This blog introduces the breeding and child-rearing struggles of little grebes in Inokashira Park in 2017.
A chick (left) was crouching on the surface of the water after being driven by her brothers and parents. September 12th.
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On September 17th (2017), although it did not hit directly, it brought a lot of rain to Inokashira Park.
Wild birds have no choice but to evacuate to a place where the wind and rain can survive, but wait for the time to pass while getting wet. Enduring strong winds and heavy rains can be quite frightening.
If it is a park with a population such as Inokashira Park, it seems that it is possible to overcome the rain and wind by making good use of artificial objects such as bridges.
The situation before and after a typhoon.
There is only one family, the little grebe parent and child breeding in Inokashira Park, the Nanai Bridge, and the family breeding near the boat landing.
Currently, this is the only parent and child who can see child-rearing at Inokashira Park.
It wasn't a very close family either.
Two chicks have survived.
One of the chicks did not receive food from the parent bird, grew slower than its siblings, had poor hair (feathers), and was a little smaller.
The big and energetic chicks move around the surface of the water, approaching the little siblings, fluttering and stretching, and thinking that they will go to the parent bird, they have one little sibling.
It seems that he learned to imitate the parent bird, chase the opponent, and peck as a play.
The little siblings were often crouched, both mentally and physically.
And this chick disappeared at the end of this day.
Attack on chicks of parent birds
As the chicks grow up, at some point you will see parent birds attacking the chicks.
Perhaps this behavior, which seems to encourage chicks to leave their parents, seems to have some other meaning.
That's because it usually seems that only one of the few chicks will be attacked intensively.
And only the weakest of the siblings can be killed.
Depending on the amount of food that can be caught, the parent bird may have selected the chicks to raise, but when looking at the chicks that can be killed, it must be very terrible and pitiful.
Is it possible that something triggers the switch on aggression?
Wild appearance, sometimes merciless things happen.
Looking objectively is efficient for leaving offspring, but it's still a mess to look at.い。
The water in the pond is muddy again, and despite the sunny weather, the water is so dark
The water in the pond, which was very clear when the caretaker started observing, is now so muddy.
It seems that purification has not caught up with the amount of well water and the capacity of the circulation device in the summer when the water temperature rises. With this, it's pitch black after diving 30 cm.
In the photo above, you can see the cross section of the pond at Inokashira Park Zoo, which is only a few centimeters in front of you.
If it's so muddy, you'll miss the fish in front of you, and maybe you're just trying to catch your own food.
The little grebe that dived for fishing is very far from the place where it dived and the place where it comes out, and it takes a long time to dive.
It seems that they are looking for fish by swimming long distances in the water.
Even so, it is difficult to catch fish, and they often float on the surface of the water by swinging.
The energy used for fishing and the energy obtained from the fish, cost-effectiveness, seems not to be worth it.
Insects such as dragonflies, which were abundant in August, have become very few, so there seems to be almost no food other than diving.
Recently, cormorants have disappeared from Inokashira Pond.
Probably due to poor fishing due to turbid water.
The little grebe parent and child, who remained until the end, spend a very long time leaving the chicks alone and going somewhere.
Isn't it hard to get the chicks to get their own food?
Maybe I'm thinking about giving up parenting.
A chick that encourages you to dive, but never tries to dive
It seems that the parent birds occasionally return to the chicks to feed them, encouraging the chicks to dive into the water.
However, it seems that this chick doesn't like to dive so much that she hardly tries to dive.
If you can't dive and fish yourself, the little grebe can't live on its own and is fatal.
Why don't you imitate diving when you're a child who imitates everything?
I can't see anything even if it gets muddy, and it may be because it doesn't feel very good to dive into the muddy water that gets dark soon.
Maybe it's because I'm hungry and I've lost that energy.
The chick left alone was wandering around the pond, searching for dead insects floating on the surface of the water and eating them on September 16th.
Now that the parent bird has gone somewhere and hasn't returned for a while and the brothers are gone, the chick, who has become lonely, just wanders around the pond, eating dead insects and so on.
Only small insects can't fill your stomach.
The next day, Typhoon No. 18 passed, causing heavy rain and strong winds.
This chick disappeared at the end of this photo.
It may not have been able to withstand the typhoon's wind and rain.
The little grebe, which had been thought to have disappeared until now, sometimes appeared after a while, so it may still be alive somewhere, so I hope so.
After the typhoon passed, around the pond, parent birds searching for chicks were seen, September 18
After the typhoon passed, the parent birds were observed to go back and forth around the pond and constantly search for chicks.
But I can't find any chicks anywhere.
No matter how much I read, the chicks wouldn't answer, and the parent bird who couldn't find the chicks seemed to have lost their energy and energy.
Neighboring grebes did not miss such a chance.
The parent bird who lost the child escapes to the far right
The parent bird who lost the child gave up the place to another little grebe without facing his teeth.
The fleeing bird on the right is a parent bird that has lost its chicks, and is being attacked by an intruder from this side.
The one that flies to the left is one of the birds that came with us from the outside.
It seems that these two birds are little grebes that came from another water place recently.
After this, the two birds that came later joined near Gama Yabu.
It seems that both birds have taken over the place.
Furthermore, after hijacking the place, he entered the Gama bush first, so he may have been a good friend brother who originally thought that he had taken over this place and flew somewhere. ("Little Grebe Observation Diary" 6
I don't know the truth because I haven't been able to identify the individual.
A young bird that hijacked this place still has a lot of brown on its wings
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to be continued
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