Parental care and the transition to independence of Spanish Imperial Eagles Aquila heliaca in Doñana National Park, southwest Spain

The behaviour of five broods of radio-tagged Spanish Imperial Eagles Aquila heliaca adalberti was studied in Doñana National Park, Spain during the post-fledging period. The distance between perching sites and nest, the mean flight duration and distance, the percentage of time spent flying and the home range all increased exponentially with age. As the young got older, the parents spent less time in their vicinity. Young were not seen hunting, but depended on their parents for food. They begged and chased their parents throughout the post-fledging period, with higher intensity at the end. Nevertheless, the adults became progressively more reluctant to feed them, as reflected in the decrease in feeding frequency and in the number of approaching flights towards the young. At the end of the post-fledging period, adults often performed aerial displays and frequently chased their offspring. The age of independence of the different young studied varied between 123 and 145 days. The correlations between individual independence and the dates when the young were last fed by their parents, and when the highest intensity of parental aggressive behaviour occurred, were higher than correlations with the variables related to the maturation of flying. Therefore, it is suggested that parental 'meanness' and aggressive behaviour may be the factors determining the date of juvenile independence and dispersal from the home territory.     

A diverse Upper Jurassic dinosaur ichnofauna from central‐west Portugal

Mateus, O. & Milàn, J. 2009: A diverse Upper Jurassic dinosaur ichnofauna from central‐west Portugal. Lethaia, Vol. 43, pp. 245–257. A newly discovered dinosaur track‐assemblage from the Upper Jurassic Lourinhã Formation (Lusitanian Basin, central‐west Portugal), comprises medium‐ to large‐sized sauropod tracks with well‐preserved impressions of soft tissue anatomy, stegosaur tracks and tracks from medium‐ to large‐sized theropods. The 400‐m‐thick Lourinhã Formation consists of mostly aluvial sediments, deposited during the early rifting of the Atlantic Ocean in the Kimmeridgian and Tithonian. The stratigraphic succession shows several shifts between flood‐plain mud and fluvial sands that favour preservation and fossilization of tracks. The studied track‐assemblage is found preserved as natural casts on the underside of a thin bivalve‐rich carbonate bed near the Tithonian–Kimmeridgian boundary. The diversity of the tracks from the new track assemblage is compared with similar faunas from the Upper Jurassic of Asturias, Spain and the Middle Jurassic Yorkshire Coast of England. The Portuguese record of Upper Jurassic dinosaur body fossils show close similarity to the track fauna from the Lourinhã Formation. □Dinosaur tracks, Lusitanian Basin, Portugal, skin impressions, Upper Jurassic.     

Inferring palaeoecology in extinct tremarctine bears (Carnivora,Ursidae) using geometric morphometrics

Figueirido, B. & Soibelzon, L.H. 2009: Inferring palaeoecology in extinct tremarctine bears (Carnivora, Ursidae) using geometric morphometrics. Lethaia, Vol. 43, pp. 209–222. In this study we explore the ecomorphological patterns of extinct tremarctine bears in South America during the Great American Biotic Interchange (GABI). These patterns are used to derive palaeoautoecological inferences in extinct tremarctines and their palaeosinecological relationships within Plio‐Pleistocene ecosystems. We used geometric morphometrics of landmark data to recover the shape of the craniomandibular skeleton of bears. The results reveal different ecomorphological specializations in extinct tremarctines during the Plio‐Pleistocene of South America. Indeed, these bears could have increased the percentage of plant matter in their diets according with the increased diversity of large carnivores in South America after the GABI. Omnivorous bears retain the ability to behave as carnivores or herbivores depending on resource availability. This fact strongly supports that bears are one of the most ecologically and morphologically adaptable members of the large carnivore guild. Moreover, their skull morphology could reflect ecological adaptations under different selection pressures with the required evolutionary time. □Evolution, GABI, geometric morphometrics, palaeoecology, Tremarctinae.     

