Although our bird project at SDU has continued, this blog has been discontinued for many years. If you would like to follow the project, you can join our Facebook group where we post occasional updates on the project.
The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog.
Here’s an excerpt:
A San Francisco cable car holds 60 people. This blog was viewed about 2,100 times in 2014. If it were a cable car, it would take about 35 trips to carry that many people.
Today we spent a few valuable hours in the woods removing the old nest material from our nest boxes. We also carried out some repairs so the boxes are ready for new arrivals, when the spring comes again. This year Kristine is in charge of “The Big Clean Up” and she will be collecting nest material from all 100 nest boxes in small paper bags. Each nest will be dried in a large oven and weighed. This information will help contribute to our understanding of the factors which affect breeding success in Blue tits (blåmejse) and Great tits (musvit).
If you have a nest box at home in your garden, now is the perfect time to clean it out. Once you are sure that the box is empty (no longer in use) you can safely remove the old nest material. Use gloves, as the nests are usually infested with parasites, including fleas, ticks and lice. By removing the old nest material you will encourage the birds to use the box the following year, and reduce the amount of parasites in the nest, giving the new chicks a head start.
It’s not only birds that use nest boxes during the summer. Nest boxes provide homes for a variety of wildlife, including many species of insects. During our visits we found many garden spiders (korsedderkop), earwigs (ørentvist) and woodlouse (bænkebider). In box 62 we found the remains of a wasps nest. During the summer, when the wasps moved in, our monitors Ane & Kamilla decided to leave them in peace and stopped monitoring this box. Now we can safely remove the interesting construction, to make way for new residents next year (feathered or otherwise!). According to the Cornell Lab of Ornithology, you can prevent wasps moving in by applying a thin layer of cooking spray or soap to the roof of a nest box!
During the cold dark months of winter, birds may roost or sleep in nest boxes. Nest boxes provide a safe place, where they are protected from predators, and sheltered from the wind and rain. In one empty nest box we found a small collection of feathers. This may indicate that a bird has been roosting in the box. The small body feathers were grey and orange, not the colour of a blue tit or great tit. Maybe a nuthatch (spætmejse) has been using the box?
The nest boxes appear to create their own micro climate, especially in the gap between the box and the tree trunk. As we moved some of the boxes, to carry out some repairs we came across a world of activity, especially at box 90 where we found hundreds of woodlouse together with what appeared to be a Hawthorn shield bug (Stor Løvtæge).
Some useful links to mention…
Short video on why and how to clean out nest boxes from the Danish Ornithological Society (DOF) video (in Danish).
Nice key to identifying shield bugs (skjoldbiller) – at this link
How everyone can get involed in monitoring Danish nature – Fugle og Natur
En resume af sæsonen (på dansk) er nu tilgængelig på SDUs hjemmeside – læse her
For the English version of our newsletter click here
In a small enclosed area, surrounded by buildings on all sides, close to the Biology Department at the University of Southern Denmark there is a garden, known as the Mexican Garden. In the garden there is a small pond, partially filled with grass and reeds.
Earlier this year, at the end of May, a group of students and staff cleaned up this small green area and pond, and it appears that the local wildlife approve! A few weeks later, in mid June, some movement was noticed among the reeds and grass, close to the edge of the pond. After watching for a while a medium sized brown bird was spotted, hiding among the dried grass. A short while later a second duck appeared, and it was clear that a pair of Mallards (Gråand / Anas platyrhynchos) had moved in! It appears that Mallards will nest almost anywhere from hay stacks to roof gardens, enclosed courtyards and even in large flowerpots on balconies several floors up (RSPB). Mallards start nesting in March, so it appears this couple are a little late in starting their family.
While walking past this signpost yesterday, outside entrance N at the University of Southern Denmark, I heard a familiar sound. Baby birds, hungry ones too! I stopped and listened carefully and tried to peer into the hollow parts of the sign. I couldn’t see anything, but the sound was very clear. I stood and waited, and watched for a few moments. Out flew an adult Tree Sparrow (Skovspurv). The clever parents have chosen this somewhat alternative home for their family. If you are walking by, keep your ears and eyes open!
(Please note: this update from the woods isn’t for the fainthearted)
While out visiting nest boxes this week we came across a taste of the wilder, more ferocious side of nature. Next to the path we found the remains of a bird on a flat concrete structure, which appears to have been used as a “plucking post”. After capturing their food, birds of prey, like Sparrowhawk (Spurvehøg) typically find a raised flat structure, to remove feathers and take apart their food so it can be eaten.
The first evidence we spotted were some narrow tube like structures, which resembled the intestine, and a round shaped reddish piece tissue, which I assumed to be the liver. On the ground there were a lot of feathers, which I began examining to attempt to determine the species. The majority of feathers were brown, showing wear at the tips, but some of the smaller body feathers were edged yellowish or green. At first I thought it might be a female blackbird, but I didn’t need to investigate too much as we soon found the unlucky birds head. It was a female Starling (Stær /Sturnus vulgaris).
We looked closer at the other remains, which included a leg and the small round piece of tissue. I assumed it was the liver, but the others suggested it might be something else, less edible. We carefully dissected it and realized it was the stomach, filled with undigested green caterpillar larvae and beetles. To get an idea of what a Sparrowhawk looks like, and how it uses a plucking post – there is a good video here. The presence of a plucking post in the woods, may indicate a nearby breeding site, especially during the breeding season. To read more about plucking posts, check out this Wikipedia link.
With the continuing warm dry weather here in Odense, a number of Great Tits (Musvit) have decided to begin a second brood, or second nesting attempt. In at least 5 boxes in the woods surrounding SDU freshly laid eggs have been discovered by our team of volunteers. It is generally accepted that the same pair use the nest a second time. Second broods are usually smaller (i.e. fewer eggs/chicks), and have a lower survival rate.
While I was out ringing the rapidly growing chicks at SDU this weekend I came across something unusual, and very exciting! When I reached box 82, on the edge of the woods, I had a quick look in to ensure the chicks were large enough to ring. All looked good and I began the process of removing chicks one at a time to ring them. I was running on autopilot, but something stopped me after the 3rd or 4th chick. I picked out a chick which was very small in my hand in comparison to the others. It isn’t unusual to see a age or development difference within a single brood. In some situations the smaller, less developed chicks have hatched one or two days later than their older bigger siblings. But this chick felt completely different.
I turned off my “autopilot” and had a closer look. To my amazement the chick was not a Great tit (musvit) like it’s brothers and sisters, but a Blue tit (Blåmejse). There were 9 chicks, 8 Great tits and one Blue tit. This is the first time I have observed a mixed brood, but it seems it’s not a unique occurrance! A long running nest box project in Wytham Woods, close to Oxford in England, has also reported a mixed brood in one of their nest boxes recently. The parents (both Blue tits) are taking care of 6 Blue tits, and 3 Great tits! We will keep a close eye on this box and try to find out who the parents are!