Hormonal control of seasonal color change in female spiny-footed lizards:an observational and experimental approach

Breeding coloration of females often signals aspects of their reproductive status,suggesting a link between color and sex steroid hormones.In this study,we examined the relationships between 2 sex steroid hormones(progesterone and p-estradiol)and reproductive coloration in female spinyfooted lizards Acanthodactylus erythrurus.We first explored natural variation in female plasma hormone levels and coloration during their reproductive cycle,p-estradiol was negatively related to brightness and positively related to red saturation,whereas progesterone was not significantly related to coloration.After identifying key relationships,plasma hormone concentrations were manipulated by creating 3 experimental female groups(p-estradiol-treated,progesterone-treated,and control),and the effects on coloration were monitored,p-estradiol-treated females,in which there was a rise in both p-estradiol and progesterone levels,lost their red coloration earlier than females in the other 2 experimental groups,whereas progesterone treatment had no significant effect on female coloration.Our results suggest that high levels of either p-estradiol alone or(3-estradiol together with progesterone trigger the loss of red coloration in female spiny-footed lizards,and that progesterone alone does not affect coloration.We hypothesize that changes in female breeding color might be regulated by(3-estradiol in species in which conspicuous coloration is displayed before ovulation,and by progesterone in species in which this color is displayed during gravidity.

Snake-like calls in breeding tits

Hole-nesting tits belonging to the family Paridae produce a hissing display that resembles the exhalatory hiss of a snake.When a predatory animal enters the nest hole of a tit,tits often hiss vigorously,while lunging their head forward and shaking their wings and tail,until the intruder retreats.We assessed the acoustic similarity between such hiss calls from 6 species of tits,snake hisses,and tit syllables used in alarm vocalizations,as well as white noise as a control.Tit hiss calls showed a high degree of similarity with snake hisses from 3 different snake families.Tit hisses had lower similarity to syllable alarm calls,suggesting convergence of tit hisses in their spectral structure.Hiss calls would only be effective in protecting nest boxes if nest predators responded to these calls.In order to test this hypothesis,we trained individual Swinhoe’s striped squirrels,Tamiops swinhoei hainanus,a common predator of egg and nestling tits,to feed at feeders in proximity to nest boxes.We compared the aversive response of squirrels to tit’s hiss calls and white noise,presented in random order.Squirrels showed a higher degree of avoidance of feeders when hiss calls were played back than when white noise was presented.In conclusion,our study suggests that hole-nesting birds have evolved convergent snake-like hiss calls,and that predators avoid to prey on the contents of nest boxes from which snake-like hisses emerge.

Health-related quality of life and stress-related disorders in COVID-19 ICU survivors:Are they worse than with other causes of ARDS?

Background:There are insufficient data regarding the impact of acute respiratory distress syndrome related to coronavirus disease 2019(C-ARDS)–caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)–on health-related quality of life(HRQoL)and the occurrence of stress-related disorders in coronavirus disease 2019(COVID-19)intensive care unit(ICU)survivors.The aim of this study is to assess HRQoL and the occurrence of stress-related disorders(acute stress disorder[ASD]and post-traumatic stress disorder[PTSD])in C-ARDS ICU survivors at 1 and 6 months following hospital discharge.Methods:This prospective observational study included 90 patients treated for C-ARDS between March and May 2020 in the ICU and discharged alive from the hospital.All patients included in the study were contacted by telephone 1 month and 6 months post-hospital discharge to assess the presence of symptoms of stress-related disorders and HRQoL using the 8-item Treatment Outcome Post-traumatic Stress Disorder scale(TOP-8)and 36-item Short Form survey(SF-36).We performed univariate analyses to evaluate differences between patients who developed stress and those who did not.We also compared SF-36 scores in our sample with data from the general Spanish population and from cohorts of non–C-ARDS and severe acute respiratory syndrome coronavirus-1(SARS-CoV-1)survivors.Results:There are 24.1%of patients showed symptoms of ASD;in 13.5%of cases the symptoms persisted 6 months later.Risk factors for the development of symptoms of ASD and PTSD are younger age,female sex,obesity,a previously diagnosed psychiatric disease and disease severity at ICU admission(P<0.05).HRQoL was greatly affected by C-ARDS;however,there was improvement on all scales of the SF-36 at the 6-month follow-up(P<0.05).The mean SF-36 score of our sample was higher than those previously reported in non–C-ARDS survivors(P<0.05)for physical functioning(78.0 vs.52.0),role functioning/physical(51.0 vs.31.0),bodily pain(76.1 vs.57.0),vitality(58.6 vs.48.0),social function(72.6 vs.63.0)and role emotional(77.4 vs.55.0),except on the general health scale.C-ARDS survivors also scored better than SARS-CoV-1 survivors on all scales except for body pain(P<0.05).Conclusions:The impact of C-ARDS on HRQoL is substantial,with frequent occurrence of PTSD symptoms.Patients are heavily affected in all areas of health in the first month of post-hospital discharge but show a dramatic improvement within 6 months,especially in terms of physical health.