The Common Crane
Symbol of pure elegance, the Common Crane is without a doubt one of the most majestic birds on the planet. Although coming from distant lands, it is quite familiar in Europe. Each year, it reminds us that we are at the gates of winter, with the alarm signal of large V-shaped flights emerging in the sky, accompanied by loud and communicative "grous-grous".
There are 15 species of cranes in the world, each one as amazing as the next. We limit ourselves here to the Common Crane, well known to all in our latitudes.
Description and identification
The Common Crane is the largest wading bird in Europe. As astonishing as it may sound, from the order of Gruiformes, cranes are more closely related phylogenetically to rails, coots and other moorhens. Its appearance is however very different! With 1.15 meter in length and around 2 meters in wingspan, it is a very large bird that is relatively easy to identify in the field. The Common Crane has long legs and a long narrow neck. Its plumage is gray-bluish. Its head and the top of its neck are black and white. The top of the head is a space of red bare skin.
In flight, its neck and legs are outstretched, which makes it easy to differentiate from herons, even from afar. The young are more uniform with the head and the neck in united tones, rather reddish / brownish. It is a gregarious migrating and wintering species, found in huge groups, sometimes of tens of thousands of individuals. They form V-shaped flights, which sometimes extend over a good part of the horizon, creating horizontal lines and succeeding each other at medium cruising speed.
Where to see the Common Crane?
The species breeds in northern Europe from Norway to Russia, passing through eastern countries (Hungary, Romania, Ukraine, Georgia, etc.) and winters in southern Europe as far as North Africa (Algeria, Tunisia mainly). Several major migration routes are known around the world, including that of Western Europe. From October-November the birds migrate to their wintering quarters and return around March-April. It was then that large numbers passed through France where certain natural sites are now known for the presence of the Common Crane during migration (halt) and wintering. The major sites include Lake Der-Chantecoq, the Brenne or the Landes.
Distribution map of the Common Crane in Europe : breeding areas in red, wintering areas in blue.
If you want to attend the show, go to one of the largest transit and wintering sites in France, Lake Der-Chantecoq, where tens of thousands of cranes are counted each year. You have to go there at favorable times in order to enjoy the best atmospheres. The birds are less discreet during this period, they are noisy, communicating with each other, which allows interesting interactions with the birds. This bird is very elegant. Its plume, its posture and its displays (visible even in winter), are all attractions to look for when taking photos. Jumps and bows between pairs are fantastic to watch!
How to approach the Common Crane without disturbing?
To make beautiful observations of this magnificent bird without disturbing it, it is necessary to remain at a sufficient distance of several tens of meters. The ideal is to position yourself in a vehicle or behind an obstacle in order to "break" the human silhouette. This bird remains tolerant at a certain distance. If you approach while the bird is feeding, observe its behavior. At the slightest sign of restlessness, stop and then slowly back up. To learn how to observe Common Cranes in the best conditions, it is recommended to go into the field with an experienced guide.
Biology of the Common Crane
Ecology
During migration and winter, the Common Crane likes open areas generally cultivated where it finds a large amount of food, especially in corn fields. The proximity to water for roosting seems to be of paramount importance. During the breeding season, it searches for humid heathland, shallow freshwater marshes and swamp forests, interspersed with open clearings. This large bird is able to move long distances during migrations.
Behaviour
The Common Crane is a bird generally known to be in flocks. It is sociable and gregarious during periods of migration and wintering. Also very noisy during this precise period of its biological cycle, its presence in sometimes very large quantities (several tens of thousands of individuals) offers us memorable shows. During migratory flights, this bird describes V or Y, legs and necks stretched out at altitudes between 200 and 1000 meters. It is estimated that around 250,000 cranes use this same Western European corridor, the one with which we are most familiar, twice each year.
On the contrary, it is very territorial during the breeding season when the pairs are united for life. The Common Crane is also known for its courtship displays which consist of performing a kind of bow dance, sometimes grabbing various objects thrown in the air with jumps, wings open, greetings and other loving signs. This change in behavior from the reproductive instinct to the gregarious instinct lets us think that it would be quite astonishing if the couples did not leave each other during the migrations. Indeed, how would they manage to find themselves among these large winter gatherings, among these mind-boggling din, traveling thousands of kilometers from their birth and breeding sites? Fortunately, nature always keeps a part of the mystery!
Reproduction and population dynamics
After courtship display and subsequent mating, the female usually lays 2 olive / fawn colored eggs, spotted with gray / brown. If this fails, the pair can perform a replacement spawn. The eggs are incubated for about 1 month by both adults, the young precocial birds feed under the supervision of the parents for about 70 days before they can take flight. Sexual maturity is estimated to be around 5 years, sometimes less. The couple always nests alone. Young people stay with their parents until their first migration journey and until the end of winter. It is for this reason that we often observe in the fall adults accompanied by a young (uniformly red head), even on the wintering quarters, they remain united for the first year. The maximum longevity observed in nature would be 26 years!
