Choix de l'emplacement des nids de Cormorans à aigrettes (Phalacrocorax auritus) aux îles de la Madeleine, Québec

1987 ◽  
Vol 65 (1) ◽  
pp. 24-34 ◽  
Author(s):  
Claire Léger ◽  
Raymond McNeil
Keyword(s):  
Nest Site ◽  
Larus Argentatus ◽  
Coniferous Tree ◽  
Phalacrocorax Auritus ◽  
Supporting Capacity ◽  
Contingency Analysis ◽  
Trunk Diameter ◽  
Nest Sites ◽  
To Come ◽  
The Stability

The periods during which cormorants build their nests in relation to various parameters describing the coniferous tree on which the nest is located (height, trunk diameter, health, supporting capacity of branches), its location with regard to the center of the colony and to areas occupied by gulls (Larus argentatus and Larus marinus), and its utilization as a nest site during previous years, were investigated using a bidimensional contingency analysis. The results reveal that the first cormorants to come back to the island in the spring choose first the coniferous trees that are located in the center of the area occupied by the colony, even if most of those trees, injured during previous years, are dead or have lost their needles. The stability of the trees (strength and diameter of trunks), the supporting capacity of branches, as well as the height and position of nests do not seem to play an important role in the choice of nest sites.

The importance of grasstrees (Xanthorrhoea preissii) as habitat for mardo (Antechinus flavipes leucogaster) during post-fire recovery

2007 ◽  
Vol 34 (8) ◽  
pp. 640 ◽  
Author(s):  
Marnie L. Swinburn ◽  
Patricia A. Fleming ◽  
Michael D. Craig ◽  
Andrew H. Grigg ◽  
Mark J. Garkaklis ◽  
...  
Keyword(s):  
Fire Management ◽  
Nest Site ◽  
Radio Telemetry ◽  
Important Resource ◽  
Nest Sites ◽  
Single Feature ◽  
Management Policies ◽  
Nesting Resources ◽  
Selection For ◽  
The One

Grasstrees (Xanthorrhoea) are an important structural component of many Australian ecosystems and also an important resource for many fauna species. Grasstrees have distinctive morphologies, with a crown of long thin leaves and skirts, the latter of which are accumulated dead leaves; both are incinerated by fire. This study determined the morphological features of Xanthorrhoea preissii, which change in response to fire from 6 months to 21 years post-burn. In addition, using radio-telemetry and spool-tracking, we determined that grasstrees are utilised as foraging and nesting resources for mardos (Antechinus flavipes leucogaster (Gray, 1841), Marsupialia: Dasyuridae). Recently burnt grasstrees (6 months post-burn) appeared not to be used by mardos at all. We found few mardos in these recently burnt sites, and the one individual we managed to track for 126 m utilised only a single grasstree: a 2-m-tall multiple-crowned grasstree that had escaped the fire was used as a nest site. For sites 5 years post-burn, mardos selectively utilised grasstrees with larger crown areas and those with a greater number of crowns compared with a random sample of available trees. At the 14-year post-burn sites, mardos still demonstrated some selection for grasstrees, although no specific single feature could be determined as most significant. We recorded humidity and temperature buffering effects in association with post-burn accumulation of grasstree skirt material and found that even dead grasstree ‘logs’ were an important resource for nests. We conclude that mardos utilise both live and dead grasstrees for foraging and nest sites, possibly owing to the availability of dense cover, a buffered microclimate, and potentially also food resources. Fire-management policies that promote habitat heterogeneity and retain several intact-skirted grasstrees within the landscape are likely to benefit mardos.

