نتایج جستجو برای: clutch

تعداد نتایج: 2466  

Journal: :Animal behaviour 1999
West Flanagan Godfray

The parasitoid wasp genus Achrysocharoides (Eulophidae) is unusual in that many of its species lay male and female eggs in single-sex clutches. The average clutch size of female broods is always greater than that of male broods, and in some species male clutch size is always one. We constructed models that predicted that severely egg-limited wasps should produce equal numbers of male and female...

Journal: :PLoS Biology 2008
Walter Jetz Cagan H Sekercioglu Katrin Böhning-Gaese

Traits such as clutch size vary markedly across species and environmental gradients but have usually been investigated from either a comparative or a geographic perspective, respectively. We analyzed the global variation in clutch size across 5,290 bird species, excluding brood parasites and pelagic species. We integrated intrinsic (morphological, behavioural), extrinsic (environmental), and ph...

2002
VLADIMIR V. PRAVOSUDOV

AnsTn.Kr. -The breeding biology of Eurasian Nuthatches (Sitta europaea asiatica) was studied in 1986-1990 in two habitats, riparian and upland forests, in the Magadan region, northeastern Siberia. Clutch sizes and breeding success averaged 6.49 eggs and 57.5%, respectively, and varied among years. Habitat influenced clutch size but not numbers of young fledged from successful nests. Within seas...

2014
Anders P Møller Frank Adriaensen Alexandr Artemyev Jerzy Bańbura Emilio Barba Clotilde Biard Jacques Blondel Zihad Bouslama Jean-Charles Bouvier Jordi Camprodon Francesco Cecere Anne Charmantier Motti Charter Mariusz Cichoń Camillo Cusimano Dorota Czeszczewik Virginie Demeyrier Blandine Doligez Claire Doutrelant Anna Dubiec Marcel Eens Tapio Eeva Bruno Faivre Peter N Ferns Jukka T Forsman Eduardo García-Del-Rey Aya Goldshtein Anne E Goodenough Andrew G Gosler Iga Góźdź Arnaud Grégoire Lars Gustafsson Ian R Hartley Philipp Heeb Shelley A Hinsley Paul Isenmann Staffan Jacob Antero Järvinen Rimvydas Juškaitis Erkki Korpimäki Indrikis Krams Toni Laaksonen Bernard Leclercq Esa Lehikoinen Olli Loukola Arne Lundberg Mark C Mainwaring Raivo Mänd Bruno Massa Tomasz D Mazgajski Santiago Merino Cezary Mitrus Mikko Mönkkönen Judith Morales-Fernaz Xavier Morin Ruedi G Nager Jan-Åke Nilsson Sven G Nilsson Ana C Norte Markku Orell Philippe Perret Carla S Pimentel Rianne Pinxten Ilze Priedniece Marie-Claude Quidoz Vladimir Remeš Heinz Richner Hugo Robles Seppo Rytkönen Juan Carlos Senar Janne T Seppänen Luís P da Silva Tore Slagsvold Tapio Solonen Alberto Sorace Martyn J Stenning János Török Piotr Tryjanowski Arie J van Noordwijk Mikael von Numers Wiesław Walankiewicz Marcel M Lambrechts

Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests,...

2007
Brett K. Sandercock David B. Lank Fred Cooke

The breeding biology of Western and Semipalmated Sandpipers was studied for four years near Nome, Alaska. Despite a short breeding season and a putatively invariant clutch size, there were seasonal declines in the fecundity of both sandpiper species. Most females produced only one clutch ( > 98%), but often laid fewer than four eggs (7.6-34.5% of first nests). Clutches of 2-3 eggs were initiate...

2003
Tatsuya Koyama Kenjiro Takemura Takashi Maeno

A novel multi-fingered exoskeleton haptic device using passive force feedback has been proposed by the authors. The haptic device solves the conventional problems of previously developed master-slave systems with force feedback, such as oscillations, complex structures and complicated control algorithm. However, some problems still remain in the conventional passive elements. In the present pap...

Journal: :The Journal of experimental biology 2007
Maaike E de Heij Alexandra J van der Graaf Dennis Hafner Joost M Tinbergen

To study the energetic costs of incubation in relation to clutch size, clutch sizes were manipulated and the metabolic rate of female great tits, Parus major (Linnaeus), during nocturnal incubation (MR(inc)) was measured using mobile oxygen analysers. Individuals were measured on consecutive nights while incubating their own or manipulated clutches. The experiment was performed under field cond...

Journal: :Biology letters 2012
Timothy J Greives Sjouke A Kingma Giulia Beltrami Michaela Hau

The hormone melatonin is known to play an important role in regulating many seasonal changes in physiology, morphology and behaviour. In birds, unlike in mammals, melatonin has thus far been thought to play little role in timing seasonal reproductive processes. This view is mainly derived from laboratory experiments on male birds. This study tests whether melatonin is capable of influencing the...

1999
Chen Li

A dynamic model of a manipulative machine for automobile clutch is setup in ADAMS and further analysis is made to an automatic clutch for AMT. Since the engaging process of clutch is complex and related to riding performance and life span of friction plate, it has to be researched intensively using modern control theory. Adaptive control is effective to avoid engine flameout, which guarantees s...

Journal: :Biology letters 2013
Geoffrey F Birchard Marcello Ruta D Charles Deeming

A recent study proposed that incubation behaviour (i.e. type of parental care) in theropod dinosaurs can be inferred from an allometric analysis of clutch volume in extant birds. However, the study in question failed to account for factors known to affect egg and clutch size in living bird species. A new scaling analysis of avian clutch mass demonstrates that type of parental care cannot be dis...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید