That I am behind in posting current news items is a fair statement. I hope to make up for that now with a catch-up race. In terms of travels and locations that I have visited, not much has changed in that time. Poland remains a favorite destination. This fall came early and that meant that, in addition to the usual search for butterflies and caterpillars, there was a possibility to see and photograph migrating Cranes. The local birds often do not yet make any moves to go to their wintering areas, but that does not apply to the Scandinavian cranes. This is recognizable because these specimens have a slightly darker plumage. That was new information for me and I had to hear and learn from my local friend Jan.Because mid-September actually falls under the heading “end of summer”, there is little point in looking for a clear autumn image. Mushrooms could be a subject, but then you need regular precipitation and the right temperatures. In short, the focus actually went directly to the group of Lepidoptera. The database that I am building up of that is slowly getting larger.Searching for caterpillars is quite labor-intensive, but again during this week we were able to add several new species. The wealth concerning this group is so great in the Biebrza area that I can continue there for many years. Due to the obligations concerning my work and family life (school holidays) it is actually always the same periods in which I visit the area. The first should be over in a few years and then completely new possibilities arise. But for now this is it and in all honesty I am far from complete and there are still plenty of species to discover in these periodes.
News
Danmark- Brovst, North Jutland summer 2022
At the request of our daughter, we went on holiday to Denmark in the summer of 2022. The decision about the location was made on the basis of some photos of the holiday home and its surroundings. The area also looked great on Google Maps. Lots of nature, close to the coast and a holiday park where the houses are at a good distance from each other. This, supplemented by reports of a very low crime rate (the ATM is literally in the parking lot) and plenty of peace and quiet, made the choice not difficult.
The travel time is also shorter than what we are used to towards Poland, but that was a bit disappointing afterwards due to a number of reasons. It was already dark when we arrived. The next morning it turned out that we had made an excellent choice. A large garden that consisted largely of heather and surrounded by a large amount of pine and oak trees. At birds we immediately saw Bullfinches, Redpolls and Hawfinches. The silence, except for the bird sounds, was deafening!
From the garden you walked directly onto the heath. The area is quite wet in winter, but unfortunately Denmark also had to deal with a serious drought in the summer of 2022. Since 1989, almost all of Europe has been affected by changes in large-scale air circulation over Europe and the North Atlantic. The result is significantly more sun and less precipitation in spring and summer. At least, that has been the situation in recent years.
A situation that is not favorable for many butterfly species. It ensures that when the caterpillars are there, there is a shortage of food plants. It literally dries up. This jeopardizes the reproductive cycle. The number of caterpillar species I found was therefore limited. This despite intensive searching, especially in the night hours. However, it has produced a number of new species and actually, that was what I’ve been hoping for. The area is home to a number of very interesting plant species, which could produce the necessary special caterpillars, especially in spring. This visit will therefore be continued.
The weather was remarkably cool. On many days the wind was strong and since it came in from the sea, it meant that the jacket had to be put on regularly. And whether the devil played with it, but the raincoat has also been out of the closet a number of times.
The fact that we were clearly further north was also noticeable by the sea water temperature. Especially because the current was northerly, it took some “courage” to take a dip in the sea. With an outside temperature of sixteen degrees, that is of course less inviting, but all that is a matter of persevering. My daughter wanted to swim in the dark, but because of the strong winds that regularly raised their head, we have given up that idea.
But oh well…… shaving stones over the water with your father is also fun.
Poland, Biebrza National Park, spring 2022
Business as usual in Spring 2022. For the umpteenth, now countless times, traveled to the above area during this time of year. Not on my own this time, but in the company of daughter and sister.
Despite the fact that the winter was again as we have known it in Europe for the last decade, too warm and with a mainly westerly wind direction, I always hope that the conditions will be back to normal. That is, a situation where the entire delta is flooded. This is due to the precipitation in the source area of the rivers Narew and Biebrza. This is mostly the case during much of the winter and then the area is home to large numbers of geese, swans and ducks. However, in the last seven to ten years this water is gone before the end of April and with it, the conditions that previously caused an explosion of bird life. The Ruffs that normally arrive around this time, are now moving on two weeks earlier.
