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| The star! Adult male Red-breasted Flycatcher (dvergfluesnapper) |
I have previously
mentioned that Red-breasted Flycatchers have bred again in Oslo this year and
promised a post on them. It has taken a long time to write the post because
there has been so much to write about that I have not known where to start. In addition, the whole affair deserves more than a simple blog post and should (and may
well) be documented in a scientific journal (Journal of Ornithology has been
mentioned). In addition, the volume of photos and especially video that needed
reviewing and editing was WAY too much.
The odd Red-breasted
Flycatcher has been noted singing in Sørkedalen (Maridalen’s sister valley to
the west) for a number of years and in 2015 we documented successful breedingfor the first time. Last year a pair was seen but then vanished and this year
two males sang 100 metres from each other but without any sign of
a female being present.
Maridalen though
provided the real excitement. Here we had more than just breeding – we had cross
species (hybrid) pairing, polygamy, adultery and general chaos. If it had been
the story line in a soap opera people would have laughed and called it
ridiculous!
Halvard Hauer
discovered a singing male 21 May. Already two days later he (the bird not
Halvard) had stopped singing although responded to playback and his behaviour
suggested that he had a female on eggs nearby. Two days after this on 25 May
Ellen Askum discovered a male singing strongly about 300m away. The next day
Halvard had males at both sites within an hour of each other and it seemed
natural to assume there were two different males especially as the bird at the
original site wasn’t singing whereas at the new site the bird was singing
strongly. I experienced the same on the 29th and also on the 29th
saw briefly what I believed was a female with the male at the second site, but
views were too brief to be certain of species (could have been a female Pied).
On June 2nd
the male was again at the second site but not singing which suggested breeding.
And then on 6th June a male was singing at a third site (site 3) which was
300m from site 1 and 600m from site 2 (see later picture). This was quite
amazing – could there be three different male Red-breasted Flycatchers in
Maridalen? Halvard had around this time noted from his pictures from the first
two sites that the male looked to be the same bird due especially to a black
spot in the white eye ring on left eye (a feature which we couldn’t find when
reviewing other random pictures of the species) and I noted that this “new”
bird also had the same black spot. It was now looking like it was the
same bird at three different sites but why was it moving around and showing
different behaviour at different sites? Later developments would give us the
answer….
On 10 June Halvard
found the male at site 1 visiting a nest box. Halvard had checked this box on
27 May (6 days after finding bird and 4 days after the male had stopped
actively singing) when it contained 2 eggs that looked like normal Pied
Flycatcher eggs (but no bird seen). On 10 June there were 6 eggs and a female
Pied Flycatcher!! Over the coming days I spent a lot of time with the birds and
the male R-b was clearly paired to the female Pied and was bringing food to
her. I saw a male Pied Fly perch at the hole of the box but there was no
interaction with the female.
On 14 June I found a
female (coloured) Rb Fly at a new site (site 4) 150m from site 2. The behaviour
of this bird suggested it was a female and not a 2cy male (which lack the red
throat of older males). On the same day the eggs hatched in the nestbox at site
1 and the male was present (no photos).
On the 15th
at the new site 4 I saw the male acting agitated and in the evening Halvard saw
the male and female together here.
On the 16th
Halvard and I decided to get to the bottom of the case and I sat at site 1 and
Halvard sat at site 4. The male was initially present at site 1 and was active
around the nestbox and bringing food to the female. Halvard hadn’t seen sight nor sound of Rb Fly but after 55 minutes of action at site 1 I could not find
the male anymore and then 5 minutes later he was at site 4 with Halvard. I
remained at site 1 for 20 minutes without the male being present but Halvard was
still seeing him. I then went up to Halvard. The male was hanging around a small
area close to a nestbox and acting as though he had a female on eggs close by
but he didn’t visit a nest and we didn’t see a female although I saw him interact
with another bird and thought I heard Rb Fly calls from another area.
On 18 June Halvard again
saw both male and female at site 4 but still without locating a nest.
On 20,21 and 22 June
the male was taking food to the young at site 1. On 22 June a male Pied Fly
also visited the nest box and was twice chased away by the male Rb Fly.