Translation, interpreting and the genealogy of conflict

2012 ◽  
Vol 11 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Luis Pérez-González
Keyword(s):  
Special Issue ◽  
Social Phenomena ◽  
The Public ◽  
Institutional Settings ◽  
Public Consciousness ◽  
The Media ◽  
Methodological Approaches ◽  
To Come ◽  
The Stability ◽  
The Impact

While the growing ubiquitousness of translation and interpreting has established these activities more firmly in the public consciousness, the extent of the translators’ and interpreters’ contribution to the continued functioning of cosmopolitan and participatory postmodern societies remains largely misunderstood. This paper argues that the theorisation of translation and interpretation as social phenomena and of translators/interpreters as agents contributing to the stability or subversion of social structures through their capacity to re-define the context in which they mediate constitutes a recent development in the evolution of the discipline. The consequentiality of the mediators’ agency, one of the most significant insights to come out of this new body of research, is particularly evident in situations of social, political and cultural confrontation. It is contended that this conceptualisation of agency opens up the possibility of translation being used not only to resolve conflict and tension, but also to promote them. Through a variety of theoretical and methodological approaches, the contributing authors to this special issue explore a number of sites of linguistic and cultural mediation across a range of institutional settings and textual/interactional genres, with particular emphasis on the contribution of translation and interpreting to the genealogy of conflict. The papers presented here address a number of overlapping themes, including the dialectics of governmental policy-making and translation, the interface between translation, politics and the media, the impact of the narrative affiliation of translators and interpreters as agents of mediation, the frictional dynamics of interpreter-mediated institutional encounters and the dynamics of identity negotiation.

scholarly journals Coal cluster as a structural factor in the development of Kuzbass

2021 ◽  
Vol 315 ◽  
pp. 04004
Author(s):  
Yuri Fridman ◽  
Galina Rechko ◽  
Olesya Khokhrina
Keyword(s):  
Value Added ◽  
Economic Transformation ◽  
Coal Industry ◽  
Macroeconomic Conditions ◽  
Employment Dynamics ◽  
The Status ◽  
Analysis Of Dynamics ◽  
To Come ◽  
The Stability ◽  
Negative Factors

The article contains the results of the analysis of dynamics and structural transformations of employment and production of gross value added (GVA), carried out by the authors on the material of Kuzbass. The study was carried out using the shift-share analysis for 2007–2018. We can state that the employment dynamics, which was negative during this period, was determined primarily by regional factors. The dynamics of GVA was influenced by national (positive) and regional (negative) factors. The contribution of structural shifts to the growth of GVA over the past decade was negative and insignificant, and the decline in the number of employed occurred with a scarcely changed employment pattern. The coal cluster remains the core of the Kuzbass economy and retains the status of its most efficient sector – there are no obvious candidates for the role of a new leader. Meanwhile, the high dependence of the coal industry on external macroeconomic conditions, fluctuations in world markets, makes the strategic outlook of the entire region's economy vulnerable and unstable. Therefore, it is important to find and implement such model of the socio-economic transformation of Kuzbass, which will help protect and ensure the stability of the region for decades to come.

Social context alters retreat- and nest-site selection in a globally invasive gecko, Hemidactylus frenatus

2019 ◽  
Vol 129 (2) ◽  
pp. 388-397
Author(s):  
Benjamin J Muller ◽  
Robin M Andrews ◽  
Lin Schwarzkopf ◽  
David A Pike
Keyword(s):  
Invasive Species ◽  
Site Selection ◽  
Nest Site ◽  
Gravid Female ◽  
Nest Site Selection ◽  
Invasion Success ◽  
Ceramic Tiles ◽  
Nest Sites ◽  
Gravid Females ◽  
Hemidactylus Frenatus

Abstract Microhabitat orientation and structure and the presence of conspecifics may strongly influence the choice of habitat. We studied how these variables influence retreat- and nest-site selection in gravid females of a globally successful invasive species, the Asian house gecko (Hemidactylus frenatus). When provided with various substrates (vertical and horizontal ceramic tiles, vertical and horizontal plywood tiles, horizontal bark over leaf litter, vertical bark over a log, and sand) gravid female geckos preferred to retreat to, and nest in, materials with crevices commonly found in urban habitats. When housed alone, gravid females most frequently retreated to vertical ceramic tile or wooden crevices, and 66.7% nested in vertical ceramic tiles. When housed with two other conspecifics, gravid females most frequently retreated to vertical ceramic tiles, but selected a wider range of nest sites. Overall, gravid geckos housed alone typically nested in the same substrates that they used as diurnal retreats; when housed in groups, however, females oviposited in locations different from those they selected as retreats. Thus, H. frenatus females use a wider range of substrates when conspecifics are present. Invasion success in this species might be driven, in part, by preferences for retreat and nest substrates that are common in human-dominated habitats.

