The Evolution of Flightless Ratite Birds

Birds are well known for their unique (other than bats) ability among vertebrates of flight. Through millions of years of evolution, before they were even classified as such, and for reasons and methods still largely unknown, birds evolved the ability to fly. However, like all evolution, there is no end goal or final product. Because of this, traits and adaptations evolve and then can disappear

: Les Struthionidae et les Pelagornithidae (Aves, Struthioniformes et Odontopterygiformes) du Pliocène final d'Ahl al Oughlam, Maroc

International audienceThe Pliocene locality of Ahl al Oughlam is situated at the southeastern limit of the city of Casablanca, in Morocco, on an ancient seashore of the Atlantic Ocean. It has yielded a very rich vertebrate fauna (macro- and micromammals, birds, reptiles, amphibians and fishes) including both terrestrial and marine forms. On the basis of biostratigraphy, the fauna has been dated at about 2.5 Ma, which corresponds to the latest Pliocene. The avifauna is very diverse and includes birds belonging to twelve different orders. In this paper we describe only the Struthionidae and the Pelagornithidae. Ostriches are represented by a large-sized form, referred to the extinct species Struthio asiaticus Milne-Edwards, and its eggshells, of struthioid type, are comparable to those of the recent species Struthio camelus, but thicker. The Pelagornithidae, giant marine birds with bony pseudoteeth, are represented by an extinct species of the genus Pelagornis. As far as we know, this species was probably the latest representative of the order Odontopterygiformes.Le gisement pliocène d'Ahl al Oughlam est situé à la limite sud-est de la ville de Casablanca, au Maroc, sur un ancien rivage de l'Océan Atlantique. Il a livré une très riche faune de Vertébrés (macro- et micromammifères, oiseaux, reptiles, amphibiens et poissons), appartenant surtout à des formes terrestres, mais comportant aussi des formes marines. Des arguments biostratigraphiques ont permis de dater cette faune de 2,5 Ma, ce qui correspond au Pliocène final. L'avifaune est très diversifiée et comporte des oiseaux appartenant à douze ordres différents. Dans cette étude nous décrivons seulement les Struthionidae et les Pelagornithidae. Les autruches sont représentées par une forme de grande taille, attribuée à l'espèce éteinte Struthio asiaticus Milne-Edwards, et leurs coquilles d'œufs, de type struthioïde, sont comparables à celles de l'espèce actuelle Struthio camelus, mais sont plus épaisses. Les Pelagornithidae, oiseaux marins géants à pseudodents, sont représentés par une espèce éteinte du genre Pelagornis. Les restes trouvés à Ahl al Oughlam correspondent probablement aux derniers réprésentants connus de l'ordre des Odontopterygiformes

The relationship between the feather tuft of the uropygial gland and terrestrial/aquatic birds

The bird´s uropygial gland has a papilla in its caudal end and it can also show a feather tuft. These feathers may have a raquis or not. The purpose of our study was to compare the number, dimensions and types of the tuft´s feathers in aquatic and terrestrial birds, as well as to investigate whether the potential differences are related or determined by their dissimilar habitats. The uropygial glands were removed and the tuft´s feathers were extracted and then measured, prepared for magnifying glass observation and photo shoot. Aquatic birds were found to have not only a larger number of feathers in the tuft but also longer feathers than terrestrial birds. However, the length ratio between calamus/raquis was higher in terrestrial birds. Almost all the species under study presented the same type of feathers except for the three penguin species that showed a peculiar type. The differences found between the tuft´s feathers of the studied species are related with the environment. Aquatic birds have a longer length of the feather tuft because they may produce a greater amount of secretion than terrestrial birds.Fil: Chiale, Maria Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Montalti, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Fauna of islands and island habitats

