The males of the Golden-collared manakin (Manacus vitellinus), a passerine bird of the Neotropical region, perform elaborate courtship displays that are among the most spectacular in the animal kingdom. During a 7-mo long breeding season, male manakins aggregate in leks of up to 12 individuals, and each male clears a small 'court' on the forest floor where he spends several hours per day performing his displays either with or without the presence of a female. Like males of other manakin species, males of M. vitellinus produce loud mechanical sounds with their wings during the displays. The elaborate displays of the manakins are thought to be the result of sexual selection, which is particularly intense in lekking species in which females choose their mate mainly on the basis of behavioural and morphological features. However, we know little about differences in display between male manakins which may be related to individual differences in reproductive success. A quantitative, detailed analysis of the courtship displays has been difficult because the birds' movements are too fast to be studied with standard video recording techniques. For the first time, we recorded the displays of male Golden-collared manakins in the forest of Panama with a high-speed camera that allows a time resolution 5-40 times higher than that of a standard video camera. We found that several elements of the displays differed significantly between individuals. In addition, the slow-motion analysis revealed the features of the displays that had not been described in previous studies. Individually different features of the displays may form the basis for female choice and will allow testing hypotheses about the evolution of the manakin displays by sexual selection and their importance for speciation mechanisms in the genus Manacus.

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Oxidative stress has been suggested as a mechanism underlying the costs of reproduction and life history trade-offs. Reproductive activities may lead to high production of pro-oxidants, whose activity can generate oxidative damage when not countered by adequate antioxidant defenses. Because interindividual differences in the efficiency of the antioxidant system are influenced by an individual's diet, food availability experienced during reproduction may affect the females' antioxidant status and, in birds, their ability to transfer antioxidants into their eggs. Moreover, a female's ability to cope with oxidative stress has been suggested to influence pigment deposition in the eggshell, suggesting a possible signaling function of eggshell maculation. Here we performed a food supplementation experiment in a natural population of great tits (Parus major) in order to investigate how nutritional conditions experienced during the egg laying period affect the female's oxidative status and egg investment and how maternal oxidative status and egg antioxidant protection relate to eggshell pigmentation. We show that food-supplemented females had lower oxidative damage levels (ROMs) than non-food-supplemented females. Furthermore, a female's ROMs levels were negatively associated with the levels of yolk antioxidant protection in her eggs, but this negative association was only significant in non-food-supplemented females. This suggests that oxidative stress experienced during reproduction influences the allocation of antioxidants into the eggs. Moreover, we observed a positive relationship between eggshell pigment distribution and maternal and yolk antioxidant protection, suggesting that eggshell pigmentation is a cue of female (and offspring) quality. protection relate to eggshell pigmentation. We show that food-supplemented females 36 had lower oxidative damage levels (ROMs) than non-supplemented females. 37Furthermore, a female's ROMs levels were negatively associated with the levels of 38 yolk antioxidant protection in her eggs, but this negative association was only 39 significant in non-supplemented females. This suggests that oxidative stress 40 experienced during reproduction influences the allocation of antioxidants into the 41 eggs. Moreover, we observed a positive relationship between eggshell pigment 42 distribution and maternal and yolk antioxidant protection, suggesting that eggshell 43 pigmentation is a cue of female (and offspring) quality.

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Background: The amount of resources provided by the mother before birth has important and long-lasting effects on offspring fitness. Despite this, there is a large amount of variation in maternal investment seen in natural populations. Life-history theory predicts that this variation is maintained through a trade-off between the benefits of high maternal investment for the offspring and the costs of high investment for the mother. However, the proximate mechanisms underlying these costs of reproduction are not well understood. Here we used artificial selection for high and low maternal egg investment in a precocial bird, the Japanese quail (Coturnix japonica) to quantify costs of maternal reproductive investment. Results: We show that females from the high maternal investment lines had significantly larger reproductive organs, which explained their overall larger body mass, and resulted in a higher resting metabolic rate (RMR). Contrary to our expectations, this increase in metabolic activity did not lead to a higher level of oxidative damage. Conclusions: This study is the first to provide experimental evidence for metabolic costs of increased per offspring investment.

