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Die jahreszeitlichen Zugmuster der häufigeren Singvogelarten auf dem Col de Bretolet im Herbst sind von Dorka (1966) dargestellt und eingehend analysiert worden. Basierend auf Beobachtungen und FängIingen legte er charakteristische Unterschiede zwischen Kurz- und Langstreckenziehern dar. Aus der Form der Zugmuster konnten in der Folge Rückschlüsse auf die Art der Steuerung der Zugaktivität gezogen werden (Berthold & Dorka 1969). Seither haben sich die Fangzahlen vom Col de Bretolet mehr als verdoppelt und die Fangzeit wurde gegen den Sommer hin ausgedehnt. Dadurch wird es einerseits möglich, bisherige Aussagen zu verfeinern ; andererseits können wesentlich mehr Arten einbezogen werden, und die bisher kaum untersuchte Phase vor der eigentlichen Zugzeit kann analysiert werden. Ein erstes Ziel dieser Arbeit ist es, die jahreszeitlichen Zugmuster nach Fänglingen für möglichst viele Arten darzustellen und damit - ohne eine eingehendere Besprechung der einzelnen Arten - eine Arbeits- und VergleichsgrundIage zu schaffen. Eine Besonderheit der Beringungsstation auf dem Col de Bretolet liegt in der subalpin-alpinen Brutvogelgemeinschaft der Umgebung. Die Durchzugsverhältnisse der Tieflandarten sind dadurch im Vergleich zu anderen Stationen in Europa, die meist im Tiefland liegen, leichter zu interpretieren. Beim Vergleich mit solchen Stationen ergeben sich bei manchen Arten augenfällige Unterschiede in der Form der Zugmuster. Solche Formunterschiede hat auch Denker (1973) beim Fitis Phylloscopus trochilus zwischen Helgoland und dem Festland gefunden. Deshalb sollen die Zugmusterformen der einzelnen Arten sowie von Bretolet und anderen Stationen miteinander verglichen werden. Dabei stehen nachbrutzeitliche Bewegungen, d. h. das Umherstreifen ohne Bindung an den Brutort zwischen dem Ende der Brutzeit und dem Beginn des Wegzuges, im Vordergrund, wobei die Lage der Fangstationen zum Herkunftsgebiet der auftretenden Arten besondere Bedeutung erhält.
Hatching asynchrony and the onset of incubation in birds revisited : when is the critical period?
(1995)
1. Birds are unique among animals in being able to influence the birthing intervals of their young through the timing of the onset incubation. However, many species hatch their young asynchronously, frequently resulting in reduced survivorship for later-hatched young. This is the Paradox of Hatching Asynchrony. 2. The Brood Reduction Hypothesis provided a resolution to the paradox by suggesting an adaptive function to the offspring mortality that results from asynchrony. Experimental tests have provided little support, and 16 alternative hypotheses have been proposed, but few have been tested. Most experimental tests have not measured important parameters such as parental effort and postfledging survival. Many have lacked adequate controls or sufficient statistical power. 3. We divide the hypotheses for hatching asynchrony into four categories based on the effects of intrinsic or extrinsic factors during a critical period of the nesting cycle which constrains reproductive success. Hatching asynchrony could be simply the consequence of the early onset of incubation during egg-laying, either as a result of physiological constraints on incubation or because parents derive fitness benefits from the protective function of early incubation. During the nestling period, hatching asynchrony could be adaptive if it allowed parents to eliminate one or more nestlings selectively, or increased parental efficiency. Alternatively, parents could manipulate the duration of the different periods of the nesting cycle to maximize benefits. 4. Because the onset of incubation generally determines hatching patterns, we encourage refocusing attention from the search for adaptive hatching patterns during the nestling period to the events surrounding the onset of incubation during egg-laying. Many factors can affect when incubation is begun, including physiology, and interactions with the environment, predators, competitors, and mates. 5. Patterns of the onset of incubation are difficult to determine and to quantify, in part because many birds begin incubating gradually, or at night. In some species, the onset of incubation varies with clutch size, but not in others. 6. The onset of incubation is the principle proximate control of hatching patterns, but other factors, such as egg size, embryonic vocalizations, and time of year may also affect hatching patterns. 7. Synchronous hatching is the primitive condition in birds, and is widespread in the lower, primarily precocial taxa. Most altricial species hatch their eggs asynchronously, although some exhibit synchrony as a secondarily derived trait. Hatching patterns show wide variation within some orders and families. 8. Patterns of the onset of incubation and hatching in a species may reflect the influence of multiplefactors. The relative importance of those factors may depend on the trade-offs associated with the potential benefits of early incubation to the survival of eggs and the potential costs to the survivor of later-hatching young associatedwith nestling size hierarchies. 9. The relative effects of multiple factors can be examined by integrating the results of empirical tests of single factors through modeling. 10. We demonstrated the use of a stochastic model by using empirical data from the House Sparrow. Results revealed the trade-offs inherent in the onset of incubation from differences in egg viability and nestling survivorship. An intermediate onset of incubation produced the greatest fledging success. 11. Other factors may be integrated into such models if they can be measured in terms of their effects on fledging success. Different factors, represented by different hypotheses, vary in how readily they may be modeled.
