LSM1303 Animal Behaviour Student Blog : ants

Friend or Foe?

LIM HWEE HOON — Fri, 21 Mar 2008 15:38:00 GMT

Many studies have established the Symbiotic Relationship between ants and aphids, that is where two or more animals depend on each other to survive. Aphids are small, soft-bodied, pear shaped insects which are commonly found on nearly all indoor and outdoor plants, as well as vegetables, field crops, and fruit trees. They feed on these plant juices and excrete a substance called honeydew which is rich in nutrients ants require. Honeydew is the clear, sticky dropping that is produced by aphids when they can't use all the sugar that they get from plants. In return, the ants will protect these aphids from their predators such as beetle, flies and wasps.

The ants will use their forelegs to stimulate the aphids to excrete honeydew, and store the honeydew collected in their abdomens until is full, whereupon they will return to the nest and regurgitate to feed other members of the colony.

Ants taking care of the aphids.

Nevertheless, while it may seem like both are benefiting from one another, ants obtaining food from aphids while aphids getting protection from the ants. Professor Vincent Jansen of Royal Holloway's School of Biological Sciences, concludes: "Although both parties benefit from the interaction, this research shows is that all is not well in the world of aphids and ants. The aphids are manipulated to their disadvantage: for aphids the ants are a dangerous liaison."

Research have shown that ants have been known to bite the wings off the aphids in order to stop them from getting away and the chemicals produced in the glands of ants can also sabotage the growth of aphid wings. In addition, new study has also pointed out that the ants' chemical footprints can also slow down the aphids' movements, thus keeping them close to the ant colony. Ants have even been known to occasionally eat some of the aphids themselves. Therefore, ants may seem like both a friend and a foe to the aphids.

References:

http://www.eurekalert.org/pub_releases/2007-10/icl-ha100907.php

http://www.ivyhall.district96.k12.il.us/4th/kkhp/1insects/aphid.html

http://www.youtube.com/watch?v=CwzUSRPo7PM&feature=related

“Aphid-Ranching Ants,” by John Walker. 10 Jul 2003.

“Herding aphids – how 'farmer' ants keep control of their food.” A joint news release from Imperial College London, Royal Holloway University of London, and the University of Reading, 10 Oct 2007.

Trench Warfare !

SHINDERJEET KAUR — Fri, 21 Mar 2008 06:36:00 GMT

If you thought Trench Warfare was a military tactic of the French and Germans of the past, you might want to you might want to reassess this hasty conclusion. A species of ants, known as the Allomerus decemarticulatus employs a somewhat similar tactic to catch its prey. These ants are masters in taking cover in the ground and setting up the ideal trap which is extremely successful in luring insects of a much bigger size than themselves. To find out the details of their master “torture” plan and of how they deceive their unsuspecting victims, have a look at the links at the end of this short write-up and the images provided should help you better visualize this unique and indeed ingenious method of feeding. Here is a quick summary of their grand plan:

Using plant fibers and fungus, the ants engineer the perfect trap.
They leave holes in the trap, big enough to poke their heads through.
Its victim happens to land at this strategic spot.
It finds its legs or antennas, or anything that the ants can grab being pulled and torn from it. This causes the victim impairment or even death.
The ants in this colony, have earned themselves a meal and will carve out their winning which they will share amongst themselves.
Here’s a limiting factor to their tactic though, the victim’s legs, hands or antennas have to be able to fit into these holes to for the plan to be successful.

I find this article particularly interesting because it is relevant to the topic of cooperative hunting we saw in the Harris Hawks as discussed in lecture. Because these ants work in a colony, they are able to feed on such a large insect which would otherwise not be possible if they were to attempt this feat alone.In fact, there is no doubt that the prey they caught collectively could be a predator if not for this method of kill.Pretty interesting reversals of prey and predator !

Besides that, the articles also mention that these ants work in a hierarchy of which we encountered during lecture again. Apparently, the oldest ants in the colony will do the work of trap building. It must come from experience that they are chosen to carry out this critical task. Any loopholes will evidently result in a failed plan which the ants overcome with the division of labor.. The younger ants will learn from their elders and the tradition will then pass down the successive generations. Reminds us a little about the archer fish too with regards to learning the exact positing from which it should sprout water and get its prey !

In sum, these articles have highlighted both feeding and predatory behavior and the importance of hierarchy in ants.

Ants; traps; torture; prey; cooperative hunting; feeding; colony; hierarchy; division of labor; group30

References

Amazing Ants Ambush Prey from Foxholes

By Robert Roy Britt, LiveScience Senior Writer ,20 April 2005

http://www.livescience.com/animals/050420_ant_trap.html

Fierce ants build 'torture rack', 23 April 2005

http://news.bbc.co.uk/2/hi/science/nature/4472521.stm

"Torture Racks" Are First Known Traps Made by Ants, James Owen, 20 April 2005

http://news.nationalgeographic.com/news/2005/04/0420_050420_ant_trap.html

Royal Corruption Even In The Ant World!

CHEW MIN RU CAROLINE — Fri, 21 Mar 2008 06:12:00 GMT

If you think that only the human society is rife with corruption, you will realise that you are wrong after reading this article!

All ants are social in habit as they live together in organized colonies. Whenever we talk about ants, we will always think of them working together for the benefit of the colony rather than for individual gain, just like what is shown in this video.

Ants may be held up as ideals of social co-operation but they can be as sneaky as humans beings and their colonies are rife with corruption – with those from the royal line the worst offenders.

Dr Bill Hughes from Leeds' Faculty of Biological Sciences has found evidence showing that genes play role in ant social status. In the past, it had been thought that queens were produced solely by nurture, with some larvae being fed special or extra food to help their development. However, this is not true for the leaf-cutting ants or Acromyrmex echinatior.

The female leaf-cutting ants carry out all the work of the colony and can become one of two types of workers. Large workers go out and harvest vegetation to grow a fungus that nourishes larvae in the nest. Small workers stick close to the nest and tend to the fungus. Large workers are two or three times the size of the small ones. The large ones cut a wider range of vegetation; small ones are better able to work within the densely packed structure of the fungus garden. The males practically did nothing but just eating, sleeping and mating. However, the genes of some male ants do help the females to cheat in order to be the queen.

DNA fingerprinting on five colonies of leaf-cutting ants are carried out and discovered that the offspring of some fathers are more likely to become queens than others. These ants have a 'royal' gene or genes, giving them an unfair advantage and enabling them to cheat many of their altruistic sisters out of their chance to become a queen themselves. Leaf-cutting ant queen mates with up to 10 males at a time and they have the choice to mate with those male ants that can allow them to produce offsprings that have higher chances of becoming a queen.

I find it surprising that even in tiny insects like ants, which always cooperate and work together in groups to achieve their aims; cheat and fight to be the one who has the most power. Thus, we can see that human beings are not the only ones cheating and fighting for power, even ants do that!

Here is another article which describes that the genetics did indeed play a part in caste determination: Unusual Reproductive Behavior Of Odd Ants Surprises Scientists

References:

1) "Genes Play Role in Ant Social Status" By Nancy Touchette, Genome News Network, 25 July 2003

2) "Royal Corruption Is Rife In The Ant World" , ScienceDaily, 17 March 2008

3) "Love cheats, nepotism and corruption" , The Times, 12 March 2008

4) "Antagonism rife in the ant world" , BBC News, 12 March 2008

5) "Unusual Reproductive Behavior Of Odd Ants Surprises Scientists" , ScienceDaily , 26 Jan 2005

Video Reference:

"Costa Rican Rainforest - Leaf Cutter Ants" from Youtube

A seaweed or sea creature?

