Navigation Links
Zoologists challenge longstanding theory that 'eyespots' mimic the eyes of predators' enemies

Circular markings on creatures such as butterflies are effective against predators because they are conspicuous features, not because they mimic the eyes of the predators own enemies, according to research published today in the journal, Behavioral Ecology[1]. Zoologists based at the University of Cambridge challenge the 150-year-old theory about why these markings are effective against predators.

Many animals possess protective markings to avoid predation, including patterns to reduce the risk of detection (camouflage), to indicate that the animal is toxic or inedible (warning colours), or to mimic another animal or object (mimicry and masquerade). In addition, many creatures such as butterflies, moths, and fish possess two or more pairs of circular markings, often referred to as eyespots. Many eyespots are effective in startling or intimidating predators, and can help to prevent or stop an attack. For the past 150 years it has been assumed that this is because they mimic the eyes of the predators own enemies.

However, recent work by University of Cambridge zoologists, Martin Stevens, Chloe Hardman, and Claire Stubbins, indicates that this widely-held hypothesis has no experimental support.

Stevens, Hardman, and Stubbins tested the response of wild avian predators to artificial moths, created from waterproof paper. Specific patterns, such as intimidating eyespots of different shapes, sizes and number, and with different levels of eye mimicry, were printed on to the paper using a high quality printer. These moths were then pinned to trees of various species at a height of one to three metres in the mixed deciduous Madingley Woods in Cambridgeshire, UK. Attached to each of the artificial moths was an edible mealworm as a temptation for woodland birds such as the blue tits, great tits, blackbirds, and house sparrows.

The zoologists discovered that artificial moths with circular markings survived no better than those with other conspicuous features and that the features of eyespots which most encouraged predators to avoid them are large size, a high number of spots, and conspicuousness in general.

As Dr Stevens explains, the birds were equally likely to avoid artificial moths with markings such as bars and squares as they were to avoid those with two eye-like markings. This leads us to conclude that eyespots work because they are highly conspicuous features, not because they mimic the eyes of the predators own enemies. This suggests that circular markings on many real animals need not necessarily, as most accounts claim, mimic the eyes of other animals.


Contact: Martin Stevens
Oxford University Press

Related biology news :

1. LSU researchers challenge analyses on sustainability of Gulf fisheries
2. From stem cells to organs: The bioengineering challenge
3. UA-led research team awarded $50 million to solve plant biologys grand challenge questions
4. Weird water: Discovery challenges long-held beliefs about waters special properties
5. Triage study challenges notions of emergency medical response to disaster
6. Choices and Challenges forum to address nuclear power issue
7. Challenges remain in reintroducing American chestnut
8. Dominant cholesterol-metabolism ideas challenged by new research
9. Model connects circuit theory to wildlife corridors
10. Innovative model connects circuit theory to wildlife corridors
11. Breakthrough technology observes synapse in real time, supporting theory of vesicular recycling
Post Your Comments:
(Date:10/29/2015)... 29, 2015  The J. Craig Venter Institute (JCVI) ... Synthesis and Biosecurity: Lessons Learned and Options for the ... and Human Services guidance for synthetic biology providers has ... --> --> Synthetic biology ... potential to pose unique biosecurity threats. It now is ...
(Date:10/29/2015)... OXFORD, Connecticut , October 29, 2015 /PRNewswire/ ... "Company"), a biometric authentication company focused on the ... Wocket® smart wallet announces that StackCommerce, a leading ... will be featuring the Wocket® smart wallet on ... NXTD ) ("NXT-ID" or the "Company"), a ...
(Date:10/27/2015)... Oct. 27, 2015 Synaptics Inc. (NASDAQ: SYNA ... that Google has adopted the Synaptics ® ClearPad ... to power its newest flagship smartphones, the Nexus 5X ... --> --> Synaptics ... provide strategic collaboration in the joint development of next ...
Breaking Biology News(10 mins):
(Date:11/30/2015)... and PETACH TIKVAH, Israel , Nov. 30, ... BCLI ), a leading developer of adult stem cell technologies ... Cell Therapeutics Ltd., has been awarded an additional grant of ... the Chief Scientist (OCS). This grant, the second this year, ... activities to approximately $1.8 million (approximately NIS7 million).  ...
(Date:11/27/2015)... PA (PRWEB) , ... November 27, 2015 , ... ... Technical Program that includes over 2,000 technical presentations offered in symposia, oral ... chemistry and applied spectroscopy, covers a wide range of applications such as, but ...
(Date:11/26/2015)... November 26, 2015 --> ... specializing in imaging technologies, announced today that it has received ... of the Horizon 2020 European Union Framework Programme for Research ... clinical trial in breast cancer. , --> ... --> --> The study aims ...
(Date:11/25/2015)... 2 nouvelles études permettent d , ... les souches bactériennes retrouvées dans la plaque dentaire ... . Ces recherches  ouvrent une nouvelle voie ... de l,un des problèmes de santé les plus ... --> 2 nouvelles études permettent d , ...
Breaking Biology Technology: