Formigues dispersadores de llavors de Rhamnus alaternus (l.)

Es presenten els resultats sobre les espècies de formigues dispersadores de llavors de Rhamnus alaternus al nord-est de la península Ibèrica. Les llavors de l'aladern tenen la particularitat de presentar un eleosoma que pot ser atractiu per a algunes formigues i que pot fer desencadenar un transport cap al niu. S'han fet oferiments directes de diferents ítems o diàspores (llavors amb eleosoma o sense) a totes les espècies de formigues presents en diferents àrees amb presència d'aladern. Aquestes àrees són cinc localitats de la província de Girona. En aquestes àrees es detecten obreres de 24 espècies diferents, que presenten comportaments diferencials enfront les llavors oferides. En aquest sentit hem registrat 11 espècies en què es genera transport de manera significativa (la majoria de les quals són de la subfamília Myrmicinae), entre les quals 8 són atretes per la presència de l'eleosoma en les llavors mentre que les altres 3 dispersen les llavors atretes per la mateixa llavor, i no pas per l'eleosoma. Finalment, 13 espècies (la majoria de les quals són de la subfamília Formicinae) no són atretes per cap dels ítems presentats, ja siguin amb eleosoma o sense.Seed disperser ants of Rhamnus alaternus (L.). The dispersion of evergreen buckthorn (Rhamnus alaternus) seeds by ants has been studied in five areas of the north-eastern Iberian Peninsula (Province of Girona). R. alaternus seeds have an elaiosome which could be attractive to ants and stimulate transport to the nest. Diaspores (seeds with or without the elaiosome) were offered to foraging ants of every species detected in the areas. Workers of twenty-four ant species were observed and their behaviour towards the diaspores differed. Eleven species that transport items significantly were recorded, basically myrmicine ants: eight of them tranport diaspore because of the presence of the elaiosome and three ant species are attracted by the seed itself and not by the elaiosome. Finally, thirteen ant species, the majority Formicinae, are not attracted by any of the items offered, whether or not they have an elaiosome

Diplocòria de Rhamnus alaternus L., a la Mediterrània Occidental: ocells i formigues com agents dispersants. Dades prèvies

L'aladern (Rhamnus alaternus) és un exemple d'arbre o arbust amb producció de fruits suculents amb un endocarp que protegeix les llavors durant el seu pas pel tracte digestiu dels ocells que les mengen. Una vegada les llavors han estat dispersades junt amb els excrements, l'endocarp s'obre i la llavor queda exposada. La presència d'un eleosoma a les llavors, que ha estat detectat com atractiu per algunes espècies de formigues, genera una última fase de dispersió per les formigues. Aquestes transporten les llavors als seus formiguers, on es mengen l'eleosoma. Amb les primeres observacions fetes a dues comarques catalanes (Girona i Baix Empordà) s'han trobat cinc espècies d'ocells (Turdus merula, Sylvia atricapilla, Sylva melanocephala, Sylvia cantillans, Erithacus rubecula), i tres de formigues (Pheidole pallidula, Tapinoma nigerrimun, Messor barbarus) com agents que poden actuar activament en aquest procés.Diplochory in a fleshy-fruited Mediterranean shrub (Rhamnus alaternus L.): ornitochory and myrmecochory. Previous data. Rhamnus alaternus L. is a freshly-fruited shrub with seeds that show an elaiosome attractive to ants. Some avian frugivores (Turdus merula, Sylvia atricapilla, Sylva melanocephala, Sylvia cantillans, Erithacus rubecula), have been observed as responsible for firts dispersal phase of Rhamnus alaternus in two experimental plots. (Girona, NE Spain). Three ant species (Pheidole pallidula, Tapinoma nigerrimun, Messor barbarus) have been observed as seed disperses of second dispersal phase. These results suggest a two phase seed dispersal process with vertebrates (avian) and invertebrates (ants) seed-disperses

Diversity, distribution and phenology of cicadas (Hemiptera: Cicadidae) in Catalonia (NE Iberian Peninsula)

