. 30 was displaying his tail, with three females in the area: two sitting nearby in a little garden, preening away, and the third seeming to mirror the male while she aggressively displayed towards the preening females.

Peahen-peahen aggression

This went on for several minutes. Eventually, one of the preeners got up and left, and a few seconds later the aggressor lowered her tail and started walking away. Almost immediately, the second preener hopped down from her perch and accepted male 30’s advances right away. This brought the aggressive female literally running back to the scene, but it was too late for her to prevent the copulation. Luckily we managed to photograph the whole thing.

Peafowl copulation

Not sure what to make of it yet, but interestingly yesterday I saw more female-female aggression in front of another one of our favoured males. Our good intentions to work this morning were foiled by some light rain (peacocks don’t do anything when their trains are wet), but hopefully I’ll see some more of this action soon.

by Roslyn

Deep archives: Further notes from the field: deliberation, surprise and a misguided attempt

A few more things worth mentioning:

The other day we saw a female following a very interesting (and rather human-like) pattern while shopping around for a mate. She was visiting a particular male, and she’d watch him for a few moments (not always directly; it’s a good idea for females to seem as though they aren’t interested even when the are). She would start walking away and he would continue displaying; she’d make it about ten metres, stop, and then decide to go back. I watched this repeat about 4 or 5 times before she finally decided to accept that particular male. There weren’t any other males in the area that she would have been comparing on these forays, but it seemed pretty clear that something was going on in that pea-brain of hers. This is the first time I’ve noticed a female doing anything like this (at least in such an obvious way), but it’s possible that they could often make one or two of these little trips before making a decision.

Yesterday I saw one of the stickered males mate for the first time! It was one of the males with the decidedly less-conspicuous black stickers. I think this might actually be a good thing, since it means the females are at least considering the stickered males as potential mates.

And finally, I watched a peacock attempt (and manage) to mount one of the helmeted guineafowl that race around the park grounds. Hope for Penelope grows.

by Roslyn

Deep archives: Numbers, gathered

With our first two weeks of observations behind us, I thought I’d write about what we’ve gathered so far.

Fifteen copulations, all involving unstickered males: 6 for male 30, 5 for male 42, 3 for male 31, and 1 for male 38 (this last one is most triumphant since 38 is a male with stickers on the backs of his eyespots!). The remaining 16 males haven’t achieved anything yet, but that sort of skew (with the majority of males missing out on mating entirely) is normal for peafowl.

Two males display to a feeding peahen

Two males display to an uninterested female, while she feeds on some seeds provided by park visitors. Feeding the peafowl is not allowed.

Twelve attempts to touch the birds: okay, we haven’t really been counting (and if we had, this would probably outnumber the copulations). On a daily basis we scold people who try to touch and stroke the feathers of displaying peacocks. The offending demographic is about half children, half grown women; I feel a little bad about scolding the children, but grownups should know better.

Three soundbites: the most ridiculous one from a lady looking at a peacock with his train unfurled, overheard by Rob: “Now look at that and tell me there isn’t a creator!” Irreducibly beautiful indeed. The most astute comments have come from children: a couple of them exclaimed in surprise that the peacock feathers looked just like eyes, and today one boy asked, referring to the peacock’s crest feathers, “Why does he have a mohawk?”

One attempt by a juvenile male to mate with another juvenile male, and one attempt by an adult male to mate with a human female (not me). I think the former was a case of the juvenile males being eager to practice on anything, but I’m not sure about the latter.

And sadly, no Easter treats: yesterday was the “Great Easter Egg Hunt” at the Arboretum, and even though we thought we’d have an advantage over all the children since we’d be arriving when the treats were still being hidden, we failed to turn up anything. We also had to cut the morning short since all the commotion was impinging on lek activities.

As for Penelope, she’s staying in for now. Since there are real females about, I think a better use of our time is to get a handle on their preferences; I’ll bring Penelope out for round two in about a week or so.

by Roslyn

Deep archives: The joys (and pains) of number-gathering

One of the best things about biology is that it means you might get to work outdoors. This is especially wonderful when it involves heading somewhere warm, or at least somewhere warmer than home.

But field work in evolutionary biology is fraught with difficulties; it’s not all “binoculars and gorillas” as David Quammen has said (he’s one of my favourite nonfiction writers, and well worth looking into if you haven’t heard of him already). Field work can be lonely and uncomfortable, often horribly so, and is almost always tedious.

