1. Has the crane population been increased in Germany?
Yes. Within the last 12 years the total population has been increased at about 60%. This equates to 5% per year. In year 1993 there were only 1,600 to 1,900 breeding pairs in Germany. In 2008, the population reached nearly 7,000 pairs and further increased to more than 9,000 breeding pairs in 2015.
2. What do cranes feed?
Cranes are omnivores, which mean they feed on vegetable as well as animal diet. Vegetable diet include different types of cereals (e.g. maize, wheat or rice), leguminous plants (peas, beans) and potatoes, fruits of oak trees, sunflower seeds, roots or bulbs. The animal diet consists of different bugs, earthworms, snails and little vertebrates (e.g. fishes, frogs, mice and lizards).
3. Are cranes the largest birds in Germany?
With a body height of 120 to 130 cm the Eurasian Crane is clearly higher than the White Stork or the Grey Heron. Relating to the body height the Eurasian Crane is the largest bird in Germany. But the wing-span of a crane reaches up to 2.2 m, which is a little bit smaller than those of a White-tailed Eagle (up to 2.5 m).
4. Are adult cranes pairs faithful to each other?
Yes. Once paired to each other, a couple of the Eurasian Crane is living usually in a permanent pair-bond. Due to results of crane ringing, cranes rarely can change their partners. Such events are relatively rare and often the result of the dead or a serious sickness of one partner, especially if the male is not able anymore to defend his breeding territory against other cranes.
5. Do all cranes have a red spot on the head?
Only adult cranes have the red unfeathered plate on the top of the head, while in juveniles this plate as well as the clear black and white contrast on the head and neck is still missing. Only from the second year onwards this plate, which consists of many small red collared cavernous bodies, is developing.
6. In which altitudes cranes fly during migration?
The average cruising altitude is between 50 and 2,000 m above sea level. It highly depends on wind and visibility conditions. Over the Pyrenees cranes are flying in altitudes of up to 3,000 m above sea level. In India, wintering cranes migrate over mountain ranges of up to 4,600 m above sea level.
7. How many grains of maize or wheat cranes are feeding per day?
During spring and autumn migration, cranes are feeding 200 to 300 g grains per day in average. This equates to a big cup of coffee filled with corn.
8. Are the ornamental feathers identical with the tail feathers?
No, the ornament feathers could easy mix with the tail feathers while the wings are flattened. Like the primaries and secondaries (the big feather in the wing), tail feathers also show a blackish coloration. The ornament feathers can vary in color (from light grey to black), form and length. They clearly hang over the tail feathers. The big ornament feathers are also called as “trail”. The trail is disposed while enragement and in display.
9. Do the cranes also stay in winter in Germany?
Yes, in the last years much more and more cranes try to overwinter in Germany. The main wintering areas in Germany are located around Berlin and the Diepholzer Moorniederung in the West of Lower Saxony.
10. Will cranes also be hunted?
The Eurasian crane as a threatened bird species is protected by law in all European countries (e.g. the Birds Directive in the European Union) and hunting of cranes is therefore not allowed. As a migratory bird, the Eurasian crane is also covered by the Bonn convention (Convention on Migratory Species) and CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Because of hunting waterbirds, quite often disturbances at staging and roost sites do happen. Especially in the Eastern Adriatic Sea, in the Middle East and in Northern Africa as well as in many regions of Asia, hunting and poaching is a serious threat to cranes and many other bird species. Some of the crane species in the world, like the Black and Grey-crowned Cranes in Africa, are threatened by hunting and collecting their eggs.
11. Where cranes are breeding?
All crane species use permanent or temporary wetlands to lay their eggs in nests on the ground surrounded by shallow water. With this behavior they try to protect their clutch against ground predators. Nests on dry ground are only exceptional. Very rarely, nests of Grey-crowned Cranes were also found in trees and bushes.
12. How long do they breed?
The breeding period takes about 30- 31 days. After hatching of the crane chicks it will take another 10 weeks until the juveniles are fully fledged.
13. Who is the leader of a migrating crane flock?
Only experienced adult cranes take a lead in migrating crane flocks. Nevertheless several adults are alternating each other.
14. Do cranes have different eye colors?
Yes, Eurasian Cranes have different eye colors. Usually this is very difficult to see because of the large flight distances of up to 300 m to humans. The iris is colored red or yellow in breeding birds in Europe. Juvenile cranes usually show a darkish iris. Crane chicks have a light to dark brownish iris.