Les cigales o cicàdids són insectes amb fase juvenil endogea, cicle vital llarg i cants audibles, importants a les xarxes tròfiques d’ecosistemes terrestres. Malgrat l’interès que han despertat arreu, la informació històrica a la península ibèrica, i en particular a Catalunya, és escassa. El catàleg d’hemípters de Martorell y Peña (1879) hi cita set espècies. Després d’aquesta data, les cigales van rebre molt poca atenció fins al segle XXI. La informació acumulada els darrers anys permet estudiar la diversitat, distribució i fenologia del grup. A tal efecte, es va realitzar una cerca bibliogràfica mitjançant cercadors acadèmics, i es van analitzar les dades del portal ornitho.cat pel període 2006-2020 (N=3468 registres). Es presenta el catàleg de cicàdids de Catalunya que conté 12 espècies, un nombre comparable al d’altres territoris europeus: les cigales grossa, del pi, de l’olivera i negra, respectivament Lyristes plebejus Scopoli, 1763, Cicada orni Linné, 1758, C. barbara Stal, 1866 (al·lòctona introduïda) i Cicadatra atra Olivier, 1790; les brunzidores ala-roja, sigil·lada, de garriga i cotonosa, respectivament Tibicina haematodes Scopoli, 1763, T. quadrisignata Hagen, 1855, T. garricola Boulard, 1983 i T. tomentosa Olivier, 1790; i les cigalelles europea occidental, vespera, culprima i argentada, respectivament Cicadetta petryi Schumacher, 1924, Hilaphura varipes Waltl, 1837, Euryphara dubia Rambur, 1840 i Tettigettalna argentata Olivier, 1790. Es mostren mapes de riquesa i distribució d’espècies en quadrícules UTM de 5 × 5 km, diagrames de distribució altitudinal i fenologia per les espècies més comunes, així com il·lustracions originals de suport a la identificació. Aquest treball il·lustra el potencial de la ciència ciutadana per ampliar el coneixement de grups d’insectes poc estudiats i estableix un escenari de referència sobre el que fonamentar futurs estudis de la distribució i ecologia dels cicàdids.True cicadas (Cicadidae) are insects with a juvenile phase spent belowground, a long life cycle and audible songs, that are important in the trophic networks of terrestrial ecosystems. Despite the interest they arouse, historical information in the Iberian Peninsula, and more specifically in Catalonia, is scarce. The catalogue of Hemipteran by Martorell y Peña (1879) cited seven species. After that date, cicadas received very little attention until the 21st century. The information accumulated in recent years allowed us to study the diversity, distribution and phenology of the group. To this end, a bibliographic search was carried out using the academic search engines, and the data hosted at ornitho.cat website was analysed for the period 2006-2020 (N= 3468 records). The catalogue of cicadas of Catalonia presented here contains 12 species, a number comparable to that of other European territories: Cicadinae Lyristes plebejus Scopoli, 1763, Cicada orni Linné, 1758, C. barbara Stal, 1866 (introduced non-native) and Cicadatra atra Olivier, 1790; Tibicininae Tibicina haematodes Scopoli, 1763, T. quadrisignata Hagen, 1855, T. garricola Boulard, 1983 and T. tomentosa Olivier, 1790; and Cicadettinae Cicadetta petryi Schumacher, 1924, Hilaphura varipes Waltl, 1837, Euryphara dubia Rambur, 1840 and Tettigettalna argentata Olivier, 1790. We provide species richness and distribution maps in 5 × 5 km UTM grids, altitudinal distribution and phenology diagrams for the most common species, as well as original illustrations to support identification. This work shows the potential of citizen science to expand the knowledge of a scarcely studied group of insects and establishes a baseline scenario on which to base future studies of the distribution and ecology of cicadas

Open-Habitat Birds in Recently Burned Areas: the Role of the Fire Extent and Species’ Habitat Breadth = Aves de medios abiertos en áreas quemadas recientemente: la importancia de la extensión del fuego y la amplitud de hábitat de las especies

To evaluate the occurrence of open-habitat and steppe-land bird species in Western Mediterranean burned areas and to assess the role of the extent and location of the fire on species richness and composition. At the species level, the relationship was explored between habitat breadth, distribution extent and the ability to occupy recently burned areas. Location: Iberia and Southern France Methods: Fieldwork and bibliography were assembled to obtain breeding bird inventories for 21 burned areas, mostly large wildfires (135- 23,800 ha). The sampling effort was standardized in relation to the area in the 11 fire locations surveyed using transects. Results: Single burned areas contained 0 to 15 open-habitat species (mean = 7.6), and in all the areas combined there were 22 species, including 17 with an unfavourable conservation status in Europe. The most frequent were Carduelis cannabina, Lullula arborea, Alectoris rufa, Oenanthe hispanica and Emberiza cia, but characteristic steppe-land birds such as O. leucura, Calandrella brachydactyla and C. rufescens also bred in particular burned areas. After controlling for the extent of the species range in the Spanish distribution Atlas, passerine occurrence in burned areas was positively related to the species’ habitat breadth in a gradient of unburned habitats. Cluster analysis separated a species-poor group of fire locations from a species-rich group, and showed that some neighbouring areas had a similar species composition. However, there was no spatial autocorrelation between burned areas, and species composition was correlated with the fire extent (Mantel test). Species richness tended to increase with increasing fire area. From the regression equation 5, 9, 12-13 and 16-17 open-habitat species may be expected to occur in burned areas of 100, 1000, 10,000 and 100,000 ha, respectively. Conclusions: This study stresses the importance of biogeographical constraints on colonisation of new habitat patches created by disturbances. The extent of the fire rather than the proximity between burned areas influenced species richness and composition of open-habitat birds in recently burned areas. The best post-fire colonisers were generalists regarding habitat structure. The role of large wildfires in the conservation of threatened open-habitat birds seems to be significant and merits further stud

