Légende : Héron agami : curiosité. Marais de Kaw, Guyane. Référence Indigo : 18981
The Agami Heron has a height of just 70 cm. It can be distinguished from other herons especially by its predominantly chocolate-coloured plumage and its very long beak (2). The bird is described as solitary, grouping together only in the reproductive period, in small colonies. They are sometimes associated with other bird species The Agami heron is observed in Central and South America. However, its rarity and discreet behaviour mean that little is known about its biology or ecological status. It is a diurnal species. Some of its characteristics, like the length of its beak, its downy plumage or its partly nocturnal activity, place it in a separate genus (Agamia), within the family Ardeidae.
In May 2002, an IRD research team (1) conducting a scientific expedition to the Kaw Swamp in French Guiana, discovered an exceptionally extensive colony of Agami Herons, numbering about 900 nests. It is the largest nesting site ever seen for these birds.
The colony is located at the heart of the Guianan nature reserve, 40 km south-east of Cayenne, in an area surrounded by open water. Access can be gained only by helicopter. The site is hidden on a vegetation-covered bar and in deep shade overtopped by palm species. This reproduction area is also the gathering ground for several other marsh bird species, like the hoatzin and the anhinga, or snake bird, with some rare Ardeidae:the Cocoi Heron and the Great Egret. Heron nests were examined. A study was also made of both nocturnal and daytime behaviour of adult birds within or outside the colony. This work led to an estimate of 1800 individuals, representing 900 couples and as many nests. These are fixed on bushes and trees at a level of a little over two metres above water and measure about 15 cm in diameter and are built to 8 cm high. The Agami Herons breed asynchronously, in that they do not all lay their eggs at the same time of the season. Consequently, these nests hold young at different stages of development: eggs, chicks or juveniles already able to fly. Thick foliage protects them from the sun.
Marie Guillaume | alfa
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
24.04.2018 | Information Technology
24.04.2018 | Earth Sciences
24.04.2018 | Life Sciences