This blog introduces the breeding and child-rearing struggle of little grebes that bred in Inokashira Park in 2018.
The chicks who had been observing the previous year were wiped out. Let's see the whole story until the chicks grow up well this year! I started writing this blog.
Introduction
Last June, 2017, I returned to Japan from Kenya and casually visited Inokashira Park. At that time, I found a little grebe raising a child in a pond and started observing it, which was the reason I started writing this blog.
See all 20 episodes of "Little Grebe Observation Diary"
All the chicks that I was observing from the eggs decreased to one and then one again as the days went by when they were killed by foreign enemies. In September, all the chicks died for various reasons.
That year, the two early breeders grew safely and left the nest.
Through observation of little grebes, how many challenges must be overcome and difficult for little grebes to become adults, such as foreign enemies, nest collapse, lack of food, rain, wind, maintenance of territory, lack of affection of parent birds, etc. I was able to feel it with my own body.
Although it is not a revenge of last year, this "Continued, Little Grebe Observation Diary" will cover the breeding of Little Grebes from April 26, 2018.
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At the beginning of the observation, the little grebe couple near the gourd bridge seemed to be a little worried between the couple at the nesting site.
One, probably the husband, seemed to be concerned about the place where the nest was last year, and he was trying to call his partner's attention by going to that place many times.
However, it seems that the location of the nest has already been decided in another place a little away, and the nest material has already been brought in considerably.
This is the place used for nesting little grebes last year, and I still like this one
I'm sure it's a male who has some regrets in this place.
It seems that it is the female that lays eggs that determines the location of the nest.
Mother, strong.
April 26 (2018) Let's go around the pond in Inokashira Park.
At the beginning of the year, the pond was drained by a crab, so I was a little worried if the waterfowl were returning, but nothing happened. I was starting to prepare.
It seems that there are 4 or 5 little grebes in the pond.
I'm sure there are three.
I'm not sure because the two weren't together when I saw them.
Is there a mixture of breeding individuals last year?
The little grebe that had been evacuated to somewhere else for a while, and the individual from last year are probably returning and mixed.
A female crouching on a nest and a male watching over it
Crouching in the nest is like a female.
Apparently, the day of spawning isn't too far away.
I'll skip the details and talk about spawning.
For the first time this year, I was able to witness a little grebe laying eggs at Inokashira Park.
The process up to that point will be covered in another blog.
May 4, Hyotan
Little Grebe spawning for the first time this year at Inokashira Park, May 4th
After 3:00 pm on May 4, a little grebe near the gourd pond spawned.
This year's first spawning at Inokashira Park.
Fortunately, he laid an egg in front of me, which the caretaker was observing.
The little grebe, which had inflated its wings for a while and crouched, stood up after a while, slowly flapping its wings.
The photo above shows the mother of a little grebe who stood up immediately after spawning.
Since little grebes are hermaphroditic, it is only possible to distinguish between males and females during mating and spawning.
I wish I could find a difference somehow.
(Later, it's not 100%, but I've come to understand it.)
It was an egg that wasn't there when I stood up four minutes ago, so I laid an egg while I was crouching.
A female who immediately started repairing the nest after spawning
The nest is still unfinished, and the female worked to reinforce the nest after resting for a while.
The first action taken after getting out of the nest was to cover the eggs by laying nest material around the eggs so that the eggs would not be visible to foreign enemies.
And I hurried to reinforce the nest.
After this, the returning male also participated in the reinforcement of the nest.
When I saw the nest, it was assembled into a solid one.
A pair behind the aquatic life house
Little Grebe spawns behind the aquatic life house on the 2nd, two days behind the gourd pond couple
And two days later, the pair behind the aquatic life house also laid the first egg.
This nest is as heartless as last year's Benten Pond pair.
I constantly bring in nest materials and repair the nests, but they are all like pieces of aquatic plants.
It sinks regardless of whether the nest material is placed on it.
As you can see, the base of the nest is also weak.
The laid eggs are still in contact with the water.
It's going to get cold, but is it okay?
Also, is it possible to respond to fluctuations in water level in such a place?
Watching it makes me very worried.
I hope it doesn't become the second dance of Benten Pond last year.
I want to keep an eye on the future.
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to be continued
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