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We used GPS data-loggers, video-recordings and dummy eggs to assess whether foraging needs may force the low incubation attentiveness (

The Socotra Archipelago is an ancient continental fragment of Gondwanan origin and one of the most isolated landforms on Earth and a biodiversity hot spot. Yet, the biogeography and evolutionary history of its endemic fauna still remain largely overlooked. We investigate the origin, tempo and mode of diversification in the Hemidactylus geckos of the Socotra Archipelago. Concatenated and multilocus species coalescent analyses of Hemidactylus from Arabia and North Africa indicate that the Hemidactylus from Socotra do not form a monophyletic group and branch as three independent and well-supported clades instead. Both the chronogram inferred using the gene tree approach of BEAST and the age-calibrated multilocus species tree obtained using *BEAST suggest that the origin of Hemidactylus from Socotra may have involved a first vicariance event that occurred in the Early Miocene, followed by two independent transoceanic dispersal events that occurred more recently, during the Pliocene. Within Socotra, we analysed patterns of genetic diversity, the phylogeography and the demographic history in all seven nonintroduced species of Hemidactylus. Results based on two mitochondrial and two nuclear loci from 144 individuals revealed complex patterns of within-island diversification and high levels of intra-species genetic divergence. The interplay of both historical and ecological factors seems to have a role in the speciation process of this group of geckos. Interestingly, the case of H. forbesii and H. oxyrhinus, which inhabit the island of Abd al Kuri with an area of 133 km 2 , may represent one of the most extreme cases of

Ultrasound imaging is a promising technique for studying the reproductive biology of reptiles, but it has yet to be validated for small lizards in field research. This study aimed both at assessing the reliability of ultrasound imaging in field research and the measurement of the breeding effort and timing of reproduction in the northern Italian female population of the common wall lizard, Podarcis muralis. To this end, we kept 22 gravid females in captivity in April and June 2010 and used ultrasonography to predict the number of eggs they laid. The following year, we applied the same technique to monitor the breeding performance of females in their natural habitat. We collected 119 females between March and June 2011 and used ultrasonography to evaluate clutch size and egg developmental stage. Our results showed that 20 out of 22 females (91%) laid the exact number of eggs predicted. The field research showed that the percentage of gravid females varied over the season, showing a clear bimodal pattern with two peaks in late April and late May. These peaks corresponded to the first and second clutch depositions, respectively. Furthermore, female common wall lizards reach sexual maturity at a body size of 50–51 mm snout–vent length, at around 2 years of age. Mean clutch size in our population ranged from 2 to 5.5 eggs, with an average of 3.6 eggs. There was a strong positive relationship between clutch and female size, which was only statistically significant in the first deposition. The female lizards in our study were smaller than those in French and central European populations, they reached maturity at 50.9 mm and they laid few eggs. In this paper, we discuss some potential explanations for such differences.

We would also like to thank the Minister Abd al-Rahman Fadhl al-Iriyani (Ministry of Water and Environment of Yemen) for his support and interest in the project. DNA work was funded by grant CGL2009-11663/BOS from the Ministerio de Educacion y Ciencia, Spain. S.C. and M.M. are members of the Grup de Recerca Emergent of the Generalitat de Catalunya: 2009SGR1462; M.M. is supported by a FPU predoctoral grant from the Ministerio de Ciencia e Innovacion, Spain (AP2008-01844). Research work by S.C. at the BMNH received support from the SYNTHESIS project GB-TAF-270, which is financed by the European Community Research Infrastructure under the FP7 ‘Structuring the European Research Area’ Program. Some phylogenetic analyses were run in the cluster facility of the IBE funded by the Spanish National Bioinformatics Institute (http://www.inab.org).