OH PEI XIAN CHRISTINA — Fri, 21 Mar 2008 05:50:00 GMT

The next time you step into an aquarium or go scuba diving deep in the seas of Australia, don't miss these graceful sea creatures!

A Leafy Sea Dragon

Native to the seas of South and East Australia, the gentle Leafy Sea Dragon is actually a type of seahorse that lives amongst large floating rafts of seaweed. The leafy sea dragons (Phycodurus eques), is one of the most remarkable examples of camouflage in the animal kingdom. Its mimicry of floating vegetation is remarkable and enables it to forage for food with little chance of being eaten itself.

Mimicry is the ability to blend in to ones surroundings or to look similar to another organism.

The name of the Leafy sea Dragon comes from their appearance, with long leaf-like protrusion all over the body. These leaf-like protrusions are not used for propulsion; they serve only as camouflage. The leafy sea dragon propels itself by its pectoral fin on the ridge of its neck and a dorsal fin on its back closer to the tail end. These small fins are almost completely transparent and difficult to see as they undulate minutely to move the creature sedately through the water, completing the illusion of swaying seaweed and kelp.

Catch a video of leafy sea dragons in the deep seas of Australia!

No wonder they belong to the same family...

The Leafy Sea Dragon belongs to the family species Syngnathidae, along with the seahorse. It is a cousin of the pipefish and a cryptic relative of the weedy sea dragon.

A Weedy Sea Dragon

The seahorse is also a master of mimicry and camouflage. It is able to change its colour rapidly in order to blend into their surroundings and evade predation. Another defense mechanism used is mimicry in which some seahorses have adapted appendages that allow them to hide among algae and corals.

Like the sea horses, male leafy sea dragons are responsible for child bearing. However, instead of a pouch like that of the sea horses, male sea dragons have a spongy brood patch on the underside of the tail where females deposit their bright-pink eggs during mating. The eggs are fertilized during the transfer from the female to the male. The males incubate the eggs and carry them to term, releasing miniature sea dragons into the water after about four to six weeks.

Watch a video of a seahorse giving birth!

Mimicry in other species of animals ...

In fact, mimicry is a very common "trick" used by many other species of animals like the Alcon Blue butterfly larvae for example. The study by David Nash and colleagues from Centre for Social Evolution (CSE) at the University of Copenhagen, Denmark, showed that the Alcon Blue Butterfly larvae mimic the surface chemicals that the ants have on their own brood. The closer the mimicry, the faster they get picked up by ants and taken back to the ant nest and put amongst their own brood.

These larvae are parasites and can be highly destructive. Once they successfully tricked the ants into bringing them back to the ant nests, they eat some of the ant brood and will also be fed by the worker ants. They are also fed in preference of the ants' own brood.

After thoughts...

Mimicry and camouflaging of animals is an interesting aspect of animal behaviour. I’m constantly amazed by the animals’ art of mimicry and camouflaging. Animals' mimicry and camouflaging is to avoid danger and ensure continuous supply of food. In the case of the Alcon Blue Butterfly larvae, its parasitic and mimicry behaviour guaranteed the continuos offspring of the Alcon Blue Butterfly. (Poor ants...)

The Leafy Sea Dragon art of mimicry and camouflaging is essential to ensure its survival in its environment. However, they are constantly threatened by human and nature. Many divers like to keep them as pets. Their soft and unstable body caused them to be easily tossed around in huge storms. These factors have caused their numbers to shrink in recent years.

Hence, the next time you are diving in the sea, keep an eye for these creatures as you may have swam past them without noticing! But, just admire them and don't bring them home yah!

References

http://library.thinkquest.org/12880/seahorse.html

http://seahorse.fisheries.ubc.ca/faq.html

http://biology.kenyon.edu/stures/Compsnelson/seafacts.htm

http://www.bbc.co.uk/nature/programmes/tv/wilddownunder/virtual11.shtml

http://members.cox.net/sandymccaw/Musica_Dolce/leafy%20dragon.htm

http://animals.nationalgeographic.com/animals/fish/sea-dragon.html

www.arkive.org/species/GES/fish/Phycodurus_eques

http://www.divegallery.com/Leafy_Sea_Dragon.htm

http://en.wikipedia.org/wiki/Syngnathidae

http://www.amonline.net.au/fishes/students/focus/seadrag.htm

http://www.divegallery.com/Weedy_Sea_Dragon.htm

http://news.bbc.co.uk/1/hi/sci/tech/7171196.stm

http://youtube.com/watch?v=BPlnqckOPdY

http://youtube.com/watch?v=rku0t40SJqY

Who packed a juicy dragonfly for lunch on campus?

TEO SHU WAN JILLYN — Thu, 20 Mar 2008 17:00:00 GMT

Caught on camera were ants carrying a dragonfly many times their size. Cooperation speaks out loud here! Also find out how these tiny but mighty creatures communicate and help each other out at work.

I took this video by chance in the toilet of the NUS arts campus. You can see many ants (House ants if I'm right) carrying a dead dragonfly significantly bigger than them and performing a turn as though they knew they were caught on camera. I found out that house ants run about in an erratic fashion when alarmed. I was grossed out but also amazed by the strength of the tiny creatures and decided to read up on how ants work together to transport food etc. I found an interesting article named “From Ants to People, an Instinct to Swarm”.

Army ants, which Dr. Couzin has spent much time observing in Panama, are particularly good at moving in swarms. If they have to travel over a depression in the ground, they erect bridges so that they can proceed as quickly as possible.

"They build the bridges with their living bodies," said Dr. Couzin, a mathematical biologist at Princeton University and the University of Oxford. "They build them up if they're required, and they dissolve if they're not being used."

Dr Couzin spent much time observing Army ants in Panama and found out that they are proficient in moving in swarms and if they had to travel over a depression in the ground, they form bridges with their bodies so that they can proceed with their “work” as quickly as they can. An interesting fact I read about was that army ants return to their nest with food travel in a dense column and a three-lane highway of army ants can stretch up to 140 meters from the ant nest, comprising hundreds of thousands of insects!

In another article “'Living plugs' smooth ant journey”, scientists from the University of Bristol investigate how ants used their own bodies to plug potholes to provide a faster route between their prey and nest. Not only did the ants plug the hole, they would size-match themselves to a hole which fits best. And amazingly, the ant could remain in place for hours, while the rest move back and forth across the trail.

Dr Powell said: "Broadly, our research demonstrates that a simple but highly specialised behaviour performed by a minority of ant workers can improve the performance of the majority, resulting in a clear benefit for the society as a whole."

He was referring to how speeding up the route by covering the holes with their bodies could increase the ant’s daily prey intake.

The communication between ants is something amazing because in my impression, they are so tiny! They communicate with each other through chemicals called pheromones and when one of them find food, they mark a trail on the way back to the colony, which is reinforced by other ants when they head back to the colony. Ants can carry up to twenty times their weight!

Besides chemical communication, I found out that another communication method used more commonly by ants who occupy wooden nest is accoustical communication. For example, carpenter ants communicate through drumming in times of danger. A drummer ant strikes the substrate with its mandibles and gaster while rocking its body back and forth. Signals would be transmitted through the nest. Another way which they produce a high pitched sound like a “chirp” is through rubbing together the organs at the rear of their bodies!

"The more ants are studied the more they reveal capabilities that exceed their small size." - Whit Gibbons

References

From Ants to People, an Instinct to Swarm by Carl Zimmer. The New York Times, 13 Nov 2007.

'Living plugs' smooth ant journey BBC News, 26 May 2007.

Sheppard software

The Miracle In The Ant

Pictures

http://www.alexanderwild.com/gallery/1455585/1/70631814#70631814

http://thinkorthwim.com/2007/05/28/ants-using-themselves-as-living-bridges/