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

You’d think mosquitoes are out to annoy you with their buzzing, but research shows that “the familiar buzz of flying mosquitoes is an important mating signal, with the fundamental frequency of the female’s flight tone signaling her presence” (Cator, Arthur, Harrington & Hoy, 8 Jan 2009).

Watch here! (Morgan, 8 Jan 2009)

For a long time, the buzzing of the mosquitoes was seen as an unintentional effect of their flapping wings. In addition, what sounded like a steady buzz to humans could range up to 2,000 hertz to the mosquitoes, exceeding their previously established hearing limit, whereby male mosquitoes could hear between 300-800Hz, while females were thought to be deaf.

However, this research has proven otherwise. With live Aedes aegypti mosquitoes tethered to the end of insect pins, tones made by both male and female mosquitoes were recorded to show that their fundamental tones – 400Hz for females and 600Hz for males – reached a synchronised note at 1,200Hz when brought within a few centimeters from each other, signifying a mating match.

According to Ron Hoy (in Bland, 8 Jan 2009), co-author of the study at Cornell University, “We think that females could use harmonic matching as a fitness measure for the males”. It begins with the female flying through the air and producing a complex sound including its fundamental tone and harmonics (multiples of the basic tone), which is an irresistable mating song to the males. However, the male must modulate his own sound to match the female’s, because only when she is satisfied with his love song will she mate with him.

Aedes aegypti is the mosquito that transmits diseases such as yellow fever and dengue fever, which has been exceptionally rampant in Singapore (National Environment Agency, 2009). By understanding their mating process, it may inspire better ideas to more effectively curb the breeding of these dangerous mosquitoes. Some of the ideas include creating sterile or genetically engineered males that cannot transmit dengue virus and tricking the females into mating with them, which will bear them no offspring or harmless ones (Morgan, 8 Jan 2009). In theory, the population of mosquitoes would then decline. However, there are still many obstacles to overcome, one such as the female’s ability to tell if a male has been altered, reducing their interest. Nevertheless, this research has opened up new areas to explore for the solution. As Professor Harrington, one of the co-authors of the study, rightly asserts (in Morgan, 8 Jan 2009), “If you eliminate the vector, you eliminate the disease.”

Now that the source of the problem has been determined, all we need is a solution.

Research study:

Cator, L. J., Arthur, B. J., Harrington, L. C. & Hoy, R. R., 8 Jan 2009. Harmonic Convergence in the Love Songs of the Dengue Vector Mosquito [On-line]. Science Magazine, 323 (5917): 1077 – 1079.

References:

National Environment Agency, 2009. Campaign Against Dengue. Accessed 14 April 2009.

“Mosquito Buzz Actually a Love Song,” by Eric Bland. Discovery News, 8 Jan 2009.

“Mosquitoes make sweet love music,” by James Morgan. BBC News, 8 Jan 2009.

“Love Song of the Dengue Vector Mosquito,” by Laura Sanders. Science News, 31 Jan 2009.

Ireton, R., 27 Jun 2007. “A Capital Offence.” Photo. Flickr.com Accessed 14 April 2009.

It is known that nonhuman primates are intelligent. However, what surprised me was that apes in this case orangutans, have the ability to make intelligent choices in the selection of mates. I always thought this only applied to humans. I knew animals make conscious choices but I thought the criteria were simple and basic.

The National Geographic article highlights the intelligence of female orangutans when it comes to the choice of a mate. The females are cunning and smart. Their criteria for a mate? Low aggression. They want to make sure their mate will not be aggressive to them if they do not follow what the male wishes especially in the area of mating. These female orangutans use tests to measure the male’s aggressiveness and in this case, by stealing the male’s food to see how he would react (Kaplan, 2009).

Female Orangutan with food

Source: http://www.flickr.com/photos/89211937@N00/210687592/

A study showed that female primates face sexual coercion from the males. Males find it costly in terms of time and energy to impress the female. Instead of wasting their energy, they use force. For orangutans, if the female is not in the mood to copulate, the male will overcome the female’s fierce resistance with violent restraint. These acts of violence may result in abortion, death of the female and disruption for estrous cycle. The study goes on to say that females are starting to find methods to gain control. With this control, they can choose to mate only during mid cycle (Slater, Rosenblatt, Milinski and Snowdon, 1993).

Thus, the National Geographic article shows us one of the ways that female orangutans have learned to overcome violent mates by testing them. If the males are overly aggressive, the females will choose not to associate with these males. This is interesting as it is very much like human behaviour. Females may manipulate and test males to see what his true nature is like.

It seems that we may not be so different from our nonhuman primate counterparts afterall.

Are we really that different?

Source: http://www.flickr.com/photos/diankarl/2282864243/

References

“Orangutan Females Steal Food to Test Potential Mates,” by Matt Kaplan. National Geographic, 2 April 2009.

Slater, P. J. B., Rosenblatt, J. S., Milinski, M & Snowdon, C. T, 1993. Male aggression and sexual coercion of females in nonhuman primates and other mammals: Evidence and theoretical implications. Advances in the Study of Behaviour, 22: 1-30.

