Giraffe

Giraffes are the tallest mammals on Earth, with their legs alone are taller than many humans at about 6 feet. Not only that, they give birth standing up, with their young falling more than 5 feet to the ground at birth! Now that’s a way to say hello to the world... by smacking into it! :p

Male giraffes are ready to mate around the age of 6 however due to the way in which the stronger, more mature bulls get to mate first, it’s not uncommon to see them in their double digits before they have a chance to charm a lady. Alternatively females are ready to mate around the age of 4.

Typically giraffes will go into estrous during a rainy season when food is abundant and stress is low.  The estrous cycle for a giraffe is around 14.7 days with regular ovarian cycles prior to conception. Adult males tend to associate, and sexually investigate, females when they are cycling. Males will taste the urine of a female to judge how much estrus is in their urine and whether they are ready for mating. The courting rituals include gentle rubbing of their necks on each other.

The conception time is approximately 15 months, with cows only having one calf at a time. The mother stands while in labour and delivers her calf standing up, with it falling several feet. The thick sac protecting the calf at birth prevents it from being harmed. The offspring can weigh up to 70kg and stand 6 feet tall when born.

Unfortunately the presence of a calf acts as a threat to the herd, attracting more predators than usual. It’s because of this that only a quarter of the calves make to do adulthood. Young giraffe feed off the milk of their mother for the first year but they will feed from grass and low lying leaves from tree at around the two month mark.

FUN FACT! A giraffe's feet are the size of a dinner plate—approximately 12 inches across. Females use their hooves as weapons to protect their young. They are strong enough to kill a lion, the giraffe's only predator aside from humans.

Juvenile and two adults

Anonymous

Giraffe’s running

Anonymous

Reference

Bercovitch, F.B., Bashaw, M.J. & del Castillo, S.M. 2006, "Sociosexual behavior, male mating tactics, and the reproductive cycle of giraffe Giraffa camelopardalis", Hormones and Behavior, vol. 50, no. 2, pp. 314-321.

Praying Mantis

 The Praying mantis has always been popularly known by the cannibalistic act of the lovely lady eating the head of her hopeful prince in waiting. Unfortunately it’s still unclear after several research cases as to exactly why she tends to feast upon the head of her mate.

Lucky for the male mantis, engaging in copulation with the female does not mean that this will be his final act in life. The female mantis won’t always devour the male, so he does have a chance of escaping if he can execute his mantis ninja skills to escape the wrath of the hungry female.

The male mantis would display that he has recognized the female visually and he then proceeds to try and court her through concealment rather than a front on approach through display. He would attempt to execute a very stealthy approach, sneaking around behind her and freezing whenever she would look towards him. Providing he was able to get into position a few inches away from her, he would leap on to her back and copulation will begin. It’s until this point that it appears as if the females take no part in the courtship.

The other outcome is not a bliss for the male. If he is spotted by the female she will prey on him like the opportunistic hunter she is, seeing him as a prey organism. The concealment approach doesn't always work and generally the male will only be attacked if he approaches her front on. When she attacks him, she reaches out and grasps the font of his body and begins to eat him. Chances of escape for the males are minimal and it’s not until a specific nerve cord is severed that his body will begin to undergo strong circling movements to bring his body in line with hers and begin copulation.

In the end the male’s body may eventually be completely consumed, but a successful copulation had occurred. Perhaps for the male mantis, being cannibalised may not be a bad way to go. He may die happily in bliss, or in excruciating pain from being eaten alive. As for the female, she gets a delicious meal from it, who could complain!

Female mantis preying on a male

Oliver Koemmerling

Orchid Mantis

Anonymous 

Reference

Loxton, R.G. 1979, "On display behaviour and courtship in the praying mantis Ephestiasula amoena (Bolivar)", Zoological Journal of the Linnean Society, vol. 65, no. 1, pp. 103-110.

Marine Turtles and Climate Change

I read this interesting journal article about turtle mating habits this week. The journal article was about how climate change may pose a unique threat to turtles by producing extreme sex ratio biases that could ultimately lead to a population’s extinction.

Marine turtles such as the famous Green Turtle are temperature-dependent sex determined animals. This means that the higher the temperature, the more females are produced. In marine turtles, high female skewed hatchling sex ratios already occur and with the predicted increase in global temperatures, they are predicted to only rise further unless they adapt otherwise.

A study was conducted and despite the offspring sex ratio of 95% females, there were at least 1.4 reproductive males to every breeding female. One suggestion was that the males move between aggregations of receptive females, an inference that was supported by the satellite tracking showing that the male turtles may have been visiting multiple rookeries.

