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!
Over the last 2 weeks things have progressed at an alarming rate in the woods. In about 18 days, the newly hatched baby birds develop from being blind, naked and helpless to alert and fully feathered strong “teenage” birds. When you consider that it takes human children around 18 years to reach this stage, it’s pretty impressive! After around 18-21 days the chicks fly from the nest (or fledge) and will remain with the parents for a short time.
As you can see from the picture of box 13, once the chicks are almost fully grown, there isn’t much room left in the box! The Blue tits (blåmejse) who usually their breeding attempts ca. 1 – 2 weeks later than the Great tits are catching up. The majority of our nest boxes are occupied with Great tits, with less than 10% providing homes to Blue tits.
At this time of year it is also possible to capture the adult birds, when they visit the boxes to feed the young birds. Some of the adult birds using the nest boxes this year, are birds which were ringed as chicks in May / June 2013, during the first year of the project.
We are also very busy ringing the chicks, and this means I get to spend a lot of time in the woods, and catch up with our six teams of volunteers. It’s smiles all round as everyone gets to follow closely in the secret lives of birds!
As usual there is a lot more than birds in the woods. If you keep your eyes open, you can see all sorts of things hidden in the undergrowth. Here are some of the things we stumbled upon over the last few days.
This week we began ringing the chicks which have been developing rapidly in the nest boxes surrounding the university at SDU in Odense. Almost all of our nest boxes are occupied, and we expect a similar number of chicks to last year (ca. 500!). There is an ideal time to ring the chicks, and we are watching carefully to try to visit the boxes at this time. Firstly it’s important the chicks legs are developed enough to hold the adult sized ring. Secondly it’s important that the chicks aren’t too big, as there is a risk of the young “exploding” from the nest if disturbed when close to naturally fledging.
Our team of monitors are keeping a close eye on the chicks development, and are at hand to assist in the bird ringing efforts too.
At this stage in development, ca. 10-15 days old, it’s possible to see the different stages of feather development. The feathers are first formed in a narrow thin tube or “pin” and they begin pushing out from inside this. In chicks, all feathers grow at the same time, which is different from adult birds, who replace feathers in specific sequence, so they can retain the ability to fly at the same time.
I joined one of our dedicated nest monitors in the woods today to get up to speed on what’s happening in the secret lives of birds. Although the weather was overcast and wet, the sights and sounds in the woods were impressive, as always. Everything green appears to have bloomed in the last few days with the recent rainfall, and it must be said, the nest boxes are significantly more difficult to find! All is progressing very well with a number of nests with small chicks and females incubating eggs.
There is always a lot to see in the woods, and if you look closely, there are some splashes of colour in the woods, especially in the wetter damper parts. Today we spotted some some Early purple orchids (Tyndakset Gøgeurt, Orchis mascula) in bloom right. [I’m not an orchid/flower expert, and will gladly accept comments or suggestions with relation to identification]. Although I knew orchids grew in the woods, it’s always a nice surprise to stumble across them during a bird walk or nest box check. Walking in the woods, there is a lot to take in, from bird song to wild flowers and mammals, sometimes the smaller things are missed!
There are 35 species of orchid in Denmark (depending on classification) and all species are protected. The Early purple orchid is found across Denmark, but only in a small number of places. Key ID featuers include the dark purple spots on the leaves, which are arranged lengthwise and the flowers smell of tomcat piss, believe it or not! To find out more about the distribution in Denmark and to see some better pictures, visit Danmarks Fugle og Natur andDK-orkiderer. For information in English visit this link.
Yesterday I heard my first Cuckoo of the season, and luckily it was very close to SDU! I didn’t see the bird, but I have a good idea where it’s territory is. The months of May and June are the best time to hear and see these long distance migrants in Denmark.
The Cuckoo (or Gøg) is famous for it’s exceptionally bad parenting skills. The female lays an egg in the nest of another bird (typically meadow pipits, dunnocks and reed warblers), and leaves the unsuspecting bird to take care of it’s young. It’s a widespread breeding bird in Denmark with 20-40,000 breeding pairs reported in 2000 (DOF). Cuckoos return to Denmark and other European countries to breed after spending the winter in sub-saharan Africa.
The BTO in England has been tracking a number of cuckoos during their migration south in the autumn and north again in the spring, and have produced some really interesting maps where you can following the progress of the birds, as they move! If you happen to see or here a Cuckoo, you can report your sighting to the Danish Ornithological Sociey via their online database – DOFbasen. Keep your ears (and eyes) open!
Today I got a call explaining that small green parakeet (undulat) was feeding along the edge of the bike path between SDU and Munkerbjergvej. I came to the location as quickly as I could, with a net and a box with the hope that we could catch the bird, which had obviously escaped from a nearby home where it was formally a family pet.
The bird appeared quite tame but grew gradually more and more wary as we (Tanya and I) attempted to catch it. We tried “dropping” our coats on top of it and using the small net which I borrowed from the biology department. I also brought some bird food from home, as it was clearly hungry, but despite the birds obvious hunger, this didn’t help. We spent about an hour attempting to catch the bird, with the hope that it could be reunited with it’s owner. Unfortunately our efforts were fruitless and the bird flew off out of sight. It was clear the bird was completely unaware of the dangers of passing cyclists on the busy bike path from the university.
So if you are cycling in the area, please keep your eye out for a small green bird on the bike path. Also if you know anyone who lost their family parakeet in the area, let them know there is one flying free in the woods at SDU. They may know a good way to catch it, otherwise, who knows it may be able to survive out there like other species of parakeet (like Ring-necked parakeet) have done in London, Barcelona and many other large cities.
If you spot the bird during your nest box checks, feel free to report it on SDU Birds.