LSM1303 Animal Behaviour

So, how clever are you? Do you know the answer?

If you think it is the Lion or Cheetah, you are wrong.

If you said Hyena, you are still wrong…

The answer is……

The Mighty Strong

HIPPOPOTAMUS!!!

Picture Credit: http://www.flickr.com/photos/travelphotos/576254119/

Weird, isn’t it?

Apparently, due to its built(chubby) and diet(herbivorve), many explorers thought that the hippo is a safe animal to approach. NoNoNo! This is the fatal mistake, hippo are territorial and unpredictable. Despite having a chubby and friendly outlook, the hippo can easily outrun most humans (other than Usain Bolt, 0lympic ‘08 Gold Medalist) and is a violent-tempered animal.[1]

“The Hippo kills more humans in Africa than any other wild animals.” [2]

“One of the rules in Africa, if you see a hippo, head the other way!” [2]

Nonetheless, there is still a very unique Hippo by the name of Jessica. Jessica is a seven years old “washed up” female hippo that lives with Tony and his wife.

She actually enjoys sweet coffee and even munch their dogs, oops, with their dogs.

When she is still hungry, she knows where to look for more food, she head to the kitchen by opening the main door. Interestingly, she is capable of opening door by using the door knob. Amazing! She actually learnt it. (Wonder how she learnt!?! )

See Jessica here! and here!

Hippo that loves sweet coffee and sleeps at Human Home.

http://www.youtube.com/watch?v=G3NueKXS6dk&feature=related

http://www.youtube.com/watch?v=1pgUerxGSsc

FEW Thinking points:

1) How did Jessica become so domesticated? Would this interaction be possible for all “washed up” hippos?

2) Are hippos capable of learning?

3) I believe most humans would like to interact so comfortably with hippos and vice versa, but would this be good for the hippos? What are the effects of urbanisation seen in this clip?

P.S. Don’t you think she look so cute in her own bed too?

Printscreen from: http://www.youtube.com/watch?v=G3NueKXS6dk&feature=related

References:

[1] “Hippopotamus”, by Wikipedia. http://en.wikipedia.org/wiki/Hippopotamus#Aggression

[2] “Jessica the Hippo”, at Youtube. http://www.youtube.com/watch?v=G3NueKXS6dk&feature=related

It is widely known that the only way to get a sex change is to have a surgical operation, but for chickens, they change their sex naturally, saving the cost for an operation! However, the known occurences are extremely rare, happening only in 1 out of 10,000 cases. “Every once in a while you hear a story about a hen that changed into a rooster. Such stories are often meet with skepticism, but sex reversals do, in fact, occur, although not very frequently,” says a 2000 report published by the University of Florida’s Institute of Food and Agricultural Sciences.

In an egg-laying barns where no roosters are present, a common behaviour arising from the hens are one of them will start crowing like a rooster. Generally, the hens only have one functional ovary, the left one, hence, once it is damaged, testorone will soar and regeneration occurs in the right gonad hypertrophies, which then regenerates as an ovotestis which consists tissues of either the testes or ovary, or both. This change is known as a spontaneous sex reversal and is extremely rare, usually happening only in barns which have a lack of roosters. The sex reversal will also occur when a rooster dies off and there is no rooster or a drastically small number of roosters left in the barn.

It is interesting to note that the hen will develop the behavioural and physical characteristics of the rooster as well. It will stop laying eggs, grow new plumage, a wattle and comb and starts the crowing behaviour. The sexually altered rooster will also try to mate with their old female mates. Although there are reports of the ovotestes producing semen and is able to reproduce, most however, are unable to reproduce.

Chicken run: George (1st in the photo) with some of the females he used to look like. The bird has become bossy since he swapped sexes and became a male Source: Daily Mail Reporter (http://www.dailymail.co.uk/news/worldnews/article-1080049/Pictured-The-sex-swap-chicken-called-Georgina-turned-cockerel-named-George.html)

Although majority of the sexually altered roosters are unable to generate semen to reproduce, the occurrence of this phenomenon is most probably to ensure a sexual balance in the brood or perhaps to maintain the need for a ‘boss’ figure in a brood of hens. However, it is intriguing to note that there are reports of these ovotestes having the ability to reproduce and another possible reason for the sexual change is to ensure reproduction is possible with non or few roosters in the brood to ensure continuation of its species.