SUMMARY 1. In sexually reproducing organisms, the energetic costs of spermatogenesis can be considerable, and can limit the reproductive potential of the males. In species where males mate more than once during the reproductive season, the costs of sperm production are generally predicted to result in a decrease of ejaculate size and quality with successive fertilizations. 2. In this study we examined the variation in ejaculate size among successive fertilizations in a long-lived freshwater crayfish species, Austropotamobius italicus. 3. Sexually active adult males of various sizes were allowed to mate repeatedly with different females on consecutive days. Trials for a given male ended when he copulated but did not release any sperm or refused to mate. 4. Males fertilized between 0 and 4 females, and most (42.5%) fertilized a single female. The overall number of females fertilized by a given male decreased with increasing male body size. Ejaculate size decreased markedly with consecutive fertilizations in a similar fashion among both large and small males, while simultaneously increasing with female body size. The total ejaculate size over successive fertilizations decreased with increasing male size. 5. Our study indicates that either sperm production or release involves non-trivial costs in freshwater crayfish, and suggests that large/old males may face greater difficulties in gamete release than small/young ones, as shown by the lower number of females fertilized by large compared with small males, which may reflect the ongoing senescence of their reproductive performance.

The throat and belly of both sexes of the common wall lizard Podarcis muralis exhibit a polymorphic coloration with three morphs (white, yellow and red). We documented the occurrence of this polymorphism in 11 populations of northern Italy, and investigated the morphometric features of the three morphs in both sexes. The white morph was more frequent (56.6%), while yellow and red morphs accounted for 28.7 and 14.7% of the lizards, respectively. Moreover, the red morphotype was more frequent among males while the white one was more frequent among females. The occurrence of the three morphs varied microgeographically from populations with a higher proportion of white individuals to those where all morphs were more equally represented. The comparisons of morphometry between morphs did not reveal any significant difference among males, while snout–vent length and head height in females increased from the white-throated to the yellow-throated morph, and from the yellow-throated morph to the red-throated one. Possible functions of this polymorphic coloration are discussed.

Decline of urban Italian Sparrows P. Br chetti et l. Recent declines in urban Italian Sparrow Passer ( domesticus ) italiae populations in northern Italy PIERANDREA BRICHETTI, 1 DIEGO RUBOLINI, 1,2 * PAOLO GALEOTTI 2 & MAURO FASOLA 2 1 CISO (Centro Italiano Studi Ornitologici), Via V. Veneto 30, I-25029 Verolavecchia (BS), Italy 2 Dipartimento di Biologia Animale, Universita degli Studi di Pavia, I-27100 Pavia, Italy

Summary 1Egg size is an important maternal trait that can have major consequences on offspring phenotype. However, the effects of the variation of different components of cleidoic eggs have been little investigated. 2Here, we addressed whether a reduction of the relative egg albumen content within the natural range of variation affects viability, time to hatching, early post-natal begging displays, morphology and immune response of yellow-legged gull Larus michahellis chicks. 3Egg mass strongly positively predicted chick size and mass at all ages, while time to hatching positively predicted tarsus length and immune response, irrespective of albumen removal. Variation in time to hatching may thus affect immune system maturation. 4Albumen removal resulted in a lower embryonic viability and increased time to hatching of individual eggs. The probability that an egg originated a chick surviving until 8 days of age increased with original egg mass among controls, but not among chicks hatching from eggs with reduced albumen content (‘albumen chicks’). 5Begging rate increased with laying order among albumen chicks while it decreased among controls. Concomitantly, begging rate decreased with egg mass among controls while it did not vary among albumen chicks. Surprisingly, albumen removal did not affect body mass or tarsus length except at 8 days of age, when control chicks were lighter than albumen chicks. 6In conclusion, our study indicates that a reduction of the relative egg albumen content can have complex effects on offspring development, behaviour and viability of a semiprecocial bird, suggesting that the relative albumen content of the eggs represents an important mechanism of maternal effects.

