Informational Mismatches: A Neglected Threat of Climate Change to Interspecific Interactions

Interspecific interactions are deeply affected by the current scenario of climate change. This is because interactions are sensitive to many traits of interacting species as phenology, distribution, behavior, and relative abundances which may be differently influenced by climate change in each species. In this scenario, positive interactions, which require temporal coordination of events of life history of interacting species, could be particularly altered due to differential effects of climate change on phenology, apart from by the effects on abundance and distribution. Hitherto, studies focusing on the effects of climate change on positive biotic interactions are scarce and mainly focused on plant-pollinator interactions. Here I propose that, by inducing informational mismatches, climate change may lead to individuals from competing species relying on heterospecific social information to making mis- or un-informed decisions. The idea is that competing species are valuable sources of social information to each other provided overlap of their activities occurs. However, whenever coordination of events fails, competing species will co-occur at the wrong moment, co-occur only in small numbers or even not co-occur at all and thus they will not be able to access useful or any social information from heterospecifics. In that scenario, interacting species would be mis- or un- informed, and, consequently, decision taking will be impaired, leading to disequilibrium in the community. Throughout the manuscript, I will develop the idea of mismatches of information and illustrate it with some case studies.The research of the author was supported by the Spanish Ministry of Education and Science/FEDER through the projects CGL2011-27561/BOS and CGL2014-56769-P. The contract of the author was supported by the Government of Extremadura by the TA13002 while writing.Peer reviewedPeer Reviewe

Black-crowned Night-herons (Nycticorax nycticorax) feeding on carcasses

L'alimentació del martinet de nit es basa fonamentalment en peixos, amfibis i insectes encara que en determinades poblacions és comuna la ingestió de joves d'altres ocells. Aquí es descriuen dues observacions de martinets alimentant-se d'ocells morts en una colònia de l'oest de Badajoz. El fet que no existeixin descripcions prèvies de l'ús d'aquest tipus de menjar per part dels martinets probablement és perquè la metodologia emprada tradicionalment per a l'estudi de la dieta d'aquesta espècie es basa en la recollida de restes de menjar com egagròpiles o regurgitacions, utilitzant molt poc l'observació directa

Aves limícolas (Charadrii) en un embalse del centro de la Península Ibérica durante el ciclo anual: zonas interiores vs. zonas litorales

The structure and dynamics of wader assernblages in a reservoir in the centre of the lberian peninsula (Los Canchales, Badajoz, SW Spain) was studied over a one-year period. The comparison between these assemblages and others from inland and coastal wetlands of the peninsula is analysed. The highest number of birds in Los Canchales reservoir was registered during the migration periods. This pattern fits that observed in other inland wetlands with slow waters, but is different from the pattern observed in inland rivers, probably dueto the smaller available surface for the majority of these species. The occurrence of Vanellus vanellus in inland wetlands brings about the dominance of the Charadriidae in contrast with coastal wetlands where the Scolopacidae is the dominant family as a result of the great numbers of birds of the Calidris genus. Key words: Waders, Reservoir, Inland, Annual dynamic, Charadrii.The structure and dynamics of wader assernblages in a reservoir in the centre of the lberian peninsula (Los Canchales, Badajoz, SW Spain) was studied over a one-year period. The comparison between these assemblages and others from inland and coastal wetlands of the peninsula is analysed. The highest number of birds in Los Canchales reservoir was registered during the migration periods. This pattern fits that observed in other inland wetlands with slow waters, but is different from the pattern observed in inland rivers, probably dueto the smaller available surface for the majority of these species. The occurrence of Vanellus vanellus in inland wetlands brings about the dominance of the Charadriidae in contrast with coastal wetlands where the Scolopacidae is the dominant family as a result of the great numbers of birds of the Calidris genus. Key words: Waders, Reservoir, Inland, Annual dynamic, Charadrii.The structure and dynamics of wader assernblages in a reservoir in the centre of the lberian peninsula (Los Canchales, Badajoz, SW Spain) was studied over a one-year period. The comparison between these assemblages and others from inland and coastal wetlands of the peninsula is analysed. The highest number of birds in Los Canchales reservoir was registered during the migration periods. This pattern fits that observed in other inland wetlands with slow waters, but is different from the pattern observed in inland rivers, probably dueto the smaller available surface for the majority of these species. The occurrence of Vanellus vanellus in inland wetlands brings about the dominance of the Charadriidae in contrast with coastal wetlands where the Scolopacidae is the dominant family as a result of the great numbers of birds of the Calidris genus. Key words: Waders, Reservoir, Inland, Annual dynamic, Charadrii

