Le criard nordique (Chauna chavaria), également connu sous le nom de criard à col noir, est une grande espèce d'oiseau de la petite famille des Anhimidae, les criards. C'est un nicheur résident dans le nord de la Colombie, dans les départements de Chocó, Antioquia, Córdoba, Sucre, Bolívar, Magdalena, Santander et Cesar, et dans le nord-ouest du Venezuela, dans les États de Zulia, Mérida et Trujillo. En moyenne, ils mesurent 88,9 cm de long et pèsent environ 3,9 kg. Ils sont désignés comme quasi-menacés en raison de l'agriculture, des transports, de l'utilisation des ressources biologiques, de la gestion de l'eau et de la pollution due aux eaux usées et à l'industrie.
Habitats et répartition
The Northern Screamer thrives in wetland habitats, predominantly frequenting marshes, swamps, and the flooded areas around riverbanks. These environments provide the shallow water and dense vegetation that support its feeding and nesting requirements. Additionally, the bird can be found in regions with abundant aquatic plants and grasses, which are vital for its diet. Geographically, the Northern Screamer is confined to northern Colombia and western Venezuela. The species' range is relatively limited compared to other waterfowl, concentrating mainly in the lowland floodplains of the Magdalena River and Lake Maracaibo basin. These areas offer the specific ecological conditions necessary for its survival, such as suitable nesting sites and ample food resources.
Comportements et reproduction
The Northern Screamer exhibits a mostly monogamous pair-bonding system, with mated pairs remaining together throughout the year. These birds often inhabit marshes and wetlands, where they establish and defend territories against other pairs. Their social structure is relatively simple, maintaining small family units primarily consisting of the mated pair and their offspring. Reproduction involves building large nests constructed from aquatic vegetation, typically hidden among dense reeds or floating on open water. Together, the pair incubates a clutch of 2-7 eggs, although usually only 2-3 chicks successfully hatch and fledge. Both parents share responsibilities in raising the young, providing protection and food. A notable reproductive strategy is their territorial vocalization; duets or loud calls serve as both mate-bonding activities and deterrents to potential predators and rivals.
Régime alimentaire
Se nourrit de feuilles, de tiges et de racines de plantes aquatiques. Ils broutent généralement comme des oies, parfois en bandes lâches.
Couleurs
Le corps est principalement gris avec le cou noir et les joues blanchâtres. En vol, le dessous des ailes est blanc. Les sexes sont semblables.
Faits amusants
Énorme oiseau disgracieux aux pattes rouges épaisses, à la face rouge et à la crête floue. Le corps est surtout gris avec le cou noir et les joues blanchâtres. En vol, le dessous des ailes est blanc. Les sexes sont semblables. Peu commun et sédentaire dans les zones humides avec quelques arbres, souvent seul ou en couple, perché au sommet des arbres ou près de l'eau. Se nourrit de plantes aquatiques. Son aire de répartition est unique.
Statut de conservation et efforts
The Northern Screamer (Chauna chavaria) is currently classified as Near Threatened on the IUCN Red List. The population of this species is believed to be declining due to habitat loss and degradation, primarily driven by agricultural expansion and pollution. Deforestation, wetland drainage, and the conversion of natural habitats into farmland are significant threats that jeopardize the existing populations. Conservation efforts focus on habitat protection and restoration. Several protected areas have been established in the Northern Screamer's range to safeguard critical habitats. Additional measures include promoting sustainable agricultural practices and implementing reforestation projects to restore degraded areas. Environmental education campaigns aim to increase local awareness about the species and the importance of biodiversity conservation.