We describe 30 new nesting sites of the Crab Plover Dromas ardeola , the main breeding grounds of which were largely unknown, and for which fewer than 30 colonies had been confirmed since 1970. Our survey included 90 islands, 53% of those existing, in the Dahlak and Howakil archipelagoes, and off the coast of central Eritrea. Colony size varied between 20 and 400 nests. We estimate the numbers of Crab Plovers breeding in central Eritrea at 5000‐6000 pairs, i.e. about 50% of the known world breeding population. We describe two cases of probable replacement clutches, a feature unrecorded in this species. Black Rats Rattus rattus seem unable to open Crab Plover eggs, and do not seem to be a threat. Crab Plover colonies are traditionally exploited by local fishermen for collection of eggs, an activity that has increased recently. Our new records solve only partially the problem of the ‘missing’ colonies that are required to account for the world wintering population of 60 000‐80 000 birds, and thus other breeding sites remain to be discovered, probably in southern Eritrea, Sudan and Somalia. We estimated that there are 4800‐6500 Crab Plovers overwintering within central Eritrea, making it an important wintering ground for the species.

The Crab Plover Dromas ardeola is the only waterbird species known to provision offspring well after the post-reproductive migration and through overwintering. A few previous quantitative studies have reported inconclusively that juveniles begged rarely, and also indiscriminately at other juveniles. Here, we describe the feeding behaviour of adult and juvenile Crab Plovers during the first part of the wintering period. Juveniles begged frequently for food, always toward adults, and obtained 0.1 prey items/min from them. Begging birds obtained the largest prey items of those captured by the adults. When foraging alone, juveniles captured prey at the same rate as adults, but captured smaller crabs. The feeding success of adults was not altered by the presence of the begging juvenile. Juveniles depended partly on adults during the first part of the overwintering period, but were almost independent towards the end. Crab Plovers may adopt such unusually prolonged care because they need to abandon their breeding areas quickly, when environmental conditions are extreme. Large numbers of Crab Plovers overwinter in a few areas, now subject to human alteration. Isolated adults may forage on other areas such as narrow and disturbed shores, but juveniles may require wide beaches, suitable for group foraging, that should be considered as key areas for the recruitment of juveniles into the population.

Although the ability to vocalize is widespread among tortoises, the mechanisms of sound production in chelonians remain undescribed. In this study, we analyze the morphology and histology of the larynx of three species of Testudinidae (Testudo hermanni, T. graeca, and T. marginata) in order to ascertain the presence of vibrating acoustic structure, and based on our findings we propose a general model for phonation in tortoises. The structure of the larynx of the three tortoises analyzed is simple: three cartilages (the cricoid and two arytenoids) form the skeleton of the larynx, while two pairs of muscles (the dilators and constrictors) control the widening and closing of the glottis. The larynx is supported in the oral cavity by the hyoid cartilage, which in tortoises assumes the same functions of the thyroid cartilage of mammals. Two bands of elastic fibers are inserted in the lateral walls of the larynx just upstream of the glottis, and can be stretched away from the hyoid by the movements of the arytenoids. Their position and structure suggest that these bands are capable of vibrating during exhalation, and therefore may be considered vocal cords. The cricoid of T. marginata and T. graeca hold two diverticula, not previously reported, which might function as a low-frequency resonating chamber, improving the harmonic structure of tortoise calls. The structure of the larynx is compared with that of other vertebrates and the relationships between morphology and phonation are discussed. This is the first detailed description of anatomical structures possibly devoted to vocalization in chelonians.

We studied polymorphism in all species of birds that are presently known to show intraspecific variation in plumage colour. At least three main mechanisms have been put forward to explain the maintenance of polymorphism: apostatic, disruptive and sexual selection. All of them make partly different predictions. Our aims were to investigate evolutionary causes and adaptive functions of colour polymorphism by taking into account a number of ecological and morphological features of polymorphic species. Overall, we found 334 species showing colour polymorphism, which is 3.5% of all bird species. The occurrence of colour polymorphism was very high in Strigiformes, Ciconiiformes, Cuculiformes and Galliformes. Phylogenetically corrected analysis using independent contrasts revealed that colour polymorphism was maximally expressed in species showing a daily activity rhythm extended to day/night, living in both open and closed habitats. All these findings support the hypothesis that colour polymorphism probably evolved under selective pressures linked to bird detectability as affected by variable light conditions during activity period. Thus, we conclude that selective agents may be prey, predators and competitors, and that colour polymorphism in birds may be maintained by disruptive selection.