Evolución de las ardeidas coloniales en la cuenca extremeña del Guadiana (Suroeste de España)

Des de 1975 es coneix molt poca cosa sobre els ardeids del curs mitjà del Guadiana. Es van estudiar l'estatus i evolució de la població nidificant de quatre espècies d'ardeides en aquesta àrea durant el període 1994-1997. Totes les espècies van mostrar un augment anual excepte l'esplugabous, el qual va mostrar un grau de creixement pròxim a l'equilibri (0,91%). Les colònies foren inestables: només dues d'elles foren ocupades els quatre anys; dues colònies van desaparèixer, i quatre foren nous establiments durant aquests anys. El nombre de colònies amb esplugabous, martinet blanc i martinet de nit va augmentar des de 7 parelles l'any 1994 a deu el 1997, mentre que les colònies de bernat pescaire foren les mateixes (dues) tot i que el nombre d'exemplars reproductors va augmentar

Social information use by competitors: resolving the enigma of species coexistence in animals?

The competitive exclusion principle states that species limited by the same factors cannot share the same environment. Challenging this paradigm, empirical studies often report competitors’ coexistence in natural communities, which has long puzzled evolutionary ecologists. Theoretical studies on animal communities have conferred a prime role to the negative effects of interactions in explaining coexistence, but largely neglected the potential positive side of interactions. Here, we propose that living close to a competitor could have beneficial aspects because competitors may provide fitness-enhancing social information, which under some circumstances may counter the negative effects of competition, thus promoting coexistence. We use conceptual models and discuss factors influencing social information use and their influence on the outcome of competitors’ interaction in terms of coexistence probability. Finally, we discuss ecological and evolutionary implications of these processes and suggest exciting avenues for future research on animal communities.Trabajo financiado por: Ministerio de Economía y Competitividad. Proyecto CGL2011-27561/BOS Gobierno de Extremadura. Ayuda TA13002 para María Deseada Parejo Mora Gobierno de Extremadura y Fondos FEDER. Ayuda GR15080peerReviewe

Common cuckoos (Cuculus canorus) do not rely on indicators of parental abilities when searching for host nests: the importance of host defenses

[EN]There is widespread evidence that individuals within and among host populations are not evenly parasitized by Common Cuckoos (Cuculus canorus). We first investigated whether the song and nest size of a host species, the Great Reed Warbler (Acrocephalus arundinaceus), reveal information on parental abilities and level of defense against Common Cuckoos. Second, we analyzed whether female Common Cuckoos’ preference for host nests is predicted by the degree of song expression and the nest size of the host. Earlier-breeding hosts built bigger nests, were more active singers, and had less rich syllable repertoires than late breeders. Host nestlings raised in a big nest received more feedings than those raised in a small nest. Host males that were active singers were paired with females that built bigger nests. All host pairs rejected nonmimetic artificial eggs, but those with a big nest were more prone to reject natural Common Cuckoo eggs. Thus, Great Reed Warbler pairs with a big nest were more willing to feed nestlings, but also had higher discriminatory abilities against Common Cuckoo eggs, than those with a small nest. These findings, and female Common Cuckoos’ inability to capture the information provided by Great Reed Warblers’ sexual signals, may explain why the females followed a simple rule of selecting the more visible host nests in the population.[ES]Existe abundante evidencia de que los individuos dentro y entre poblaciones hospederas no son parasitados de manera uniforme por Cuculus canorus. Primero, investigamos si el canto y el tamaño del nido de una especie hospedera, Acrocephalus arundinaceus, otorga información sobre las habilidades parentales y el nivel de defensa en contra de C. canorus. Segundo, analizamos si la preferencia de las hembras de C. canorus por los nidos hospederos es predicha por el grado de expresión del canto y el tamaño del nido del hospedero. Los hospederos que criaron más temprano construyeron nidos más grandes, fueron cantantes más activos y presentaron repertorios menos ricos en sílabas que los individuos que criaron más tarde. Los pichones de los hospederos criados en nidos grandes recibieron más alimento que aquellos criados en nidos pequeños. Los machos hospederos que fueron cantantes activos se aparearon con las hembras que construyeron nidos más grandes. Todas las parejas de hospederos rechazaron los huevos artificiales no miméticos, pero aquellas con nidos grandes fueron más propensas a rechazar los huevos naturales de C. canorus. Así, las parejas de A. arundinaceus con nidos grandes estuvieron más dispuestas a alimentar a los pichones de C. canorus, pero también presentaron mayores habilidades para discriminar sus huevos, que aquellas parejas con nidos pequeños. Estos resultados, y la incapacidad de la hembra de C. canorus de captar la información suministrada por las señales sexuales de A. arundinaceus, pueden explicar por qué las hembras siguieron una regla simple de seleccionar los nidos hospederos más visibles de la población.The study was supported by the Hungarian National Research Fund (OTKA, grant no. T48397 to C.M.) and by a bilateral grant from the Spanish and Hungarian governments (TéT, grant no. E-23/2005 to J.M.A. and C.M.)Peer reviewe