Marked genetic structuring and extreme dispersal limitation in the Pyrenean brook newt Calotriton asper (Amphibia: Salamandridae) revealed by genome-wide AFLP but not mtDNA

Direct estimation of dispersal rates at large geographic scales can be technically and logistically challenging, especially in small animals of low vagility like amphibians. The use of molecular markers to reveal patterns of genetic structure provides an indirect way to infer dispersal rates and patterns of recent and historical gene flow among populations. Here, we use mitochondrial DNA (mtDNA) sequence data and genome-wide amplified fragment length polymorphism markers to examine population structure in the Pyrenean brook newt ( Calotriton asper ) across four main drainages in the French Pyrenees. mtDNA sequence data (2040 bp) revealed three phylogroups shallowly differentiated and with low genetic diversity. In sharp contrast, variation in 382 amplified fragment length polymorphism loci was high and revealed a clear pattern of isolation by distance consistent with long-term restriction of gene flow at three spatial scales: (i) among all four main drainages, (ii) between sites within drainages, and (iii) even between adjacent populations separated by less than 4 km. The high pairwise F _ST values between localities across numerous loci, together with the high frequency of fixed alleles in several populations, suggests a combination of marked geographic isolation, small population sizes and very limited dispersal in C. asper . The contrasting lack of variation detected in mtDNA sequence data is intriguing and underscores the importance of multilocus approaches to detect true patterns of gene flow in natural populations of amphibians.     

Plant fossil record and survival analyses

Cascales‐Miñana, B. & Cleal, C.J. 2011: Plant fossil record and survival analyses. Lethaia, Vol. 45, pp. 71–82. Survival analysis is a classic palaeobiological method widely used on the animal fossil record. This study reports the first application of survivorship analyses on the plant fossil record from a global viewpoint and provides a new comparative approach of this methodology. The results reveal three important plant extinction events in the history of plant life at a global scale. The results also clearly suggest that the origination events are more intensive than extinction processes and that the origination moment of several lineages of vascular plants is an important factor that conditions their longevity. This study supports the general idea that vascular plants tended to be less affected by the environmental changes that caused mass extinction in other groups of organisms. □Extinction events, fossil record, survival patterns, taxonomic survivorship curves, vascular plants.     

Isolation of polymorphic tetranucleotide microsatellite markers for the wedge‐billed woodcreeper Glyphorynchus spirurus

We have isolated six polymorphic microsatellite markers for the wedge‐billed woodcreeper Glyphorynchus spirurus from a genomic library enriched for (AAGG)_n repetitive elements, and characterized them in 25 individuals. The number of alleles ranged from eight to 20 per locus, with observed heterozygosity ranging from 0.43 to 0.78.     

The germarium of panoistic ovarioles of Bacillus rossius (Insecta Phasmatodea): Structure and function during imaginal life

Summary

In adult females of Bacillus rossius (Insecta Phasmatodea) the germarium, localized at the ovariole tip just below the terminal filament and above the vitellarium, progressively reduces in size and eventually disappears at the end of the ovulatory period. The observations with light and electron microscopes show that in the end-chamber most germ cells are arrested in a post-pachytenic diffuse stage, which just precedes diplotenic oocyte growth. These observations also indicate that the reduction in size of the germarium of ovulating females should probably be ascribed to a progressive and extensive activation of the resting germ cells. The average number of ovulated eggs per ovariole (6.7±0.9) is consistent with this view. However, occasional findings of lepto-zygotenic germ cells in some preovulatory ovarioles of adult females do not completely rule out the persistence of scarce undifferentiated germ elements (oogonia) in the larval germarium at the onset of adult life. Furthermore, the reduction of the germarium in ovulating females and its subsequent disappearance in post-ovulating ones also includes the somatic cells, which are always present among the germ cells in previous stages. Since each early growing oocyte becomes surrounded by a thin monolayer of follicle cells, the diminution of end-chamber somatic cells supports the view that they actually represent prefollicular cells, which are progressively utilized from the onset of imaginal life onwards.     

