Till death brings us closer.

It was a lazy afternoon on 5 June 1995. Kees Moliker was settling into his chair, minding his own business when he heard a loud thud outside his window. An ornithologist by training, his office was situated within the Natuurmuseum Rotterdam in Nethlerlands. Cautiously he approached the window where the thud was heard and he witnessed a horrifying sight! An adult male mallard was lying dead on the ground. There was another mallard mounting the corpse and raping it. Moliker stared transfixed at the sight before him…for nearly 75 minutes. When he couldn’t stand it anymore, he left his office and approached the crime scene to stop the hideous crime from continuing.

Scene of Crime

Scene of Crime

What just happened? Sex with a corpse? How is that possible? Contrary to what many people believe about animal sexual behavior, there are species whose sexual behavior are promiscuous and opportunistic in nature. A wide range of animals appear to masturbate and use objects as tools to help them do so. In many species it seems that animals try to give and receive sexual stimulation where procreation is not the aim.

gay mallards

On that fateful day in June 1995, Kees Moliker witnessed animal homosexual necrophilia. Necrophilia in animals is essentially when a living animal engages in a sexual act with a dead animal. What happened on that day was when a drake mallad (Anas platyrhynchos) was in full flight, it hit the glass facade of the Natuurmuseum Rotterdam building and died 2 metres away from the facade. According to Moliker, he speculated that the 2 mallards were involved in some kind of aerial chase or pursuit flight and while the victim flew into the glass building, the drake that was pursuing managed to avoid collision and landed next to the dead mallard. This is a common motif in duck behavior which is also known as rape flight. It was unlikely that the other drake was just passing by and saw the dead mallard as it appeared beside the corpse in less than a minute after the mallard’s death.

mallard

After landing, the “rapist” forcibily picked into the back, the base of the bill and mostly into the back of the head of the dead mallard for about two minutes, then mounted the corpse and started to copulate, with great force,
almost continuously picking the side of the head. The necrophilic rapist only reluctantly left his victim when Moliker approached the dead mallard and “rescued” it from the “rapist” after 75 minutes. So it seemed that it could have gone on even longer if Moliker hadn’t intervened.

Upon inspection of the dead mallard, it was revealed that it was a male mallard. This was unusual as necrophilia was known in the mallards but only among heterosexuals. Essentially, this made the first observed case of homosexual necrophilia in mallads. This discovery netted Moliker an Ig nobel prize in biology awarded for improbable research; research that “first make people laugh, and then make them think.”

You can check out the video Homosexual Necrophilia

Now a few questions that deserve further research are these. Did the gay duck just broke up with his partner? And is he doing this to vent his frustration? Well, these are interesting things to contemplate on.

References

Moeliker.C.W., 2001. The first case of homosexual necrophilia in the mallard Anas platyrhynchos (Aves: Anatidae). DEINSEA, 8: 243-247.

“Necrophilia among ducks ruffles research feathers” by Donald.Macleod. Improbable Research, 8 March 2005. URL: http://www.guardian.co.uk/education/2005/mar/08/highereducation.research (accessed on 8 Apr 2010).

Minimovies-Ig Nobel  Prizes Episode 1/6. (Homosexual necrophilia in the mallard duck), 2 October 2009. URL: http://www.youtube.com/watch?v=NfWiqdlmsm4 (accessed on 8 Apr 2010).


Long tails no enough?

There is a considerable amount of sexual dimorphism in great-tailed grackles (Quiscalus mexicanus), a type of blackbird. Sexual dimorphism is the difference in form between individuals of different sex in the same species.

Male great-tailed grackles can grow up to about 43 cm, including a tail that is almost as long as the body, and are jet-black in colour with a violet-blue iridescent sheen to the feathers. Females, on the other hand, are significantly smaller at about 33 cm, and are mainly brownish-black, with a pale brown throat and belly.

Great-tailed Grackle (Quiscalus mexicanus), Male

Great-tailed Grackle (Quiscalus mexicanus), Male

Great-tailed Grackle (Quiscalus mexicanus), Female

Great-tailed Grackle (Quiscalus mexicanus), Female

Sexual dimorphism is mainly attributed to sexual selection. Longer tail length has always been associated with territory acquisition and social mate attraction, in combination with size.

There can also be another explanation to sexual selection. Larger males have the advantage in acquiring territories, and females preferred to settle on the territories of larger males, probably because larger males were able to acquire trees with the most desirable nest sites.

Larger males have the advantage in acquiring territories

Larger males have the advantage in acquiring territories

Recently, it came into question whether animals also use glossiness, where their hair or feathers reflect light like a mirror, to signal to the opposite sex.

In a recent study conducted by PhD researcher Mr Matthew Toomey and colleagues from Arizona State University, Tempe, US, birds were captured, with photographs taken of them and their tails measured before being released. The glossiness of the bird’s feathers in each photograph was calculated using a reflectance spectrophotometer and computer software.

According to Mr Toomey, it was found that male great-tailed grackles were significantly glossier than females. Another discovery was that males with the glossiest feathers also had the longest tails. One possibility arising from this study is that glossiness may play a role in visual signaling and glossier males may be more attractive and better competitors for mates.