Spawning Behavior of Chum Salmon (Oncorhynchus keta) and Rainbow Trout (Salmo gairdneri)

1975 ◽  
Vol 32 (5) ◽  
pp. 633-642 ◽  
Author(s):  
A. F. Tautz ◽  
C. Groot
Keyword(s):  
Rainbow Trout ◽  
Chum Salmon ◽  
Nest Site ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Spawning Behavior ◽  
Current Pattern ◽  
Chum Salmon Oncorhynchus Keta ◽  
Nest Sites ◽  
Gravel Size

Detailed accounts of the spawning behavior of chum salmon (Oncorhynchus keta) and rainbow trout (Salmo gairdneri) in laboratory flumes are provided. The behavioral activities, quivering, probing, and crossing over increase in frequency as a function of time prior to spawning whereas digging remains constant or decreases slightly. Maps of digging locations and movie films suggest nest shape and current pattern are monitored by the female, allowing her to intensify her digging activity near the center of the nest. Probing appears to be a signal to the male indicating approach of oviposition and also provides information to the female regarding the shape and suitability of the nest site. The probing act is also used in the synchronization of the male and female spawning acts. Changes in velocity do not appear to markedly affect nest construction either in terms of number of digs to oviposition or in size of nest constructed. It is inferred that velocity and gravel size are important insofar as they influence the construction of a suitable nest depression. Nest sites would appear to be selected on the basis of acceleration of flow rather than velocity per se though high limits must obviously exist.

Nest-site selection in the barn swallow, Hirundo rustica: What predicts seasonal reproductive success?

2006 ◽  
Vol 84 (11) ◽  
pp. 1533-1539 ◽  
Author(s):  
Rebecca Jo Safran
Keyword(s):  
Reproductive Success ◽  
Site Selection ◽  
Nest Site ◽  
Individual Characteristics ◽  
Nest Site Selection ◽  
Hirundo Rustica ◽  
Barn Swallow ◽  
Nest Location ◽  
Nest Sites ◽  
Site Characteristics

Despite hundreds of studies, we know very little about the causes and fitness-related consequences of nest-site selection. For example, it is not typically known whether the rarely reported fitness consequences of site selection are the result of nest, individual, or nest-site variables or combinations of these factors. Reuse of previously constructed nest sites is a prevalent behavior in many animals and offers the opportunity to experimentally tease apart whether seasonal reproductive success is a function of nest, individual, or nest-site characteristics. I used observational and experimental data to test three hypotheses related to these factors in association with barn swallow ( Hirundo rustica L., 1758) nest reuse. While both nest and individual characteristics explain variation in seasonal reproductive success, nest location per se is not an important factor defining the outcome of nest-site selection. Whereas traits related to habitat and individual characteristics are likely confounded in correlational studies, my experiments demonstrate a causal relationship between seasonal reproductive success and aspects of the nest and individual, the latter explaining more variation in the model than nest characteristics. Knowledge of the relative roles of individual, nest, and nest-site attributes are important for understanding the causes and consequences of habitat selection behavior.

The Availability of Tree Hollows for Use as Nest Sites by White-tailed Black Cockatoos

1979 ◽  
Vol 6 (2) ◽  
pp. 205 ◽  
Author(s):  
DA Saunders
Keyword(s):  
Western Australia ◽  
Nest Site ◽  
Mature Trees ◽  
Breeding Range ◽  
Nest Sites ◽  
Tree Hollows ◽  
Selection Of

