Eurasian Wryneck

Language:
Swedish English

A Eurasian Wryneck.
© Ulf Risberg/N

The Eurasian Wryneck belongs to the woodpecker family but is in many ways the odd one out. It cannot peck its own hole like other woodpeckers, because its beak is not strong enough. For that reason, the Eurasian Wryneck has to live in holes left by other woodpeckers or in natural holes. The Eurasian Wryneck will inhabit nesting boxes if the boxes are put out in the Eurasian Wryneck’s biotope.

The Eurasian Wryneck is also the only woodpecker which is a migrant. It arrives in the middle of April and leaves soon after mating, flying south to Africa.

The Eurasian Wryneck is a very shy bird and many will never have seen the bird in its natural habitat. Before mating starts, one can hear their mating call, which is very special. Click on these links to hear what it sounds like: audiofile 1, audiofile 2. Here is also two movies whith sounds taken by Stig Norell. Click on these links to watch the movieclips: clip 1, clip 2.

The Eurasian Wryneck is struggling in our habitat. Since the 1980s the number of birds has decreased by half, and it is believed that the number of pairs in Sweden is between 5,000 to 10,000. That means there are only 1.5 to 3 pairs per 10 square kilometre on average, which is a very low number. The Eurasian Wryneck is therefore redlisted in Sweden and classified as ”not favoured by” in the database of species (Artdatabanken). In the county of Strängnäs, where I work with the Eurasian Wryneck, the bird is overrepresented because I had 26 nestings in my nesting boxes this year.

The reasons for the Eurasian Wryneck’s problems, we believe, are many. The transition from small-scale agriculture to professional agriculture has definitely influenced the bird’s living conditions negatively. Several enclosed pastures have become overgrown, which means that their food supply has diminished. Another reason is large-scale forestry. The Eurasian Wryneck is dependent upon deciduous forest like other woodpeckers, and the deciduous forest decreases in size every year because it is not considered viable by forestry companies.

In the spring of 2002, I was asked by a scientist at the University of Stockholm if I would like to join the newly formed Eurasian Wryneck group. At the time I did not know much about the Eurasian Wryneck, but I still gave them a positive answer.

Quickly, I made 30 nesting boxes that I put out in time for the Eurasian Wryneck mating season. The result was the worst possible. Not one single nesting.

For the year 2003, I had learnt more about the Eurasian Wryneck biotopes, and now the result was three nestings and 21 birds ringed. The number of nesting boxes had increased to 133, which obviously helped. The day I held my first Eurasian Wryneck in my hand, it became my favourite species of bird. The Eurasian Wryneck’s defence mechanism - to turn neck and head - has fascinated me. Even the nestlings have this mechanism from early on.

After 8 years with the Eurasian Wryneck, I have now made almost 900 nesting boxes for the Eurasian Wryneck and ringed over 1000 Eurasian Wrynecks.

Nesting box for the Eurasian Wryneck.
© Erik Arbinger

A good way for us birdwatchers to help the Eurasian Wryneck, is to put up nesting boxes for them. I have now around 891 nesting boxes specially made for the Eurasian Wryneck placed in suitable locations.

Specifications:
1 st front piece 22 x 120 x 400
1 st back piece 22 x 120 x 400
1 st floor 22 x 120 x 125
2 st side pieces 22 x 170 x 400
1 st roof 22 x 170 x 250

The entrance hole should be made with a diameter of 35 mm. Also, fill the bird box with approximately 3 centimetre of wood chips or moss for the Eurasian Wryneck to lay their eggs in.

If you would like a full description on how to build a Eurasian Wryneck nesting box, click on this link: Drawing for a nesting box.

Alternatively, if you have no opportunity or energy to build your own nesting box, you can buy one from me: Buy nesting box.

All my nesting boxes have been positioned with a GPS. The coordinates are sent to SLU, Sweden’s Agricultural University in Uppsala. They will run the biotopes in their map programmes.

A hornet and a fly Potamia littoralis.
© Erik Arbinger

It is not only the Eurasian Wryneck that uses the nesting box. The nesting box is also popular with the Great Tit and the Wood Nuthatch who also like this tall box. Even certain insects are drawn to this box. The hornet is a common guest and in the photograph it is on guard in the blocked up entrance. It will not let the fly, who wants to lay its eggs on the bottom of the box, pass.

