Ecology of a relict population of the vulnerable butterfly Pyrgus sidae on the Iberian Peninsula (Lepidoptera: Hesperiidae)

Abstract

Abstract. There are isolated populations of the endangered butterfly, Pyrgus sidae, on the Iberian Peninsula. The mark-releaserecapture method was used to study the population parameters, the use of resources and the spatial distribution of a population in the centre of Spain. The estimated number of males and females within the population were similar and did not differ significantly from a ratio of 1 : 1. Total population size was estimated to be 569 ± 83 individuals. Potentilla recta is the principal adult nectar source and larval food plant, and its abundance is correlated with the number of marked and recaptured butterflies. The average total distance moved between capture and recapture was significantly greater for males than females, but the average daily distances moved were similar for both sexes. The spatial distribution of the movements of males and females was of a uniform type and lacked a predominant flight direction, which is typical of sedentary species. Continuing the traditional land use (cattle grazing or hay mowing) of the habitat of the species keeps the habitat open, which is necessary if the butterfly is to survive at this locality. These management practices favour P. recta, which would otherwise succumb to competition from invasive shrubs. Taking into account the habitat requirements of this species, it is important to conserve the mosaic of meadows already present in the area.

<span lang="EN">Comparative analysis and taxonomic use of the morphology of immature stages and natural history traits in European species of Pyrgus Hübner (Lepidoptera: Hesperiidae, Pyrginae)</span>

“…The females layed eggs on fresh leaves of the larval foodplants in all cases, with the exception of P. cinarae (Rambur), which used the fruits (head of achenes of Potentilla recta and P. hirta or the polyachenes of Filipendula vulgaris) and P. sidae, which laid eggs on the flowers. These exceptions are congruent with the ecological specialization of both species (Nel 1984, Hernández-Roldán et al 2009, Hernández-Roldán et al 20092011a).…”

“…Larvae of all species feed on the leaves and again the exception is P. sidae, which feeds on the flowers and stipules of the plant during the first instars and after that also feeds on the leaves (Hernández-Roldán et al 2009). All species build larval shelters by joining leaves with silk threads.…”

Tracing the origin of disjunct distributions: a case of biogeographical convergence in Pyrgus butterflies

“…Being restricted to habitats not strongly affected by climatic oscillations could be the product of an unusually limited dispersal capability, which would account for the inability to have expanded during interglacial periods, producing a long‐term disjunct distribution. If this hypothesis is correct, the predicted dispersal capability of P. cinarae should be substantially lower than that of P. sidae , which is difficult to imagine because a capture–mark–recapture study on Iberian P. sidae showed that this is already a typical sedentary species with low dispersal capabilities (Hernández‐Roldán et al. , 2009).…”

“…We reported the mode and 95% highest posterior densities (HPD) for each parameter (2,000,000 Markov chain interactions; burn‐in = 500,000; M = 0; T max = 5; θ = auto‐initialize). In the absence of a specific mutation rate for Pyrgus , we assumed a generation time of 1 year based on the evidence that these species are univoltine (Hernández‐Roldán et al. , 2009; Wagner, 2009), and a 1.5% Myr −1 divergence rate for arthropod COI (Quek et al.…”

“…Despite the apparent presence of suitable habitats and host plants ( Potentilla recta and Potentilla hirta ) between the Iberian and non‐Iberian populations, no studies have suggested their connectivity. Pyrgus cinarae and P. sidae display similar ecological preferences (they frequently co‐occur in the same habitats and share host plants), and both have low dispersal ability (Hernández‐Roldán et al. , 2009; Wagner, 2009), especially across water surfaces (they are not present on islands or in North Africa), a trait shared by all members of the genus Pyrgus .…”