Freaky- The sexually altered rooster

  Source: Bristol Evening Post

 (http://i7.photobucket.com/albums/y286/helena_the_chicken_lady/eveningPostChickenSexChange.jpg)

References:

1. Jacob, J and F. Ben Mather, 2000. Sex Reversal in Chickens. Department of Animal Sciences, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, FACTSHEET PS-53.
2. “The Sex-Swap Chicken Called Georgina that Turned into a Cockerel Named George,” by Daily Mail Reporter. Daily Mail Online, 23 October 2008.
3. “Letters: Sex-Change Chicken,” by M. A. Crooks. New Scientist, 16 May 1992.
4. “Strutting Super-Rooster is a Real Gender Bender,” by Geoff Bennett. Europe Intelligence Wire, 18 April 2006.

When was the last time anyone mention sex and your immediate reaction was DEATH? Well, at least for the Golden Orb Web spiders (Nephila plumipes), they should be familiar with this deadly sacrificial ritual. The Golden Orb Web spiders are come under a category of arachnids in which sexual cannibalism is practised. They can be found in Eastern and Northen Australia, especially in Sydney and coastal areas. According to Kenywn Suttle (1999):

“Sexual cannibalism is a special case of cannibalism in which a female organism kills and consumes a conspecific male before, during, or after copulation.”

For those who find this unbelieavable, get real with this video:

Golden Orb Web Spider – Sexual Cannibalism

While the phenomenon of sexual cannibalism is very rare, it has been observed mainly in spiders, scorpions and mantis. While some scientists in the earlier days, such as Gould (1984) dismisses the significance of sexual cannibalism because it is too rare to be deemed an important aspect of animal mating behvaviour, many subsequent studies contradicted this dismissal. So what are the benefits of sexual cannibalism?

According to research, sexual cannibalism are in the interests of both the male and female sexes. For the female spider, it is obvious that the eaten male provides a source of nutrition for the female to improve fecundity (quantity or quality of offspring). What about the poor male which gets eaten up? Most studies point towards the advantage of male spiders sacrificing themselves as a form of paternal investment (Randy, 1976; Elgar and Fagey, 1996). This means that the males offer their bodies to be eaten in return for longer time to copulate and hence increasing the number of eggs fertilized. In this way, sexual cannibalism is an evolutionary characteristic of male Golden Orb Web spiders as an adaptive strategy in sexual reproduction.

However, Schneider and Elgar (2001) offers a more complicated insight into this sacrificial ritual performed by male Golden Orb Web Spiders:

“males only gain from cannibalism when mating with mated females, not when mating with virgin females”

In their study, they found that cannibalized male spiders generally copulate longer than non-cannibalized males; however, longer copulations correspond with increased paternity only in mated females. Hence, while the female spiders are almost at full advantage in the phenomenon of sexual cannibalism, it is not always guaranteed that male spiders can achieve higher paternity chances, if the hypothesis of paternal investment is really true. 

An advice for the male Golden Orb Web Spiders – don’t go for the virgins next time round if they want to make their sex worthwhile!

p.s. Still curious about the appetite of female Golden Orb Web Spiders? Check this out:

According to the article , the web is so strong that a bird can be trapped and the huge spider eats it! Experts claim that the photograph has been verified to be authentic.

Additional Reading: The male Red-Back Spider (Latrodectus hasselti: Theridiidae) has been identified as one of the only two species which demonstrates complicity and active participation in sexual cannibalism (Suttle, 1999).

Andrade, M., 1996. Sexual selection for male sacrifice in the Australian Red-Back Spider. Science, 271(5245):70-72.

References

Elgar, M. A.; Fagey, B.F., 1996. Sexual cannibalism, competition and size dimorphism in the orb-weaving spider Nephila plumipes Latreille (Araneae: Araneoidea). Behavioral Ecology, 7:195-198.

Gould, S. J., 1984. Only his wings remained. Natural History , 93:10-18.

Randy T., 1976. Sexual selection and paternal investment in insects. The American naturalist, 110: 153–163. 

Schneider, J.M.; Elgar, M.A., 2001. Sexual cannibalism and sperm competition in the golden orb-web spider, Nephila plumipes(Araneoidea): female and male perspectives. Behavioral Ecology, 12(5): 547-552.

