BUSCADOR RECOLECTA

Files contain information on flight parameters obtained from lesser kestrel (Falco naumanni) commuting flights or foraging trips (depending on the variable) and the mean values of those parameters per 6-hour interval. Data were collected using high-frequency GPS-dataloggers to track individual lesser kestrels from two breeding colonies in southern Spain. The study was conducted throughout the breeding season of 4 consecutive years (2011-2014). For additional information contact Jesús Hernández-Pliego, email: jhpliego@ebd.csic.es, Peer reviewed

Nest materials used by animals can have profound effects on developing offspring. They can modify the bacterial and parasitic environment of the nest, and can influence parental investment through sexual signalling processes. In spotless starlings, Sturnus unicolor, green plants and feathers are known nest materials with such functions. The aim of our study was to experimentally assess their influence on nestlings’ telomere length and attrition, which are good predictors of their survival prospects. In a full-factorial experiment, we explored these effects in two different populations, together with the potential effects of hatching date, ectoparasitism, bacterial environment and nestling growth. Telomere length and attrition largely depended on population identity and hatching date. After correcting for these effects, the addition of feathers resulted in higher rates of telomere attrition. The addition of plants did not affect nestling telomeres in general, but did in interaction with location: in Hueneja, the experimental addition of green plants resulted in longer telomeres. Feather pigmentation also did not affect telomere length or attrition in general, but did in interaction with location: in Hueneja, the experimental addition of unpigmented feathers resulted in nestlings with longer telomeres and lower attrition rates. Moreover, prevalence of staphylococci on the skin of 8-day-old nestlings was negatively related to telomere lengths of fledglings. Taken together, these results suggest a direct link between nest material composition and nestling telomere length and dynamics. This relationship could be partially mediated by the antimicrobial and/or antiparasitic properties of nest materials or by sexual signalling, Funding was provided by the Spanish Ministerio de Economia y Competitividad and European funds (FEDER) (CGL2013-48193-C3-1-P, CGL2013-48193-C3-2-P, CGL2012-30759, CGL2015-65055-P). J.M.P., G.T. and M.R.R. were supported respectively by Juan de la Cierva, Ramón & Cajal and Talentia postdoctoral contracts., Peer reviewed

Tri-axial accelerometry has proved to be a useful technique to study animal behavior with little direct observation, and also an effective way to measure energy expenditure, allowing a refreshing revisit to optimal foraging theory. This theory predicts that individuals should gain the most energy for the lowest cost in terms of time and energy when foraging, in order to maximize their fitness. However, during a foraging trip, central-place foragers could face different trade-offs during the commuting and searching parts of the trip, influencing behavioral decisions. Using the lesser kestrel (Falco naumanni) as an example we study the time and energy costs of different behaviors during the commuting and searching parts of a foraging trip. Lesser kestrels are small insectivorous falcons that behave as central-place foragers during the breeding season. They can commute by adopting either time-saving flapping flights or energy-saving soaring-gliding flights, and capture prey by using either time-saving active hovering flights or energy-saving perch-hunting. We tracked 6 lesser kestrels using GPS and tri-axial accelerometers during the breeding season. Our results indicate that males devoted more time and energy to flight behaviors than females in agreement with being the sex responsible for food provisioning to the nest. During the commuting flights, kestrels replaced flapping with soaring-gliding flights as solar radiation increased and thermal updrafts got stronger. In the searching part, they replaced perch-hunting with hovering as wind speed increased and they experienced a stronger lift. But also, they increased the use of hovering as air temperature increased, which has a positive influence on the activity level of the preferred prey (large grasshoppers). Kestrels maintained a constant energy expenditure per foraging trip, although flight and hunting strategies changed dramatically with weather conditions, suggesting a fixed energy budget per trip to which they adjusted their commuting and searching strategies in response to weather conditions, Peer reviewed

Global warming and direct anthropogenic impacts, such as water extraction, are largely affecting water budgets in Mediterranean wetlands, thereby increasing wetland salinities and isolation, and decreasing water depths and hydroperiods (duration of the inundation period). These wetland features are key elements structuring waterbird communities. However, the ultimate and net consequences of these dynamic conditions on waterbird assemblages are largely unknown. We combined a regular sampling on waterbird presence through the 2008 annual cycle with in-situ data on these relevant environmental predictors of waterbird distribution to model habitat selection for 69 individual species in a typical Mediterranean wetland network in south-western Spain. Species association with environmental features were subsequently used to predict changes in habitat suitability for each species under three climate change scenarios (encompassing changes in environment that ranged from 10% to 50% change as predicted by climatic models). Waterbirds distributed themselves unevenly throughout environmental gradients and water salinity was the most important gradient structuring the distribution of the community. Environmental suitability for the guilds of diving birds and vegetation gleaners will be reduced according to future climate scenarios, while most small wading birds will benefit from changing conditions. Resident species and those that breed in this wetland network will be also more impacted than those using this area for wintering or stopover. We provide here a tool that can be used in a horizon-scanning framework to identify emerging issues on waterbird conservation and to anticipate suitable management actions, Peer reviewed