Field work has taught me what it feels like to sleep in a house where the scorpions outnumber the people. It has taught me the psychological terror of infestation with tiny biting mites that give you new welts daily, when other people working in the same environment receive not a single bite. It has taught me that I’m willing to wear my pants tucked into my socks, and keep them that way even if it includes a stop at the grocery store on the way home from work. But it has also taught me that most bugs really aren’t anything to be afraid of, and that not having to worry about what other people think can be a luxury.

As for the tedium, coming to terms with that is another thing entirely. As Quammen puts it, raw number-gathering can be dull even for the biologist with the “soul of a mathematician”, and the risk of boredom is one that will certainly increase with time. Absence of scorpions, centipedes, and tropical diseases in California aside, I still have to contend with the painful task of sitting still for hours and watching, even when the birds aren’t doing anything. I realize now that this kind of prolonged tedium is not unique to field work (perhaps it’s a defining characteristic of graduate research in general).

During the more inactive lek watches, I get myself through by thinking about what I’m going to eat for lunch, write in my next letter home, or do when I get back to Kingston. My friend Mike has described his endless hours of microscopy (for his Master’s research) as intellectually unstimulating yet strangely rewarding. I find the same is true of number-gathering in the field. As boring as it can be, I enjoy the fact that it gives me a chance think about the things I’m looking forward to in the future as well as reflect on those that I’m lucky to have now.

There’s one final difficulty – this is one that I fear more than centipedes, and still haven’t figured out how to reconcile. I’ll let Quammen describe it since he does it so well:

Besides tedium and reductionism, snakebite and dysentary, one other danger faces the biological fieldworker. This one is so large and scary, so terrifyingly amorphous, that it’s best described in the negative: lack of validity. Are you really measuring what you think you’re measuring? Are you really counting what you think you’re counting? Are you really therefore proving what you claim to be proving? Or possibly not? Maybe you’re rowing like hell but your oars aren’t in the water.

Quantification must be meaningful as well as precise, and the assumptions by which number are linked to biological realities must be correct. If so, you have not only precision but validity. If not, you’re wasting your time. Does the number of rings in a tree trunk really represent years of age? In most cases, yes. Does the number of wolf sightings in Glacier National Park really represent the current wolf population in that area? Possibly. Does the number of UFO stories in The National Enquirer, this year compared with last year, really represent the trend in visits by alien spacecraft? Uh, maybe not. Mathematized meaning, like any other kind, can be illusory.

I think I’ll make it mandatory reading for future field assistants.

David Quammen. 2000. “Certainty and Doubt in Baja” in The boilerplate rhino: Nature in the eye of the beholder. Simon & Schuster.

by Roslyn

Deep archives: A discovery

I learned something exciting the other day: apparently the satellite view in Google Maps has enough resolution for me to map out the precise display territories of individual peacocks. What’s more, this is as true for Winnipeg as it is for Los Angeles.

Upon realizing this, I spent the afternoon obsessively gathering co-ordinates for the 39 peacocks I’ve come to know intimately over the past year, and then using them to work out the relative distances between the different male territories on each lek.

I thought I’d mention it here in case this turned out to be useful for anyone currently planning their field work – I guess the nice thing about my study species is that the habitat is open and surrounded by easily distinguished man-made things!

Anyways, I told Charlie how excited I was about this internet discovery, and happily, he understood.

ps. We went for a walk in the mountains north of Los Angeles (near Palmdale) the other day while visiting some more of Rob’s relatives, and it snowed! And then, a couple of hours later, it hailed! California is fantastic.

by Roslyn

Deep archives: Eyeful or eyesore?

Experimental peacock

One of the main reasons for coming to California this year is that I’m doing an experiment to understand how peahens choose their mates. Specifically, I’m testing whether the colour of the males’ eyespot feathers is important.

My methods? Hundreds of coloured stickers, cut from sheets of sail tape.

The good news is the sail tape seems to work – most of the stickers stay on the feathers, and, since they’re so light, they don’t seem to have any effect on how easy it is for the males to display their tails.

I have a couple of treatment groups: control males with no stickers, males with black stickers (like the rather unlucky one pictured above; compare him to the male pictured here), and males with white stickers…

Experimental peacock

Everyone at the Arboretum wants to know what we’ve been finding. I have to shrug when they ask me – it will take many hours of observation over the next few weeks before I can say whether the black/white treatments have any effect on the females (we haven’t seen a single copulation yet). One thing I didn’t anticipate is the extent to which the white dots manage to captivate human observers. The black dots, on the other hand, don’t even get noticed by people. My guess is that the peahens won’t be so oblivious.

ps. The new header photograph of mechanical birds was taken by Charlie at the MIT museum. And, for those concerned about the possible effect of the weight of the stickers [Martin], we’ve applied stickers to the backs of the feathers of a bunch of birds as well…

Experimental control