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Uploaded:2017-02-19
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Humans are not the only animal that use cheats to make things easier. Some of the animals and plants have weird but very clever cheating skills to survive in their environment, too.


Hosted by: Michael Aranda

Learn more about Brood Parasitism: https://youtu.be/HpIhSLXQ5oc

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Sources:
https://www.britannica.com/science/nectar
http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=634796
http://www.jstor.org/stable/4163964
http://www.jstor.org/stable/3450570
http://zootis.zoologi.su.se/research/leimar/fulltext/Bshary_etal2008.pdf
http://www.iucnredlist.org/details/187396/0
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1809949/pdf/14667394.pdf
http://www.nature.com/scitable/knowledge/library/the-ecology-of-avian-brood-parasitism-14724491
https://www.allaboutbirds.org/guide/Brown-headed_Cowbird/
http://www.sciencedirect.com/science/article/pii/S0003347212004010
http://www.pnas.org/content/94/18/9723.full
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC411366/pdf/pnas00014-0377.pdf
http://www.amjbot.org/content/92/8/1342.full

Image Sources:
https://commons.wikimedia.org/wiki/File:Slaty_Flowerpiercer_RWD5.jpg
https://commons.wikimedia.org/wiki/File:Cleaning_station_konan.jpg
https://commons.wikimedia.org/wiki/File:Brown-headed_Cowbird_(14115656207).jpg
https://commons.wikimedia.org/wiki/File:Eastern_Phoebe-nest-Brown-headed-Cowbird-egg.jpg
https://commons.wikimedia.org/wiki/File:Savannah_Sparrow,_Passerculus_sandwichensis,_and_Brown_headed_Cowbird,_Molothrus_ater,_nest_eggs_parasitism_closeup.jpg
https://commons.wikimedia.org/wiki/File:Hyla_arborea_(Marek_Szczepanek).jpg
https://en.wikipedia.org/wiki/Photuris#/media/File:Photuris_lucicrescens.jpg
https://www.flickr.com/photos/52450054@N04/31759434616/in/photolist-J8hPju-dfTB3w-xZvStE-QotpqU-G9gb3b-u2mifa
https://commons.wikimedia.org/wiki/Photinus#/media/File:Photinus_sp.jpg
https://www.flickr.com/photos/mwhitehead/12662876285/in/photolist-khYxXc-dVU7gy-dVU5dW-dVNvLp-dVU55N Photo by Michael Whitehead
https://www.flickr.com/photos/129808517@N08/16616316055/in/photolist-umSs7P-rjjXRR-dSPtf3-qnydRH-8dpRY7-2PdyE4-2Pdytp-CKkLmY-5WgS3U-QHs9sw-umSrEX-viH4Ck Photo by alice nicolson

 Introduction (0:00)


Michael: Animals have all sorts of bizarre adaptations to get stuff done, whether that's finding enough to eat, wooing a mate, or raising their offspring. But some species have figured out shortcuts to make things a little easier for themselves. These five animals and one plant take advantage of other organisms, co-opting mating rituals and interspecies partnerships for their own ends. In other words, they cheat.

 The Slaty Flowerpiercer (0:30)


Plants can't just sprout legs to move around and look for mates -they're rooted in place. So that means their ability to reproduce usually depends on luring in pollinators, which, as you might've guessed, pick up pollen from one flower on one plant and deposit it in a flower on another. Flowers have a lot of tricks to attract these pollinators, like bright colors, sweet smells, and a sugary liquid called nectar. Insects, hummingbirds, and even bats, stick their faces into flowers to drink up some sweet, sweet nectar, and get pollen all over themselves in the process.

But some animals, known as nectar robbers, have developed sneaky tactics that let them get a reward without actually helping the plant. One such thief is the slaty flowerpiercer, a small bird from Central America that perches on a plant's stem and uses its hooked beak to make a hole in the base of a flower. Then, it extract the nectar with its tongue, never touching the flower's anthers, where the pollen is.

This burglary works on all kinds of flowers, giving the birds an extra advantage: flexibility. Pollinators usually have to specialize to nab nectar, with a beak or probosces that fit certain flower shapes and sizes. Flowerpiercers, though, can puncture any flower they want, to get the tastiest food.

So the plants face a complicated evolutionary dilemma: On one hand, they need to defend themselves against nectar robber, like by diluting their nectar to make it less appealing. But their nectar needs to be sweet enough so pollinators, like hummingbirds, don't lose interest.  For now, at least, flowerpiercers' breaking-and-entering M.O. keeps them well-fed in the tropical forests of Costa Rica and Panama. 

 Cleaner Wrasse (1:49)


For slaty flowerpiercers, the reward for cheating is a sweet sweet nectar. For a fish called the cleaner wrasse, it's sweet sweet mucus. Cleaner wrasse are small, striped fish found in coral reefs. They make their living by providing a service for the reef's other residents.

Fish come to spots known as cleaning stations, and let the wrasse pick off and eat parasites on their skin. The cleaner wrasse gets and easy meal, and the other fish gets its pesky parasites removed. But some cleaner wrasse also cheat their customers. In addition to munching on parasitic crustaceans, wrasse will sneak bites of protective mucus coating that covers their customers' scales.

In lab experiments where cleaner wrasse were given a choice between plates of parrotfish mucus and plates of parasites, the wrasse actually preferred the nutritious mucus. In the wild, though, fish don't visit the cleaning stations of wrasse who cheat frequently, so wrasse have an incentive to behave themselves to keep the easy meals coming.

Cleaner wrasse also tend to work in pairs, and a cheater will often be punished by its partner, who doesn't want to lose all of its clients to this bad behavior. If one partner sneaks a bite of mucus and the customer fish storms away, the other partner will aggressively chase the cheater, which is fish for "hey, cut that out." So, if you're a fish on a reef looking for a good delousing, steer clear of cleaner wrasse swimming solo. 

 Brown-Headed Cowbird (2:57)


Passing your genes onto another generation takes a lot of work. You have to feed your offspring, shelter them and protect them from predators. But some crafty birds have figured out a way around the labors of parenthood. Why spend weeks raising your chicks when you can just dump your eggs in another brid's nest and let them do it for you?

This is called brood parasitism, and the most infamous cheating birds in North America is the brown-headed cowbird. Because she doesn't have to spend any time or energy raising her young, a female cowbird can produce a lot of eggs - as many as three dozen in a single summer. She lays each of those eggs in other songbird nests, sneaking them in at just the right time so that they'll be accepted by the host and incubated.

Once a cowbird chick hatches, it will sometimes act like a little assassin and roll the other eggs out of the nest, eliminating competition for its foster parents' attention. And even if that doesn't happen, cowbird chicks tend to grow faster than those of their host species. That lets them bully the smaller nest mates out of their share of the food. So, watch out step-brothers and sisters.

Songbird chicks unlucky enough to have a cowbird foster sibling rarely survive long enough to leave the nest. This situation has created an evolutionary arms race. If a host bird realizes it has a brood parasite egg in its nest, it'll dump the intruder before it hatches. So many parasitic birds have evolved to produce eggs that look almost exactly like those of their hosts. In turn, hosts have gotten better and better at recognizing the imposter eggs for what they are.

But brown-headed cowbird may have an unfair advantage in this fight, thanks to humans. Cowbirds like brushy habitat and woodland edges, which crop up as we bulldoze forests to make room for more houses. For songbirds already facing habitat loss it's a one-two punch - even if they can find a decent spot to nest, they might find themselves raising a monster. 

 Satellite Frog (4:36)


A lot of male frogs and toads use sound to attract mates. Every spring, they gather in ponds and marshes at night and sing their mating calls. The ladies listen to their options and go for the males with the longest, loudest, or fastest calls. It's a good system, because great calls take a lot of effort to produce. So males who manage it are probably tough and well-fed, which might give their offspring a genetic edge.

But in some frog species, a few males cheat and use a strategy that lets them find a mate without making a single croak. These satellite males will wait quietly near a male whose call is top-notch. Then, when a female approaches to check out the really studly male, a sneaky satellite male swoops in an mates with her instead of the actual caller.

Some male frogs switch back and forth between calling and being a satellite, depending on who else is in the pond. Experiments with European tree frogs, for example, found that males were more likely to resort to satellite tactics if they were small, which probably made it harder to make really attractive calls. But these frogs also listened to the calls around them, and if they decided that the competition wasn't so hot either, they'd start croaking again too.

 Femme Fatale Fireflies (5:34)


For another case of mating going wrong, at least for some participants, take a look at fireflies. Fireflies use specific patterns of flashes to find mates. Each species has its own unique code, which helps prevent accidental interspecies hook-ups. But one genus of fireflies co-opted this system for a more nefarious purpose.

Female Photuris fireflies mimic the flashes of females from another genus, the Photinus fireflies. When the femme fatales attract these other guys, they kill and eat them.

But there’s more to this than just an easy meal. See, their victims have special chemicals in their blood called lucibufagins, but we’ll just call them LBGs. These compounds are steroids, similar to toxins found in some species of toad. When these fireflies feel threatened by predators like spiders and birds, they excrete droplets of LBG-filled blood, called “reflex bleeding,” to say, “I’m gross! Don’t eat me!” And femme fatale fireflies can’t produce these defensive chemicals themselves – they have to eat their more chemically-gifted cousins to get this added protection.

A group of researchers from Cornell University figured all this out using a clever series of experiments. They captured both types of fireflies and measured the LBG levels in femme fatale Photuris fireflies before and after feeding them Photinus males.

They also tried feeding different fireflies to jumping spiders, confirming that the spiders wouldn’t eat insects with high levels of LBGs in their blood. So black widows aren’t the only dangerous ladies out there, Photuris fireflies give them a run for their money.

 Empty orchids (6:57)


Now, nature isn’t only full of animals that cheat. Plants do it, too. The slaty flowerpiercer may take advantage of flowers for their nectar, but an orchid in southern Africa has flipped the script, tricking insects into pollinating it while offering nothing in return.

Remember how some insects specialize in pollinating a specific plant? That’s thanks to coevolution. Over time, the plant gets really good at attracting and rewarding a specific species of insect, and the insect gets really good at pollinating that kind of plant. That’s the case for a plant in southern Africa called Z. microsiphon, which produces long, tube-shaped flowers.

It’s pollinated by a single species of fly with a very long proboscis that lets it reach deep into the narrow flower to sip its nectar. Both organisms benefit – the fly gets a meal, and the plant gets pollinated and can reproduce. But a second plant species is taking advantage of this partnership.

In some areas where Z. microsiphon lives, there’s a rare orchid that grows alongside it. The flowers of the orchid look suspiciously similar to Z. microsiphon’s – long, tube-shaped, pink and white. The orchid will even go so far as to mimic the slight variations in Z. microsiphon’s flowers to match its specific neighborhood.

But the flowers of the orchid are dry: there’s no nectar to be found. It’s all a deception – the orchid attracts the other flower’s pollinators without putting any resources into producing nectar. So if you’re one of those people who peeked when you were “it” during hide-and-seek, or you just can’t resist using cheat codes to skip levels in games... you might have a new excuse. You’re just the latest in a big group of cheaters in nature, who are all in it to win it – even at the expense of others.

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