LSM1303 Animal Behaviour

Photo courtesy of :
http://today.mun.ca/news.php?news_id=3607

We are often being described as pigs when we do things that are not so intellectually accepted by our peers or family members. However, I was amazed when I was googling for behaviors and facts about pigs as many websites and researches have shown that pigs have extremely high intelligence level.

As mentioned by Dr. Donald Broom, Cambridge University professor and former scientific advisor to the Council of Europe, pigs have the cognitive ability to be quite sophisticated. Even more so than dogs and certainly [more so than] three-year-olds.

Pigs not only can play video games like many of you do, they are able to distinguish items and pick up tasks when there are rewards given to them. In a research done at Penn State from 1996 to 1998 by Stanley Curtis, the pigs are able to distinguish the scribbles of different children by maneuvering a modified joystick to move the cursor on a monitor. In addtion, using food as motivator, pigs are able to learn many new tasks within five to ten attempts.

Furthermore, pigs’s brains are more similar to human beings as than rats and they are able to remember and regconise objects that they have interact or seen before. They also have the tendency to pick things that they have never see before.

“I don’t think a pig is a good pet for everyone,” warns Brenda Coe, adjunct assistant professor of animal science.
Maybe they’re just too smart for that.
So next time when your friend calls you a pig, think twice, it might not be something bad afterall (:

References :
”Are pigs smarter than dogs?”by Lisa Duchene. Research Penn State
”Delving into the memories of pigs” by Kelly Foss. today.mun.ca, 22 February 2008.

Websites :
http://www.peta.org.uk/factsheet/files/FactsheetDisplay.asp?ID=124
http://today.mun.ca/news.php?news_id=3607
http://www.rps.psu.edu/probing/pigs.html

YES. the title is not deceiving at all. The kinky animal I will be mentioning in my blog post does practise oral sex while mating.

Cichlid fish (courtesy of Paul Wheeler)

I stumbled upon an article from sciencedaily.com which featured Cichlid fish. Cichlid fish are a family of fish which includes Tilapia and Angel Fish. It has been discovered that after female Cichlid lays her eggs, she picks them up and carries them around in her mouth. The male Cichlid on the other hand has a gene that produces spots on his anal fins to resemble the eggs. He swims by the female and upon seeing the fake eggs, thinking her eggs had fallen out, she swims towards him and attempts to suck the eggs back into her mouth. The male Cichlid then takes advantage of this situation and deposits his sperms into her mouth!

This is a short video of the mating process:

cichlid mating!! –> do watch it. It’s very interesting.
A study in the journal BMC Biology conducted by Walter Salzburger, Ingo Braasch and Axel Meyer, identifies that the gene in male Cichlid Fish, scientificaly known as colony-stmulating factor 1 receptor (or csf1ra) ”produces yellow pigment cells in oval spots on the fishes’ fins”. These yellow pigment markings are also known as egg-dummies, are generally located on the anal fins of the male fish and are essential to mating.

In another study, evolutionary biologist Ole Seehausen and his co-authors demonstrate that female cichlids whose eyes are more sensitive to blue tend to prefer blue-coloured males, while females with photoreceptors better able to detect red light choose males with red nuptial coloration. These different visual receptors are present because of DNA and protein sequences and all these shows that natural selection is involved in the mating between the Cichlid species.

Isn’t the way these cichlid fish mate just bizzare?

If you want to read up more about this and the challenges posed to these fish in recent years, do visit this link.

References:

“Gene in Male Fish Lures Females into Sex“, BioMed Central (19th November 2007).

“New Fish Species may emerge because of how females see males“, EAWAG: Swiss Federal Institute of Aquatic Science and Technology (2008, October 2).

“Adaptive sequence evolution in a color gene involved in the formation of the characteristic egg-dummies of male haplochromine cichlid fishes” , Walter Salzburger, Ingo Braasch and Axel Meyer (Published online 15 November 2007)

“Cichlid Fish Diversity Threatened by Eutrophication That Curbs Sexual Selection“, Ole Seehausen, Jacques J. M. van Alphen and Frans Witte (19 September 1997)

Getting attention from animals of the same species from a far distance is a tough task, especially if the surroundings are noisy. However, the male anole lizards are able to get around that problem. According to a study, they devised a “look at me” technique which is performing full body, four-legged push-ups to get their fellow lizards to turn their heads.

Terry Ord (courtesy of UC Davis)

“The main signal consists of rhythmic head bobs and flashy displays of their colorful neck flaps, called dewlaps. The underlying message is sort of like a bodybuilder flexing his muscles in front of another bodybuilder. If one male is clearly stronger and fitter than the other, the scrawnier fellow is unlikely to challenge the first individual in a fight, saving a lot of injuries and deaths” (Viegas, 2008). Here is a video on the lizard’s ‘antics’.

Laborin\’ Lizards (Apologies for the lack of knowledge on embedding videos here)

Males did not usually add the push-up sequence because it burns a lot of energy, could be seen by predators and the alert would lose its punch if overused. However, use of push-ups and dewlapping act as predator deterrent signals too because these signals communicate to the predators that they have been detected which discourages the attack (Leal & Robles, 1997). Therefore, when a predator approaches it, they might do the push-up sequence as the benefits outweigh the costs.