Colonial waterbirds are unusual in that competition for nest-sites or mates may occur at a scale of a few metres, whereas thousands of birds may overlap in their foraging range at a larger scale. Dispersal has been evaluated for only a few such species, and its adaptive significance remains unclear. We studied Little Egret dispersal among all the colonies within the Camargue, southern France. The overall probability of dispersal between successive years was 0.45. The probability of dispersal was unaffected by a bird’s age, or by any density-dependent effect of colony size. Juveniles dispersed at distances that would be expected if colony selection were random, while adults tended to remain within 10 km of their previous colony. We found no obvious environmental ‘trigger’ for an individual to disperse. Although our evidence is inconclusive, the short dispersal distances of adults are not consistent with foraging conditions as the primary trigger for dispersal. Little Egrets generally forage within 8 km of their colony, so birds dispersing less than 10 km would gain little advantage in response to unfavourable foraging conditions. Our data, with 75% of dispersing birds coming from decreasing colonies and 72% joining increasing colonies, suggest that individual dispersal depended on colony dynamics as a whole, i.e. (1) a social component of dispersal at the individual level, or (2) a simultaneous colony response to unfavourable environmental conditions or (3) both. Further investigation at a higher social level may be necessary to understand dispersal of this colonial nesting species.

We describe an unknown mode of solar-assisted egg development in the crab plover Dromas ardeola, a shorebird that breeds in self-excavated burrows. The insulating properties of the nest burrow and the intense solar radiation allowed egg development at near-optimal temperature (35.2°C±0.2) and humidity (60.2%±4.4), allowing a very low incubation attendance by the parent birds (28.3% of time, with recesses lasting up to 58 h). Crab plovers did not abandon completely parental incubation, possibly because of the need to turn their egg, and because the slight warming provided by parents (0.8°C) may improve hatching. This is the first case of solar assisted incubation in a species unrelated to the Megapodiidae, the only birds known to develop their eggs without contact incubation.

Of the 42 dominant species of waterbirds at Lake Turkana, Kenya, 14 foraged uniformly throughout the day and night, five foraged mostly during the night, five foraged during both the night and day but with diurnal peaks, 17 were exclusively diurnal and only one was exclusively nocturnal. Species with uniform feeding activity usually captured small prey, using tactile or visual plus tactile cues; most diurnal species captured large prey, using visual cues. However, some species which fed mostly at night, or uniformly, relied exclusively on visual cues. We found support from only one species that moonlight influenced foraging activities. Palaearctic immigrants spent significantly more time foraging than partial migrants and residents; they were also smaller and mainly microphagous. Only gulls and terns were restricted to diurnal feeding, presumably by their need to see and capture prey while flying. The other groups were formed by species which foraged uniformly over 24 h or partially by day or night. These patterns indicate that in most waterbirds feeding activities are not basically tied to any phase of the diel cycle. Since most waterbirds display some degree of nocturnal activity, time budget studies based only on diurnal observations are likely to be misleading.

This paper describes the multidimensional niche of syntopic smooth newts Triturus vulgaris. alpine newts Triturus alpestris. and Italian crested newts Triturus carnifex. which constitute a complex community of eight components (the three species and their larvae, plus juvenile and neotenic alpine newts) All the potentially limiting resources (seasonal time, diel time, habitat and food) are analyzed as single niche dimensions, and then the real multidimensional niche is calculated Resource states are objectively defined, using an algorithm that groups the significant resource categories The larvae were segregated by prey, season, habitat, and water depth, in order of decreasing importance, their overlap was very low when their complete multidimensional niche was considered, and therefore they have few opportunities for present–day competition The adults were largely segregated by season and water depth, and to a lesser degree by habitat and prey, their multidimensional niches overlapped to a certain degree, thus leaving conditions for ongoing competition Considenng all the species and the life stages together, the order of importance for segregation was season, prey, habitat, water depth and diel activity, with a low overlap in the complete niche Differences m prey size were probably due to morphological constraints, differences in diel activity had very little effect on segregation except m separating larvae from the adults, and were likely promoted by need to avoid mutual predation and cannibalism It remains to be tested whether seasonal, habitat, and water depth differences are due to competitive pressures or to ecophysiological constraints