At site 4 I had no
certain sightings of Rb fly (of either sex) on 20 and 21 June but on 22 June I
had a number of sightings of the female (and photos) and suspected that she was
on eggs and leaving them occasionally to feed but could still not locate nest.
It was Halvard again
who made the important observation when on 24 June he found the nest. It was
quite incredibly placed on a piece of broken off bark and looked to be very
unsafe. But finding the nest was only the half of it – there was also a singing
male and it was a 2cy bird lacking a red throat!!
The next day the new
young male was bringing food to the female on the nest!!!!!
That was my last
sighting as I then left Oslo for summer holidays but Halvard was able to follow
the birds at site 1 until 4 young they fledged over 28-30 June and also the
young at site 4 until the 3 young fledged on 15 July. The original male
continued to feed the young at site 1 and was not seen again at site 4 (last
sighting on 18 June) whilst the young male (first sighting 24 June) fed the
young at site 4 until fledging.
The fledging date at
site 4 was 15 July and Halvard believed the young begun hatching on 1 July
which is at the upper end of fledging times given in BWP 11-15 days. Working
back from this with a given incubation period of 12-13 days means the 3 eggs
were most likely laid between 16-18 June. Which tallies well with my first
sighting of the female on 14 June and the presence of the 3cy+ male and is well
before the 2cy male turned up.
Per Christian Moan
also observed the birds and had sighting close to site 3 on 1 July of a 3cy+
male (presumably the original male) with a female (coloured) Rb Fly and giving
alarm calls. We will never know who these birds were but hint at the
possibility that the original male may well have had a third female (of his own
species) at site 3.
The young that fledged
from site 1 looked to be pure Pied Flycatchers and had no plumage characters
suggesting that their genetic farther was the male Rb Fly. We also have a
feather from one of the young plus 2 unhatched eggs from which we are (still…)
waiting for DNA results from Oslo University where we involved Glenn-Peter
Sætre who has spent years researching Pied Flycatchers.
The theory here is
that the male Rb Fly had indeed formed a cross species pair with a female Pied
(not sure if this can be called a hybrid pair as it is the young that are
hybrids) but that she had already mated with a male of her own species
(presumably the bird seen on a couple of occasions at the nestbox). This Pied
Flycatcher male was most likely a polygamous male and the female was his second
pairing (other Pied Flycatcher broods in the area were more advanced than this
brood). He was therefore giving nearly his entire attention to his first female
and this gave the opportunity for the male Rb Fly to pair with the female Pied
Fly who presumably was happy to have a male bringing her food. We can find no
reports of a hybrid pairing between Rb Fly and Pied Fly so this would appear to
be a world first!
The other interesting
behaviour we observed was polygamy in Rb Flycatcher as the older male had two
females (of two different species). Polygamy was not reported in BWP but there
is a subsequent paper from Poland which records this. Our sighting though would
appear to be only the second documented observation.
What I find most
amazing chapter to this story though is that the older male Rb Fly never
actually raised his own young. He used all his energy bringing food to the Pied
Flycatcher young and although he sired his own young with a female Rb Fly (although
this is not proven by DNA) he then gave up paternity of these to a young Rb Fly
male who paired with the female (but after the eggs were laid) and then raised
the young. So, there were two Rb Fly males who raised another males young.
It will be very
interesting to see what happens next year when hopefully a number of these
birds will return. There were three breeding Rb Flys, 3 young Rb Flys, 4 young
Pied Flys who think their dad is an Rb Fly and have heard his song plus a
female Pied Fly who clearly likes the sight and sound of male Rb Flys. So
series 2 looks like it could be even more scandalous!
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| comparison headshots of the male from different sites on different dates. Note the black spot in the lower left of the white eyering |
The following two videos tell the story of both nests. The good quality video is taken by Halvard Hauer (HH) using his Nikon P900 and a tripod whereas the rest is my usual hand held quality from my Canon SX60.
Video of the mixed pair:
Video of the mixed pair:
Video of the breeding female Rb Fly and her two males:
