LSM1303 Animal Behaviour

We have heard of males impressing females with colourful plumage, melodious singing, physical strength, ability to source for food and the like. However, the Australian male Bowerbirds are more interested in building bowers and displaying in them all the bright and colourful items that they have collected. The male bower birds do not simply collect items from nature like flowers, berries and leaves. They even collect man-made products like bits of aluminium foil; basically anything shiny or colourful. For 9 to 10 months, they painstakingly arrange and rearrange their collections so as to achieve the most impressive arrangements. Their attempts at creating a beautiful interior to impress females do not stop at that. The highly creative male bowerbirds also “paint” the interiors of their bowers with chewed berries, plant juice or charcoal so as to increase the attractiveness of their bowers.

However, female bower birds are easily impressed. That, or male bower birds all build equally outstanding bowers. In a recent study, 75 per cent of female bower birds mated with the owner of the first bower they visit. Female bower birds also tend to return to the males that they have mated with before. Therefore, a younger male bower bird is usually at a disadvantage, sometimes only getting to mate with one in a dozen female visitors to his bower.

Interesting, male bower birds do not depend solely on impressive bowers during courtship. Their sexual displays also consist of “song mimicry, ritualized prancing, and brilliant plumage coloration”. All of these sexual displays can reveal a lot of information about the males; from their body sizes to their health conditions. For example, a bright plumage may hint at a male’s parasite load while bower quality can predict body size (Stéphanie M. Doucet and Robert Montgomerie, 2002). This is because a physically larger bower bird may have an advantage when it comes to stealing ornaments from other bower birds. Therefore, these sexual displays often shape a female bower bird’s choice of a mate.

Image courtesy of bdonald.

References

“Bower Bird Blues” Nature. April 1997.

Stéphanie M. Doucet and Robert Montgomerie, 2003. Multiple sexual ornaments in satin bowerbirds: ultraviolet plumage and bowers signal different aspects of male quality. Behavioral Ecology, 14(4): 503-509

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Humans are obsessed with punctuality. Most of us probably think this stems from a need to do things efficiently, because we have lots to do, and little time to waste. However, humans are not the only animals that are particular about timing and time efficiency.

Henderson et al. used false flowers that had their nectar refilled at timed intervals. Hummingbirds in this experiment learnt to visit the ‘flowers’ which were refilled at 10 minute intervals significantly more frequently than those that were refilled at 20 minutes, in order to avoid wasting energy coming back to a flower that has not yet replenished its nectar. This shows efficient energy allocation and that some animals can discriminate periods of time as short as ten minutes. Another point of interest in this article is that the animals memorized the location and timing of 8 different ‘flowers’, a feat that perhaps not even humans could perform this well.

Penney et. al also demonstrated interval timing in other species, namely pigeons and mice. Interval timing behavior among these animals in this research was comparable to that of humans.

Research such as that by Clayton et al., which studied memories of western scrub jays in where and when they hid their food, also showed that animals use their sense of time and time related memory for much more complex things that we previously gave them credit for.

Thus such research points to animals using an innate ability to time periods of time, more specific to their own circadian rhythm, and using such an ability to forage for food, and to retrieve previously acquired food in an energy efficient manner that also minimizes competition from other animals.

References:

<!–[if gte mso 9]> Normal 0 false false false MicrosoftInternetExplorer4 <![endif]–><!–[if gte mso 9]> <![endif]–> Clayton, N., Bussey, T and Dickinson, A. (2003).  Can animals recall the past and plan for the future? Nature Reviews Neuroscience, 4, 685-691.

Henderson, J., Hurly, T.A., Bateson, M., Healy, S. (2006). Timing in free-living Rufous hummingbirds, Selasphorus rufus. Current Biology, 16, 512-515.

Penney, T.B., Gibbon, J., Meck, W.H. (in press). Categorical Scaling of Duration Bisection in Pigeons (Columba livia), Mice (Mus musculus), and Humans (Homo sapiens). Psychological Science.

Source: http://www.quedat.com/2007/09/02/25-of-the-worlds-most-interesting-animals/

If you’re looking for something more functional than a Barbie doll, (besides plaiting her hair), how about a Komondor dog?

Tough WWII Hero..

Of Hungarian breed and  declared as one of Hungary’s national treasures, Komondor is a livestock and property guardian dog. In fact, many Komondors were killed during World War II because when the Germans invaded, they had to kill the dog before they could capture the farm or house that it guarded. To read more about how they protect sheep from coyote, read this article.

Comes with armour protection..

Big, strong, and armored with a thick coat, the cute-looking Komondor is surprisingly quick and agile. The coat provides protection against wild animals, vegetation and the weather, and looks similar to that of a sheep so it can easily blend into a flock and camouflage itself giving it an advantage when predators such as wolves attack.

But as high-maintenance as a Barbie doll..

While the puppy coat is soft and fluffy, thee coat gets wavy and tends to curl as the puppy matures. To prevent the Komondor from turning into one large matted mess, you need to spend perhaps an hour or two every week to separate the cords. But I suppose that’s only about half the time our ladies spend on their hair, isn’t it?