Purpose. To evaluate efficacy and safety of intravitreal dexamethasone 0.7 mg implant in treatment-naïve DME patients and to assess the utility of OCT structural biomarkers as predictors of functional response after treatment. Methods. Thirty-nine eyes of 39 diabetic patients with center involving DME were enrolled. Best-corrected visual acuity (BCVA) and SS-OCT (DRI SS-OCT Triton, Topcon, Japan) to evaluate central retinal thickness (CRT), serous retinal detachment (SRD), intraretinal cysts (IRC), number of hyper-reflective spots (HRS), integrity of the ellipsoid zone (EZ), disorganization of the inner retinal layers (DRIL), vitreomacular adhesion (VMA), vitreomacular traction (VMT), and posterior vitreous detachment (PVD) were evaluated at baseline and at 3, 6, and 12 months after treatment. Multiple logistic analysis was performed to evaluate the possible OCT biomarker as predictive factors for final visual acuity improvement at the end of treatment. Results. At 12 months after treatment, the mean BCVA improved from 51.6 ± 17.5 to 56.9 ± 17.3 ETDRS letters ( p = 0.03 ). Furthermore, there were statistically significant changes in CRT, IRC, HRS, and SRD. Nineteen patients presented a  >10-letters improvement in BCVA; the presence of SRD at baseline was a predictor of good functional treatment response at 12 months (OR 2.1; 95% C.I. 1.2–4.9; p = 0.001 ) as well as the presence of EZ integrity preoperatively (OR 1.3; 95% C.I. 0.5–2.4; p = 0.001 ) and the absence of vitreoretinal interface alteration (OR 1.1; 95% C.I. 0.3–2.3; p = 0.02 ). No significant changes in the IOP and lens status were observed throughout the follow-up period. Conclusion. This study empathized the importance of structural biomarkers as predictors of favorable response and confirmed the efficacy and safety of intravitreal dexamethasone implant in treatment-naïve DME patients showing a better functional response in the presence of SRD integrity of EZ and absence of vitreoretinal alterations.

The early life period is characterized by fast growth and development, which can lead to high reactive oxygen species (ROS) production. Young animals thus have to balance their investment in growth versus ROS defence, and this balance is likely mediated by resource availability. Consequently resources transferred prenatally by the mother and nutritional conditions experienced shortly after birth may crucially determine the oxidative status of young animals. Here, we experimentally investigated the relative importance of pre-and early postnatal nutritional conditions on the oxidative status of great tit nestlings (Parus major). We show that resources transferred by the mother through the egg and nutritional conditions encountered after hatching affect the oxidative status of nestling in a sexspecific way. Daughters of non-supplemented mothers and daughters which did not receive extra food during the early postnatal period had higher oxidative damage than sons, while no differences between sons and daughters were found when extra food was provided pre-or postnatally. No effect of the food supplementations on growth, fledging mass or tarsus length was observed, indicating that female nestlings maintained their investment in growth at the expense of ROS defence mechanisms when resources were limited. The lower priority of the antioxidant defence system for female nestlings was also evidenced by lower levels of specific antioxidant components. These results highlight the important role of early parental effects in shaping oxidative stress in the offspring, and show that the sensitivity to these parental effects is sex-specific. 2 AbstractThe early life period is characterized by fast growth and development, which can lead to high reactive oxygen species (ROS) production. Young animals thus have to balance their investment in growth versus ROS defence, and this balance is likely mediated by resource availability. Consequently resources transferred prenatally by the mother and nutritional conditions experienced shortly after birth may crucially determine the oxidative status of young animals.Here we experimentally investigated the relative importance of pre-and early postnatal nutritional conditions on the oxidative status of great tit nestlings (Parus major). We show that resources transferred by the mother through the egg and nutritional conditions encountered after hatching affect the oxidative status of nestling in a sex-specific way. Daughters of non-supplemented mothers, and daughters, which did not receive extra food during the early postnatal period had higher oxidative damage than sons, while no differences between sons and daughters were found when extra food was provided pre-or postnatally. No effect of the food supplementations on growth, fledging mass or tarsus length was observed, indicating that female nestlings maintained their investment in growth at the expense of ROS defence mechanisms when resources were limited. The lower priority of the antioxidant defence system for female nestlings wa...

Multitemporal analysis of forest landscape in the province of Siena (Italy) using historical maps. The analy sis of land use and land cover change has long been a key topic in landscape ecology. In particular, forest fragmentation is known to affect plant species composition and diversity, thus threatening the integrity of forest habitats. In many areas of Mediterranean basin, a particular pattern of land cover change has been re ported, consisting in the increasing agriculture use of plain areas and the abandonment of hilly and moun tain areas, with these latter undergoing a process of natural forest expansion. The aim of this paper is to exa mine forest expansion and dynamics over a whole province (Siena) in central of Italy, by comparing histori cal and recent forest maps. The historical map has been georeferenced and digitized in a GIS environment and classified in 3 forest classes: deciduous, conifer and mixed forests. Image processing techniques and landscape pattern metrics have been applied to quantify the changes in forest cover patterns. Further, stan dard statistical descriptors have been to investigate the relationship between land cover changes and topo graphical factors. The results show that forest expansion resulted in a landscape transformation according to well defined topographic patterns.