We all know that reptilian romances, like most Hollywood romances (Hello Jennifer Aniston and Brad Pitt!), do not last beyond  a single mating season. In fact, reptiles have the tendency to seek out various mating partners within a season (Madsen et al. 1992; Olsson 1995; Olsson and Madsen 1995). This points to a polygynous mating system in which the male mates with several females.

But unlike the serial-womanisers in Hollywood (Yes, I’m talking to you, Jude Law) who simply cannot keep their hands to themselves, polygyny within the reptilian community is linked to territoriality. Bull (2000) states the following:

In many lizard species males are also more active in the mating season because they are defending a territory. Dominant males can hold territories that contain the home ranges of several females…leading to a territorial polygynous mating system.

However, do not even for one second think that the ladies are then relegated to the passive role of being a member of the men’s harem. Female reptiles like the sand lizard (Lacerta agilis) are also known to mate with several males within a mating season (Olson and Madsen, 1995). The act of mating with several males is to ensure enhanced genetic variabilty among their offspring which will greatly improve reproductive successes.

So…is there “true love” in the reptilian kingdom?

I caught an episode of David Attenborough’s Life in Cold Blood series which documents the monogamous relationship between two Shingleback lizards (Tiliqua rugosa). The documentary prompted a quick search online for the Shingleback lizard and I came across Michael Bull’s article titled “Monogamy in Lizards” (2000), which also led me to Bull et al.’s article titled “Social monogamy and extra-pair fertilization in an Australian lizard, Tiliqua rugosa” (1998).

Before moving on to the discussion proper, here are some unknown facts of the Shingleback lizard. Below is an excerpt from Wikipedia:

Tiliqua rugosa is a short tailed and slow moving species of blue-tongued skink found in Australia. It has a heavily armored body and can be found in various colors, ranging from dark brown to cream. It is often seen sunning itself on roadsides or other paved areas.The skink is known by a variety of common names such as bobtail, shingleback or stump-tailed skink, bogeyes, and the Pinecone or Australian sleepy lizard. They have short, wide stumpy tails that resemble their head, and may confuse predators. The tail also contains fat reserves, which are drawn upon during hibernation in winter. The shingleback skink is an omnivore that eat snails and plants and spends much of its time browsing through vegetation for food.

Shingleback lizard

Knowing that prosmicuity is widespread within the reptilian community, it is even more shocking to know that Shingleback lizards are generally monogamous. I say “generally” because Bull et al. (1998) found that there exist certain cases of extra-pair copulation i.e. it was found that 79% of the females were with the same male partners while the remaining were found to be with different male partners. Still, I doubt the anomalous cases take anything away from how amazingly monogamous these creatures are. Bull (2000) describes the following:

Adult males and females of this species form monogamous pairs for an extended period before mating each spring, and they select the same partner in successive years.

If the mating pair gets separated, the male Shingleback lizard will attempt to track down the female by following her scent trail. When the male has finally located its mate, it was observed to nudge the female flank or back leg with its nose, and to tongue flick the female’s flank (Bull et al., 1993). In fact, Bull documents a story that took place in 1997 in which a male Shingleback lizard was found lying next to the carcass of a female Shingleback lizard who had died after being stuck in wired fence.

Bull proposed the following reasons for the monogamous bond between Shingleback lizards:

1. Having a single partner is advantageous because familiarity with the partner will improve one’s chances of feeding and detecting predators. (I figure that it’s somewhat like developing a certain chemistry with your significant other, one wouldn’t want to shop around for other mates if your current mate makes you happy. Seriously, why would you want to look for someone else if your current partner makes excellent spaghetti or helps you hold off the insane crowds during the Great Singapore Sale?)

2. The reason for “sticking” to a partner for years may be due to genetic compatibility. (This reminds me of the “Sweaty T-Shirts” video shown in class.)

3. Long term monogamy is also helpful in preventing the spread of parasites and diseases. An individual lizard would want to stay with a partner for many more years to come if it does not contract any diseases from that partner the first time round. (If you’ve been with a partner for years without contracting any sort of disease, chances are, you’d stay around him or her instead of actively searching for other partners who may have some forms of diseases . Then again, I should not give too much credit to humans, seeing how fickle we can be.)

So, is the monogamous partnership motivated by biological needs and concerns, or is there something more to it? You decide.

References:

Bull, C.M., Bedford, G.S. and Schulz, B.A., 1993. How do sleepy lizards find each other?. Herpetologica 49: 294–300.

Bull, C. Michael. Cooper, Steven J.B. Baghurst, Ben C. (1998). Social monogamy and extra-pair fertilization in an Australian lizard, Tiliqua rugosaBehav Ecol Sociobiol 44: 63-72

Bull, C. Michael. (2000). Monogamy in Lizards. Behavioural Processes 51 (1-3): 7-20

Madsen T, Shine R, Loman J, Hakansson T (1992). Why do female adders copulate so frequently? Nature 355:440-441

Olsson M (1995) Territoriality in Lake Eyre dragons Ctenophorus maculosus: are males “superterritorial”? Ethology 101:222-227

Olsson M, Madsen T (1995) Female choice on male quantitative traits in lizards – why is it so rare? Behav Ecol Sociobiol 36:179-184

Wikipedia.org

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

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