Great spotted cuckoo disregard information on conspecific breeding success while parasitizing magpie

Supplementary data are available at Behavioral Ecology online.The study of mechanisms underlying host selection by brood parasites usually lays on selection by parasites of host traits that inform on host parental abilities or location. However, brood parasites might use information extracted from past reproductive performance of either their hosts or themselves, a possibility almost neglected. In this study, we use a long-term data set to analyze whether the probability of parasitism by great spotted cuckoos (Clamator glandarius) of a magpie (Pica pica) nest in a given year is related with the reproductive outcome of any of the 2 species in the surroundings of that nest the previous year. We found that probability of parasitism for a nest in a year was explained by previous year cuckoo reproductive outcome and parasitism rate in the area surrounding the focal nest, but not by host reproductive outcome. To discern between the effect of parasitism rate and that of parasite reproductive success on parasite choices, we carried out an experiment modifying the natural correlation found between parasitism status and host and parasite success in the patches. The results showed that neither host nor cuckoo reproductive outcome in a patch after the experiment explained probability of parasitism in the following year. Only parasitism rate in the surroundings of a nest before the experiment explained probability of parasitism for this nest in the following year. Hence, these results indicate that great spotted cuckoos disregard social information related to past parasitism outcome, probably because parasitism outcome is tightly correlated with parasitism itself.Programa Juan de la Cierva-Formación Fellowship (FJCI-2015–26257)Junta de Andalucía (Proyecto P06-RNM-01862)Ministerio de Economía (proyectos CGL2014-56769-P y CGL2017-83503-P)Junta de Extremadura (contrato TA13002

Do spotless starlings place feathers at their nests by ultraviolet color?

Abstract A considerable number of bird species carry feathers to their nests. Feathers' presence in the nests has traditionally been explained by their insulating properties. Recently, however, it has been suggested that feathers carried to the nests by females of the spotted starling (Sturnus unicolor L.) could have an ornamental function based on their ultraviolet (300-400 nm) and human-visible longer wavelength (400-700 nm) coloration. In our population, 95.7% of feathers found inside next-boxes occupied by nesting starlings were rock dove fly feathers. Of these feathers, 82.7% were naturally positioned with their reverse side oriented toward the entrance hole and 42.4% of all found feathers were situated within the nestcup. Here we experimentally assess the signaling function of ultraviolet coloration of feathers in nests of spotless starlings by providing nests with a number of pigeon flight feathers that were respectively treated on their obverse, reverse, both, or neither side with a UV blocker. Starlings placed 42.5% of the experimental feathers in the nest-cup irrespective of the UV block treatment. Orientation of feathers toward the entrance hole was not related with their ultraviolet radiation. However, feathers placed within the nest-cup were more likely found with their reverse side oriented toward the entrance hole confirming our correlative findings. These results suggest a minor role of ultraviolet coloration on feather location by spotless starlings