Therefore because of the male mating patterns, the marine turtles may have the potential the buffer the disruptive effects on the sex ratios that climate change has posed on marine turtle populations, many which are already seriously threatened.

Reference

·         Wright, L.I., Stokes, K.L., Fuller, W.J., Godley, B.J., McGowan, A., Snape, R., Tregenza, T. & Broderick, A.C. 2012, "Turtle mating patterns buffer against disruptive effects of climate change", Proceedings. Biological sciences / The Royal Society,vol. 279, no. 1736, pp. 2122-2127.

Ridley Sea Turtle Hatchlings 

Photograph by Bill Curtsinger

Green Sea Turtle

Photograph by Tim Larman

Red Foxes

Red foxes, (Vulpes vulpes) are one of the largest and most abundant true foxes in the fox species. During their mating period foxes are usually monogamous but males breeding with several females are known to occur. Females that mate with the same males may also share a den. However, although a female may be mated by several males, she will partner with one male.

Mating pairs will spend increasing amounts of time with each other and undergo playful and affectionate fighting with one another. A majority of time is spent in close contact with one another during season. Hunting is still solitary but partners will maintain vocal communication through the range.

Mating season varies with geographic location. A vixen’s oestrous period ranges from 1-6 days with copulation lasting 15-20 minutes with vocal clamour. A vixen will stay in the den close to and after giving birth to her pups.  Gestation lasts from 51-53 days with a litter size of 1-13 pups, averaging at 5. During this time, the male will provide food for his vixen but will not enter the maternity den. Pups leave the den 4 or 5 weeks after birth and are fully weaned by 8 to 10 weeks. Mother and pups remain together until the autumn after the birth. Sexual maturity is reached by 10 months.

Photos: Roeselien Raimond

  References

Cavallini, P. 1996, "Ranging behaviour of red foxes during the mating and breeding seasons", Ethology Ecology & Evolution,vol. 8, no. 1, pp. 57-65.

Coastal (Eastern) Carpet Snake

The other day my little Coastal Carpet Python named Aoda passed away. So in recognition of his passing I’ll be blogging about the mating behaviours of his kind, Morelia spilota (mcdowelli).

The Coastal Carpet Python is one of the most common and widely distributed species of snake in Australia who are often mistaken for Diamond pythons. Interesting Fact! Those two species are known to interbreed which is unheard of in most other species of reptiles. During the mating season, the male pythons tend move relatively little and aggregate around reproductively active females, however only staying with the females briefly. The males also tend to engage in male-male combat in the vicinity of females. This combat included vigorous biting and ritualistic “wrestling” matches.

These mating aggregations lasted around 4-6 weeks. After mating the females would lay a clutch of up to 30 eggs, to which she would coil around to incubate them. Unlike other snake species she will care for her eggs and defend them violently. While she has coiled around them she will shiver to keep a stable temperature. Approximately after 50 days her babies will begin to hatch. At this point her maternal duties are completed, she goes off to feed and her hatchlings are left to disperse freely, fending for themselves.

Photos taken of Aoda by my neighbour Sophie Kirkham

Reference

Shine, R. & Fitzgerald, M. 1995, "Variation in Mating Systems and Sexual Size Dimorphism between Populations of the Australian Python Morelia spilota (Serpentes: Pythonidae)", Oecologia, vol 103, no. 4, pp.490-498.

I've always been interested in everything animal related and the behaviours they display. It is also particularly interesting the different mating behaviours they display. Mating behaviour is typically viewed as being all events from pair formation through to copulation and final mating pair breakup. Sexual selection is generally greater on males than females and is in the context of competition for more or the best mates. In order to maximise chances animals have developed many different sexual dimorphisms, like vibrant peacock tails to complex genitalia.

Not only have animals developed these physical aspects to increase success rate, they also have developed different behavioural adaptations. An example of this is the amazing dance moves of the Manakin bird, or the life breeding partners that wolves establish. In the animal kingdom there are endless different behaviours that both the males and females uptake in order to successfully find a suitable mate and therefore past their genes into the next generation.

References

Nicholson, C. 2008, "Behaviour Mating games", Nature Reviews Neuroscience, vol. 9, no. 2, pp. 80-81.

Mating Behaviors 2009, , Elsevier Science & Technology. Hardy, I.C.W., Ode, P.J. & Siva-Jothy, M.

2005, "Mating Behaviour" in Springer Netherlands, Dordrecht, pp. 219-260.

Images

http://britton.disted.camosun.bc.ca/fractals/white-and-blue-peacock.jpg

http://data2.whicdn.com/images/24927801/large.jpg