 References

1. John C. McGrew and Cindy S. Blakesley, 1982. How Komondor Dogs Reduce Sheep Losses to Coyotes. Journal of Range Management, 35(6): 693-696.
2. http://www.quedat.com/2007/09/02/25-of-the-worlds-most-interesting-animals/
3. “Komondors”. Heaney, Richard; Therese Heaney (1995).
4. http://clubs.akc.org/kca/aboutthe.htm
5. “The FCI Hungarian standard”. Soskin, Arthur R. (1998).
6. http://www.dogbreedinfo.com/komondor.htm

Screen capture of the Youtube video
‘Alcoholic Vervet Monkeys! – Weird Nature – BBC animals’
(Links to the actual video as embedding is disabled)

Vervet monkeys, brought to the island of Saint Kitts in the Caribbeans more than 300 years ago, have developed a taste for alcohol by eating fermented sugarcanes left in a corner. Today, they satisfy their cravings by stealing alcoholic drinks from beach-goers.

Watch the video to see some interesting cocktail-poaching action going on as well as Drunk Captain Jack Sparrow impersonations by various monkeys. An interesting observation of the monkey hierarchies is that monkeys capable of stealing drinks are more respected by other monkeys.

Studies have been done on this intriguing phenomenon, spawning papers such as:

• Ervin et al (1989). Voluntary Consumption of Beverage Alcohol by Vervet Monkeys: Population Screening, Descriptive Behavior and Biochemical Measures. Pharmacology Biochemistry & Behavior, Vol. 36, 367-373.
• Juarez et al (1992). Voluntary Alcohol Consumption in Vervet Monkeys: Individual, Sex, and Age Differences. Pharmacology Biochemistry and Behavior, Vol. 46, 985-988.
• Mash et al (1996). Altered dopamine transporter densities in alcohol-preferring vervet monkeys. NeuroReport 7, 457 – 462.

It may also be interesting to note that Vervet Monkeys are not the only species capable (?) of getting drunk – there are many other recorded observations of other animals (e.g. elephants, cats, squirrels, rabbits…) that get drunk on alcohol.

So we wonder, while humans drink mostly for recreational purposes (or post-tragedy expressions), do animals drink merely for the high brought on by alcohol?

Man, being reasonable, must get drunk; the best of life is but intoxication. – Lord Byron

References:

“Alcoholic Vervet Monkeys! – Weird Nature – BBC animals” by BBCWorldwide. 26 January 2009.

The flocking behavior of thousands of starlings, flying in incredible aerial formations, to their roosting sites before settling into trees for the night never fail to amaze by-standers. Collective animal behavior of large groups of animals, such as bird flocks, fish school and mammal herds, is a fascinating natural phenomenon. The main goal of collective behavior among individuals is to maintain cohesion of the group. This cohesion is an important requirement for survival: small groups and individuals are significantly more susceptible to predation than animals belonging to large and highly cohesive aggregations. For example, when a flock of starlings is under attack by a falcon, the flock contracts, expands, and even splits. Despite continuously changing its structure and density, no bird remains isolated, and soon, the flock reforms as a whole.

A common starling, sturnus vulgaris

A group of starling in 'aerial display'

The question to answer is: what kind of interaction enables the birds to maintain cohesion in such a robust way? One proposed theory is that individuals align and attract each other base on metric distance [Couzin et al (2002)] which they can estimate by stereovision, retinal image size and optic flow [Goodale et al (1990)]. This means that such interaction would decay when distance between individuals is increased. For example, 2 birds 5metres apart would attract each other less than 2 birds separated by 1metre in between them. However, if such interaction is based on metric distance, changes observed during predator attack cannot be explained. This is because one would expect the loss of cohesiveness of the flock when metric distances between individuals become larger than the interaction range.

An alternative hypothesis has been proposed [Ballerini et al (2008)] regarding collective behavior: individuals attract each other based on topological interactions. This means that each individual interacts and tracks a fixed number of neighbors despite their metric distance. In this case, 2 birds in a sparse flock and separated by 5metres would attract each other as much as 2 birds in a denser flock and separated by 1metre in between them, provided the number of individuals between the 2 birds is the same. The strength of interaction would thus remain the same for flocks at different densities, enabling the flock to stay together during strong density fluctuations (for example in predator attacks).

To test this hypothesis, Ballerini et al (2008) observed and reconstructed the 3D positions of individual birds in flocks of a few thousand members using stereo-metric and computer vision techniques. Computational numeric simulations were also conducted to test the topological hypothesis with the metric distance hypothesis. The research group concluded that cohesion in flocks, interacting based on topological cues, are much more robust under perturbations than metric ones, and that topologically, each bird interacts on average with six to seven neighbors.

In conclusion, collective animal behavior is an interesting phenomenon which allows large groups of animals to maintain cohesion that is necessary for survival. However, the underlying principles of interaction between the animals are still not fully elucidated, and might be attributed to topological cues between individuals.

References:

ID Couzin, J Krause, R James, GD Ruxton and NR Franks. (2002). Collective memory and spatial sorting in animal groups. Journal of Theoretical Biology 218: 1–11.

MA Goodale, CG Ellard and L Booth. (1990). The role of image size and retinal motion in the computation of absolute distance by the Mongolian gerbil (Meriones unguiculatus). Vision Res 30:399–413.

M Ballerini, N Cabibbo, R Candelier, A Cavagna, E Cisbani, I Giardina, V Lecomte, A Orlandi, G Parisi, A Procaccini, M Viale and V Zdravkovic. (2008). Interaction ruling animal collective behavior depends on topological rather than metric distance: evidence from a field study. Proceedings of the National Academy of Sciences, U.S.A. 105: 1232–1237.