Suttle, K.B., 1999. The evolution of sexual cannibalism. Available: http://ib.berkeley.edu/courses/ib160/past_papers/suttle.html. [13 April 2009].

Fainting Goats

(Images via: Discover Magazine and Jim Knapp)

If you thought tree climbing goats (Video at bottom) were strange, meet the breed of goats that faints and falls over when spooked. Fainting goats are a slightly smaller version of the standard goat. Singularly and en masse these weird goats freeze for a number of seconds and generally fall over in the process. I will definitely scream for help if i did not know about this “Fainting Goats”, if happened i see any goats fall down.

There are also several names for it such as the most common are Myotonic, Tennessee Fainting, Nervous, and Scare goats. The names refer specifically to myotonia congenita, a condition in which the muscle cells experience prolonged contraction when the goat is startled. The transitory stiffness associated with these contractions can cause the goat to stop moving, stiffen, and even fall down. This is not a true faint, but a muscular phenomenon unrelated to the nervous system. The actual degree of stiffness may vary widely from goat to goat and is based on a number of factors, including age, species purity, and degree of fright.

Fainting Goats (Video)

Others stuff to be share is that goat can climb tree and goat can scream like a man! (I thought they only know how to “meh”)

Goat climb tree (Video)

Goat yelling like man (Video)

Read more about fainting goats:

http://animals.howstuffworks.com/mammals/fainting-goat.htm

http://www.flickr.com/photos/mmparsons/2912026029/

The Homepage of James C. Knapp, Jr./ jimknapp@umich.edu/ Last modified 2 January 2003.

http://www-personal.umich.edu/~jimknapp/goats.html

National Geographic. Acessed on 13 April 2009.

http://video.nationalgeographic.com/video/player/kids/animals-pets-kids/mammals-kids/goat-fainting-kids.html

Mind control is a word that is not usually associated with the real world. What comes to mind when this word is mentioned are images from horror movies. However, in actual fact, the manipulation of the mind for the benefit of self is not that far fetched after all! There have been recorded instances of animals that appeared to have the ability to control the behaviour of others through parasitism.

Parasitism refers to a type of relationship between two organisms, in which one receives benefit from the other at the expense of the other organism. Some examples of well known parasites are the tapeworms and fleas.

Tapeworm

While some parasites induce pain, spread diseases and cause general deterioration of the host’s health, there are some parasites that do far more than merely affecting the physical being of the host.

wasp eggs deposited on caterpillar

The trematode parasite, Microphallus sp. was found to affect the behaviour of infected snails radically. The snails are the intermediate host for the parasite while birds are the eventual host. It was found that snails that were infected by the parasite were more prone to linger in open areas, where they were more noticeable by its predators. This bizzare behaviour greatly increases the possibility of the snails being spotted and consumed by birds. Once the parasitized snail is consumed by a bird, the parasite is then able to complete its developmental cycle in the bird’s body. Hence, through the modification of the behaviour of the snail, the parasite significantly increased its chances of completing its development (Levri, 1999).

Another example of such mind control actions of parasites include how wasps affect the behaviour of orb weaving spiders. The wasp Hymenoepimecis argyraphaga parasitizes on its host, the orb-weaving spider Plesiometa argyra by laying eggs on the abdomen of the spider. The spider is then able to carry out its normal daily function and appeared unaffected by the infection while the larva of the wasp feeds on the spider through small holes made on the spider’s abdomen. However, on the night before the larva kills off its host, the spider is induced to make a cocoon web that is able to support the cocoon of the larva, instead of its usual orb shaped web. Upon completion of this task, the spider is then killed and becomes food for the growing larva (Eberhard, 2001).

Normal orbweb vs Web spun by parasitized spider

Researchers are currently looking into the mechanism behind such phenomenon and if successful, this could translate into highly effective pest control measures.

References

Eberhard, W.G. (2001). Under the influence: Webs and building behaviour of Plesiometa argyra (Araneae: Tetragnathidae) when parasitized by Hymenoepimecis argyraphaga (Hymenoptera: Ichneumonidae). Journal of Arachnology 29, 354-366.

Levri, E.P. (1999). Parasite-induced change in host behaviour of a freshwater snail: parasitic manipulation or byproduct of infection? Behavioural Ecology 10, 234-241.