Data on nest hollows were collected from four study areas throughout the range of the short-billed form of the white-tailed black cockatoo, Calyptorhynchus baudinii latirostris, in south Western Australia. Hollows in trees are formed as a result of some destructive agent such as termites or fungi attacking the heartwood of the tree and breaking down the structure of the wood cells. The breaking off of part of the tree provides access to the hollow from the outside, and allows it to be used as a nest site. Throughout their breeding range, white-tailed black cockatoos will nest in any species of eucalypt which has a hollow of suitable size. The aspects of the entrances of hollows are not randomly distributed among compass groups, but the birds' selection of hollows was random. The aspect, depth to the floor and height of the entrance from the ground do not affect the success or failure of the nesting attempt. Female white-tailed black cockatoos searching for and preparing nest hollows chase female conspecifics from an area around their prospective nest tree. They continue this activity until they are incubating; this may result in suitable hollows not being accessible to other females. The rate of loss of hollows was 4.8 and 2.2% at two of the study areas. Hollows are being destroyed by all causes, particularly clearing for agriculture, faster than they are being created. Guidelines for the management of woodland must be drawn up so as to maintain a continuing supply of mature trees and protect hole-nesting species.

scholarly journals Understanding resource driven female–female competition: ovary and liver size in sand gobies

2019 ◽  
Vol 6 (9) ◽  
pp. 190886 ◽  
Author(s):  
Aurora García-Berro ◽  
Johanna Yliportimo ◽  
Kai Lindström ◽  
Charlotta Kvarnemo
Keyword(s):  
Baltic Sea ◽  
North Sea ◽  
Nest Site ◽  
Operational Sex Ratio ◽  
Female Competition ◽  
The Baltic Sea ◽  
Nest Sites ◽  
The North ◽  
The North Sea ◽  
The Baltic

The operational sex ratio (OSR, ready-to-mate males to females) is a key factor determining mating competition. A shortage of a resource essential for reproduction of one sex can affect OSR and lead to competition within the opposite sex for resource-holding mates. In the sand goby ( Pomatoschistus minutus ), a fish with paternal care, male readiness to mate depends on acquiring a nest-site, whereas food abundance primarily impacts female egg production. Comparing body condition and gonadal investment of fish from two populations with different availability in resources (Baltic Sea: few nest-sites, more food; North Sea: many nest-sites, less food), we predicted females carrying more mature eggs in the Baltic Sea than in the North Sea. As predicted, ovaries were larger in Baltic Sea females, and so was the liver (storage of energy reserves and vitellogenic compounds) for both sexes, but particularly for females. More females were judged (based on roundness scores) to be ready to spawn in the Baltic Sea. Together with a nest colonization experiment confirming a previously documented difference between the two areas in nest-site availability, these results indicate a more female-biased OSR in the Baltic Sea population, compared to the North Sea, and generates a prediction that female–female competition for mating opportunities is stronger in the Baltic population. To our knowledge, this is the first time that female reproductive investment is discussed in relation to OSR using field data.

scholarly journals Nest-site selection in a fish species with paternal care

Hydrobiologia ◽  
2020 ◽  
Author(s):  
Theo C. M. Bakker ◽  
Beat Mundwiler
Keyword(s):  
Dissolved Oxygen ◽  
Water Temperature ◽  
Oxygen Concentration ◽  
Fish Species ◽  
Nest Site ◽  
Paternal Care ◽  
Small Fish ◽  
Dissolved Oxygen Concentration ◽  
Nest Sites ◽  
Higher Temperature

AbstractFish that perform paternal care may increase their fitness by choosing nest sites that enhance survival and development of embryos. We studied nest-site choice with respect to dissolved oxygen concentration and water temperature in males of the three-spined stickleback (Gasterosteus aculeatus), a small fish species with exclusive male parental care that usually breeds in the littoral zone of freshwaters of the Northern hemisphere. Fathers oxygenate the embryos by fanning movements of their pectoral fins. We expected choice for conditions at potential nest sites that would benefit offspring development, i.e., higher temperature and higher dissolved oxygen concentration. In the laboratory, we offered males a choice between two potential nest sites that differed in dissolved oxygen concentration or water temperature. Males preferred to build a nest at sites with a higher dissolved oxygen level or higher temperature and thus chose sites that would promote embryo development.

scholarly journals Nest Predators, Nest-Site Selection, and Nesting Success of the Dusky Flycatcher in a Managed Ponderosa Pine Forest

