- Hill-topping
Hill-topping is a mate-location behaviour seen in many
insect s including butterflies, dragonflies,wasp s, [Alcock, J. 1985. Hilltopping behaviour in the wasp "Pseudomasaris maculifrons" (Fox) (Hymenoptera: Masaridae). J. Kansas. Entomol. Soc. 58:162-166.]beetle s [Schaedla, W. H. 2005. Hilltopping on termitaries by the Indochinese tiger beetle, "Heptodonta analis" (Cincindelidae). Insect Science 12(2):151] and flies. [Alcock, J. 1989. The mating system of "Mydas ventralis" (Diptera: Mydidae). Psyche 96:167-176 [http://psyche.entclub.org/96/96-167.html] ]Males of many butterfly species may be found flying up to and stay on a hilltop - for days on end if necessary. Females, desirous of mating, fly up the hill. Males dash around the top, competing for the best part of the area - usually the very top; as the male with the best territory at the top of the hill would have the best chance of mating with the occasional female, who knows the "top male" must be strong and thus genetically fit. Many authors consider this as a form of lekking behaviour. [Alcock, J. 1987. Leks and hilltopping in insects. J. Nat. Hist.21:319-328.] Many butterfly species including swallowtails, nymphalids, metal-marks and lycaenids are known to hill-top.
In some "Acraea" butterflies widespread infection by "
Wolbachia " results in a rarity of males and in these species the females widely engage in hill-topping behaviour. [Jiggins, Francis M. 2002. Widespread ‘hilltopping’ in "Acraea" butter£ies and the origin of sex-role-reversed swarming in "Acraea encedon" and "A. encedana" Afr. J. Ecol. 40:228-231] Female butterflies at hill-topping sites are predominantly of unmated individuals. [Shields, O. (1967) Hilltopping. J. Res. Lep. 6:69-178]Studies have shown that even slight elevation differences on flat terrain can trigger hill-topping behaviour. [Baughman, John F., Dennis D. Murphy 1988. What Constitutes a Hill to a Hilltopping Butterfly? American Midland Naturalist. 120(2):441-443 doi:10.2307/2426017]
The concentrating effect of hill-topping on butterfly populations makes such locations of special conservation significance. [New, T. R. 1993. Conservation Biology of Lycaenidae (butterflies). The World Conservation Union (IUCN) ISBN 2831701597]
References
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