Coping with drought?Effects of extended drought conditions on soil invertebrate prey and diet selection by a fossorial amphisbaenian reptile

Arid climates are characterized by a summer drought period to which animals seem adapted.However,in some years,the drought can extend for unusually longer periods.Examining the effects of these current extreme weather events on biodiversity can help to understand the effects of climate change,as models predict an increase in drought severity.Here,we examined the effects of“unusual”extended drought on soil invertebrate prey availability and on diet composition(based on fecal contents)and diet selection of a fossorial amphisbaenian,the checkerboard worm lizard Trogonophis wiegmanni.Weather data show interannual variations in summer drought duration.The abundance and diversity of soil invertebrates in spring were high,and similar to those found in a“normal”early autumn,after some rain had ended with the summer drought.In contrast,in years with“unusual”extended drought,abundance,and diversity of soil invertebrates in early autumn were very low.Also,there were seasonal changes in amphisbaenians’diet;in autumn with drought,prey diversity,and niche breadth decreased with respect to spring and autumns after some rain had fallen.Amphisbaenians did not eat prey at random in any season,but made some changes in prey selection that may result from drought-related restrictions in prey availability.Finally,in spite that amphisbaenians showed some feeding flexibility,their body condition was lower in autumn than in spring,and much lower in autumn with drought.If extended drought became the norm in the future,amphisbaenians might suffer important negative effects for their health state.

Epistatic interactions between pterin and carotenoid genes modulate intra-morph color variation in a lizard

Color polymorphisms have become a major topic in evolutionary biology and substantial efforts have been devoted to the understanding of the mechanisms responsible for originating such colorful systems.Within-morph continuous variation,on the other hand,has been neglected in most of the studies.Here,we combine spectrophotometric/visual modeling and genetic data to study the mechanisms promoting continuous variation within categorical color morphs of Podarcis muralis.Our results suggest that intra-morph variability in the pterin-based orange morph is greater compared to white and yellow morphs.We also show that continuous variation within the orange morph is partially discriminable by conspecifics.Genotyping results indicate that allelic variants at the BCO2 locus(responsible for deposition of yellow carotenoids)contribute to generate continuous variation in orange individuals.However,other intrinsic and/or extrinsic mechanisms,such as body size,might be involved,opening a new avenue for future research on the drivers of continuous variation within-morphs.

Viability,behavior,and color expression in the offspring of matings between common wall lizard Podarcis muralis color morphs

Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature.Two of the mechanisms of balancing selection currently thought to explain the long-term persistence of polymorphisms are the evolution of alternative phenotypic optima through correlational selection on suites of traits including color and heterosis.Both of these mechanisms can generate differences in offspring viability and fitness arising from different morph combinations.Here,we examined the effect of parental morph combination on fertilization success,embryonic viability,newborn quality,antipredator,and foraging behavior,as well as inter-annual survival by conducting controlled matings in a polymorphic lacertid Podarcis muralis,where color morphs are frequently assumed to reflect alternative phenotypic optima(e.g.,alternative reproductive strategies).Juveniles were kept in outdoor tubs for a year in order to study inter-annual growth,survival,and morph inheritance.In agreement with a previous genome-wide association analysis,morph frequencies in the year-old juveniles matched the frequencies expected if orange and yellow expressions depended on recessive homozygosity at 2 separate loci.Our findings also agree with previous literature reporting higher reproductive output of heavy females and the higher overall viability of heavy newborn lizards,but we found no evidence for the existence of alternative breeding investment strategies in female morphs,or morphcombination effects on offspring viability and behavior.We conclude that inter-morph breeding remains entirely viable and genetic incompatibilities are of little significance for the maintenance of discrete color morphs in P.muralis from the Pyrenees.