15. Why do cranes fly in V-shaped flight formations?
Like geese and swans, also cranes show V-shaped flight formations. The V-formation possibly improves the energy efficiency of flying birds. All the birds except the first fly in the upwash from one of the wingtip vortices of the bird ahead. The upwash assists each bird in supporting its own weight in flight, in the same way a glider can climb or maintain height indefinitely in rising air.
16. How large is the flight distance of cranes?
The flight distance highly depends on the regions or countries, where cranes are staying. In Spain, where cranes are often exposed to disturbances, the flight distance is up to 1 km. In Germany, cranes could usually be observed in distances of 200 to 300 m. In the Nordic countries (like Sweden and Finland) the flight distance is the least (150 m).
17. How cranes do sleep, standing or laying?
Cranes are sleeping while standing on both legs in shallow water. Rarely do they only stand on one leg, which is changed from time to time. Only adult cranes during breeding and chicks are sleeping while laying down.
18. Do juveniles migrate alone southwards?
No, adults and their juveniles have a close relation to each other for a long time. During their first migration, juveniles fly together with their parents in family groups. Also in large flocks, family members keep closely together. The family bond will start to break off in wintering areas or during spring migration. In spring, sometimes juveniles also return from wintering areas together with their parents and family bond will end, if adults start their new breeding season. Juvenile birds, which were separated from their parents in winter areas, often migrate back together towards their breeding areas.
19. Why cranes are trumpeting and how these calls are created?
Cranes have a big repertoire of calls, which are important for the intraspecific communication and social behavior. The loud trumpeting is possible because of a big resonating cavity, based on a very large trachea, which is up to 1.3 m long and double layed.
20. Do cranes breed every year?
Usually the adult crane pairs return to their breeding territories every year and try to breed annually.
21. How you can differentiate cranes and geese in flight?
Geese show a much faster wing beat and a more turbulent flight pattern. Cranes show a slower wing beat and a more even-tempered flight pattern. Another characteristic feature of flying cranes are the strait long legs, which clearly hang over the tail.
22. Are cranes able to swim?
Yes, the chicks are precocial birds and follow their parents from the second day of life onwards. Therefore they have to swim away from the nest to follow the adults while feeding in the breeding territory. Adult cranes are also able to swim, but only swim from and to the nest, if water levels are too deep for walking.
23. Is the White Stork competing with cranes for food?
The diet of cranes and storks is partially overlapping. The White Stork is also feeding on earthworms, insects and amphibians. Nevertheless the diet of cranes is very variable and storks and cranes only compete in times if the food is very limited.
24. Can cranes from Scandinavia and Germany understand each other?
Yes. On observation stations, like the KRANORAMA near Lake Günz, you can regularly see cranes from different origins standing next to each other. Occasionally it also happens that a German crane follow Swedish cranes like in spring 2017, when the GPS-crane Blacky went to southern Sweden.
25. What cranes are feeding in Spain?
In the main wintering areas in southwestern Spain (Extremadura and Andalusia) cranes use a variety of food resources. They can feed on crop left overs, like wheat, maize, and rice. While feeding in the Dehesas, cranes prefer to feed on the numerous fruits (acorns) of the holm or cork oak trees. They open the shell of the acorns with their bill to feed on the delicious flesh. In northwestern Spain, like around the Laguna de Gallocanta, they also feed on sunflower seeds.
26. How long does it take from copulation to egg laying?
The courtship behavior, which can mainly be observed in the morning hours, usually starts about three weeks before the egg laying. Sometimes cranes show courtship behavior when stopping at staging sites during spring migration.
27. Do cranes eat fishes, too?
Yes. Cranes can sometimes eat small fishes, but fishes are not part of their regular diet. In opposite to herons, free swimming fishes is difficult to catch by cranes, as they do not have a curved neck like herons and are therefore often not quick enough to catch fish.
28. How large is the percentage of color-marked cranes?
Beginning in the late 1980ies, more than 5,000 Eurasian Cranes were ringed in Europe. Due to a large total crane population of more than 500,000 cranes in Europe, the percentage of ringed cranes is less than 1%.
29. How large is the juvenile percentage?
The juvenile percentage differs from 5% to 15% at the staging areas. The percentages strongly fluctuate from year to year and between different regions.
30. Do hybrids between two crane species exist?
Yes. Rarely different crane species form mixed pairs, like in Eurasian and Hooded Cranes in Eastern Asia and sometimes produce even hybrid juveniles. According to observations in the field, such crane hybrids seem to be not fertile and also pair formation with pure cranes species seems to be doubtful.