LSM1303 Animal Behaviour

Listed as one of the top 10 craziest animal behaviours, the courtship ritual of the penguin certainly spells ‘commitment’ and ‘dedication’. Famously noted for being monogamous, male  penguins mate with a single partner and expresses its intentions by rolling a stone between the feet of the female penguin. And the male certainly goes through a long and arduous trek to find its partner. Every male penguin has to choose a single female amongst a colony of more than a million. Used for building walls around penguin nests, the presentation of the stone at the female penguin’s feet certainly makes a suitable symbol for lifetime union. 

Other views however, provide an alternative perspective towards the seemly dedicated relationships between penguins. In fact these relationships could be seen to be materialistic. Such ‘consummations’ of marriages are also cost-benefit exchanges- the stone in exchange for pro-creation of more offspring. These stones actually help prevent the eggs from freezing in the cold weather, so females do hold a vested interest in collecting such stones. 

In fact they value these stones so much that female penguins are even reported to have ’stolen’ these stones from other nests or other ‘unattached’ males. Surprisingly still, these unassuming males don’t seem to mind that at all. If the conditions are right, some of these ‘prostitute’ female penguins even get to mate with these males. 

Although such reports of ‘prostitute’ penguins are low, researchers are still baffled at this strange behaviour. It certainly challenges the traditional thought on classical theories on natural selection. Males were previously thought to challenge with other males over the female. This however proves that females do have a choice in choosing their mate in order to secure healthy offspring. At least they find their own ways to do so here at least.

Researchers suggest that such female ‘extra-marital affairs’ could result when a female is scouting for potential future partners in a case where their current partner is ill or dying. Mating with more males also allows more competition between male sperms inside her for the eventual fittest chick.

Whatever the case, penguin relationships are certainly not as idealistic nor monogamous as previously thought. We see here that these penguins do steer from the conventional in response to situations in order for self-benefit. 

See also: 

‘Pick up a Penguin’: http://news.bbc.co.uk/2/hi/asia-pacific/60302.stm

‘Mating in a Material World’: http://www.nwf.org/nationalwildlife/article.cfm?issueID=73&articleID=1039

‘10 Craziest Animal Behaviour’: http://www.2spare.com/item_55014.aspx

Yes, yes I am aware that the above expression is desperately corny and am obviously raising goosebumps and prompting gags. Yet, it must be the most appropriate summary of how female iridescent Heliconius butterflies find mating partners and possibly love! Recent research has shown that visual cues used by female Heliconius butterflies as mating signals, are made possible by polarized light. Polarized light refers to light that is reflected from shiny surfaces. White light is diffused off “20 layers of transparent scales” on the butterfly’s wings, creating the “brilliant blue” color and what we call “iridescence” of its wings. The sheer beauty of this phenomenon is so striking that passengers in planes flying over forests have picked up on the extraordinary scene.

An experiment was carried out by Sweeney who attempted to create the mating of male and female butterflies, in environments that vary in the presence of depolarizing light filters. She found out that when polarized light was created (in the absence of depolarized filters), iridescent males were more likely to approach iridescent females. Of course, the fundamental physical properties of the butterfly wings would affect such a process. Not all butterfly wings are able to create polarized light and thus, iridescence after reaction to sheer light.

heliconius butterflies mating

It might be interesting to explore the dimensions of the aged dichotomy of nature and nurture. At least from this phenomenon, we can see that nature holds certain reins but nurture and the opportunities the external environment provides to allow one to uncover natural gifts are also of importance. The Heliconius butterflies definitely cannot flaunt their shimmering hues cotteqishly in a low- white light context. As the journal articulates, “The color of … living creatures is determined by the wavelength-dependent interaction of incident light with the object.”