Habitat, food and population dynamics of the field vole Microtus agrestis (L.) in south Sweden
(1971)
The habitat, food and population dynamics of the field vole (Microtus agrestis) were studied mainly in southernmost Sweden (Scania) with a few comparisons from a northern locality. The habitats of Microtus agrestis consist mainly of successional stages, arising from abandoned cultivated fields, drained mires and felled mature forests. They were characterized botanically and classified according to moisture and time since abandonment. Capture distributions were significantly clumped, being most contagious at the lowest densities. Microdistribution was affected more by shelter than by food conditions. The weight of the stomach contents showed various skewed distributions, giving indications of the feeding behaviour of various population categories. The staple food in southernmost Sweden was various grasses, while herbs, gnss seeds, vegetative storage organs and moss were primary food items during summer, summer-autumn, winter and early summer respectively. In a northern locality herbs played a more important role in summer. Among plant species e.g. Agrostis spp., Festuca rubra, Achillea millefolium and Ranunculus spp. were often eaten, while the common Deschampsia caesjJiiosa and Charnaenerion angustifoliurn were disliked. There were clear differences between habitats but plant species belonging to the same group replaced each other in the diet. There were few differences between populatipn categories. Experiments disclosed the same preferences as found at stomach analysis. Digestibility was higher during spring than winter, that of the preferred species being highest. The digestibility was most affected by the proportions of crude protein but the changes in weight by the amounts consumed. The animals showed a decided interest in certain carbohydrates and fatty substances with differences between seasons and years. The interest in sugars was not correlated with the similar interest in bark. The probability of capture was especially low in juveniles and during winter. Trap lines and grids showed the same trappability, but, the intervals between checkings influenced the removal rate. The density changes on two distant, large, dry fields in southernmost Sweden were correlated, while a nearby isolated population in a spruce plantation fluctuated out of phase. The increases during the reproductive season were significantly lower than those expected at exponential increase. The density in various habitats did not depend on the moisture conditions. Differences in population structure and body weight in various areas were partly related to the phase of population development. However, there were also differences in the same area between habitats, which might differ in plant nutrient supply. The animals had a low energy reserve in their depot fat, which would only sustain the animals for 5-14 hours in an emergency. It was highest during midwinter but with significant depressions in April and December. Drier habitats could sustain populations of little more than 200 animals/ha over :winter and these densities were not realized in southernmost Sweden. The spring-summer density variations in a northern locality were correlated with the spruce seed supply during the following autumn-winter. A relation was assumed with the quantity or quality of previous storage tissues. In southernmost Sweden, with irregular and low-amplitude fluctuations, there was no clear relation to primary production.