In a nutshell, this adaptation for communication in unfavourable conditions has allowed the anole lizards to display territorial ownership, reduce aggression between other male lizards and deter predation by a higher degree.

References

Leal, M. & Robles, J.A.R. (1997). Signalling displays during predator–prey interactions in a Puerto Rican anole,
Anolis cristatellus. Anim. Behav., 1997, 54, 1147–1154. Retrieved April 10, 2009, from http://www.sciencedirect.com.libproxy1.nus.edu.sg/science?_ob=MImg&_imagekey=B6W9W-45R73BW-9-1&_cdi=6693&_user=111989&_orig=search&_coverDate=11%2F30%2F1997&_sk=999459994&view=c&wchp=dGLbVlb-zSkWz&md5=f1fc3fde9dcd086d75363d3d0eb4b49b&ie=/sdarticle.pdf

Ord, Terry (2008). Watch me now. UC Davis. Retrieved April 10, 2009 from http://dsc.discovery.com/news/2008/11/25/lizard-zoom.html

The Scientist LLC (2009). Labourin’ Lizards. Retrieved April 10, 2009 from http://www.youtube.com/watch?v=NZgUp30Ad6o

Viegas, Jennifer (2008). Male lizards do push-ups to get attention. Discovery News. Retrieved April 10, 2009 from http://dsc.discovery.com/news/2008/11/25/lizard-push-up.html

If you think life’s tough, then you should spare a thought for the Sand Tiger Shark. Its battle for survival starts even before it is born! While still in their mother’s uterus, sand tiger shark embryos develop teeth and an appetite to eat their own siblings while inside the womb so that only the strongest will emerge.

Model of a cannibalistic Sand Tiger Shark embryo.
source:National Geographic

This is a classic example of the survival of the fittest. The sand tiger shark produces as many as 25,000 pea-sized eggs in a lifetime. Periodically 15 or 20 eggs pass from the ovary into each uterus, where they are fertilized and packaged inside an avocado-shaped egg case and where the shark embryos begin to develop (Sullivan, 1982). The litter starts with several embryos in each of two uterus. When the yolk has been depleted, the embryos swim around the uterus and the largest embryo feeds on the smaller ones (intra-uterine cannibalism or adelphophagy), and then grows to birth size by feeding on unfertilized oocytes supplied by the mother (oophagy) (Lucifora et al., 2002). As a result, only one ’supershark’ in each uterus survives to birth, leaving only two pups born per litter, one for each uterus.

source: Shark eats siblings in womb on Youtube

The practice of cannibalism (eating of the flesh of an animal by another animal of its own kind) is actually not as rare in nature as we may tend to believe. Cannibalism is surprisingly widespread across the animal kingdom, and not unique to the sharks. Other animals that occasionally eat members of their own specie include chickens, rattlesnakes and spiders, just to name a few.

Literature cited:

“In Shark Womb, Fetus ‘Cannibalizes’ Rivals” by Walter Sullivan, The New York Times, 07 Dec 1982. Accessed: 10 Apr 2009.

Luis O. Lucifora, Roberto C. Menni, and Alicia H. Escalante, 2002. ICES Journal of Marine Science, 59: 553–561.

While out in the field at night, one occasionally can notice a gecko without its tail. This rather strange looking individual has autotomised its tail (which is part of its body part) and this process is scientifically known as autotomy.

Autotomy is defined as the ability to voluntarily shed a body part, typically along a predetermined breakage plane (Wasson et.al., 2002). This unusual behaviour is relatively widespread in certain animal groups and has been observed in rodents, salamanders, lizards, crabs, spiders and sea stars (Juanes and Smith, 1995). As different groups of animals have developed and maintained this behaviour, this implies that there must be strong selective benefits to it.

Spider with missing leg

Why do animals choose to autotomise their limbs or body part? Several reasons have been proposed. Firstly, autotomy enables the animal to reduce injury to body parts. For example, certain species of crabs are known to break off their injured limbs. Secondly, this allows the animal to distract a predator and enable it to get away without being eaten. For example, certain lizards will often drop their tail when grasped in order to escape from predators.

Lizard missing part of the tail

However, losing a limb or a body part does not come without any cost and the animal may be at a disadvantage when its limb is temporarily absent. Firstly, the animal may suffer from a reduced ability to forage or defend. For example, when a crab loses a cheliped, it will be less capable in feeding and defending against potential predators. Secondly, the animal will also have to expend precious resources to regenerate the lost body part. This will come at the expense of growth and reproduction.

In conclusion, autotomy can be beneficial to the animal and may be important for survival in certain animals. However, it is not without any negative impacts to the animal.

Literature Cited

Juanes, F. & L. D., Smith, 1995. The ecological consequences of limb damage and loss in decapod crustaceans: a review and prospectus. Journal of experimental marine biology and ecology 193: 197-223.

Wasson, K., B. E., Lyon  & M. Knope, 2002. Hair-trigger autotomy in porcelain crabs is a highly effective escape strategy. Behavioral Ecology, 13, 481–486.