The Condor ◽  
2002 ◽  
Vol 104 (3) ◽  
pp. 507-517 ◽  
Author(s):  
Joseph R. Liebezeit ◽  
T. Luke George
Keyword(s):  
Site Selection ◽  
Nest Site ◽  
Nesting Success ◽  
Nest Site Selection ◽  
Potential Prey ◽  
Nest Sites ◽  
Dusky Flycatcher ◽  
Shrub Patches ◽  
Empidonax Oberholseri ◽  
Nest Predators

AbstractAmong hypotheses explaining nest-site selection, the potential-prey-site hypothesis predicts that birds place nests in areas with many potential nest sites, while the nest-concealment hypothesis predicts nest placement in sites with greater surrounding vegetation. We examined these hypotheses by comparing habitat attributes between Dusky Flycatcher (Empidonax oberholseri) nest sites and random sites, successful and unsuccessful nests, and nests depredated by birds versus mammals. Nesting success was 28% (n = 167), and predation was the most important cause of nest failure (96%) during the study (1998–2000) at our site in northeastern California. We identified 28 nest predators using surveillance cameras. Sciurid mammals were the most common predators (17 of 28, 61%), with Cooper's Hawks (Accipiter cooperii; 25%), small owls (11%), and Steller's Jays (Cyanocitta stelleri; 3%) accounting for the rest. Raptors preyed on nestlings more frequently than on eggs, while small mammals depredated nestlings and eggs in proportion to their availability. Dusky Flycatchers nested in larger shrub patches with greater shrub cover than at random sites, supporting the potential-prey-site hypothesis. Successful nests were in larger shrub patches surrounded by fewer seedlings and saplings compared to depredated nests, providing equivocal support for the potential-prey-site hypothesis. Nests depredated by birds were less concealed, located in smaller shrub patches, surrounded by fewer seedlings and saplings, and were closer to the shrub edge than nests depredated by mammals. Our results, strengthened by identification of nest predators, suggest that differences in search strategies among predators may constrain the ability of Dusky Flycatchers to optimize nest-site selection.Depredadores de Nidos, Selección de Sitios de Anidación y Éxito de Anidación de Empidonax oberholseri en un Bosque Manejado de Pino PonderosaResumen. Entre las hipótesis que explican la selección de sitios de anidación, la de “presa potencial” predice que las aves ubican sus nidos en lugares con muchos sitios de anidación, mientras que la de “ocultación del nido” predice la ubicación de nidos en sitios con mayor vegetación circundante. Nosotros examinamos estas hipótesis comparando características del hábitat entre sitios de anidación del mosquerito Empidonax oberholseri y sitios aleatorios, entre nidos exitosos y no exitosos, y entre nidos depredados por aves y por mamíferos. Entre 1998 y 2000 en un área del noreste de California, el éxito de anidación fue del 28% (n = 167) y la depredación fue la causa más importante del fracaso de los nidos (96%). Identificamos 28 depredadores de nidos utilizando cámaras. Los mamíferos sciúridos fueron los depredadores más comunes (17 de 28, 61%), mientras que los demás nidos fueron depredados por Accipter cooperii (25%), búhos pequeños (11%) y Cyanocitta stelleri (3%). Las aves rapaces se alimentaron con mayor frecuencia de pichones que de huevos, mientras que los mamíferos pequeños depredaron pichones y huevos en proporción a su disponibilidad. Los mosqueritos anidaron en parches con mayor cobertura de arbustos que sitios aleatorios, lo cual apoya la hipótesis de presa potencial. Los nidos exitosos se ubicaron en parches de arbustos más grandes rodeados por menos plántulas y renovales en comparación con los nidos depredados, lo que apoya equívocamente la hipótesis de presa potencial. Los nidos depredados por aves estuvieron menos ocultos, ubicados en parches de arbustos más pequeños, rodeados por menos plántulas y renovales, y estuvieron más cerca del borde del matorral que los nidos depredados por mamíferos. Nuestros resultados, fortalecidos por la identificación de los depredadores, sugieren que las diferencias en las estrategias de búsqueda entre depredadores pueden limitar la habilidad de los mosqueritos para optimizar la selección de sitios de anidación.

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