Garden netting in Zwolle and more of the same Ring-necked Parakeets in Amsterdam, The Netherlands (January 19)

Coal Tit Periparus ater

On January 19 my friends and colleagues Jan van Dijk and Reinier Smabers visited me and the garden in which I grew up. This garden is located in a green suburb to the north of Zwolle, The Netherlands. I’ve been the ecological caretaker for it for many years. Due to the current high temperatures in this country, the majority of the wintering birds has not yet arrived. Bird’s, however, are always abundant in this garden (and fed regularly) and they were the reason that my guests brought 48 meters of mist nets...

Between 8:30 am and 1:00 pm we caught 77 birds. The following 76 were ringed, measured and released:

Long-tailed Tit Aegithalos caudatus  (2)

Eurasian Wren Troglodytes troglodytes   (1)

Short-toed Treecreeper Certhia brachydactyla  (1)

Eurasian Blue Tit Cyanistes caeruleus (37)

Great Tit Parus major (12)

Dunnock Prunella modularis (3)

European Robin Erithacus rubecula  (1)

Coal Tit Periparus ater (1)

Eurasian Tree Sparrow Passer montanus  (9)

Common Chaffinch Fringilla coelebs  (5)

Common Blackbird Turdus merula (4)

We caught one bird that was already ringed. This immature Eurasian Sparrowhawk Accipiter nisus was ringed on June 20 2013, as a pullus on a nest located about 4 kilometers from the garden, on the south side of the city, by Jan himself.

 

In the afternoon I travelled to Amsterdam, in order to participate in a national count of roosting Ring-necked Parakeets that was being held this same day. The parakeets at a roost site in Amsterdam North (which I’ve regularly counted the past few years) also have to deal with the presence of raptors, often resulting in mass disturbance, making it difficult to count the birds. Fortunately the raptors remained quiet last night and the evening resulted in an easy count of 680 Ring-necked Parakeets (no idea yet how many were counted in the rest of the city or country this evening).

Northern Hawk-Owl Surnia ulula in Zwolle, The Netherlands

Finally found time today for some ‘twitching’, with only a small camera; Since November 28 2013, there’s a Northern Hawk-Owl Surnia ulula residing in Zwolle, The Netherlands. This is the fourth record of this species in the country, attracting large numbers of birders and other enthusiasts to an electric distribution station.

 

 

The most popular spotting field.

The Harculo power - and ringing station

On March 31st I visited the bird ringing station Harculo, located in the gardens of a power plant, just south of Zwolle (The Netherlands). This ringing station started in October 2012 and is being operated by some of my friends and colleagues on a regular basis. The following birds were netted, measured, ringed and released (with the number of recaptures in parentheses) during a pleasant but early easter morning:

Great Tit Parus major 3(2)

Blue Tit Parus caeruleus 2(2)

Common Blackbird Turdus merula 3(1)

Long-tailed Tit Aegithalos caudatus 4(0)

Common Chaffinch Fringilla coelebs 3(0)

Eurasian Wren Troglodytes troglodytes 1(0)

Greenfinch Carduelis chloris 2(0)

White Wagtail Motacilla alba 1(0)

We were working under the careful eyes of this Peregrine Falcon Falco peregrinus, which inhabits the power plant. Its mate currently incubates eggs in a nest box mounted in the top of a 60 meter high wall of the site.

An adult Greater Black-backed Gull Larus marinus at the cooling water inlet.

Gaining some insight in a Barn Owl’s diet. Part 1: diet sampling

Today’s afternoon I found some time to collect the pellets that were regurgitated by a Barn Owl Tyto alba that had spent the winter in a wall-mounted nest box in Zwolle, The Netherlands (http://www.timvannus.blogspot.nl/2013/01/barn-owl-tv-zwolle-netherlands.html). After connecting the infra-red camera earlier during the day I noticed the owl was gone, so it was safe for me to climb the ladder and open the box for an inspection. 64 pellets were collected. Based on my observations the owl inhabited the box for at least two months and, assuming that the box was permanently in use, produced about 1.05 pellet there per day. This is considerably less than during previous years, when about 1.3 – 1.5 pellet got produced per day. Additionally, this sample round included a considerable number of small sized pellets, possibly another indication that food had not been abundant during the last couple of months. These pellets will be analyzed by an expert. What exactly the owl was living on during these two winter months will be presented in a later entry.

Most of the pellets had accumulated in the ‘lobby’ of the nest box.

 

 

 The breeding chamber still contains a Eurasian Jackdaw Corvus monedula nest from the previous year. I noticed there was at least one jackdaw present near the nest box today.

 

After being collected, the pellets were put in a plastic bag and frozen. 

 

I am not sure why the owl always abandons this box around this time. I doubt that food shortage is a cause, as I am getting the impression that there currently is a good number of mice present in the garden (and I assume in its surroundings). Therefore I was not completely surprised this evening, when seeing a Barn Owl perched in an apple tree in the same garden, where it was overlooking bird feeders and compost mounds. Now did the jackdaws expel it from its nest box, or did it move in with a mate elsewhere to breed?