Butterfly wings are coated with a layer of scales which are systematically and elaborately patterned. One can get an idea of how highly intricate the structure of butterfly wings is from the extract below, taken from my choice of scientific journal:

“The upper surface of the scales bears longitudinal ridges roofed with overlapping lamellae, which covers a series of folds, perpendicular to the lamellae, the microribs. The longitudinal ridges are connected by crossribs, and together they frame so-called windows to the scale interior”.

In fact, such a physical structure of butterfly wings is highly flexible and can create a whole spectrum of possible iridescence and delightful colour, depending on the texture and quantity of light available. Isn’t it a wonder how Heliconius butterflies with their astounding colours are also known aptly as passion- vine butterflies?

Reference 

• Smithsonian Institution (2003, May 1). Butterflies Use Polarized Light To Attract Mates. ScienceDaily. Retrieved April 15, 2009, from http://www.sciencedaily.com­ /releases/2003/05/030501080033.htm.

   

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  D. G. Stavenga, S. Stowe, K. Siebke, J. Zeil and K. Arikawa, 2004. Butterfly Wing Colours: Scale Beads Make White Pierid Wings Brighter. Proceedings: Biological Sciences, vol. 271 (1548):1577-1584.  

• “Melpomene mating” by Chris Jiggins. Heliconius Homepage. http://heliconius.zoo.cam.ac.uk/heliconius/2008/129/, 24 July 2008. 
   

   

Lone Nazca booby

Just as divorce and separation takes place amongst humans, I was wondering if the phenomenon of divorce too applied to the animal kingdom.  Do animals readily divorce their mates?

Well, guess what. They do!

At least, according to:

David Anderson and Terri Maness of Wake Forest University in North Carolina University, the Nazca boobies of the Galapagos Island certainly do!

First and foremost, the Nazca boobies are long-living birds in the Galapagos Island. Until recently, they were treated as a subspecies of the Masked Bobbies. It has now been recognized and confirmed that the Nazca boobies are a separate species. The Nazca Booby can be idenitified by its reddish-pink to orange bill and it has white central recrtices. They feed primarily on fish and they come ashore to nest or roost. These sea-birds are also particularly known because they engage in habitual siblicide.  This means that the older chick, according to David Anderson in Live Science, “unconditionally attacks and ejects the younger form the nest within days of hatching.”

While that is itself, an interesting study, the focus of this entry is on the birds’ sexual behaviour. Previously, the question that I had in mind was whether or not animals engaged in deliberate acts of divorce. Indeed, according to the fieldwork research of Anderson and Maness, there was evidence of female Nazca boobies abandoning their previous partnerships in a bid to search for other males.  In some cases, the female even appeared to “cooperate with a male intruder, causing her former partner to leave the test.”   The males that were turned out from the nest would sometimes put up aggression against the incoming male and even at the female, although most of the time, it was really the females that were more aggressive towards their former partners. Ah-Ha, so it was the females and not the males, that were the real instigators of divorce. In their research, 72.9% of divorces were female-driven. ( At this point, although the comparison may put the boobies in somewhat a derogative light, ssome of us may be compelled, against our better judgement, to compare the behaviour of these females to the instances of lust, betrayal and sexual affairs that had characterized the lives of some femme fatale personalities in History. ) In addition, the female sometimes took off by abandoning her former mate to join a new mate at another nest site.

Saying hello?

While their behaviour may seem very startling, Anderson and Maness conclude that there is a very logical explanation in such an act.  They found that females have a perfectly good reason to “abandon ship” and search for new males because “an initial increase in reproductive output correlated with pair bond length, but after a period of time together, the reproductive success of the pair declined”. In other words, with divorce, there was an overall increase in producing a young, as opposed to the that of a long partnership where no divorce has occurred.  To quote some figures, 14 of 19 divorces noted by Anderson et al were mover females.  Interestingly, 6 of these 14 fledged a chick the following year.  The reproductive success of a female was generally higher than before prior to divorce.  Wouldn’t it be interesting if female humans employed a similar excuse when cheating on their partners?!