Geschlechts- und Gattungsunterschiede an Metapodien und Phalangen mitteleuropäischer Wildwiederkäuer
(1968)
Zur Beurteilung der Geschechtsunterschiede und zur Bestimmung der Gattungsunterschiede wurden die Metapodien und Phalangen von im ganzen 258 Exemplaren von Cervus elaphus hippelaphus Erxleben, 1771, Dama dama dama (Linne, 1758), Capreolus capreolus capreolus (Linne, 1758), Rupicapra rupicapra rupicapra (Linne, 1758) und Capra ibex ibex Linne, 1758, ausgewertet. 93 Tiere entfielen auf Capreolus capreolus, von denen aber zur Geschlechtsunterscheidung nur 78 Tiere verwendbar waren; die restlichen 15 Tiere waren ohne Geschlechtsangabe und konnten auch nachträglich nicht bestimmt werden. Weiterhin kamen zur Untersuchung 56 Tiere von Cervus elaphus, 22 von Dama dama, 49 von Rupicapra rupicapra und 38 von Capra ibex (5. Tab. 1).
Was die Geschlechtsunterscheidung betrifft, so gilt mit Ausnahme von Capreolus capreolus die Regel, daß die Metapodien und Phalangen der Weibchen alles in allem länger und stärker sind als die der Männchen. Zur Bestimmung erwies sich die Länge des jeweiligen Knochens - an der Phalanx 3 die diagonale Sohlenlänge - als am besten geeignet. Dabei ließen sich Gesmlechtsunterschiede nicht nur in den Mittelwerten aufzeigen, sondern auch zum Teil in absolut größeren Maßen, wie das bei Dama in der Länge und bei Caprn ibex in der Breite der Fall war (s. Tab. 2-7).
Für die Unterscheidung zwischen den Gattungen waren in erster Linie Gestaltunterschiede von Bedeutung, in zweiter Linie die absoluten Maße und Indices, wovon letztere für sich allein oft schon Gattungsbestimmungen zulassen. Die Unterscheidung der hier behandelten Arten ist nahezu immer möglich, wenn man davon absieht, daß unter Siedlungsabfällen kleine, uncharakteristische Fragmente sein können. Schwierigkeiten können entstehen bei der Unterscheidung von Steinbock- sowie manchen Gemsenknochen von solchen der Gattungen Capra hircus und Ovis ades; auf sie wurde in dieser Arbeit nicht näher eingegangen.
Comparing the modern level in the biology of gastrointestinal stem cells with that achieved in the hemopoietic stem cell studies, we can say, using Till's expression (1982), that at present the "morphological phase" in the investigations of the former is continuing. Still urgent is the problem of morphological verification of presumable stem cells in colonic crypts and gastric glands. Also important is to clarify the ways of renewal of the well-differentiated but low proliferating activity endocrine cells, the chief cells of the fundic glands, and the cells of Brunner's glands. Further studies of interaction between epithelial and stromal cells are needed. The knowledge of relationships between stem cells and their differentiated "neighbors" in the niches, as well as of peculiarities of contacts between epithelial cells proper and of the cells with the basement membrane is of major importance. It is also necessary to clarify the mechanisms of the stem cells "anchoring" as well as of the disturbances of this important property during carcinogenesis. Briefly summarized below are the most essential, in our opinion, directions of the study of stem cells; some of these have already been started, whereas others can only be predicted. 1. The isolation from normal tissues of the fractions of intact cells enriched with the stem cells, with their subsequent culture. 2. The clarification of the factors governing the regulation of renewal of stem cells: specific stimulators and inhibitors of proliferation; and characterization of the receptor apparatus of stem cells, particularly for the enteropancreatic hormones. 3. The antigenic characteristic of stem cells. 4. The study of molecular peculiarities of DNA replication of clonogenic cells. 5. The molecular aspects of commitment and differentiation of stem cells. 6. The quantitative and qualitative characteristics of stem cells in the process of carcinogenesis. 7. The qualitative evaluation of the dynamics of formation and disappearance of carcinogenic DNA adducts in stem cells. 8. The clarification of interspecies features of stem cells as well as of their morphogenetic potentialities in onto- and phylogenesis. 9. The characterization of metaplastic changes in stem cells.
In 1080 samples (feathers, nesls, pellets, droppings, cloaca contents and visceral organs) collected from 92 species of free-living birds in many localities and habitats, a total of 6266 fungi was found; we identified 232 species and 112 genera of fungi (73.4 % Ascomycetes, 12.4 % Fungi imperfecti, 8.0 % Zygomycetes, 5.7 % Endomycetes, 0.3 % Oomycetes; and 0.2 % Basidiomycetes). The most common fungal genera were, in plumage, Alternaria. Cladosporium, Arthroderma, Chaetominum, Aspergillus, Penicillium and Chrllsosporium; in nests, Alternaria, Arthroderma, Penicillium, Aphanoascus and Scopulariopsis; on pellets, Penicillium, Mucor, Aspergillus, Chrysosporium and Rhizopus; in droppings, Scopulariopsis, Mucor, Aspergillus, Penicillium and Candida; from the cloaca contents, we isolated Penicillium, Candida, Aspergillus, Scopulariopsis, a. o., and from the visceral organs, Aspergillus, Penicillium, Rhodotorula, and some others. Of the fungi with a potential pathogenicity for homeotherms, we obtained, e. g., Absidia corymbifera, Aspergillus fumigatus, Candida albicans, Cryptococcus neoforrnans and Microsporum gypseum. We confirmed also the presence of several species of toxinogenic fungi (e. g., Aspergillus flavus), of the fungi with a potential pathogenicity for poikilotherms (e. g., Beauveria bassiana. Paecilomyces jarinosus, P. fumoso-roseus), and of plant parasites (Cylindrocarpon radicicola, Fusarium oxysponom and Verticillium albo-atrum). Aphanoascus reticulisporum has been described as comb. nov. (basionym: Anixiopsis: reticulispom ROUTIEN). 66 species of the fungi have not been recorded earlier in Czechoslovakia. Similarly, the occurrence of 111 species had, apparently, not been confirmed in free-living birds on a world-wide scale.
Gastropod molluscs were collected by the author between May and September 1962 from a variety of freshwater habitats in Ethiopia. Twenty-eight forms are represented in the collection of which a total of eleven have not been previously recorded from Ethiopia or have been recorded with doubt by previous authors. Two forms in each of the genera Bulinus and Ancylus appear to be new. It is considered that seven of the forms recorded from Ethiopia for the first time belong to the African component in the fauna, whereas only three are possibly of palaearctic origin. It is concluded that the wide distribution and diversity of some of the palaearctic forms justify the importance attached by Bacci (1951) to the palaearctic element in the molluscan fauna of the Ethiopian Plateau.
In this study the rich variety of fossil microorganisms and other ultrastruchlres in the Messel oil shale is documented. The taphonomy of the micro- and the macro organisms is discussed and a basic model for microbial life in the Eocene Lake Messel is proposed. Documentation of the Messel microbiota was made using a scanning electron microscope fitted with an energy-dispersive X-ray analyzer, and a transmission electron microscope. The most common objects discovered were fossil bacteria in the form of cocci, coccobacilli, bacilli, curved rods and filaments, preserved as moulds, crusts, casts, encrusted casts and clay-coated casts. The main lithifying mineral is apatite, followed by siderite. The bacteria occur on fossil remains of macroorganisms. Sideritic bacteria are usually found on keratinous substrates, whereas apatitic bacteria occur preferentially on fish remains. Lithification of the bacteria was selective. It is suggested that the preserved bacteria were heterotrophic, Gram-positive anaerobes, which may have belonged to the group of clostridians.
Six clearly separable evolutionary levels in the floral evolution of the Ranunculaceae were found to coincide with the six corresponding stages of sensory development of their pollinators as follows: amorphic -> haplomorphic -> actinomorphic -> pleomorphic -> stereomorphic-zygomorphic. This is a basic trend of floral evolution, fully recapitulated in a single family. Except for the first (amorphic), all upper levels are represented in the present-day floras as clearly separable type-classes. They are therefore accessible to direct observations and experimental study. Extensive statistical data on flower visitors of the Ranunculaceae confirm the proposed theory of the mutual interrelationship between the evolutionary levels of flower types and sensory stages of pollinating insects. The new picture, obtained by this study, gives us a better understanding of the evolutionary relationship between insects and plants and explains the extreme diversity in the floral structure of the Ranunculaceae.