Kestrels rely on two different types of social information from conspecifics when choosing breeding habitats

La información social, que es aquella extraída del comportamiento y éxito de otros individuos, puede determinar la elección de hábitat de reproducción. Además, las señales, que han evolucionado para transmitir información, podrían también constituir una fuente de información social comunicando la calidad de sus portadores. Aquí, primero comprobamos experimentalmente si una especie de ave rapaz, el cernícalo vulgar (Falco tinnunculus), usa información social proporcionada por el éxito de los congéneres para elegir sus sitios de reproducción, y después aportamos la primera evidencia correlativa del uso de la coloración del plumaje de los con específicos como otra fuente de información social en este contexto. Para ello estudiamos el impacto de una manipulación del éxito reproductor local de con específicos a escala de parche sobre la selección de hábitat durante 2 años consecutivos. Además recogimos información sobre la coloración del plumaje de los individuos durante un año y analizamos la relación con la elección de hábitat al año siguiente. Nuestros resultados muestran que los cernícalos usan el éxito de reproducción de los congéneres en sus decisiones de emigración y que podrían fijarse en la coloración del plumaje de las hembras como señal de calidad de las hembras residentes para las decisiones tanto de emigración como de inmigración. Por tanto, parece que esta especie puede usar ambas fuentes de información, el éxito de los congéneres y las señales que indican calidad, en su elección de hábitat.Breeding habitat selection is strongly influenced by social information, which is that extracted from the behaviour and performance of other individuals. Also, signals shaped by selection to convey information may be used by unintended receivers as a particular form of social information that has been neglected in a breeding habitat selection context so far. Here, we first tested experimentally whether Eurasian kestrels (Falco tinnunculus) rely on social information provided by conspecifics’ performance by studying the impact of patch scale manipulations of the local reproductive success of conspecifics on their habitat selection during two consecutive years. Second, we provide correlative evidence for the use of plumage coloration of conspecifics as a potential source of social information in the same context of breeding habitat choice in the species. For this purpose, we collected information on individual plumage colouration during one year and analysed its relationship with the habitat choices of individuals in the following year. Our results show that Eurasian kestrels rely on conspecific breeding performance during their emigration decisions, and might rely on female plumage colouration as a signal of resident females’ quality for emigration and immigration decisions. That is, both sources of information, conspecific performance and signals indicating quality, may be used in habitat selection decisions by this species.• Fondo Social Europeo. Beca doctoral para Nadia Silva • Fondo Social Europeo. Contrato I3P-doctores, para María Deseada Parejo Mora • Ministerio de Educación y Ciencia y Fondos FEDER. Proyecto CGL2005-04654/BOS • Gobierno de Extremadura. Contrato TA13002, para María Deseada Parejo MorapeerReviewe

Armed Rollers: Does Nestling’s Vomit Function as a Defence against Predators?

Chemical defences against predators are widespread in the animal kingdom although have been seldom reported in birds. Here, we investigate the possibility that the orange liquid that nestlings of an insectivorous bird, the Eurasian roller (Coracias garrulus), expel when scared at their nests acts as a chemical defence against predators. We studied the diet of nestling rollers and vomit origin, its chemical composition and deterrent effect on a mammal generalist predator. We also hypothesized that nestling rollers, as their main prey (i.e. grasshoppers) do from plants, could sequester chemicals from their prey for their use. Grasshoppers, that also regurgitate when facing to a threat, store the harmful substances used by plants to defend themselves against herbivores. We found that nestling rollers only vomit after being grasped and moved. The production of vomit depended on food consumption and the vomit contained two deterrent chemicals (hydroxycinnamic and hydroxybenzoic acids) stored by grasshoppers and used by plants to diminish herbivory, suggesting that they originate from the rollers’ prey. Finally, we showed for the first time that the oral secretion of a vertebrate had a deterrent effect on a model predator because vomit of nestling rollers made meat distasteful to dogs. These results support the idea that the vomit of nestling rollers is a chemical defence against predators.Financial support was provided by the Junta de Andalucía (project P06-RNM-02177) and the Spanish Ministry of Science and Education/FEDER (projects CGL2008-00718 and CGL2011-27561)