Nazca boobies preening each other

Interestingly, in another article by Anderson on Nazca boobies, he found that non-breeding males who were divorced by the females or that were younger than older breeding males, demonstrated sexual interest in chicks. These males were categorized as “unemployed” and they showed aggression against young chicks by scratching them.  Is this another version of a pedophile? Perhaps so.   These young chicks often died young as a result of the scratches inflicted from the attacks by the “pedophiles”.

While reading up on these Nazca boobies, I also realized that this behaviour of divorcing one’s mates was not exclusive to these sea-birds. Oystercatches also divorced their mates. Just like the boobies, the female oystercatchers were also more likely to divorce mates as compared to males. However, compared to the Nazca boobies, the reproductive success of new pairs of oystercatches were very much lower to the old breeding pairs.  It has been surmised also that any increase in reproductive success was due more to the increase in breeding age of the female. Mate change depended largely on competiton for good mates and resources. Hence, while divorce may be a recurrent behaviour amongst different species, the reasons underlying such an act differ from animal to animal.

So, while the female Nazca booby may seem pretty “fickle” in human terms to change partners and invoke divorce, on the grounds that such an act increased reproductive success, WHY NOT?

Here is a video of the boobies courting and attending to their chicks! Have a look!

Video of Nazca boobies

References:

Terri J . Maness & David J . Anderson, 1993. Mate rotation by female choice and coercive divorce in Nazca boobies, Sula granti. Journal of Animal Behaviour, 76(4):1199-1217

Ens, B. J., Safriel, U. N. & Harris, M. P. 1993. Divorce in the long lived and monogamous oystercatcher, Haematopus ostralegus: incompatibility or choosing the better option? Animal Behaviour, 45,1199-1217

David Anderson et al. Non-breeding Nazca boobies. 2004. http://www.wfu.edu/~djanders/labweb/reprints/Anderson%20et%20al%20NAV%202004.pdf (accessed April 15, 2009).

Female Boobies Dump the Best Males by Robert Roy Britt. LiveScience, 13 June 2007.

Wilson, Angus. Annotated List of the Seabirds of the World . 2002. http://www.oceanwanderers.com/NazcaBooby.html (accessed April 15, 2009).

Taylor, Christopher. Nazca Booby Pictures – Photography- Bird . 2006. http://www.kiwifoto.com/galleries/birds/nazca_booby/ (accessed April 14, 2009).

YOUTUBE. YOUTUBE – Nazca Boobies. February 26, 2007. http://www.youtube.com/watch?v=dfrrVheajdU (accessed April 14, 2009).

Praying Mantis, Mating

IS sex always a good thing? Unfortunately Male Praying Mantis says NO. This is because Female Praying Mantis consume the head (and sometimes the rest) of her mate during copulation. Yes i know what you are thinking. Even nymphomaniacs squirm at this thought.

Praying Mantis have a carnivorous appetite that include moths, crickets, flies, grasshoppers and other insects as well. These insects are also prone to eating others of their own kind. The most famous example of this is the notorious mating behavior of the adult female, who sometimes eats her mate just after-sometimes during- mating.

Yet this does stop the males from courtship and mating. The most common courtship of the males would be when he approaches the female frontally, slowing his speed as he nears. The second most common courtship is when the male approaches the female from behind, speeding up as he nears.

But research has challenged this notion of sexual cannibalism among the praying mantis. Eckehard Liske and W. Jackson Davis made videotapes of sex lives of 30 pairs of praying mantises. They discovered that the none of the 30 male mantises had their heads eaten during the mating process. Although female mantises sometimes ate their mates, the deadly act by no means occurred in every case. They observed that the behavior is influenced by captivity: Female mantises became unusually became aggressive thanks to the unusual laboratory conditions and feeding times observed by the researchers.