Support by funding was provided by Spanish Ministerio de Ciencia e Innovación, European funds (FEDER) (CGL2009-14006, CGL2010-19233-C03-01, CGL2010-19233-C03-03, CGL2013-48193-C3-1-P, CGL2013-48193-C3-2-P) and Junta de Andalucía (P09-RNM-4557). AM-G had a predoctoral grant from the Junta de Andalucía (P09-RNM-4557)., Peer reviewed

En la tabla se indican características de los nidos y pollos de estornino negro (Sturnus unicolor) utilizados en el artículo: Juan J. Soler, Cristina Ruiz-Castellano, Jordi Figuerola, Josué Martínez-de la Puente, Magdalena Ruiz-Rodríguez and Gustavo Tomás (2018) Egg colouration predicts brood size, telomere length and body condition of spotless starling fledglings. Journal of Avian Biology, e01686. doi: 10.1111/jav.01686 Nest identity: identidad de los nidos utilizados . feather treatment: si se añadieron plumas a los nidos durante el crecimiento de los pollos o no. plant treatment: si se añadieron plantas verdes a los nidos durante el crecimiento de los pollos o no. Brightness: Brillo (luminosidad) de los huevos de estorninos de los distintos nidos. Blue-Green chroma (400-580): Croma verde-azulado, reflectancia en longitudes de onda. comprendidas entre 400 y 580 nm dividida por la reflectanca de todo el espectro (300-700nm) en tanto por ciento. hathing date (1=1st april): fecha de eclosion (el valor 1 corresponde al 1 de abril). Clutch size: tamaño de puesta. Brood size: tamaño de pollada. Body mass: peso corporal de pollos de 14 dias de edad. Tarsus length: longitude del tarso de pollos de 14 días de edad. Body condition: condicion corporal de pollos de 14 días de edad estimada como los residuos del peso después de controlar por la longitud del tarso. Telomere length (hatchlings): longitud de los telómeros de pollos recién eclosionados. Telomere length (fledglings): longitude de los telómeros de pollos poco antes de abandonar el nido., Para la recogida de los datos se ha seguido la reproducción de dos poblaciones de estornino negro. Además de anotar información sobre distintas variables reproductoras (fecha de puesta, taño de puesta y de pollada,, y éxito reproductor, se ha medido el color de sus huevos, se han tomado muestras de sangre de pollos recién eclosionados y poco antes de abandonar el nido. También se midió el tarso y el peso corporal de los pollos poco antes de abandonar el nido. La estima del tamaño de los telomeros se realizó en el laboratorio, a partir de ADN de los glóbulos rojos de las muestras de sangre recogidas en el campo., Funding was provided by the Spanish Ministerio de Economia y Competitividad and European funds (FEDER) (CGL2013-48193-C3-1-P, CGL2013-48193-C3-2-P, CGL2012-30759, CGL2015-65055-P). JMP, GT and MRR were supported by Juan de la Cierva, Ramón & Cajal and Talentia postdoctoral contracts, respectively. JMP was partially supported by a 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation., Peer reviewed

Nestlings of most avian species produce faecal sacs, which facilitate the removal of nestlings’ excrements by parents, thereby reducing proliferation of potentially pathogenic microorganisms and/or detectability by predators and parasites. The nest microbial environment that birds experience during early life might also affect their development and thus, faecal sacs facilitating parental removal may be a strategy to decrease bacterial contamination of nests that could harm developing nestlings. Here, we tested this hypothesis by experimentally broken faecal sacs and spreading them in nests of spotless starlings (Sturnus unicolor), thereby avoiding their removal by adults. In accordance with the hypothesis, experimental nests harboured higher bacterial density than control nests. Nestlings in experimental nests were of smaller size (tarsus length) and experienced lower probability of survival (predation) than those in control nests. Moreover, nestlings in experimental nests tended to suffer more from ectoparasites than those in control nests. We discuss the possible pivotal role of bacteria producing chemical volatiles that ectoparasites and predators might use to find avian nests, and that could explain our experimental results in starlings, Ministerio de Ciencia, Innovación y Universidades and European (FEDER) funds (CGL2013-48193-C3-1-P, CGL2017-83103-P), Peer reviewed