Trends and patterns in the evolution of vascular plants: macroevolutionary implications of a multilevel taxonomic analysis

Cascales‐Miñana, B., Muñoz‐Bertomeu, J., Ros, R., Segura, J. 2010: Trends and patterns in the evolution of vascular plants: macroevolutionary implications of a multilevel taxonomic analysis. Lethaia, 10.1111/j.1502‐3931.2009.00212.x Studying the macroevolutionary patterns of vascular plants from the Silurian to the present‐day provides a global record of plant life history. Evolutionary rates (origination, extinction and diversification) for families, orders, classes and divisions were analysed, as was abundance and richness for 21 time intervals. An accumulative analysis, based on the total plant fossil record, the accumulated extinctions and relative diversity, was also carried out. The diversification rate shows a uniquely constant and progressive reduction from the end of the Carboniferous to the Permian when the lowest values are registered. Very small peaks seem to reflect Cretaceous extinction for families. At family level, only two time intervals present higher extinctions, than originations. Richness and accumulative analyses reveal that only 32% of the families analysed became extinct, and that approximately 90% of them disappeared at the end of the Palaeozoic. Our results indicate that plants did not undergo mass extinction events in the ‘big five’ sense, but rather, mass ecological reorganization the absence of important extinction events or evolutionary innovations producing diversification patterns without abrupt changes. □Diversification, evolutionary, extinction, fossil record, innovations, radiation, vascular plants.     

Space and habitat use by Red Kites Milvus milvus during winter in the Guadalquivir marshes: a comparison between resident and wintering populations

Differences in habitat selection, diet and behaviour of resident and wintering Red Kites Milvus milvus were studied in Donana National Park, southwest Spain. Adult resident Red Kites roosted at their nests, while immature residents and wintering birds gathered at communal roosts. Individuals remained on average for two consecutive nights (range 1–8) at the same communal roost. Wintering kites spent significantly more time foraging gregariously than residents. The use of the marsh was greater by wintering kites while residents more often used the forest. Wintering birds consumed more goose carrion than the residents. Wintering kites had larger core areas, moved farther from their roost sites to feed and changed foraging areas more frequently than residents. Among residents, adult females had the smallest home ranges (core area, distances travelled and time spent flying). We suggest that Red Kites wintering in Donana occupy the marsh because it provides high food availability, and is vacated by Black Kites M. migrans which exploit this profitable habitat during the breeding season.     

Patterns of divergence in the olive sunbird Cyanomitra olivacea (Aves: Nectariniidae) across the African rainforest–savanna ecotone

In the debate over modes of vertebrate diversification in tropical rainforests, two competing hypotheses of speciation predominate: those that emphasize the role of geographical isolation during glacial periods and those that stress the role of ecology and diversifying selection across ecotones or environmental gradients. To investigate the relative roles of selection versus isolation in refugia, we contrasted genetic and morphologic divergence of the olive sunbird (Cyanomitra olivacea) at 18 sites (approximately 200 individuals) across the forest–savanna ecotone of Central Africa in a region considered to have harboured three hypothesized refugia during glacial periods. Habitats were characterized using bioclimatic and satellite remote‐sensing data. We found relatively high levels of gene flow between ecotone and forest populations and between refugia. Consistent with a pattern of divergence‐with‐gene‐flow, we found morphological characters to be significantly divergent across the gradient [forest versus ecotone (mean ± SD): wing length 60.47 ± 1.81 mm versus 62.18 ± 1.35 mm; tarsus length 15.51 ± 0.82 mm versus 16.00 ± 0.57 mm; upper mandible length 21.77 ± 1.09 mm versus 23.19 ± 0.98 mm, respectively]. Within‐habitat comparisons across forest and ecotone sites showed no significant differences in morphology. The results show that divergence in morphological traits is tied to environmental variables across the gradient and is occurring despite gene flow. The pattern of divergence‐with‐gene‐flow found is similar to that described for other rainforest species across the gradient. These results suggest that neither refugia, nor isolation‐by‐distance have played a major role in divergence in the olive sunbird, although ecological differences along the forest and savanna ecotone may impose significant selection pressures on the phenotype and potentially be important in diversification. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 821–835.