Diet
In many species of birds, the diet differs between the breeding season and the interbreeding period. This is the case with the Common Crane, which mainly consumes breeding animals (small mammals, insects, molluscs) and rather plants over the rest of the year (young shoots, seeds, stems, leaves).
Conservation status of the Common Crane
The species has been protected in France since 1967 and listed in Appendix I of the Birds Directive and in Appendix II of the Bern Convention. In terms of its state of conservation, it is classified as Least Concern (LC) globally and in Europe according to the International Union for the Conservation of Nature (IUCN). In France, the species is classified as critically endangered in breeding (CR) due to a few fragments of populations still in place and in near-threatened (NT) when overwintering. Its conservation status is unfavorable in the Auvergne region (NT).
Evolution of populations
The species had declined significantly until the 1970s, since the Common Crane is sharply increasing. Its formerly unfavorable conservation status in Europe with a “Vulnerable” (VU) status in the early 1990s is now favorable, considered Least Concern (LC). Numbers have increased considerably in recent decades, from a European population of between 52,000 and 80,000 pairs in the 1990s to more than 200,000 pairs today. The counts carried out each year on sites such as Lake Der-Chantecoq in France clearly prove that the workforce is on the rise. Large historic dormitories tend to burst, creating new wintering areas (Petite Camargue for example).
Potential threats
The Common Crane can be disturbed by humans on its nesting areas, which leads to lower reproduction rates. The species is less disturbed in Russian latitudes, as spaces are large and humans are less frequent there. A few natural predators have already been identified, such as the Red Fox. Collisions with power lines or wind turbines is also a potential threat. Obviously, the drying out of wetlands, often by extension of crops, and the massive use of pesticides can lead to downsizing locally.
Research and studies on the Common Crane
As the species is increasing, new nesting and wintering sites are to be found. It would be wise to maintain monitoring, or even to intensify it, in order to have a more precise idea of the number of breeding pairs in France and elsewhere. Studies need to be improved or developed, concerning the dispersal of nesting birds or the exchanges between the different wintering sites, moreover since we are witnessing the extension of the roosting areas. Is this a colonization strategy to possibly expand to new nesting areas?
Thibaut
Guide Salva Fauna
References:
MULLARNEY, K., SVENSSON, L., ZETTERSTROM, D. & GRANT, P. J. (1999).- Le guide ornitho. Delachaux et Niestlé, Lausanne. 401 pages.
Cahiers d’Habitat « Oiseaux » - MEEDDAT-MNHN-Fiche projet, Grue cendrée, grus grus (Linné, 1758). Document PDF.
La Grue cendrée, Migraction. www.migraction.net/index.php?m_id=1517&bs=96 (consulté le 04/01/2021).
Suivi de la migration et de l’hivernage en Europe, LPO Champagne-Ardenne. champagne-ardenne.lpo.fr/grue-cendree/grus (consulté le 04/01/2021).
Union Internationale pour la Conservation de la Nature (UICN), Common crane (Grus grus). www.iucnredlist.org/species/22692146/86219168 (consulté le 11/11/2020).
BirdLife International(2004).- Birds in Europe : population estimates, trends and conservation status. Cambridge, U. K. : BirdLife International (BirdLife Conservation Series N°12). 374 pages.
COUZI, L. & PETIT, P. (2005).- La Grue cendrée. Histoire naturelle d'un grand migrateur. Editions sud ouest, Luçon. 189 pages.
CRAMP, S. L., SIMMONS, K. E. L., Snow, D. W. & Perrins, C. M. (1998).- The Complete Birds of the Western Palearctic on CD-ROM.Version 1.0 for PC, 1998. Oxford University Press. London, UK.
DEL HOYO, J., ELLIOTT, A & SARGATAL, J. eds (1996).- Handbook of the Birds of the World. Volume 3 : Hoatzin to Auks.Lynx Edicions, Barcelona. 821 pages.
LE ROY, E. (2006).- La Grue cendrée. LPO Champagne-Ardenne. Imprimerie Estudios Graficos ZURE, Bilbao, Espagne. 36 pages.
PRANGE, H. (2004).- Kranichzug, -rast und -schutz 2004. Rapport Martin-Luther-Universität Halle-Wittenberg. Halle / Saale. 85 pages.
ROCAMORA, G. & YEATMAN-BERTHELOT, D. (1999).- Oiseaux menacés et à surveiller en France. Listes rouges et recherche de priorités. Populations. Tendances. Menaces. Conservation. Société d'Etudes Ornithologiques de France / Ligue pour la Protection des Oiseaux, Paris 152 – 153.
TUCKER, G. M. & HEATH, M. F. (1994).- Birds in Europe : their conservation status.Cambridge; U. K. : BirdLife International (BirdLife Conservation Series n°3). 600 pages.