Yes, the female praying mantis does sometimes eat the male. In fact, it is the male mantises who actually want to offer themselves as food. There is a simple, yet, rational explanation behind it. That is, there is no point in having sex if she is going to die of starvation before she can lay eggs and pass the father’s genes onto the next generation. Some might call this True love.

Now, Guys, how far are you willing to go to sacrifice your lives for true love?

Reference:

“The Female Praying Mantis: Sexual Predator or Misunderstood” by Doughty Michele, Biology 103, 2002 First Paper, http://serendip.brynmawr.edu/exchange/node/1801

Praying Mantis by National Geographic http://animals.nationalgeographic.com/animals/bugs/praying-mantis.html

Liske, E.; Davis, W.J.(1984) Sexual behaviour of the Chinese praying mantis v. 32(3): 916-918

An Adelie penguin choosing its pebbles

While prostitution has been around for many years, it was thought to be something that humans engage in. That does not seem to be the case. Adelie Penguins, a species found along the coasts of Antartica, were discovered to engage in extra-pair copulations, sex with other penguins other than their partners. This is rare as penguins are known to be monogamous.

So how does prostitution happen in the penguin world? The female Adelie penguin will look for a single male Adelie penguin. The female will offer herself by showing courtship moves and then lying prone for the male to mount her. This action tricks the single male penguin into thinking that this female could be a possible partner and the male penguin will copulate with the female penguin. After copulation, the female will then be able to take a pebble from the single male’s nest. Permission is needed in order for the female to get the pebble as the male usually attacks other penguins who tries to steal his pebbles. After getting a pebble, the female would then return to her ‘husband’ with a new found pebble.

The next burning question in everybody’s mind would be, why pebbles? Why don’t the penguins exchange sexual favours for something more practical, like fishes? This is because pebbles are very precious to female penguins as they are the main materials to build a large good nest. Because the Adelie penguins live  near the coasts, flood waters from melted ice during spring might wash away the egg if the nest was not large enough. Larger nests built with enough pebbles will keep the egg in place and also elevate the egg so that it would not be immersed in floodwaters, which might stop it from hatching . Because pebbles are so precious to these penguins, thefts of pebbles often happen and agression will occur when pebble stealing is involved. Thus, in order to be able to build decent nests without being attacked, the females , instead of stealing pebbles, exchange sexual favours from sexually frustrated single males in exchange for pebbles.

While some behaviorist speculate that this behaviour could be something the penguins are doing in order to test for a future change in mates, but there are not enough evidence to support this claims yet. Currently, what is known is the exchange for pebbles using sex. Interestingly, beneath all this promiscuity, female Adelie penguins can still be considered monogamous. After all, all this exchange of sexual favours was in exchange of materials for a safer nest in order to increase reproductive success. Let’s salute the female Adelie penguins for their selfless behavior for their families!

Sources:

Female Adélie Penguins Acquire Nest Material from Extrapair Males after Engaging in Extrapair Copulations
F. M. Hunter and L. S. Davis
The Auk, Vol. 115, No. 2 (Apr., 1998), pp. 526-528

Mating in a Material World
Maggie McKee
URL: http://www.nwf.org/nationalwildlife/article.cfm?issueID=73&articleID=1039

Pick a Penguin
URL: http://news.bbc.co.uk/2/hi/asia-pacific/60302.stm

“Wild male chimps that share meat with females double their chances of having sex with those females, a new study says” nationalgeographic.com

www.flickr.com

“Steps to Win a Girl’s Heart:

-          Prove that you really love her

-          Most girls like guys with confidence and courage

-          Care for her    “ wikiHow.com

See any similarities?

This goes to show that guys engaging in courtship for sex is purely an evolutionary trait passed down from our ape ancestors. So don’t blame them for being sexually rather than emotionally driven when it comes to love, blame it on our genes.

On a more serious note, this article does provide insights into aspects of chimpanzee behavior, in particular, the idea that hunting has an additional sexual motivation.