This synonymic list of the flat bugs (Aradidae) ofthe world enumerates 1,798 species in 211 genera. Names of eight fossil species are given in their original combination in modern genera. The list is introduced by brief discussions of habits, food, ecology and distribution. Many taxonomic innovations are included, as follows: Subfamily Chinamyersiinae is divided into two new tribes, Chinamyersiini and Tretocorini; the subfamily Prosympiestinae is divided into two new tribes, Llaimacorini and Prosympiestini. All currently recognized subgenera are raised to generic rank: Aneurillus, Breviscutaneurus, lralunelus, and Paraneurus from Aneurus; Miraradus and Quilnus from Aradus; Lissaptera and Nesiaptera from Acaraptera; Neoproxius and Nesoproxius from Proxius (see list below for new combinations resulting). Three genus-group names are raised from synonymy: Aneurosoma; Burgeonia and Brachyrhynchus. One genus-group name is reduced to synonymy; Zimera as a junior synonym of Brachyrhynchus. The following new species-genus combinations are made, these mostly resulting from elevation of subgenera to generic status or species transfers. In Aneurillus - borneensis, cetratus, cheesmanae, consimilis, doesbergi, foliaceus, glaberrimus, gracilis, jacobsoni, longicollis, papuasicus, pumilus, superbus; in Aneurosoma - dissimile; in Aneurus - septentrionalis; in Aradus - dignatus; in Arbanatus - asiaticus, loriae; in Brachyrhynchus - affinis, amplicollis, andamanensis, angolensis, armigerus, australis, bergrothi, bergrothianus, bhoutanensis, breuiceps, burmensis, confectus, confusus, consimilis, crenatus, dentipes, discrepans, dispar, duboisi, elegans, exarmatus, funebrus, furcatulus, furcatus, germari, gracilicornis, granos us, hospidus, hoberlandti, horridus, hsiaoi, incisus, incognitus, insignis, intermedius, javanensis, kachenensis, kerzhneri, lindemannae, longicornis, longirostris, luberoensis, luzonicus, machadoi, madagascariensis, mauricii, membranaceus, micronesicus, monedulus, mario, ouerlaeti, parallelus, pauper, philippinensis, piliferus, poriaicolus, projectus, quadridentatus, quadrispinosus, rossi, rugosus, scrupulosus, serratus, similis, solomonensis, spinipes, stolidus, subinermis, subtriangulus, sulcatus, sulcicornis, sumatrensis, taiwanicus, teter, thailandicus, triangulus, tristis, urijdaghi; in Breviscutaneurus - breviscutatus, helenae, madagascariensis, medioscutatus; in Burgeonia - burgeon, dilatatus, froidebisei, intermedius, kormileui, madagascariensis, maynei, paruus, schoutedeni, usingeri; in Chiastoplonia - pusio; in lralunellus - aibonitensis, bergi, bispinosus, boliuianus, carioca, costariquensis, flavomaculatus, ftitzi, gallicus, leptocerus, longicornis, marginalis, monrosi, plaumanni, politus, sahlbergi, simulans, subdipterous, tenuis, westwoodi, wygodzinsky; in Miraradus - foliaceus, himalayensis, mirabilis, oeruendetes; in Neoproxius - amazonicus, carioca, costariquensis, gypsatus, incaicus, lindemannae, magdalenae, nicaraguensis, palliatus, panamensis, personatus, peruuianus, schwarzii; in Nesiaptera - denticulata, gibbosa, ouata, rotundata, tuberculata, zimmermani; in Nesoproxius - angulatus, constrictus, gracilis, hexagonalis, malayensis, minutus, punctulatus, vietnamensis, yoshimotoi; in Neuroctenus - ghesqueri; in Oreossa - insignis; in Quilnus - amurensis, breuirostris, discedens, heidemanni, niger, nigrinus, oregonicus, paruicollis, subsimilis, usingeri. Three new species names are proposed: Brachyrhynchus pauper for the preoccupied Mezira modesta Kormilev, 1972; Mezira uicina for the preoccupied Mezira proxima Kormilev, 1982; and Mezira doesburgi for the preoccupied Mezira surinamensis Kormilev, 1974. Five new species-synonymys are made: Aradus centriguttatus as a junior synonym of Aradus similis; Mezira jacobsoni as a junior synonym of Daulocoris cornigerus; Mezira modesta as a junior synonym of Brachyrhynchus membranaceus; Neuroctenus breuicornis as a junior synonym of Neuroctenus ater; Notoplocaptera malaisei as a junior synonym of Zoroaptera malaisei. Four new emendations of gender endings are proposed for the species name "halaszfyi": Artabanus halaszfyae, Chelysosoma halaszfyae, Ctenoneurus halaszfyae, Mezira halaszfyae.
