Early on in this blog I did a report on the Peacock spider that dances and flashes his pretty colours to attract females. I have chosen to do another spider, the Jumping spider, who also dances but instead of colours he uses ‘hypnotism’. It’s not real hypnotism of course but the use of seismic vibrations to essentially mesmerise the female.

In a study conducted on a male jumping spider (Habronattus dossenus), the scientists found that in addition to the ornaments and movements, the males also use a complex repertoire of seismic signals for courtship. Virgin females were paired with either one of two males: they were either muted or non-muted. In this context the term ‘muted’ refers to unable to sense vibration.  

The results showed that females were significantly more likely to mate with a non-muted male to a muted one and that the latency to copulation, and the likely hood of cannibalism (the price for not putting on a good show), were both shorter in the non-muted males. This infers that the use of seismic vibrations is a critical component in the successful courtship of female H. dossenus.

References

Elias D. O, Hebets E. A, Hoy R. R & Mason A. C. (2005). Seismic signals are crucial for male mating success in a visual specialist jumping spider (Araneae: Salticidae). Animal Behaviour, 69(4), 931-938.

Unlike most courtship in animals, this week I have chosen an example where it is the female who courts the male. It is the courting behaviour of the Capuchin monkey.

A study was conducted on the tufted Capuchin monkey, Cebus apella, to observe their courtship and sexual behaviour. Courting typically takes place between a female and an alpha male. It starts as a one-way exchange by the females who court by trying to get the attention of the males. This only becomes a two-way exchange once the male is actively involved. Females will essentially conduct a hit and run approach on the males i.e. they will poke and/or grab parts of the male while he is not looking and then quickly run away. Quite often the male will ignore these advances at first or even get a little agitated. If the female eventually initiates a positive reaction from the male, he will reciprocate her advances with an eyebrow raise and then the mating will take place not long after.

More recently, studies on Capuchin monkeys in Brazil have shown that females in certain populations have resulted to throwing rocks at the males to get their attention. This could be a safety precaution as the males could be well known to be grumpy and throwing something at them from a distance is safer then actually grabbing them.

References

Carosi M & Visalberghi E. (2002). Analysis of tufted capuchin (Cebus apella) courtship and sexual behavior repertoire: Changes throughout the female cycle and female interindividual differences. American journal of physical anthropology, 118(1), 11-24.

It is often the case that males use their bright colours and strong presence to attract females and also to warn off other males. Male Augrabies flat lizards, Platysaurus broadleyi, have brightly coloured appendages that are used for both courtship and to deter other males. For courtship, males use visual cues for gender recognition and chemical cues for enticing females. If she permits close proximity then the male will use a tongue-flicking technique at her posterior end which is presumed to be in order to assess her reproductive viability. Males only use visual cues to present their masculinity to other males.

This system of honest signalling can be problematic for young males as gaining territory and proximity to females can be quite tough with other mature males around. Therefore some males employ a tactic known as female mimicry.

This involves delaying the onset of their colours, therefore their male appearance, to look like a female. This allows them to walk around other males with a decreased chance of getting into an altercation, as males can be very territorial, and get close to females without other males knowing. This can work as its mainly chemical cues that females use to assess the males.

There are limits to this adaptation though as the disguise only works in a visual sense. If these young males stay far enough away from other males they will be fine however if they stray too close, mature males will sense, through chemical cues, that they are males, not females, and therefore are more likely to frighten off or hurt the young males.

References

Whiting M. J, Webb J. K & Keogh J. S. (2009). Flat lizard female mimics use sexual deception in visual but not chemical signals. Proceedings of the Royal Society B: Biological Sciences, 276(1662), 1585-1591.