Na otocima nalazimo mnogo različitih staništa i životinja, koje se u većini slučajeva razlikuju od njihovih srodnika na kopnu. Te razlike ovise o vrsti otoka (kojeg je postanka), površine i udaljenosti od najbližeg kopna. MacArthurova i Wilsonova „teorija ekvilibrija“ nam to objašnjava u obliku matematičkog modela. Broj vrsta koje nastanjuju otok u bilo kojem vremenu je ravnoteža između imigracije novih vrsta i izumiranja vrsta koje su već na njemu. Kao odgovor na posebne uvijete na otocima životinje se tijekom vremena polako mijenjaju, dolazi do evolucije i zbog toga na otocima možemo pronaći mnogo endema. To sve utječe da otoci postaju „hot spots“ bioraznolikosti. Otočna staništa su područja okružena područjem ne odgovarajućeg staništa. Imaju ista obilježja kao i otoci, što je važno prilikom određivanja novih zaštićenih područja kako bi mogli povećati broj i uspješnost preživljavanja vrsta u njima. Otoci i otočna staništa su među najugroženijim staništima na planeti, zbog svoje veličine, izolacije i osjetljivosti. Utjecaji klimatskih promjena i zagađenja, zajedno sa uništavanjem biotopa, pretjeranim iskorištavanjem i invazivnim vrstama sve će biti veći, vidljiviji i pogubniji za faunu tih staništa.Islands offer a wide range of habitats for wildlife. Most hold a different animals from mainland, but that depends of types, sizes and distances from nearest mainland. The „Equilibrium Theory“ proposed by MacArthur and Wilson attempts to explain this in the form of a mathematical model. The number of species living on an island at any given time is an equilibrium between immigration and extinction rate. In response of particular conditions on the islands animals slowly change over time, they evolve. We can find lot of endemic species on islands and because of that islands are biodiversity „hot spots“. Islands habitat are areas surrounded by an area of unsuitable habitat, they can be treated like real islands. That is important to know when we are trying to define the protected areas and maximize the carrying capacity of species in them. Biodiversity loss is a particular concern on islands and island habitats. There are “among the most threatened habitats in the world”, due to their small size, isolation and fragility. It is projected that the impacts of climate change and pollution will become increasingly severe and that the impacts associated with habitat change, over-exploitation and, particularly, invasive species will continue to be very high

Ontogenetic scaling patterns and functional anatomy of the pelvic limb musculature in emus (Dromaius novaehollandiae)

Emus (Dromaius novaehollandiae) are exclusively terrestrial, bipedal and cursorial ratites with some similar biomechanical characteristics to humans. Their growth rates are impressive, as their body mass increases eighty-fold from hatching to adulthood whilst maintaining the same mode of locomotion throughout life. These ontogenetic characteristics stimulate biomechanical questions about the strategies that allow emus to cope with their rapid growth and locomotion, which can be partly addressed via scaling (allometric) analysis of morphology. In this study we have collected pelvic limb anatomical data (muscle architecture, tendon length, tendon mass and bone lengths) and calculated muscle physiological cross sectional area (PCSA) and average tendon cross sectional area from emus across three ontogenetic stages (n = 17, body masses from 3.6 to 42 kg). The data were analysed by reduced major axis regression to determine how these biomechanically relevant aspects of morphology scaled with body mass. Muscle mass and PCSA showed a marked trend towards positive allometry (26 and 27 out of 34 muscles respectively) and fascicle length showed a more mixed scaling pattern. The long tendons of the main digital flexors scaled with positive allometry for all characteristics whilst other tendons demonstrated a less clear scaling pattern. Finally, the two longer bones of the limb (tibiotarsus and tarsometatarsus) also exhibited positive allometry for length, and two others (femur and first phalanx of digit III) had trends towards isometry. These results indicate that emus experience a relative increase in their muscle force-generating capacities, as well as potentially increasing the force-sustaining capacities of their tendons, as they grow. Furthermore, we have clarified anatomical descriptions and provided illustrations of the pelvic limb muscle–tendon units in emus

Range Management Affects Native Ungulate Populations in Penísula Valdés, a World Natural Heritage