Evidence from archaeological fish bone assemblages from the southern North Sea region of Europe is used to illuminate fishing, fish consumption and fish trade from the 1st to the 16th century AD. The fish species represented in the material indicate a very strong influence from the local fish fauna at almost all sites. The species and size of the fish indicate that several fishing methods have been employed throughout the period studied, including nets, hooks and weirs. A chronological development in fishing, for example, a tendency towards more sea-going fishing, is reflected in the fish bone assemblages in some countlres. Evidence from fishing in the Baltic region from the 5th century BC to the 16th century AD is included in the discussion. Indications of fish trade include bones of exotic species (for instance, matinc species at inland sites) and an unbalanced representation of skeletal clements (trade with decapitated stockfish or gillless hering). Of particular interest are assemblages which indicate a fish industry, for instance, large-scale processing (removal of gills) of herring in 13th century Denmark.
In this study we attempt to develop a synthesis of previously published work concerning the feeding habits of fourteen European freshwater fish: Anguilla anguilla L., Salmo trutta L., Rutilus rutilus L., Leuciscus leuciscus L ., Leuciscus cephalus L., Phoxinus phoxinus L., Gobio gobio L., Abramis brama L., Cyprinus carpio L., Tinca tinca L., Barbatula barbutula L., Gasterosteus aculeatus L., Perca fluviatilis L. and Cottus gobio L. Data presented in this paper were obtained frorn 98 studies in 16 European countries. Great Britain with 40 studies was the most documented country. In order to synthetize the maximurn information for each species, all methods used for analysing feeding habits and found in the different studies have been taken into account. Results are presented on tables with a commentary for each species analysed. The fourteen species were then classified into major trophic guilds.
The Siwalik formations of northern Pakistan consist of deposits of ancient rivers that existed throughout the early Miocene through the late Pliocene. The formations are highly fossiliferous with a diverse array of terrestrial and freshwater vertebrates, which in combination with exceptional lateral exposure and good chronostratigraphic control allows a more detailed and temporally resolved study of the sediments and faunas than is typical in terrestrial deposits. Consequently the Siwaliks provide an opportunity to document temporal differences in species richness, turnover, and ecological structure in a terrestrial setting, and to investigate how such differences are related to changes in the fluvial system, vegetation, and climate. Here we focus on the interval between 10.7 and 5.7 Ma, a time of significant local tectonic and global climatic change. It is also the interval with the best temporal calibration of Siwalik faunas and most comprehensive data on species occurrences. A methodological focus of this paper is on controlling sampling biases that confound biological and ecological signals. Such biases include uneven sampling through time, differential preservation of larger animals and more durable skeletal elements, errors in age-dating imposed by uncertainties in correlation and paleomagnetic timescale calibrations, and uneven taxonomic treatment across groups. We attempt to control for them primarily by using a relative-abundance model to estimate limits for the first and last appearances from the occurrence data. This model also incorporates uncertainties in age estimates. Because of sampling limitations inherent in the terrestrial fossil record, our 100-Kyr temporal resolution may approach the finest possible level of resolution for studies of vertebrate faunal changes over periods of millions of years. Approximately 40,000 specimens from surface and screenwash collections made at 555 localities form the basis of our study. Sixty percent of the localities have maximum and minimum age estimates differing by 100 Kyr or less, 82% by 200 Kyr or less. The fossils represent 115 mammalian species or lineages of ten orders: Insectivora, Scandentia, Primates, Tubulidentata, Proboscidea, Pholidota, Lagomorpha, Perissodactyla, Artiodactyla, and Rodentia. Important taxa omitted from this study include Carnivora, Elephantoidea, and Rhinocerotidae. Because different collecting methods were used for large and small species, they are treated separately in analyses. Small species include insectivores, tree shrews, rodents, lagomorphs, and small primates. They generally weigh less than 5 kg. The sediments of the study interval were deposited by coexisting fluvial systems, with the larger emergent Nagri