Meat is not only nutritionally important as a protein source for chimps, it is socially important as well. Meat is highly prized in their diet, and most of the time the males do the hunting. Furthermore, the killer usually has full rights to the meat. In this way, being able to kill and share meat with a female gives an indication of social stature and ability in the male. Since the social structure of chimps is based on hierarchy, males with more meat to share are more dominant when it comes to matings.

However, a study conducted by Mitani and Watts (2001) on chimps at Ngogo in Kibale National Park does not support the hypothesis that male chimps hunt solely to obtain meat that they swap for matings. It shows that the presence of oestrous females did not predict the tendency for chimps to hunt. Although several factors are likely to affect chimpanzee hunting decisions and meat sharing, the results indicate that primary causes will not be found through invoking simple reproductive considerations.

Reference

John C. Mitani and David P. Watts (2001). “Why chimpanzees hunt and share meat?” Animal Behaviour 61 pp. 915-924.

Toad ‘riding’ on a carp

Ever seen a carp piggy- backing a toad? This is it. I was flipping through the newspaper and was drawn to a really interesting photograph that featured a toad ‘riding’ on a carp. However, as I read on, I found out that the poor carp was eventually ‘sexually abused’ to death by the toad!

This is the link to the article:

http://news.wenxuecity.com/messages/200902/news-gb2312-788428.html?SubID=news&MsgID=788428&c_lang=big5

As link is from an online Chinese newspaper agency website, I have translated it as below:

It was the time of the year for the breeding season of toad starting from September to March. In a farm of Taiwan, approximately ten toads gathered at the pond and began their harassment of the inhabitants there. This incident took place on last year’s December where two toads of 6- 7 cm long managed to grasp hold of the heads of two carps respectively. Despite the struggle of the carps to get free, their efforts were futile. The relentless ‘clinging’ of the toads on carps lasted for 4 days and finally ended with the tragic death of the carps. According to biologist Dr Qu, the death of the carps could be due to the possibility that the carps had swallowed the venom of the toads and such an act may be a display of mating behavior of the toads which coincided with the concurrent breeding season of the toads. Others suggested the possibility that the death could be caused by extreme exertion of force on the carps or infection.

Wood frogs in amplexus

Now viewing from a more scientific perception, the toad’s display of this special kind of embrace is referred to as amplexus. As you can see from the photograph above, the smaller sized male is always on top of the female during mating. The male will grasp the female’s trunk with his forelimbs and external fertilization will occur outside the female’s body. During amplexus, the female discharges eggs into the water while the male will fertilize them by shedding sperms over the eggs. By comparing both photographs, it is clear that the toad had mistaken the carp as his mate!

This is an interesting video which I found for frogs in amplexus. Your may wish to have a look.

 Attenborough: Golden Frog: Fighting & Mating – Life in Cold Blood – BBC wildlife

 Appalled and awed by this carelessness of the toad? Well, yes I am. AND this is not the only ‘spouse mistaking’ incident that has ever occurred. There are also other instances where this happened on other toads as well (picture below). In fact, according to a study conducted by Dr. Susumu Ishii in Japan, it was found that when adult male toads find ANY pliable object as large as an adult toad during the breeding season, they will mount and try to clasp it. Sounds ‘despo’? I think so. Even if the object they have mounted does not respond, they will persist and keep holding on for hours or even for days. This was the tragedy that befell on the poor carp. However, if the object is a ‘mentally prepared’ female for mating, amplexus will proceed under normal circumstances. On the other hand, if the object mounted is a ‘mentally unprepared’ female for mating, she will send vibrational signals through her body. Upon receipt of the vibrations, the clasping male will then loosen his grip and back off.

The link to the article on the study conducted by Dr. Susumu Ishii is as follows: http://www.backyardnature.net/frogsex.htm

Toad clasping a Green Frog

I really felt sorry for the two dead carps. Looks like the toad have to do some soul- searching on his ‘despo’ character or should at least wear a pair of spectacles to help him spot his right ‘bride’ the next time. If not more may fall victim and suffer under his ‘love’ or I should say ‘forbidden love’.