The fly in this picture is Potamia littoralis, a member of the family Muscidae, like our common house fly. Potamia is considered to be a hemisynanthropic species, occurring in domestic siruations, however not indoors. Instead it lives in the burrows of small mammals and in the nests of birds and social wasps such as the hornet (Vespa crabro). The larvae live in the rubbish in the bottom of the nests. Below a hornet nest there is a filthy waste, an excellent environment for fly larvae. However, the fly larvae are not alone here but are accompanied by several other predators living on them, for example the rare and large staphylinid beetle Velleius dilatatus.
The fly you see in the picture had two reasons for trying to get into the nest box: the hornet nest and the abandoned wryneck nest in there. It made several attempts to sneak in but the door-keeper kept it away. Other members of the Swedish wryneck project have reported observations of the fly slinking in in spite of the guard in the entrance

A Eurasian Wryneck stretches out its tongue.
© Bruno Sundin

The Eurasian Wryneck is equipped with a very long tongue to be able to access ants and ant eggs and other edible food.

The Eurasian Wryneck has for some odd reason a very high number of unhatched eggs. In year 2007, I have counted 245 laid eggs and of these 57 remained unhatched. A loss of 23,3 percent. If you take a look at the picture, the result is even worse. Of the 11 laid eggs only one became a nestling.

A Eurasian Wryneck nestling and 10 eggs not hatched
© Erik Arbinger

Eurasian Wryneck nestlings.
© Erik Arbinger

Newly hatched Eurasian Wryneck nestlings always lays in a heap to keep warm.

In the nesting box called Marietorp 2, have the Eurasian Wryneck laid 16 eggs in year 2008. This is a record for me, but not for the Eurasian Wryneck.

16 eggs.
© Erik Arbinger

Eurasian Wryneck nestings 2011

Show table

Show tables from previous years.

Annual table – Eurasian Wryneck data

-----
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
Number of nesting boxes
30
133
243
385
406
592
753
891
994
1082
1215
Number of nestings
0
3
17
26
22
26
35
37
48
66
74
Number of discontinued nestings
0
0
3
9
4
2
8
5
5
11
9
Ringed nestlings
0
28
130
129
135
177
232
215
334
404
502
Ringed juvenile
0
23
100
108
125
145
203
173
300
383
466
Ringed adults
0
2
29
29
28
41
48
49
58
73
55
Own checks
0
0
1
5
4
5
6
10
7
15
15
Checks by others
0
0
0
1
0
0
0
0
0
0
0
Total
0
30
160
164
167
223
286
274
399
492
572

"The Edsala-mystery"

Edsala nesting box number 14.
© Erik Arbinger

In 2004 a peculiar story began. It involves Eurasian Wrynecks from my local area of Edsala, and what happened took place in one of my best nesting box locations. The area includes 11 nesting boxes, and the biotope is a deciduous forest with thorny bushes and juniper shrubs, stones and rotten deciduous forest. Everything that the Eurasian Wryneck needs to thrive. Even food for the Eurasian Wryneck can be found in great quantities.

So let me begin; In 2004 a pair of Eurasian Wrynecks mated in the box marked Edsala 14. The pair were ringed and got numbers 3 503 333 and 3 503 357. Together they had 11 eggs and 9 nestlings.

Edsala nesting box number 25.
© Erik Arbinger

In 2005, when I enter the area for the first time on the 20th of May, I come across a box with two eggs that are broken. A 100 metres away in another bird box there is another broken egg. Who is the predator, is my first thought. Or can it be that the Eurasian Wrynecks have done it themselves? A week later I return to the area and find eggs in two new boxes numbered Edsala 25 and Edsala 27.

Edsala nesting box number 27.
© Erik Arbinger

All these four boxes are closely sitauated. The shortest distance is 102 metres and the farthest distance is 292 metres. When I later catch the adults it appears that in box Edsala 25 the old aquintances 3 501 357 from 2004 with a new partner, which I number 3 507 590. In Edsala numer 27 I am very surprised when I find 3 503 333 from 2004, now with a new partner, which I label 3 513 806. Apparently there seems to have been a ”divorce” from last year, but when and where? Can birds be so intensely angry with each other that they sabotage nests? All this I have called the Edsala-mystery.

In 2006 the story continues. In box Edsala 18,5, and unmarked couple mates, they receive numbers 3 513 962 and 3 514 012.

But, in box Edsala 11 something strange happens. First I catch 3 503 333 and two days later 3 503 357. The couple from 2004 is together again! This year they have 11 eggs and 9 nestlings, just like in 2004.

I wonder if I will see them again this year?



Buy nesting boxes for the Eurasian Wryneck – click on ”övrigt” – or click here.

Edsala nesting box number 11.
© Erik Arbinger