Brothers on a Hotel Bed

I’m a few days late on this one, but it’s never the wrong time to learn about the fascinating mating habits of turkeys. They don’t call them wild turkeys for nothin’.

You know that saying “It takes two to tango”? Well, in their case it takes three, four, or five.

File:Male north american turkey supersaturated.jpg

Male north american turkey (Meleagris gallopavo) – Wiki Commons

No, no, no – not in that sense.

Mating systems where males form large groups to attract females are called leks, which means ‘play’ in Swedish . Many bird species form leks, in which the males competitively display their stuff to get female attention. Meanwhile, the female wanders from male to male to judge them before making her final pick.

The thing about leks is that they are competitive. Males of most organisms engage in competition of some kind to win the girl. Which is why something like this rhinoceros beetle is equipped with such fabulous weaponry.

But in turkeys, within the larger, competitive leks, are smaller coalitions of two to four males that cooperate with one another. These unique display partnerships in which males cooperatively court females are found in only a few species of birds.

What’s even weirder is that only one of the males (the dominant) actually gets to mate with the female that the group attracts. The other male or males, the subordinates, get no reproduction at all. Nothing. Zilch. Nada. This is akin to Batman getting all the ladies and Robin helping for no other reason than to help Batman get all the ladies. Rather strange, isn’t it?

So why would these subordinate males engage in such altruism, benefiting another at a cost to itself?

Further investigation by Alan Krakauer (then a PhD student) revealed that these duos or groups are formed by close relatives, often brothers. So while it seems that the subordinates are getting nothing for their efforts, they are actually indirectly benefiting by helping out a close relative.

Both of them gain by cooperating. The dominant does better with the subordinate’s help. Likewise, the subordinate does better as a back-up strutter rather than trying to strut his stuff all by himself. Most important of all is that the benefits for helping outweigh the costs.

This famous saying by J.B.S. Haldane gets at the heart of the matter: “Would I lay down my life to save my brother? No, but I would to save two brothers or eight cousins.”

In other words, you share roughly 50% of your genes with your siblings, so saving two of them is equal to saving yourself, who you are 100% related to. Similarly, you share roughly 12.5% of your genes with your cousins, so eight of them equals 100% of you. All this to say, the number of genes you share with your relatives matters.

And in the case of the turkeys, subordinate males gain no direct benefit (i.e. having offspring of their own) by helping, but they do gain indirect benefits by helping their close relatives have offspring. This is called kin selection, and it provides us with an explanation for such altruistic acts as cooperative male display in turkeys.

Now, if we could just figure out what’s in it for Robin.

You can read the original work on turkey courtship displays here and a popular press story about it here.

Totally Enormous Extinct Dinosaurs

Just as I’m sure watching movies involving *your* profession is annoying because they can never quite get it right in the film biz, it’s excruciating for scientists to watch movies with bad science in it. Case in point: I came across this funny blog advertisement for an entomologist (a person who studies insects) for the new Jurassic World movie set to come out in June of 2015.

And this is completely irrelevant to the science in it, but here is a funny comic of the original Jurassic Park with a slight twist in perspective. Enjoy!

Kelly Watch The Stars

Chances are that if you are reading my blog, you like science. But you don’t need to be a scientist to contribute to scientific research.

You can contribute through citizen science, which is a collaborative form of scientific research that involves the voluntary participation of public citizens (i.e. YOU). Citizen science projects can be done by individuals or by teams, and they’re often under the direction of a leading scientist or institution.

Do you think that one or two scientists alone could follow the entire fall migration of the Monarch butterfly from the US and Canada all the way down to Mexico, across thousands of miles?

Photograph of a Monarch butterfly (Photo Credit: Kenneth Dwain Harrelson) – Wiki Commons

Well, they certainly could.

But how long would it take for only a few individuals to collect data on the Monarch’s population size and travel patterns? And how much funding would that require? With citizen science butterfly counts, you can have many participants living in the migration corridor volunteer to collect data based on their observations. Such wildlife-monitoring programs are not only cheap, but they allow for large-scale data collection. Quite efficient they are.

So for the scientist, citizen science is a very powerful way to improve scientific research because it can greatly improve the sheer quantity of data that is collected, and it’s a great solution to a shrinking science budget.

But what’s in it for you?

Citizen science makes research a more democratic process, which means you get a say. Also, a fresh set of eyes on an old problem can lead to creative innovations. Isn’t it wonderful to think that you can discover something new and contribute to our scientific knowledge? Plus, it’s a nifty way to engage with the world (for more, read this).

Everyone wins!

There are a large number of projects and online outlets for you to share and contribute to science, so I am including links to them below. Some of them are regional. But no matter your interests, there is likely to be a perfect project for you. So get on out there and start collecting!

Combat Baby

Let’s return to the brood parasitism story.

Last time I left off wondering if it’s possible for hosts to defend themselves against their brood parasites or if they’re damned for eternity. If you’ll recall, cuckoo parasites have evolved incredible visual mimicry of their eggs, which makes it ever easier for them to deceive their hosts.

Eggs laid by different host-races of the Common Cuckoo are on the top row, with eggs laid by their target hosts shown directly below. Photos by M. C. Stoddard and copyright the Natural History Museum.

Eggs laid by different host-races of the Common Cuckoo are on the top row, with eggs laid by their target hosts shown directly below. Photos by M. C. Stoddard and copyright the Natural History Museum.

If you look closely, you’ll notice that these eggs are nearly matched, but not perfectly. Could these imperfections contain information that the host species can use to its benefit?

Some theoretical work done by Cassie Stoddard, a post-doctoral researcher in the Harvard Society of Fellows, indicates that hosts can fight back by developing highly elaborate but recognizable eggs. By developing a tool that mimics a bird’s visual perception capabilities and analyzing the complex patterns on eggs, she uncovered something quite remarkable – host species that have been subjected to the best cuckoo egg mimicry have evolved the most distinguishing and easy to recognize egg patterns. Pretty nifty, huh? You can read the original work here.

This is a fantastic system for exploring the evolution of visual signals. What’s more, it provides a classic example of a coevolutionary arms race. The cuckoo evolves a trait that will benefit it but cost the host (i.e. egg mimicry), and the host species in turn evolves a trait that allows it to overcome the cuckoo (i.e. egg pattern discrimination abilities). And so on and so on.

It’s almost hard to imagine the incredible pressure these brood parasites have put on their hosts for millions of years. And it appears that, given enough time, hosts can evolve strategies that help them fight back. But what of species that have not had adequate time to coevolve with a brood parasite?

Human activities are changing the environment at an alarming rate, and this is causing species that have never interacted with one another before to do so. This is precisely what is happening with brood parasites and new, unsuspecting victims due to shrinking habitat. In the short term, it’s unlikely that these new hosts can adapt quickly enough to evolve strategies that will allow them to overcome their brood parasites. Why should we care? Because many songbird populations are in decline due to brood parasitism. And we are a catalyst.

So not only can brood parasitism be an interesting area of study behaviorally, it can also provide us with a better understanding of how hosts overcome their brood parasites. Knowing this will allow us to predict how their new victims will fare, which will in turn provide us with a new framework for where and how we focus our future conservation efforts.

Now put yourself in the boots of a behavioral ecologist. To better understand this system, where would you start? And what would you do if I told you that some brood parasites actually target the nests of members of their own species?

Next time on The Birds.

Enemies Like This

Yesterday had a theme, and it was this: mimicry.

Mimicry is the similarity between one species and another. And there are just as many flavors of mimicry as there are means for animals to sense the world around them, referred to as modalities. As animals, we humans have several of these as well. We perceive the world through our senses, which includes the visual modality, chemical (smell/taste) modality, or auditory modality. Of course there are others.

But what I want to convey here is that mimicry can exist within any one of these modalities.

The Titan Arum I wrote about yesterday is a great example of chemical mimicry. It mimics the putrid smell of rotting flesh to attract its carrion-eating pollinators. It benefits from this mimicry by being pollinated. As for the pollinator? It’s been duped into responding to the deceptive signal because that chemical scent mostly means a meal or site for laying eggs is close by.

There’s also auditory mimicry, for which the superb lyrebird is the master dj. I saw a talk on these magnificent birds yesterday, and I learned that they can incorporate into their calls a remix of over a dozen different songbirds, not to mention opossums!

In the cuckoo-host system I mentioned in a previous post, the colorful egg mimics of the cuckoos are a form of visual mimicry.

Here’s another:

Planthopper, Siphanta acuta, mimics a leaf (Wiki Commons)

Got predators? Not a problem – just mimic a leaf to avoid being perceived and subsequently eaten!

Sure, plant-mimicking animals seem silly (albeit effective), but what happens when the tables are turned?

Ophrys speculum, the Mirror Bee Orchid; photo taken in Portugal, Algarve, in March 2004 by Carsten Niehaus (Wiki Commons)

This orchid mimics a female bee, which is not so silly if you’re a male bee. He’ll think he’s landed on the sexiest female on the flower patch, only to discover that not only is she not a female, she’s not even an animal!

Never you mind though. The male bee will be duped into mating with it. While this kinky, plant-animal mating will go nowhere for the bee, it will serve as a way for the orchid to be able to mate (not with the bee, but by spreading its pollen when the bee moves to the next deceptive orchid).

There are countless other cool examples of mimicry. It abounds in nature. The question for you to think about is this: what have you mistaken lately?