Reference

1. Apple Daily (Taiwan), (7 February 2009), retrieved on 14 March 2009. http://news.wenxuecity.com/messages/200902/news-gb2312-788428.html?SubID=news&MsgID=788428&c_lang=big5
2. ‘Frog Reproduction’, by Conrad Jim, 14 March 2009. http://www.backyardnature.net/frogsex.htm
3. ‘Wood Frog’, by Rana Sylvatica, 17 March 2009. http://www.uri.edu/cels/nrs/paton/LH_wood_frog.html
4. Attenborough: Golden Frog: Fighting & Mating – Life in Cold Blood – BBC wildlife, 17 March 2009. http://www.youtube.com/watch?v=A1FWQvaBoRg

Source: National Geographic http://animals.nationalgeographic.com/animals/mammals/humpback-whale.html

Do you know that only the male humpback whales sing? Male humpbacks often sing when a female is present. Traditional explanation has it that male humpbacks sing to court the females and females are especially attracted to songs that are currently in trend. Songs which are out-of-date will fail to get the ladies’ attention and the males will need to constantly update themselves with new songs in this game of love according to cognitive neuroscientist Eduardo Mercado III of the State University of New York in Buffalo.

Joshua Smith, a doctoral student at the University of Queensland in St. Lucia, Australia who has spent three migration seasons collecting the songs of humpback whales supported this traditional explanation of why male humpbacks sing. According to Smith, it is during the migration periods that male humpbacks emit verbal communication that sound like barks, chirps, and moans. Smith believes that male humpbacks use songs to court the females and the way the males structure their songs (for instance, higher or lower frequencies) reflect the traits and characteristics of the male.

Interestingly, songs sung by the male humpbacks not only attract the females but the other males as well. Scientists said that this may be a strategy used by the males to locate a female as another singing male may have a female in his presence. On the other hand, Jim Darling, a Whale Trust researcher who has been studying the male humpbacks song for 25 years suggests that male humpbacks may sing to recruit male allies to help locate a female and act as the primary escort should the female attempt to bolt off.

However, there are other interesting arguments and findings that do not support the traditional explanation of male humpbacks singing to get the girls. Eduardo Mercado of the State University of New York in Buffalo argues that male humpbacks sing not to court the ladies but to navigate new locales. Mercado suggests that male humpbacks sing to locate the others as it can be challenging to rely on just listening in the complex underwater world. The males make use of singing to determine the distance the sound has travelled. Though there is no direct evidence that support his argument, Hawaii Institute of Marine Biology bioacoustician Whitlow Au agrees that Mercado’s idea is “interesting and reasonable”.

Thus, whether or not male humpbacks sing to get the girls is still a question mark. While traditional explanation has it that they sing to attract the females, there is still no direct evidence that support the males sing to court the ladies. Further researches and studies need to be done in order to ascertain if humpback songs are used for courtship

References

Stephanie Peatling. (September 15, 2006). Humpback Whale Calls Are Love Songs, Biologist Suggests. Retrieved April, 13 2009 from http://news.nationalgeographic.com/news/2006/09/060915-humpback-whales.html

Douglas H. Chadwick. (January 2007). What Are They Doing Down There. Retrieved April, 13 2009 from http://ngm.nationalgeographic.com/2007/01/humpback-whales/chadwick-text/6

Charles Q. Choi. (December 6, 2007). Why Whales Sing. Retrieved April, 13 2009 from http://www.livescience.com/animals/071206-sound-whales.html

Darling, J. D., & Berube, M. (2001) Interaction of singing humpback whales with other males. Marine Mammal Science, 17 (3), 570-584.