Can salvage logging affect seed dispersal by birds into burned forests?

The recovery of vegetation in Mediterranean ecosystems after wildfire is mostly a result of direct regeneration, since the same species existing before the fire regenerate on-site by seeding or resprouting. However, the possibility of plant colonization by dispersal of seeds from unburned areas remains poorly studied. We addressed the role of the frugivorous, bird-dependent seed dispersal (seed rain) of fleshy-fruited plants in a burned and managed forest in the second winter after a fire, before on-site fruit production had begun. We also assessed the effect on seed rain of different microhabitats resulting from salvage logging (erosion barriers, standing snags, open areas), as well as the microhabitats of unlogged patches and an unburned control forest, taking account of the importance of perches as seed rain sites. We found considerable seed rain by birds in the burned area. Seeds, mostly from Olive trees Olea europaea and Evergreen pistaches Pistacia lentiscus, belonged to plants fruiting only in surrounding unburned areas. Seed rain was heterogeneous, and depended on microhabitat, with the highest seed density in the unburned control forest but closely followed by the wood piles of erosion barriers. In contrast, very low densities were found under perches of standing snags. Furthermore, frugivorous bird richness seemed to be higher in the erosion barriers than elsewhere. Our results highlight the importance of this specific post-fire management in bird-dependent seed rain and also may suggest a consequent heterogeneous distribution of fleshy-fruited plants in burned and managed areas. However, there needs to be more study of the establishment success of dispersed seeds before an accurate assessment can be made of the role of bird-mediated seed dispersal in post-fire regeneratio

La migració primaveral d'ocells als Aiguamolls de l'Empordà (Girona): primer anellament de Becadell Gros (Gallinago Media) a la Península Ibèrica

En aquest treball s'exposen els resultats obtinguts en la campanya 1994 d'anellament d'ocells inclosa dins del projecte italià Piccole Isole. Es demostra que el factor meteorològic afecta directament la fenologia migratòria de diferents espècies d'ocells. Es pretén també estudiar la influència dels diferents hàbitats en el nombre i en la diversitat de captures. Es recullen també en aquest treball les principals espècies visualitzades durant la campanya, com també l'elevat nombre de controls estrangers recuperats. Dintre de les captures i l'anellament posterior, destaca sobretot la d'un becadell gros (Gallinago media) fets per primera vegada a la peninsula IbèricaThe results obtained on the birds' ringing scientific campaign included in the Italian project Piccole Isole 1994, are exposed. The purpose of this project is to study the role of the islands and the coast territories in the birds' spring migration. The direct effect of the meteorological factors to the migratory fenology of different species, and too, the habitat influences on the number and diversity of captures, are showed. The main visualized species and the high nnmber of recaptured foreign controls are also exposed. The capture and later ringing of a Great Snipe (Gallinago media) is emphasized because it's the first time that this specie is ringed in the Iberian Peninsul

Morphological and structural characterization of evergreen buckthorn (Rhamnus alaternus L.) fruits in the northeastern Iberian Peninsula