But, not taking a chance is always wrong, and so I brought my floating hide again. Fortunately, I know one location where there is always water enough. Unfortunately, this piece is slowly overgrowing, partly because it remains too wet during the summer to mow. And when spring is also very cold and the other birds arrive later then “normal”, there are not so many opportunities left. The few mornings I spent in the water yielded almost nothing. A pair of Red-necked Grebe that was about to nest was actually the only real opportunity. Because disruption then constitutes a clear risk, extremely careful action is required.
The cold spring in turn meant that there were no leaves on the trees yet and the herbal vegetation had yet to get going. The well-known search for caterpillars was therefore again a challenge this time. A month later, the situation within this group is completely different, but my school-going daughter ánd work prevent me from going then. Bring on the pension I would say. From the stories of my Polish friend Jan I pretty much conclude that every bush is then loaded with many species. This does not seem to be an exaggeration as I always get a bunch of photos to see, taken with his smartphone. In between there is always a large batch of species that I have not seen before. There’s something to look forward one might say. The beauty of that time is also that the numbers of butterflies are large. Not to mention the end of June when species such as Emperor butterflies populate the area.
In short, to be continued!
Poland, Biebrza National Park, summer 2021
Setting up a website is one thing, posting news regularly is another. And the latter is sometimes the case. Although sufficient material has become available, I have neglected the latter.
This is the impetus for catching up. A series of at least four items to be current again.
This series is the footage of yet another visit to the Biebrza swamps in northeastern Poland. The period is August 2021. Also this time the focus was mainly on finding caterpillars and butterflies. And if there is enough of that, there is little time left for some other subjects.
Visiting the same area regularly does not mean that you will only encounter the same species. One year is not the next turns out every time. Species of which you have not found a single specimen for years, suddenly appears everywhere. It may well be possible to explain what underlies this, but I do not have that information available for the time being. I don’t think it is due to a change in the landscape, because hardly anything happens with it. Weather conditions may play a role, but as with many other animals, species occasionally have a year in which they occur in significantly larger numbers. For some species, this is also referred to as a “mast year”. With a next news item I will try to find out this info.
For some of the caterpillars, breeding to a butterfly only provides complete certainty about the species. For example, the caterpillar of the Pine Carpet, Pennithera firmata, was about to pupate. A search for comparable recordings of this stage turned up nothing. Fortunately, about two weeks later the butterfly emerged from the pupa and the species was known. With the “gathering” of caterpillars is also an important factor on which plant you find the species. Often the host plant is also directly the food plant. The species mentioned earlier is a good example of this. The caterpillar was therefore not photographed on the correct plant. During the “tapping” of caterpillars, one will have to pay very close attention to where it came from. In other words, check the moment you switch to another tree species or shrub.
Poland, Biebrzanski Park Narodowy 2021
In the spring of 2021 I received good news from Poland. For the first time in years, the water level in the Biebrza area was once again old-fashioned high. The height of the water level there is mainly determined by the amount of precipitation, especially that of the previous winter. An excellent opportunity to get started with the floating hide again and to focus attention on the birds.
At the end of April it was time and despite the very cold spring I had good hopes that I would find enough waterfowl. Unfortunately, immediately upon arrival it turned out that the water level had dropped dramatically in two weeks time. The inhabitants of the area had not often seen it flow away so quickly.
The consequence was that all Ruffs, first present in large numbers, had moved on to more suitable places. The numbers of the other waterfowl were also small. Of the many songbirds that abound in the Biebrza swamps, I did not observe many species because their arrival time had been pushed back considerably due to the cold weather. The numbers of Storks were also low and the number of occupied nests was significantly less than in previous years.
