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The life time, looks a biologist on the Being and Time - September 21, 2010

Males light shine for females ... Several

fireflies (Coleoptera : Lampyridea ) attract females by flashing at a different frequency for each species. Females respond by flashing their way to them, which allows the meeting and reproduction. It has been observed in some species that numerous individuals sync, sometimes in an entire forest, producing a kind of effect "Christmas garland" startling. The reason for this synchrony is not well established. A recent study published in Science reveals that this would be to facilitate detection by females.

Fig 1: The fireflies emit light from the underside of their abdomen. [Img

] Source: Firelfly-pictures here

Some perspective for understanding the experience ... It may be noted that this experiment and fit is meaningful - in certain circumstances: namely that it is mainly the frequency of blinking is the stimulus-signal (the useful component to trigger this behavior) light response in the female. And that this exchange is part of the courtship behavior.

The reproductive behavior of fireflies
• According Discover Life in America (dlya) , upon nightfall, the female Photinus carolinus waiting on the ground that males who spend emit their signal flashing (a burst of 5 - 8 flashes followed by a dark phase of 5-8 seconds). They meet during this "silence" with their visual flashing signal specific. While the male finds the female and breed with. The reasons for these flashes are specific: for each species succession of flashes and the time between bursts is different. Figure 3 shows the temporal patterns of males from 6 different species. Figure 3: Reasons for specific flashes several species of fireflies, the succession of flashes and the time between bursts is specific. [Img ] Source: Discover Life in America

here

Why this exchange stereotypical flashes?
• I think we can consider this specific exchange of flashes of male and the female as a stereotyped behavior, equivalent to that of the stickleback (
intranet.jpg
• ). It would have the effect of select individuals for mating of the right species, good sex, and ready for breeding. However, according
(

Milne and Milne, 1980

) in the excellent article on ADW predators intercept and exploit the communication and females of another species of firefly Pho

turis pyralis

• mimic the signal Pho
tinus pyralis

and thus attract males

(no comments thank you feminists) that are eaten. Or more precisely, the predatory injects a poison that paralyzes and liquefies the prey, whose contents are then aspirated. Bon appetite! Why males kindle more ... ? It may be noted that males assume a greater share of risk by being more visible, as in birds with their singing, for example.

was often explained this difference by the asymmetry of reproductive investment: as the sperm are smaller than eggs, the males take more risks that produce more offspring, while Females were more cautious more descendants.

"intrasexual selection means the selection that takes place between individuals of the same sex. It is through direct competition to gain the favor of an opposite-sex partner. Intrasexual selection is usually more obvious in males because for male reproductive success depends much more on the ability to find a partner that produce the cells necessary for this function (although this will be the reverse for females). "
• Campbell, NA, et al. (2004). Thus the fireflies are the current descendants of males who were kind flashed the speed that suited to attract the attention of females ... and those who chose a male and discreetly flashed but adequately their consent.
• (No comments macho feminist or thank you).

More info on these fireflies?

• Very beautiful images of fireflies and their journeys to the site Firefly-pictures.com
• Very rich in information (what they eat, their life, etc.. ) Photinus
@ ADW Animal Diversity Web

Explanations on the rhythms of flashing

Discover Life in America and the Great Smoky Mountains National Park's : dlya

How have they measured the stimulus that triggers the flash of the female?

The reason for this mass synchronous flashing led many circumstances, but the search Moiseff, A. et al. (2010) provides some answers based on rigorous data and discussed critically and carefully. It's called science ... To explore how females responded to various stimuli frequency and position Moiseff, A. et al. (2010) have placed North American firefly females (Photinus carolinus
• )
in an environment with artificial male (light diodes LED) that flashed in a more or less synchronously.
• Fig 2: male artificial lures made of a light emitting diode (LED) have explored the reactions of females. [Img ] Source: Scientific American in Andrew Moiseff here
They responded to 82% of "male" artificial synchronous and only 3% of males out of sync. See Figure 4.

Fig 4: Response Rate (F) females at various degrees of synchronization (AD) of males artificial. (E) normal pattern of flashing of the male Photinus carolinus

. [Img

] Source: Moiseff, Andrew, et al. (2010). Full figure and legend
here It is clear that females respond more to a male who flashes in unison with other than a male who flashes in the "noise" visual fireflies uncoordinated, even if each product although the rate specific to the species. What has been encouraging males flash in unison? They note that as male fireflies fly, detecting the frequency of blinking of an individual among other means to keep this individual in his movements while measuring the time of extinction and ignition. Loaded in a visual environment, they think that this task may be too difficult for females,

(no comments macho 'thank you)

that does not detect some flashes outside the region observed. A bit like if we tried to follow a blinking ball the night on a street lined with flashing neon signs. Or like trying to play tennis in a disco with strobe lighting. The authors note that one can not exclude an alternative hypothesis: females simply prefer synchronous stimuli. Difficult to determine. In science it is not sufficient to show that the proposed model is compatible with the data, we must also show that other possible explanations are not supported by the data. Or not as well.

"Future experiments Will Be required to Differentiate Between Alternative thesis.

However, behavioral considerations lead us to favorites The pattern recognition

interpretation."

Prudente conclusion ... Drown in the mass to be better identified? Thus

paradoxically, to be better identified each male's interest to blink at the same time as the others. Maybe the dress of young conformism is also an indirect way to enhance and attract the attention of the other in the overabundance of stimuli they face? Sources

Campbell, NA, & Reece, JB (2004). Biology: De Boeck.

dlya

: Discover Life in America and the Great Smoky Mountains National Park's

Moiseff, Andrew Copeland, Jonathan. (2010). Firefly Synchrony: A Behavioral Strategy to Minimize Visual Clutter

. Science

9 July 2010: Vol. 329. no. 5988, p. 181