Se caracterizan, morfológica y estructuralmente, los frutos y semillas de Rhamnus alaternus. Los frutos del aladierno presentan alta variabilidad en volumen (media ± s.e. = 192,77 ± 47,21 mm3) y peso (240,15 ± 59,14 mg), siendo la pulpa el mayor porcentaje en referencia al volumen y peso fresco. El resto del fruto corresponde a endocarpos y semillas, los cuales suponen globalmente el 19% del peso total del fruto. El número de endocarpos fluctúa entre 2 y 5, presentando una media de 3,10 ± 0,09 endocarpos/fruto. Cada endocarpo suele presentar una semilla desarrollada en su interior (95% de los casos) originando una media de 2,93 ± 0,03 semillas por fruto. Existe mayor viabilidad en las semillas procedentes de endocarpos abiertos que en las procedentes de endocarpos cerrados. Las semillas presentan un eleosoma que representa el 4,05% del peso de la semilla. Las características de las diásporas tendrán influencia en la biología dispersiva de esta especie: frutos carnosos atractivos para vertebrados frugívoros y semillas con eleosoma atractivos a hormigas.We present a structural and morphological description of fruits and seeds of the evergreen buckthorn, Rhamnus alaternus. The evergreen buckthorn fruits have a great variability on volume (mean ± s.e. = 192,77 ± 47,21 mm3) and weight (240,15 ± 59,14 mg), being the pulp the most important fraction both of volume and dry mass. Endocarps and seeds represent the 19% of fruit global mass. Fruits have 3,10 ± 0,09 endocarps with a range of 2-5 endocarps. 95% of endocarps presented one developed seed inside with a total of 2,93 ± 0,03 seeds/fruit. The seeds obtained from naturally opened endocarps have a major level of viability than those from closed endocarps. The seeds present an elaiosome that represents 4,05% of the total seed mass. Diaspore assemblages could influence on dispersal biology of R. alaternus, where vertebrates and ants take part as seed dispersers for attraction of the fleshy fruits and seeds, respectively

Building wood debris piles benefits avian seed dispersers in burned and logged Mediterranean pine forests

Salvage logging is a common practice carried out in burned forests worldwide, and intended to mitigate the economic losses caused by wildfires. Logging implies an additional disturbance occurring shortly after fire, although its ecological effects can be somewhat mitigated by leaving wood debris on site. The composition of the bird community and its capacity to provide ecosystem services such as seed dispersal of fleshy-fruited plants have been shown to be affected by postfire logging. We assessed the effects of the habitat structure resulting from different postfire management practices on the bird community, in three burned pine forests in Catalonia (western Mediterranean). For this purpose, we focused on the group of species that is responsible for seed dispersal, a process which takes place primarily during the winter in the Mediterranean basin. In addition, we assessed microhabitat selection by seed disperser birds in such environments in relation to management practices. Our results showed a significant, positive relationship between the density of wood debris piles and the abundance of seed disperser birds. Furthermore, such piles were the preferred microhabitat of these species. This reveals an important effect of forest management on seed disperser birds, which is likely to affect the dynamics of bird-dependent seed dispersal. Thus, building wood debris piles can be a useful practice for the conservation of both the species and their ecosystem services, while also being compatible with timber harvesting.This study was funded by the Spanish Ministry of Science and Innovation (CGL2005-0031/BOS and CGL2008-05506/BOS) and J.R. held a FPU grant of the Ministry of Education

Reduction of the Ant Mandible Gap Range After Biotic Homogenization Caused by an Ant Invasion (Hymenoptera: Formicidae)

After most of the native ant species are displaced by the Argentine ant invasion, it is probable that some ecological processes carried out by natives are not replaced. In some cases this could be due to a morphological difference between the Argentine ant and the displaced native ants. The significant decrease in ant richness after the invasion (only two species detected in the invaded zones vs. 25 species in surrounding non-invaded zones) implies a drastic reduction in the ant mandible gap range (the mandible gap spectra of all the ant species in a community) in the invaded zones. This reduction could explain why some roles that were previously carried out by the displaced native species are not performed by the invasive species. This could be due to a functional inability to carry out these activities. The mandible gap waspositively correlated with the ant body mass in the 26 ant species considered. The functional inability hypothesis could be applied to other invasive ants as well as to the Argentine an

Daily activity of sardinian warbler sylvia melanocephala in the breeding season = Actividad diaria de la curruca cabecinegra sylvia melanocephala durante el periodo reproductor

El momento concreto del periodo reproductor puede incidir sobre la actividad diaria y los periodos de reposo de las aves paseriformes. Para investigar este aspecto, hemos analizado los movimientos diarios de 7 machos de curruca cabecinegra Sylvia melanocephala mediante radioseguimiento en un matorral mediterráneo. La actividad tiende en general a decrecer a lo largo del día aunque con algunas variaciones dependiendo del momento concreto del periodo reproductor de cada macho en particular. Se han registrado largos periodos de reposo que no dependen ni del estado reproductor ni del momento del dí