Krasheninnikova A.,University of Hamburg |
Brager S.,Dorfstrasse 10 |
Wanker R.,University of Hamburg
Animal Cognition | Year: 2013
A comparative approach is required to investigate the evolutionary origins of cognitive abilities. In this paper, we compare the performance of four parrot species, spectacled parrotlets (Forpus conspicillatus), rainbow lorikeets (Trichoglossus haematodus), green-winged macaws (Ara chloroptera) and sulphur-crested cockatoos (Cacatua galerita triton) in standardized string-pulling and string-choice paradigms. We varied the spatial relationship between the strings, the presence of a reward and the physical contact between the string and the reward to test different cognitive skills requiring means-end comprehension. The species tested showed a high individual and inter-specific variation in their ability to solve the tasks. Spectacled parrotlets performed best among the four species and solved the most complex choice tasks, namely crossed-string task and broken-string task, spontaneously. In contrast, macaws and cockatoos failed to identify the correct string in these two tasks. The rainbow lorikeets were outperformed by the parrotlets, but outperformed in turn the macaws and the cockatoos. The findings can be best explained by the variation in social complexity among species, rather than in their ecology. © 2013 Springer-Verlag Berlin Heidelberg.
Schluter N.,University of Gottingen |
Kutscher M.,Dorfstrasse 10 |
Smith A.B.,Natural History Museum in London |
Jagt J.W.M.,Natuurhistorisch Museum Maastricht |
Lees J.A.,University College London
Zootaxa | Year: 2012
A revision of Late Cretaceous species of the common regular echinoid genus Phymosoma Haime in d'Archiac & Haime, 1853 has revealed that Cidarites granulosus Goldfuss, 1829 has generally been misinterpreted in the literature. The type specimen of this species is undoubtedly conspecific with material from the lower Maastrichtian of Rügen, northeast Germany. What authors have referred to as Phymosoma granulosum in northern temperate (boreal) regions of western Europe and in the Middle East in fact represents an undescribed form which we here name Phymosoma ravni sp. nov., which differs from Cidarites granulosus in having better-developed biserial pore zones adapically, proportionally larger mamelons on primary tubercles, a flush peristome, and stout, non-facetted primary spines. The proper placement of Cidarites granulosus within the family Phymosomatidae Pomel, 1883 is ambiguous; it appears to be most closely related to Phymosoma. Copyright © 2012. Magnolia Press.
Brager S & von Tschirnhaus M 2013: Phenology, population trend, biometry and ectoparasites of Savi's Warblers Locustella luscinioides in northern Germany: Results of a long-term ringing study [Phänologie, Bestandsentwicklung, Biometrie und Parasitenbefall holsteinischer Rohrschwirle Locustella luscinioides: Ergebnisse einer 34-jährigen Beringungsstudie]
Brager S.,Dorfstrasse 10 |
Von Tschirnhaus M.,Bielefeld University
Vogelwarte | Year: 2013
Between 1973 and 2006, a local population of Savi's Warblers Locustella luscinioides was studied at 20 wetlands in Schleswig-Holstein, Germany (centre: 54°13'N, 10°18'E) representing a core distribution of this species in northwestern Germany. The aim of this long-term study was to investigate the warbler's phenology and to collect biometrical data at the edge of its northwestern range. In addition, changes in local abundance provided an excellent indication for population trends of this recent immigrant whose abundances prove difficult to study by other means. From April to September, territorial males (sometimes with their females) were caught with a mistnet and a tape lure, and from July to September, adult and immature warblers were caught opportunistically at semi-permanent ringing sites in reedbeds (n = 301 in total). Breeding adults returned from Africa between the second half of April and late May and departed again by the end of September. Seasonal changes in singing activity and observations of other behaviours indicated second broods. Out of250 adult males, only 7.2% were encountered in more than one season. Fourteen of these 18 males were generally faithful to their previous territory (site-fidelity to original wetland), whereas four established new territories at wetlands about 10 km distant. Habitat characteristics of the territories included the presence of wide reedbeds (52 m on average) with at least several of 24 listed indicative phanerogames and bushes (mostly Salix spec, in 68% of the territories) and a nearest-neighbour distance of 40-200 m (60 m on average). Furthermore, information on ectoparasites (Acari, Siphonaptera, Diptera) collected included four species recorded on Savi's Warblers for the first time and two species reported for Germany for the first time (Analges behbehanii Gaud et Al-Taqi, Trouessartia kratochvili Cerny). In addition, seven biometrical measurements were collected for adult males, adult females and independent fledgelings: wing length, tail length, bill length, skull+bill length, tarsus length, tarsus+toe length, and body mass. Immatures were significantly lighter than adults and had longer tarsi. Over the last 16 years, the warbler population in the study area decreased by approximately 65% with the most drastic decline during the mid-1990s from which the population has not recovered yet. Habitat changes in the wintering areas (e. g., due to a decrease in annual precipitation) or in the breeding areas (e. g" reed-bed loss due to increased Salix encrouchment) are discussed as potential causes of the population decline. Final answers, however, will have to await the results of large-scale studies of passerine trends using constant-efFort ringing sites. © DO-G, IfV.MPG 2013.
Schluter N.,University of Gottingen |
Wiese F.,Ludwig Maximilians University of Munich |
Kutscher M.,Dorfstrasse 10
Cretaceous Research | Year: 2016
Based on representatives of the Late Cretaceous genus Gauthieria (. Gauthieria radiata - Gauthieria spatulifera - Gauthieria princeps), ontogenetic trajectories within the family Phymosomatidae are described for the first time. Due to shared similarities in their ontogenetic development, an intimate evolutionary relationship must be assumed. This interpretation is most supported by analyses of the development in the ambulacral plating pattern (alternation of simple plates and compound plates), which is not commonly found among the Phymosomatoidae. This pattern, however, is present among all three species during development. The developmental trajectories of 8 further characters were included in this study (arrangement of the adapical pore pairs, number of pore pairs, pore pair numbers in ambital ambulacral plates, number of interambulacral plates, peristomal opening, apical opening diameter, test height, radial ornament of the areoles). The evolution in this lineage is characterised by several different heterochronic processes, which suggest a dissociated heterochronic evolution, indicating a developmental modularity. Additionally, the systematic treatment of G. princeps is discussed on account of the presented results. © 2015 .