Intersexual niche segregation in Cepero’s Ground-hopper, Tetrix ceperoi

Abstract

Sexual differences in habitat preferences have been reported from a variety of animal taxa. However, the ultimate causes for this intersexual niche segregation remain poorly understood. It has been suggested that sexual dimorphism is a consequence of dimorphic niches based upon different reproductive costs and activities of the sexes. Here we provide evidence from field data to examine this hypothesis by studying the behavioral background of niche segregation in Tetrix ceperoi. Our data revealed distinct sexual differences in the substrates on which the insects perched and in the solar radiation of these locations. Males were found at brighter locations and more often on bare ground than females. Incorporation of behavioral data in our analysis showed that patches of bare ground were mainly utilized during mating behavior, in which males invested more time than females. In contrast, females spent more time resting and feeding in the vegetation. Intersexual differences in the proportion of autotomized individuals indicate that males might suffer higher predation risks. These patterns support the dimorphic niches hypothesis, which suggests that differential habitat utilization is caused by differences in the life history strategies of males and females, since males should accept a higher predation risk due to the benefits of multiple matings. Females should invest more time in gaining nutrients and energy for egg production and survival, whereas males should spend more time with searching for mates. We suggest that behavioral covariates should more often be implemented in ecological analyses, since these might have a strong explanatory power.

The importance of validated alpha taxonomy for phylogenetic and DNA barcoding studies: a comment on species identification of pygmy grasshoppers (Orthoptera, Tetrigidae)

“…Colour polymorphism is widespread within Tetrigidae species, even within the same populations (e.g. Nabours 1930; Hochkirch et al 2007, 2008), see also the current study by Zhao et al (2016). From the beginning of Tetrigidae taxonomy, colour variation has caused taxonomic uncertainties until it was recognized as an intraspecific phenomenon, see e.g.…”

Niche overlap in allotopic and syntopic populations of sexually interacting ground‐hopper species

“…In all Tetrigidae sexual size dimorphism is distinct (Hochkirch & Gröning, 2008): Females are substantially larger than males as they pass through one additional nymphal instar (Ingrisch & Köhler, 1998). Males of both species exhibit a stronger preference for bare ground than females, possibly due to the greater energetic requirements of the females (Forsman & Appelqvist, 1999; Hochkirch et al , 2007b). Females of both species oviposit in moist soil.…”

Niche Conservatism among Allopatric Species of the Grasshopper Genus Afrophlaeoba Jago, 1983 in the Eastern Arc Mountains (Tanzania)

“…Most grasshopper species are specialised on a particular vegetation structure and many species exhibit behavioural adaptations to their microhabitat (Sänger 1977;Uvarov 1977). In many cases, there are also intersexual differences in microhabitat utilisation due to sex-specific differences in energy budgets (Hochkirch et al 2007). …”