Daphnia lumholtzi – on the left, reared in the presence of fish, on the right, in the absence of fish

A study about to be published in Behavioural Ecology and Sociobiology shows that these kind of effects can also involve prey learning, even before they have hatched out of the egg. Maud Ferrari and Douglas Chivers investigated the behaviour of woodfrog (Rana sylvatica) tadpoles in response to a predator, the Tiger salamander. These tadpoles show no innate prey recognition, but if they are exposed to the smell of salamander before they hatch from they egg, they avoid predators when they have turned into tadpoles, by reducing their movement. [It may seem counter-intuitive to talk of "smell" in water, but many aquatic animals (including fish) have clearly distinct smell and taste pathways. I'll blog about this in the future.]

Ferrari and Chivers have taken this a step further, by seeing whether the tadpole embryos can actually learn the threat posed by a predator. To test this, they presented frogspawn with salamander odour coupled with cues from injured tadpoles, for two hours a day over five days, then tested the tadpoles for their responses to the predator.

They found that the amount of freezing shown by tadpoles was dependent on the concentration of the injured tadpole cues coupled with salamander smell, demonstrating that the embryos had learned to associate the two signals. There also seemed to be a time of day effect – the effect was stronger when learning took place in the afternoon, compared to the morning or early evening – although further experiments need to be done to confirm this.

In some species (especially insects), early experience can lead to the non-genetic transmission of preferences from one generation to another. This study shows that interactions between predator and prey can be extremely complex, involving innate responses, and learned changes in behaviour, which may even occur before birth.

Original article (open access).

BBC page, with quotes from Ferrari.

This video from Natalie Beresford (First Year). Why might this cockatoo dance? Is it like a bored tiger or an emprisoned polar bear, or is there something else going on? Why does it do the bow at the end?

Those Final Years who have done the Animal Behaviour course may remember me showing videos of robots behaving like ants. The same Belgian group led by Deneubourg has now turned its attention to cockroaches, as shown by their article in this week’s issue of Science. If you cover a robot with cockroach pheromone, the real roaches follow it. I’m not sure what this is really telling us, apart from indicating the power of the pheromones, or the effect of introducing another object into the cockroaches’ shelter, but the results are impressive.

BBC article (with video); Science news article, Science research article, with supplementary videos (subscription needed).

Definitely a video that will make you laugh! The male red-capped Manakin (Pipra mentalis), a bird found in Costa Rica and Belize (watch out for it if you go there on the Field Course), does a rather cool moonwalk as part of its courtship ritual. It also produces some rather bizarre clicks with its wings. Two YouTube videos show these behaviours:

Researcher describes her work on the Manakin, including excellent high-speed film of how the wing-clicking, concluding with an odd imitation and a rather obvious M Jackson soundtrack.

Better footage, but the English soundtrack has been irritatingly overdubbed in what my ignorant ear thinks is either Russian or Polish. The bird will make you laugh, though.

If a chimp is being attacked, it will exaggerate its cries if there is a high-ranking chimp around who could challenge the aggressor.

BBC summary; original research article in PNAS (open access).

The smell of a hunter!  New study, to appear in Current Biology, shows that elephants apparently remember the smell and look of clothes worn by Maasai hunters, but are not perturbed by the clothes of Kamba agriculturalists who pose no threat.

BBC summary; Current Biology article (open access).

Slightly cheesy US video about the amazing effects of nematode infestation on snail behaviour and its role in the nematode life-cycle. But the close-ups of the snail are pretty cool.

This story appeared on the BBC website and the national press today. What’s wrong with it? My 9-year old daughter spotted it straight away (which is obviously more than the journalists did!). Clue: you’d only have to change one letter to get a more likely explanation.

“Visitors to a Somerset stately home have been warned to keep away from a peacock – after he seriously damaged a luxury car he mistook for a mate. The amorous bird caused £4,000 worth of damage to an employee’s Lexus in the grounds of Sir Benjamin Slade’s country manor, Maunsel House, near Bridgwater. “It started when he fell in love with a Lexus, which was in a very distinct peacock blue,” said Sir Benjamin.”

Pictures from The Guardian showing various ways in which tracking devices are used in studying animal movement and migration.

Crow tool use, as you’ve never seen it before! Videos from Oxford group who strapped miniature cameras onto crows in New Caledonia and watched how they made tools out of bits of twig, and what they used them for. There’s an excellent summary on the BBC website, together with links to all the videos. The original article is published in Science, but you or your institution will need a subscription to see more than the abstract.