Sexually selected signals reliably reflect individual phenotypic or genetic quality and, thus, survival prospects of holders. Telomere length is considered a good predictor of life expectancy and, consequently, exploring the links between telomere length and sexually selected traits is much needed to better understand the mechanisms that maintain the honesty of sexual signals. We manipulated the length of throat feathers in spotless starling (Sturnus unicolor) males (a sexually selected signal) before reproduction and explored its effects on telomere shortening and breeding performance in subsequent reproductive events. We did not detect an effect of the feathers clipping manipulation, but males with longer throat feathers before the experiment had shorter telomeres that also shortened more slowly than those of males with shorter throat feathers did. Moreover, length of throat feathers of males before manipulation was positively related to hatching success of second clutches. Thus, correlative but not experimental results support the expected associations between sexually selected signals, telomeres and reproduction. We discuss such results in scenarios of sexual selection where feather length reflects, but does not directly cause, telomere attrition and enhanced reproductive success. Males with longer throat feathers might be older, more experienced males (i.e., with shorter telomeres), able to buffer telomere shortening between reproductive events. Because of the absence of experimental effects, differential incubation effort of females cannot explain the detected association with hatching success, but other sexually selected traits that covary with throat-feather length could be responsible. Exploring those physiological and/or morphological characteristics related to throat-feather length should therefore be the matter of future research, This work was supported by the currently named Ministerio de Ciencia, Innovación y Universidades and European (FEDER) funds (CGL2013-48193-C3-1-P, CGL2017-83103-P, CGL2017-89063-P, CGL2015-65055-P and PGC2018-095704-B-100). MAG was financed by a predoctoral contract (BES-2014-068661) from the Spanish Ministerio de Economía y Competitividad, and GT by the Ramón y Cajal Programme., Reproductive data; Telomere data, Peer reviewed

Data file includes (i) average values of melanised (M) and non-melanised (NM) feather wear of nestling birds that grew in different nests. The file also included (ii) information of feather mass degradability of nestlings and adult birds from different nests and species estimated as the olipeptide concentration (μg x mL1) of tubes containing 4mL of PBS buffer and a colony Bacillus licheniformis D13 after 21 days of incubation at 37 ºC in constant agitation at 120 rpm in an orbital agitator (VWR, Spain). The third excel sheet contain information of bacterial loads in terms of terms of mesophilic bacteria (TSA), Enterobacteriaceae (HK), Staphylococcus (VJ), and Enterococcus (KF), and average wear of melanised (M) and non-melanised (NM) wing feathers of nestlings that grew in the same nests where bacterial loads were estimated. The last excel file contain information on feather wear of melanised and non-melanised feathers of each sampled nestlings and adult. All these data were collected the Guadix region (southern Spain) and used to perform the statistical analyses in Tables 2 and 3 in Azcárate et al. 2020 (Doi: 10.1111/jav.02320)., This work was supported by the currently named Ministerio de Ciencia, Innovación y Universidades and European (FEDER) funds (CGL2013-48193-C3-1-P, CGL2013-48193-C3-2-P, CGL2013-48193-C3-3-P, CGL2017-83103-P). MAG and SDL were financed by predoctoral contracts (BES-2014-068661, BES-2014-069116) from the Spanish Ministerio de Economía y Competitividad., Peer reviewed

Study area and study species The study was conducted during the years 2015, 2016 and 2017 in a south-eastern region of Spain (Hoya de Guadix, 37º15’N, 3º01’W), where nest-boxes attached to tree trunks or walls at 3–4 m above-ground are available for starlings to breed in (for further information on the study area see Soler et al. (2017)). In the studied starling population, the reproductive season starts in early April and most individuals lay a second clutch during May-June. The most common clutch size is 62 plants to the nest, which have been shown to have antimicrobial-beneficial functions4-5 eggs. Here, we will focus on the colouration of the base of the beak, a trait with a more marked sexual differentiation as we can see in its reflectance at different wavelengths (Fig. 1). Fieldwork and experimental procedure In this population, courtship activity (e.g. singing, introducing fresh green plants and feathers in nest boxes) starts in February, more than one month before egg laying (pers. obs.). During this period, some birds roost in nest-boxes and we take advantage ofthis fact for conducting yearly bird trapping sessions in the study area (twice a year between February and mid-March). One hour before dawn, we closed the entrance of all nest boxes in the study area, and immediately after dawn, we captured by hand all individuals found roosting inside. Captured birds were kept individually in clean cotton bags hanging from a stick to keep birds quiet, and were released immediately after sampling. The maximum time that a captured starling was in the bag did never exced three hours. We explored the possible effect of time that birds were kept in the bag on bird colouration and body condition measures of the males that we recaptured by classifying them as being kept in the bag less than 1 hour (N(males) = 10), between 1 and 2 hours (N = 5), and between 2 and 3 hours (N = 7). After controlling for the effect of date of first and last capture, time between captures, treatment and size of throat feathers in the first capture, results showed that retaining time 184 in first captures did not significantly affect blue, red-yellow, or brightness colouration of the beak of males (F1,15 < 2.66, P > 0.124), nor body condition (F1, 10 = 2.19, P = 0.170) in subsequent captures. It neither had any apparent long-term consequences (see Ruiz-Rodríguez et al. (2015)), nor imply apparent negative effects on breeding performance of captured birds (Soler et al. 2008), This work was supported by the currently named Ministerio de Ciencia,es and European (FEDER) funds (GL2013C-48193-C3-1-P, CGL2017-83103-P Innovación Universidad, CGL2017-89063-P). MAG was financed by a predoctoral contract (BES-2014-068661) from the Spanish Ministerio de Economía y Competitividad, and GT by the Ramón y Cajal Programme, Peer reviewed