Mosquitoes have their own ways of attracting a compatible mate. In one species, the Aedes aegypti—popularly known as the culprit of Dengue Fever–mates are capable of harmonizing, performing love duets, by subtly adjusting their buzz frequencies using their wings.

The study done by Ronald Hoy of Cornell University in New York and his associates recorded the wing-flapping frequencies of mosquito pairs and discovered that in approximately 70 percent of the pairs tested, both mosquitoes altered their wing-flapping speeds to synchronize their frequencies to a love duet of approximately 1,200 Hertz.

In general, the male’s wing-beat frequencies ranged between 550 to 650 Hertz while the female’s ranged between 350 to 450 Hertz. And how this works is that when a male approaches a female, she will flap a tune and wait for him to respond in harmony. If the duet converges at a frequency of 1,200 Hertz, she will mate with him.

The team of researchers deems such a form of sexual selection as the female’s way of measuring a male’s fitness before mating. As commented by Hoy, “We think what the females are doing is saying, “Can you match this harmonic, and how fast does it take you to match it?”

This phenomenon is not new, as seen from an earlier study in 2006, which revealed that another mosquito species, Toxorhynchites brevipalpis, also made use of alteration in wing-beat frequencies to match each other’s tones in search of the opposite sex (Gibson& Russell, 2006).

For coverage of the full article, please view it from: http://www.livescience.com/animals/090108-mosquito-love-songs.html

For audio version of mosquitoes’ harmonics, please view it from:

Download

References:

Jenna Bryner. (08 January 2009). Bug Love: Mosquitoes Sing Duet in Harmony. LiveScience. Retrieved on April 12, 2009 from http://www.livescience.com/animals/090108-mosquito-love-songs.html

Cator, L.J., Arthur, B.J., Harrington, L.C. &, Hoy, R.R.(2008). Harmonic convergence in the love songs of the Dengue Vector Mosquito. Science Express, 323(5917), 1077-1079

Gibson, G & Russell,I.(2006). Sexual Recognition in Mosquitoes. Current Biology, 16(13), 1311-1316

Video extracted from:

http://www.sciencemag.org/content/vol0/issue2009/images/data/1166541/DC1/1166541s1.mov

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Red-sided Garter Snakes live in Canada and the Northwestern United States. Not only are they small and poisonous, they are definitely the naughtiest snakes around. During mating, more than 20 000 of them slither together in a den, bringing orgy to another level! In that pile of copulating mass, there can be 100 males courting one single female!

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However, bad news for the males – only one single male snake can successfully court and impregnate the female. This is hardly depressing for the male snakes as they become “the transvestite serpents” and court other males instead!

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The males which are courted are termed as “she-males”. It is not just kinkiness at play here. Instead, it is female mimicry. These she-males are biologically male but received lipids when they have “rubbed” against females. This makes the he-males confused. But being driven by instincts, once female pheromones are detected, the he-males court. Even if the she-males are of their own kind.

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Contrary to what you may think, the she-males are not grappling with issues of identity and sexual orientation. They have other motivations in mind. Imitating the females can distract the he-males in the mating ball from the one female snake. With this sexual interference, the she-males can get the best position with the female snake; which in turn increases their success in courting the females. Sneaky indeed, but you have to admit it is very clever.

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References

“10 Craziest Animal Behaviour”, by 2Spare. 2Spare.com, 06 May 2006

Crew, R. T., 1986. Pheromone mimicry in garter snakes, Chemical Signals in Vertebrates 4, 279-283.

R. Shine, P. H..1999. The transvestite serpent: why do male garter snakes court (some), Journal of Animal Behaviour, 349 – 352.

R. Shine, M. J. Elphick, P. S. Harlow, I. T. Moore, M. P. LeMaster, and R. T. Mason, 2001.Movements, Mating, and Dispersal of Red-sided Gartersnakes (Thamnophis sirtails parietails)  from a Communal Den in  Manitoba., 82-91.

Pictures taken from

Allposters.com

Howstuffworks.com