Viviparity is associated with larger female size and higher sexual size dimorphism in a reproductively bimodal lizard.

Squamate reptiles are central for studying phenotypic correlates of evolutionary transitions from oviparity to viviparity because these transitions are numerous, with many of them being recent. Several models of life-history theory predict that viviparity is associated with increased female size, and thus more female-biased sexual size dimorphism (SSD). Yet, the corresponding empirical evidence is overall weak and inconsistent.

Polyandry and non-random fertilisation maintain long-term genetic diversity in an isolated island population of adders (Vipera berus).

Conservation genetic theory suggests that small and isolated populations should be subject to reduced genetic diversity i.e., heterozygosity and allelic diversity.

Negative frequency-dependent selection on polymorphic color morphs in adders.

Color pattern polymorphism occurs when more than one form is found within the same population. It is widespread in a variety of taxa, leading us to ask what maintains this variation. One stabilizing mechanism is negative frequency-dependent selection, also known as apostatic selection, in which the fitness of a phenotype decreases with its frequency.

Genetic and demographic vulnerability of adder populations: Results of a genetic study in mainland Britain.

Genetic factors are often overlooked in conservation planning, despite their importance in small isolated populations. We used mitochondrial and microsatellite markers to investigate population genetics of the adder (Vipera berus) in southern Britain, where numbers are declining. We found no evidence for loss of heterozygosity in any of the populations studied.

Seasonal variation of mortality, detectability, and body condition in a population of the adder ().

We analyzed seasonal variation in mortality rates in adult males and females of the European adder (), using data collected during a 13-year capture-recapture study (2005-2017) in a large population. We concurrently obtained quantitative information on the seasonal variation in the detectability and body condition of adders. Our results show strong seasonality in body condition, encounter, and capture rates of adult adders, and these patterns differ markedly between sexes and between breeding and nonbreeding females.

Intermittent reproduction, mortality patterns and lifetime breeding frequency of females in a population of the adder (s).

Female adders () are "capital breeders" that exhibit delayed maturity and intermittent reproductive frequency. We studied the attainment of sexual maturity, the initiation of annual breeding in mature females, the energy and mortality costs associated with breeding, the length of the reproductive cycle and female lifetime reproductive frequency. We use longitudinal data obtained during an 18-year (2000-2017) mark-recapture study in a large population of adders in northern Belgium.

Genotyping validates photo-identification by the head scale pattern in a large population of the European adder ().

Capture-mark-recapture procedures are a basic tool in population studies and require that individual animals are correctly identified throughout their lifetime. A method that has become more and more popular uses photographic records of natural markings, such as pigmentation pattern and scalation configuration. As with any other marking tool, the validity of the photographic identification technique should be evaluated thoroughly.

A possible effect of electromagnetic radiation from mobile phone base stations on the number of breeding house sparrows (Passer domesticus).

A possible effect of long-term exposure to low-intensity electromagnetic radiation from mobile phone (GSM) base stations on the number of House Sparrows during the breeding season was studied in six residential districts in Belgium. We sampled 150 point locations within the 6 areas to examine small-scale geographic variation in the number of House Sparrow males and the strength of electromagnetic radiation from base stations. Spatial variation in the number of House Sparrow males was negatively and highly significantly related to the strength of electric fields from both the 900 and 1800 MHz downlink frequency bands and from the sum of these bands (Chi(2)-tests and AIC-criteria, P<0.

EVOLUTION OF SPRINT SPEED IN LACERTID LIZARDS: MORPHOLOGICAL, PHYSIOLOGICAL, AND BEHAVIORAL COVARIATION.

Organismal performance abilities occupy a central position in phenotypic evolution; they are determined by suites of interacting lower-level traits (e.g., morphology and physiology) and they are a primary focus of natural selection.

Thermal biology, microhabitat selection, and conservation of the insular lizard Podarcis hispanica atrata.

We studied aspects of the thermal biology and microhabitat selection of the endangered lizard Podarcis hispanica atrata during autumn in the field and laboratory. Body temperatures (T ) of active lizards were within a narrow range, were largely independent of ambient temperatures, and exhibited little diel variation. Activity T s largely coincided with the selected temperatures maintained in a laboratory thermogradient and with T s that maximize running performance.

Altitudinal variation of the thermal biology and running performance in the lizard Podarcis tiliguerta.

We studied, in the field and laboratory, aspects of the thermal biology in two populations of the lizard Podarcis tiliguerta along a 1450 m altitudinal gradient. Body temperatures (T) at high altitudes average lower, are more variable, but are more elevated above environmental temperatures than at sea level. Lizards partially reduced the impact of altitudinal changes in thermal loads through presumable subtle behavioural adjustments.