Glossiness may play a role in visual signaling

Glossiness may play a role in visual signaling

Glossiness can be a potential step towards the evolution of iridescence where selection for glossiness can result in a refinement of the microstructure of a feather.

Long tails are no longer enough to attract mates? Further research will be required to prove this theory.

References:

“Female birds find males with glossy feathers more sexy,” by Jody Bourton. BBC, 23 March 2010. URL: http://news.bbc.co.uk/earth/hi/earth_news/newsid_8577000/8577316.stm (accessed on 3 April 2010).

Kristine Johnson, Emily DuVal, Megan Kielt & Colin Hughes, 2000. Male mating strategies and the mating system of great-tailed grackles. Behavioural Ecology, 11(2): 132-141

William A. Searcy and Ken Yasukawa, 1981. Sexual Size Dimorphism and Survival of Male and Female Blackbirds (Icteridae). The Auk, 98(3): 457-465

William A. Searcy, 1979. Sexual Selection and Body Size in Male Red-Winged Blackbirds. Evolution, 33(2): 649-661

“2 of 2 Great-tailed Grackle (Quiscalus mexicanus), Male,” by Michael “Mike” L. Baird, mike at mikebaird.com. URL: http://www.flickr.com/photos/mikebaird/4495734086/in/photostream/ (accessed on 5 April 2010)

“Great-tailed Grackle (Female) (Quiscalus mexicanus),” by Mike Baird, BairdPhotos.com. URL: http://www.flickr.com/photos/mikebaird/339193969/ (accessed on 5 April 2010)

“Quiscalus mexicanus,” by Pablo Lèautaud. URL: http://www.flickr.com/photos/pleautaud/2662384817/ (accessed on 5 April 2010)

“Quiscalus mexicanus,” by Pablo Lèautaud. URL: http://www.flickr.com/photos/pleautaud/3217071624/ (accessed on 5 April 2010)

Why arrows? Strike with love darts!

Why let the cupids decide? Learn from the helicid land snails ( for e.g. Helix Aspersa) and do it yourself!

 Most of us know that snails are hermaphrodites, meaning they have both male and female sexual organs, and they do not self-fertilize. But do you know that their genitals are on the necks, right behind their eye-stalks?

 Not interesting enough?

 They are the cupids themselves! But instead of arrows, the “male” (male sexual organs at work) shoots mucus-covered calcium “love darts” during the final stages of courtship to its partner preceding copulation!

Initially, it was thought that the “love darts” were gifts of nutrients, just like how we give presents to the person we fancy. However, further research has shown that there is more to it!

dart with mucus

“Love darts” are actually filled with sperm. When it is being shot to the partner, it penetrates into the body of the recipient and may get digested. However, the mucus outside paralyses the partner’s reproductive tract, allowing the sperm to avoid digestion and thus greater number of sperms can make it to the sperm storage sacs within the reproductive system (Pomiankowski et al. 2001). Good news, as the stored sperms may be enough to be used over a period of months or even years! Say YAY to more offspring!

So, why is there a need for “love dart” when snails can just simply copulate? Sadly, the chance of survival of sperm through copulation is extremely low, like only thousands in millions. Thus with “love dart”, it provides the edge over reproduction because more sperm will be available: Applying Darwin’s theory of sexual selection, snails want to reproduce as much as they can, so if one snail has a way of ensuring that its sperm and not others’ is used to fertilize the eggs, it will have advantage over other snails and sire more offspring!

Sperm competition is somehow present. Basically, 2 or more snails can shoot “love dart” at the same partner (they are promiscuous!). The depth of penetration will determine how good the shot is; the deeper the higher amount of sperm stored! Thus, if one snail is better than the other, higher percentage of the newborn will be its offspring since its sperm has greater chances of being selected by the female for fertilization!

2 snails

Sounds cool right? While the “male” can enjoy shooting the “love dart” showing its affection, the recipient would be OOL (ouching out loud). This may be a very horrifying process because the darts are just like hypodermic needle and can rip off the skin of the recipients!  So sometimes snails will try to avoid getting hit on! How apt to human beings relationship, right? =p

References:

Website

“Are Snails’ ”Love Darts” Source of Cupid Lore?” by Ian Popple. National Geographic, February 13, 2002. URL: http://news.nationalgeographic.com/news/2002/02/0213_020213_wiresnail.html (accessed on 5 April 2010)

Journals

 Menno Schilthuizen, 2005. The darting game in snails and slugs. TRENDS in Ecology and Evolution 20 (11):581-584.

Janet L. Leonard, 1992. The “love dart” in helicid snails: a gift of calcium or a firm commitment? J.theor.Biol 159:513-521.

Pomiankowski.A and Reguera.P, 2001. The point of love. TRENDS in Ecology & Evolution 16(10):533-534

Photo

Dr Ron Chase- Home Pagehttp://biology.mcgill.ca/faculty/chase/ (accessed on 6 April 2010)