My last post mentioned Mute (and Whooper) Swans and Lapwings in Maridalen but I realised I never posted about the situation at the end of June. I visited Maridalen on 28 June when we had a few days at home between part I and part II of our summer holidays and had unexpected sightings of both species.
Taking Lapwings first I had an adult with 2 juveniles that
were able to fly across the lake and flew from Skjerven to Kirkeby. With a
fully grown young seen on 16 June, these two from 28 June and then the three
seen on 26 July then we have a minimum of 6 fledged young from 3 broods
from in total 6 pairs which is perhaps enough to keep the population stable but
hardly enough for it to grow.
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| adult and 2 fledged young Lapwings (vipe) 28 June |
The swan situation is far more intriguing. I had seen a single Mute Swan on Maridalsvannet fairly regularly in May and June but had seen a pair only on 3 May and had seen no sign of nesting. Suddenly on 28 June there was a pair with two tiny young! I have no idea where they nested although had seen the single bird fairly often by Geitøya where they had started nesting last year before being seen off by the Whoopers who took over their nest. I had searched in the telescope to see if there was a swan on the island but never found one. Clearly though they were good at hiding and I have seen no other reports of the family on Maridalsvannet except for on 10th and then 17th July when the whole family of four was also reported.
The Whooper Swan pair nested on Dausjøen this year which is
where they first nested in Maridalen from 2011 (probably also 2010) until 2013
before then choosing a new site where they nested with great success until 2023
but in 2024 lower water levels made that site no longer suitable and they then
chose to take over the Mute Swan nest on Maridalsvannet. This year at Dausjøen
they had 3 young on 11 June, were still there on 2 July, and were first
reported on Maridalsvannet on 17 July when they had lost one of the young.
Maybe an encounter with a predator (fox?) resulted in the loss of a young and
them moving the nearly 2km to Maridalsvannet. (last year they moved the opposite
direction having nested on Maridalsvannet for the first time and then quickly
moving upstream to Dausjøen with the young).
It is perhaps no coincidence that 17 July is also the last
date the Mute Swan family was seen as the arrival of the Whooper Swans may have
caused a return to the territorial, bullying behaviour that characterises this
Whooper Swan pair. Maybe they beat up the Mute Swans and drove off the parents??
This would help explain my sighting today of a single baby Mute Swan on
Maridalsvannet. Despite lots of searching I could not see the rest of his family
although the Whooper Swan family were very much at home, and out of sight, 2km
away. The baby will be just short of 5 weeks old and was barely larger than a
male Mallard. Both the parents were colour ringed and a check of ringmerking.no
shows that both parents were seen at Holtekilen, Fornebu on 20 July so have
clearly abandoned Maridalsvannet. I believe the only theory that supports these
sightings is that the Whoopers attacked the Mutes sending them in all
directions and killed one of the young and separated the other from its parents.
They then abandoned it either because they never managed to find it again or
did not dare return due to the Whoopers.
Baby swans and ducks are not fed by their parents but the
parents do lead them to food and in the case of swans can stir up the mud or uproot
vegetation that the young eat. So, a baby swan (The Ugly Duckling) can survive
on its own but will be disadvantaged and I doubt it will have been easy nor
will it be easy over the many coming weeks before it can fly especially if the
Whoopers discover it and decide it is a rival.
30 July. Baby Mute Swan (knoppsvane) around 5 weeks old and all on its own
The colour rings on the parents show that they were indeed
the same pair that started nesting last year and were also briefly present in
the early spring of 2023. The female (PC79) who was born in 2017 was also present
spring 2021 with another mate but were chased off by the Whoopers and her mate was
later found dead on the fjord. In 2022 she had found another mate and they also
visited Maridalen in the spring before again being chased off and then this new
mate was also found dead on the fjord. She didn’t give up though and found her
current mate P578 (who was born in 2019 and has not been reported to be in a
pair previously) early in 2023 and finally this year she raised young only to
abandon them….
Video and pictures from 28 July when young just a few days old and possibly newly hatched
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| the adults sought me out and were clearly of the bread eating variety |
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