Plant life had only just started due to the cold spring. Fields that normally show a sea of flowers, were bare. What that would mean for the numbers off caterpillar was briefly questioned, but it soon became apparent that with the help of a UV lamp, there was enough to be found. An interesting strip under a high-voltage line turned out to have been worked with a forest flail during winter. There is a large amount of Heather on this route, together with a variety of small trees such as Oak,Prunus serotina and Birch. In September the year before I had already found quite a few caterpillar species on this stretch and they should be fully grown by spring. After the work, of course, there was nothing left of it. Still a disappointment because I had the idea that this would give me a number of new varieties. Later, in August 2021, I went back again and I could see that the recovery was going smoothly. More about that in a later article.
I also intended to spend the necessary time with the group of amphibians. The Green toad in particular was high on the wish list. A beautifully colored species that was suspected to occur in the area. And with species such as Garlic Toad (Bufotes viridis) and Red-bellied Toad (Bombina bombina), there is also plenty to do in this area. The Grass Snakes, however, were again nowhere to be seen. Too cold!. The positive side of the latter is that I have not seen any dead vehicles. In particular, the road that runs through the national park can be littered with squashed snakes. Especially now that a new layer of asphalt has been applied, the speed of traffic has increased considerably. Previously, the quality of the road was so bad that people simply took it easy.
All in all and with the necessary ups and downs, this trip turned out to be a success again. But just staying there is already very pleasant.
Butterfly cocoons varia
Butterfly cocoons, not the first thing you would expect on a website. But on the other hand, it is perhaps a conceivable subject given the fact that in recent years I have been busy photographing butterflies and caterpillars. I mainly show here what I am interested in. These are not the most common topics and that could just be one of the reasons why I started working on this.
Since about a year I have also been engaged in breeding caterpillars and butterflies. And the butterfly pupa is the stage between both manifestations. When I also went looking for images of these coccons, it soon became clear that there was very little footage available. And so, one plus one is two!
There is not much variation. A large part of the pupae are similar, with the understanding that there is a clear distinction between those of the common butterflies and moths. The sizes of the cocoons will also contribute little. Of those close to a thousand macro butterflies in our country The Netherlands, the size varies between roughly 9 mm to about 23 mm. With a few exceptions there. That means large group of cocoons has the same length. However, there are differences in shapes of dots, fringe-like appendages or brackets. Furthermore, one coccon is slimmer and another a bit rounder. But with such large numbers, ….. be my guest.
All in all, it’s not a difficult subject. There is little movement and if you have documented three sides of each one you are almost complete.
But the most important aspect is that I’ll like to show the combination of the caterpillar, the cocoon and finally the butterfly itself.
Orange Tip growing up
For some time now I have been breeding butterflies. Now that is a big word, because besides providing fresh food, hygiene and oxygen, the animal does everything itself.
It usually starts with finding caterpillars that I then take with me. Occasionally I started with eggs, but then it is of course important that you know which species you are dealing with. This in connection with the food choice. However, the plant on which the eggs are found is also usually the food plant. If the caterpillar is fully grown after weeks of eating, all that remains is to ensure that there is something available for the caterpillar to pupate on ór in.
Often these are moths, but a species that was high on the list to also grow once is the Orange Tip, Anthocharis cardamines. Besides the fact that the butterfly is beautiful to see, the cocoon also has a special shape. And it is also attached to a twig in a very special way. First, a kind of anvil is made on the branch where the caterpillar with the retractors rests on. These are the last legs on the back. Then the caterpillar makes two threads and attaches it around his / her “waist”. It is a somewhat plastic description of how the caterpillar manufactures something so that it can hang on the branch, … and that for about ten months!
With this specimen, the entire process ultimately took about thirty nine hours. Quite long for when you are in a vulnerable position!
At the end of the entire period, when the butterfly is about to hatch, the pupa becomes transparent. You can already see whether it will be a male or a female. In the male, the large orange wing spot is already clearly visible.
Fortunately, this caterpillar chose a moment when I was free of work so I was able to eyewitness the pupation process. Hopefully that will get a sequel when the hatching of the butterfly takes place, but I’m not counting on that.