Sheep rearing is the main productive activity in Patagonian rangelands, where guanacos are the only native ungulate. Ranchers perceive a decrease in range carrying capacity as guanaco numbers increase, therefore guanaco conservation within private lands becomes a considerable challenge. This issue is particularly evident in the World Natural Heritage Penı´nsula Valde´s (PV), where there is a need to harmonize livestock production and biodiversity conservation. While sheep rearing prevails as the primary land use in the area, some ecotourism initiatives have been implemented to complement livestock production. In order to study how land use affected guanaco distribution, we characterized PV’s ranches in termsof land subdivision, primary productivity, stocking-rate and management type, and assess how these variables affected guanaco encounter rates. Smaller ranches were composed of smaller paddocks (mean size 4.8 km2 ), which showed highervalues of the remote-sensing derived Enhance Vegetation Index (EVI) (mean 0.14) and held higher sheep densities (mean 108.0 sheep/km2 ), while larger management units (mean size 23.8 km2 ), showed lower EVI values (mean 0.12) and lower stocking-rates (mean 36.7 sheep/km2). This pattern suggests that primary productivity has been a decisive factor to determine the minimal paddock size set by ranchers in PV, apparently precluding excessive land-subdivision in less productive areas. Guanaco encounter rate, expressed as number of guanacos per travelled kilometre, was inversely relatedto EVI and stocking-rate. However, land subdivision was the better predictor of guanaco encounter-rate within only sheep ranches, finding more guanacos per kilometre as paddock size increased. In contrast, in ranches where ecotourism was implemented as a complementary activity, guanaco encounter-rates were greater, regardless of paddock size. Our results suggest that the implementation of an additional activity by which landowners derive benefits from wildlife has prompted a beneficial outcome for guanacos, presumably through a decrease in harassment intensity. Finally, we propose possible mechanisms by which land subdivision may affect guanaco distribution and potential alternatives for the inclusion of wildlife conservation in a context of extensive livestock production.Fil: Nabte, Marcela Janina. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Nacional Patagonico;Fil: Marino, Andrea Ivana. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Nacional Patagonico;Fil: Rodriguez, Maria Victoria. Consejo Nacional de InvesOt.cientif.y Tecnicas. Centro Nacional Patagonico;Fil: Monjeau, Jorge Adrian. Consejo Nacional de Invest.cientif.y Tecnicas;Fil: Saba, Sergio Leonardo. Universidad Nacional de la Patagonia "san Juan Bosco"

Generation of pcdna 3.1+-gh as a recombinant expression vector of ostrich growth hormone cdna in saccharomyces cerevisiae

Growth hormone is essential hormone for vertebrates like the ostrich (Struthio camelus) for growth stimulation, carbohydrate metabolism, protein assimilation etc. Growth hormone is secreted by the pituitary gland and expressed in many cells and tissues. The purpose of this study was generation of pcDNA 3.1+-GH recombinant expression vector in order to sub-clone ostrich growth hormone cDNA into Escherichia coli. In brief, total RNA was extracted from the pituitary gland tissue and cDNA sample was synthesised. The cDNA was amplified by PCR and revealed a 672 bp fragment on 2% agarose gel electrophoresis. Then, the ostrich growth hormone cDNA was extracted from the gel and was cloned into pCR8/GW/TOPO vector by T/A cloning technique to produce pCR8/GW/TOPO-GH. After obtaining the sequence of cDNA of the ostrich in Iran, it was submitted in GenBank (Accession number: JN559394). Finally, the GH cDNA was sub-cloned using pcDNA 3.1+ into Saccharomyces cerevisiae and pcDNA 3.1+-GH recombinant expression vector was generated. The results of present study were showed that ostrich growth hormone cDNA was successfully sub-cloned into Saccharomyces cerevisiae. Therefore, the pcDNA 3.1+-GH recombinant expression vector generated in this study could be useful to express the ostrich growth hormone in yeast cells as a simple and affordable way to produce this hormone at a large scale

La colección de huevos del Museo de La Plata: especies de Eurasia, Oceanía, África y Norteamérica

Fil: Scheffer, Maila. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Olmedo Masat, Olga Magali. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Segura, Luciano Noel. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Montalti, Diego. División Zoología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin