Forest ranger Frans Kapteijns shares his knowledge of nature every week. Anyone can submit questions via [email protected]. This time Frans pays attention to, among other things, an early cockchafer, rats in the compost heap, a housemother’s caterpillar, large bumblebees in February and woodpeckers in the grass. Part two of this Stuifmail will be published on Sunday morning.
Flying cockchafer in the house on February 27, is that possible?
Herman Siepel found a live cockchafer in the hallway of his house on February 27 around ten o’clock in the evening. Isn’t that a bit early, he wondered. The answer is yes, but. If you’re up Waarneming.nl If you look, you will see a whole row of reports of flying cockchafers. There you will see that reports are coming from various provinces such as Zeeland, Groningen, Drenthe and North Brabant. Including from Eindhoven, Veen and Oosterhout. In short, quite a lot. In the Stuifmail of April 5, 2025 I also talked about early cockchafers, but that was a cockchafer in April.
What about those cockchafers and whether they will fly around sooner or later?
In principle, cockchafers hibernate underground as adult beetles (imago). One of the researchers has sometimes two adult cockchafers found in a mole nest in December.
In the spring, these adult cockchafers lie underground waiting to emerge. Herman’s cockchafer apparently thought that it was already May and that it was time to wake up. The warm weather of last week in particular has confused this cockchafer and the others listed on Waarneming.nl.
Perhaps this is a fatal mistake, because their chances of survival are now very small. In addition, there are no partners to mate with, so there will be no offspring from this cockchafer. If the weather is nice and warm again in April, the cockchafers will emerge at the end of that month. This is a small shift from the past, when they only occurred in May. However, if April is cold and chilly this year, they will not emerge until May.
Holes in the compost heap, who did that?
Ria Jans saw three dug holes in a compost heap. She wonders who the perpetrator could be. I think brown rats have been busy there. These animals dig burrows and extensive tunnel systems in which to nest.
It will not be black rats, because they live more near water. In urban environments, black rats more often live in higher places, such as attics or in cavity walls. Brown rats, on the other hand, often dig their burrows in the ground, preferably in sheltered places such as under a sidewalk, under piles of firewood, near a chicken coop or along walls. In addition, compost heaps are favorite places.
Their tunnels are usually no deeper than half a meter, but can sometimes go as deep as three meters. They often form a complex network. The entrances to rat holes are often easily identified by a narrow, well-used entrance with a diameter of about nine centimeters. Perhaps Ria can also find evidence, as their droppings are often found around their burrows.
You will also often find eaten materials and fresh excavation work there. The brown rat originally occurred in the steppe areas of East Asia, especially northern China and Mongolia. From the eighteenth century onwards, they spread further around the world via trade routes and shipping. Now the brown rat has grown into a true culture follower. It is one of the most successful mammals in the world and is now found almost everywhere in the world, even inland Africa.
The little owl pair is being harassed, what to do?
Els Scheepers has had a couple of little owls living in her garden for years. Today, that couple is harassed by squirrels. What can be done about this? My counter question is: will an owl working group come and check the hive? If so, you should definitely ask them for advice, because they know the local situation.
Little owls are perhaps the best known among the owls living in our country. Presumably because little owls have traditionally been well-known appearances in small-scale agricultural landscapes. They do not shy away from the human environment and often breed on farmyards, especially if these offer sufficient natural variation. If these elements are present, little owls can find everything they need in small areas.
They station themselves from posts or other elevations and search their surroundings for food. Once they have spotted something, they fly towards it in an undulating flight. At this moment the mating season is already in full swing. Then it is wise to do nothing for a while and certainly not to look in the nest box.
In addition, little owls not only suffer from squirrels, but also competition from other cave nesters. These cave brothers would also like to crack a cupboard to bring a young couple to earth. Fights involving chewing, among other things, are very well known. Then things can sometimes get tough. The little owls themselves attack other species of cave nesters in flight from above and that is not wrong either. So the little owls are used to some competition and they will face it. In short, let everything happen, because the little owls are often the victors.
Of course, Els can offer more breeding opportunities in her garden, for example placing a second little owl box or a squirrel nest. Do the squirrels also have an alternative?
Which larva was in the pond?
According to her, Wilga de Waard came across a pupa or larva in her pond some time ago. She wonders if the animal still had to pupate. I think it is indeed a larva, but the larva of a butterfly. We call such larvae caterpillars and it looks like this is the caterpillar of the moth called house mother. These house mother caterpillars can have both a green and brown color and are busy eating all kinds of plants at night.
Caterpillars of the house mother moth overwinter and can therefore still be seen quite late in the year. You can even encounter them in the middle of winter in nice, mild winter weather. After winter, pupation takes place in the ground. After pupation, one of the most common moths in our country emerges.
The menu of house mother moths includes nectar from all kinds of plants. They also like rotting fruit. House mothers are not only active at night, they are also active during the day. The scientific name, given by Linnaeus, is noctua pronuba Noctua is owl or night in Latin and pronuba means bridesmaid. The latter refers to the custom of giving female names to moths with strikingly colored hindwings.
It is unclear how the Dutch name housemother came about. This common moth has had this name for centuries and it probably arose because the butterfly is often seen in and around the house. The name may also have arisen because these moths are attracted to light. In the summer months they easily fly into houses through open windows and doors, where they often sit quietly behind curtains or in dark places.
Why are there so many bumblebees now?
Ted Vernooij asked me two questions. He’s seeing a lot of bumblebees at the moment. Moreover, they are very large. He asks for an explanation. He also regularly sees a green woodpecker on the lawn. He ‘digs’ holes there and takes ‘something’ out of the ground. He is curious why this happens and what is extracted from the ground?
It is absolutely true that there are a lot of bumblebees flying around now. In February the first bumblebee queens emerge from hibernation. These are usually ground bumblebees. When the temperature is above 5 degrees and there is sunshine, their urge to go outside is enormous. They are then feverishly looking for nectar from the first blooming flowers of, for example, willow species. They need that nectar to regain strength after hibernation and to find a good nesting site. Great nesting sites to start their colony are in a sheltered and dry environment, such as old mouse holes or compost heaps. It is also true that they are large bumblebees, because it is the queens that are flying around now.
What is the green woodpecker doing on my lawn?
The fact that Ted sees a green woodpecker on his lawn means that Ted’s lawn is full of ants and their pupae/larvae. This is the staple food of green woodpeckers. With their strong beak they make holes in the grass to reach ant nests – the so-called grass ants – after which they eat the ants with their long, sticky tongue. In addition to ants, they are also fond of grubs (the larvae of leaf beetles), which also live under the turf.
In addition, many people nowadays extend their indoor living room with a large terrace as an outdoor room. Because of the large tiles, ants find a true paradise here. Green woodpeckers have discovered this and therefore come to these gardens. Especially because they are losing more ground in nature reserves, because the black woodpecker is a large and fierce competitor.
