Stork Year 2013 with its Ups and Downs in Germany/Bavaria
Sunday, January 05 2014 @ 08:58 PM EST
Contributed by: Gabi
The number of breeding stork pairs reached a new record - but sadly many of the storklets died.
Almost every year there is a new breeding record of storks in Germany. Bavaria-wide, the number of storks has risen from 272 to 300 this year, but more than half of the storklets froze or starved to death as a result of the long, cold and wet periods regionally. In some regions the rate has been higher than 70% of all young storks. Especially the chicks of the experienced adults died because they'd bred earlier in the spring and the chicks hatched in the cold and wet weather period. The elder chicks were too big to find protection under the feathers of the parents, and some of the little chicks didn't get enough food because the adults couldn't find enough mice, frogs and snakes (the main food of the storks) on the high meadows because the farmers were not able to cut because of the wet period. An adult must bring one kilogram (1000 grams, or about 2.2 pounds) of food per day to each chick; the weight of a mouse is about 20-40 grams (30 grams is about one ounce).
The picture on the right is the Bornheim/Sportplatz nest © AKtion Pfalzstorch www.pfalzstorch.de.
In 2013 the number of breeding pairs has been the best of the last centuries all across the states of Rheinland-Pfalz and Bavaria, and never before have so many stork pairs bred in Westmiddle-Franconia (where I live) as they did this year. There are several reasons why the number of storks reaches new records every year. It is a favorable effect for the population that as a result of the global warming the storks are more frequently taking the western route to Spain, where they can find nourishing food from garbage dumps and a new species of crab in the region after flying only a few hundred kilometers - so they don´t have to fly further to the south to Africa (the eastern route), which would be a journey of 8000-10,000 kilometers. The picture on the left is from the Worms nest, © Freizeitbetriebe Worms.
The stork has also profited from the reversion of flow-straightening in the rivers - the stork needs a wet habitat to survive. People originally straightened the rivers for economical/financial reasons, so the water would flow faster and the boats would arrive more quickly at their destination ports, but animals lost their habitats and the quality of the water took a turn for the worse and the meadows dried out. Now the people are making the rivers more crooked and winding and indeed slowing them down. Today the quality of the water is getting better and better and the animals are going back to their original habitats.
Many thanks to AKTION PFALZSTORCH for the permission to post the graphic on the right.
Brutpaare = breeding pairs
Jungvögel = young birds (Storks)
On the graphic of the wild White Stork in Rheinland-Pfalz we can see that the number of breeding pairs in 2013 reached 165 pairs, up from 134 pairs in the previous year, but on average only 1.1 babies survived. In West-Pfalz only 0.4 storklets survived. In Hessen we do have a better balance, and on average 1.9 chicks survived. Most nests hatched at least 3-4 chicks. On average one stork pair raises two chicks but the female lays a clutch of usually 4-5 eggs which hatch 32-33 days after being laid. Usually all eggs hatch but only on average 2 chicks survive.
The very experienced female at the Hoechstadt nest has done better than average in recent years, with 6 eggs laid, 4 hatched and 4 fledged in 2009; 5 eggs laid, 5 hatched and 4 fledged in 2010; 5 eggs laid, 5 hatched and 5 fledged in 2011; and 5 eggs laid, 4 hatched and 4 fledged in 2012; they are so fascinating stork parents. Only 2013 was an exception - the female laid 5 eggs and 5 chicks hatched, but as a result of the very cold rainy period in the late spring 3 chicks died at the age of 4 weeks. They were too big to find enough warm and dry space under the plumage of the parents.
The surviving two chicks were taken from the nest by firefighters, and then were blow dried and fed. On the next day the firefighters brought them back to nest with another female storklet of another nest. Immediately the adult adopted the new child and all three chicks were raised up to beautiful healthy storklets. The picture on the left is the five original chicks, and the picture on the right is the two chicks who survived, with their adopted sibling; both are © www.hoechstadt.de. The picture below, from the Worms nest, © Freizeitbetriebe Worms, shows the chicks in a thermal pyramid, which helps them conserve their body heat.
The reason that on average only 2 chicks survive is that stork adults do not feed their babies by beak to beak. They swallow small whole prey, pre-digest the prey and vomit this food on the nest. If the pre-vomit food is too big for the little ones, they cannot eat that and they starve. This can happen when the adult storks are not experienced and they don´t know that the little babies have to eat only earthworms in the first days or weeks. In the last breeding season I´ve seen at the Dinkelsbuehl nest that one adult gave the one-week-old chicks a whole mouse. They couldn't eat that, so all the babies died at that nest. Another problem is that the older chicks eat all the food very quickly and the smallest babies do not have a chance to get food. If the adult do not find enough food for all the babies, they may kill the smallest, and either throw it off the nest or eat it and vomit it a few hours later on the nest as a food for the living chicks. The adult storks also do that when one chick is ill. It´s very hard to watch, but that is nature.
Storks are scavengers, as are bald eagles. Sometimes it happens that the parents bring poisoned food to the nest, and they love to collect plastics they find in the nature. The babies pick up the smaller pieces of plastic and eat them, which can be fatal. The adults place the bigger pieces of plastic in the nest between the sticks and the moss. In many of our stork nests the rain cannot flow out because the films or plastic leaves have insulated the nest. The chicks have to freeze in what has become a water bowl.
Also a result of the global warming is the effect that more and more stork pairs stay at their nest during the winter. In Hoechstadt we have the stork-couple Anna von Steinfeld and Gerome de Vias that has stayed at their nest since 2009 during the winter. Due to the drastic stork slump in the years 1900 – 1986, only about 60 White Stork pairs were counted in Bavaria. To stabilize the local stork population we decided in 1979 not to let our winter storks starve but to provide them a supplementary feeding in winter .This conservation-based measure will be made as long as necessary until a self-sustaining population size of 1000 pairs is reached. In the region of Hoechstadt we have at this moment 10 pairs. Before 1900 we had had 250 pairs of storks Bavaria wide.
The stork couple in Dinkelsbuehl spent the last winter on their nest, as did the stork couple Manuela and Manfred from Luisenpark nest. Romeo and Julia, the stork couple of the Isny nest, have overwintered together on their nest since 2005. On the outskirts of Isny town they have discovered the very rich feeding grounds of the nature reserve "Rotmoos." The winter storks do not migrate any more but all of their babies have to fly to the south because they have the genetically inherited sense of direction and the magnetic sense that enables them to use the Earth's magnetic field. The picture at the right is the Dinkelsbuehl storks © www.storch24.de.
For those who wish to see the migration routes of the White Stork of Germany and Europe, I have found a migration map on the website of the MAX PLANCK INSTITUTE FOR ORNITHOLOGY - http://www.orn.mpg.de/46985/Stork.
Please visit our thread The White Stork of Germany and Europe on the Hancock Wildlife Discussion Forum for more information and wonderful pictures of many stork nests in Germany and other parts of Europe.