system being displaced between 10.1 and 9.0 Ma by an interfan Dhok Pathan system. In comparison to Nagri floodplains, Dhok Pathan floodplains were less well drained, with smaller rivers having more seasonally variable flow and more frequent avulsions. Paleosol sequences indicate reorganization of topography and drainage accompanying a transition to a more seasonal climate. A few paleosols may have formed under waterlogged, grassy woodlands, but most formed under drier conditions and more closed vegetation. The oxygen isotopic record also indicates significant change in the patterns of precipitation beginning at 9.2 Ma, in what may have been a shift to a drier and more seasonal climate. The carbon isotope record demonstrates that after 8.1 Ma significant amounts of C4 grasses began to appear and that by 6.8 Ma floodplain habitats included extensive C4 grasslands. Plant communities with predominantly C3 plants were greatly diminished after 7.0 Ma, and those with predominantly C4 plants, which would have been open woodlands or grassy woodlands, appeared as early as 7.4 Ma. Inferred first and last appearances show a constant, low level of faunal turnover throughout the interval 10.7–5.7-Ma, with three short periods of elevated turnover at 10.3, 7.8, and 7.3–7.0 Ma. The three pulses account for nearly 44% of all turnover. Throughout the late Miocene, species richness declined steadily, and diversity and richness indices together with data on body size imply that community ecological structure changed abruptly just after 10 Ma, and then again at 7.8 Ma. Between 10 and 7.8 Ma the large-mammal assemblages were strongly dominated by equids, with more balanced faunas before and after. The pattern of appearance and disappearance is selective with respect to inferred habits of the animals. Species appearing after 9.0 Ma are grazers or typical of more open habitats, whereas many species that disappear can be linked to more closed vegetation. We presume exceptions to this pattern were animals of the mixed C3/C4 communities or the wetter parts of the floodplain that did not persist into the latest Miocene. The pace of extinction accelerates once there is C4 vegetation on the floodplain. The 10.3 Ma event primarily comprises disappearance of taxa that were both common and of long duration. The event does not correlate to any obvious local environmental or climatic event, and the pattern of species disappearance and appearance suggests that biotic interactions may have been more important than environmental change. The 7.8 Ma event is characterized solely by appearances, and that at 7.3 Ma by a combination of appearances and disappearances. These two latest Miocene events include more taxa that were shorter ranging and less common, a difference of mode that developed between approximately 9.0 and 8.5 Ma when many short-ranging and rare species began to make appearances. Both events also show a close temporal correlation to changes in floodplain deposition and vegetation. The 7.8 Ma event follows the widespread appearance of C4 vegetation and is coincident with the shift from equid-dominated to more evenly balanced large-mammal assemblages. The 7.3 to 7.0 Ma event starts with the first occurrence of C4-dominated floras and ends with the last occurrence of C3-dominated vegetation. Absence of a consistent relationship between depositional facies and the composition of faunal assemblages leads us to reject fluvial system dynamics as a major cause of faunal change. The close correlation of latest Miocene species turnover and ecological change to expansion of C4 plants on the floodplain, in association with oxygen isotopic and sedimentological evidence for increasingly drier and more seasonal climates, causes us to favor explanations based on climatic change for both latest Miocene pulses. The Siwalik record supports neither “coordinated stasis” nor “turnover pulse” evolutionary models. The brief, irregularly spaced pulses of high turnover are characteristic of both the stasis and pulse models, but the high level of background turnover that eliminates 65–70% of the initial species shows there is no stasis in the Siwalik record. In addition, the steadily declining species richness and abrupt, uncoordinated changes in diversity do not fit either model.
Fauna of Isopoda and Tanaidacea in the coastal zones of the Antarctic and Subantarctic waters
(1968)
This work presents results of the processing of the material collected by the Soviet Antarctic Expedition (1955 - 1963), chiefly on the "Ob" and to a lesser extent by the geographer E. S. Korotkevich and the ichthyologist V. M. Makushek., during their wintering at the Mirnyi station, as well as by the hydrobiologist G. A. Solyanik on board the whalers "Slava" and "Ivan Nosenko."