Black Stork Nest 3 (Kergu) 2024

[Swenja]

11:19 Kergu is back and sings.
It looks like a conspecific is near the nest.

11:20 He flies away.
11:21 and back in the nest. He is looking and singing and looking.
11:22 Kergu flies away again.
11:25 He is back and sings.
Kergu seems to be asking a female into the nest.

[Swenja]

11:26 He sits down.

He follows a desirable being with his eyes.


11:31 He stands up and is singing.
11:31/32 sits down.
11:33/34 stands up, sits down.
11:35/36 and stands up, sits down, stands up.
11:37 Of course, Kergu sits down again. What else?

[Swenja]

11:42 Kergu stands up again. He sings beautiful.
11:46 Kergu stands from one leg to the other and doesn't seem to know what to do.
He just sits down again.
11:49 He stands up and sings his song.

11:51 Kergu shows off his beautiful white feathers and sings. Then he sits down again.



11:54 stands up, sits down.
I hope the lady appears soon.

11:56 stands up, sings.
11:58 sits down.

[Swenja]

12:00 He gets up and sits again.
12:02 Kergu gets up and stands from one leg to the other.
He follows the female with his eyes. He sings and
12:03 he sits down again.

Noble lady please come into the nest.

12:06 here she is!



It seems to be the female from yesterday.

12:07 Kergu sits down.

[Swenja]

12:10 Kergu jumps into the stand and the lady is startled.



12:13 The female flies high up into the tree.



Kergu stands up and sings and sits down again.

open wings

[Swenja]

12:18 She flies away and Kergu follows.

Video link
https://youtu.be/wHFr5dWWl1U

He comes back and sings.
12:19 Kergu flies away again.
12:21 He is back and he flies away.
12:22/23 He is back again and flies away again and back.
Kergu sings a long song.
12:25/26 sits down and stands up, singing.

12:28 Kergu is preening.

12:32/33 He sits down and stands up, singing again and sits down.

The microphone scratches without a break.

12:34 Kergu stands up and flies away.

Kergu is gone and the microphone scratching is also gone.

[Swenja]

12:36 Kergu is back in the nest and flies away again.
12:37 Kergu is here and gone again.

[Anne7]

Noble lady please come into the nest.

12:06 here she is!

When Kergu sat down at 12:07:30, the visitor was startled. Probably a shy, young bird?


When Kergu stood up again at (almost) 12:10, the visitor was startled again.


But when Kergu sat down again at 12:10:23, the visitor was no longer (visibly) frightened.
Trust has to slowly build up.



Thanks again, Swenja. Great work!

[Swenja]

13:03 Kergu is back and sings. He seems to be alone.
He is preening.

13:29 He flies away.
15:24 Kergu is back.

Hello @Anne7
Many thanks for the beautiful pictures!
The female does not seem to want to enter the nest. But maybe Kergu will have a chance next year if he is charming enough.

[Anne7]

The female does not seem to want to enter the nest. But maybe Kergu will have a chance next year if he is charming enough.

I suspect it doesn't help that the access to this nest is a bit complicated.
Perhaps the young, shy lady fears that any quick escape could be difficult, if needed?

Yes, Kergu will have to be patient, demonstrate all his qualities and use all his charms (and tricks).

[brofasa]

I have a question to all the veteran watchers of the forum.

Are we sure this was a female and not just a young male?

Yes, Kergu was courting but does he truly know it is a female or he is just courting any bird that does not behave like a mature male does?

So far, I was 100% positive that storks can tell the sex of the birds around them and behave accordingly. Meaning, that if Kergu was courting, then the target of his attempts must be a female.

However, recently, I have seen a video on YouTube that contradicts this assumption. A white stork male clearly courted and called, then welcomed a slightly smaller white stork into his nest. Then, he attempted mating, only for the other stork to clearly not take on the signature female bill position for rattling and it did not shift its tail either.

Once the mating failed, the white stork male chased the other stork out of his nest. I guess that was when he realized he had a young male with him.

So this made me wonder... Do storks know the sex of another just by looking? Or is this all about behavior and response to a behavior?

So, can a relatively immature young male be confused for a female by a courting male? Until the bird's behavior clearly differs from a female's. Eg.: singing too sharp, lack of right mating behavior.

I mean, this stork was certainly lured in but it did not want to join Kergu, whereas on other nests I observed in the past years, the female (no matter how young) readily joined the male on his nest once she was close enough. They needed little convincing.

The stork did not look particularly young (feather shimmer on head and neck like a relatively mature bird). Most certainly older than Janika or Kaia was when they joined the nests. So, it cannot be immaturity.

[Swenja]

Kergu has rested.

16:10 He flies away.

Hello @brofasa

We humans can really only speculate about the storks' gender reactions. For us, they cannot be visually distinguished as male or female.
Storks, however, will recognize which gender they are interacting with. I suspect that otherwise they would have died out long ago.

There seem to be certain circumstances why sometimes even storks do not recognize each other. (Distance or other behavior)

As an observer, however, you can read the storks' reactions. Sometimes we are wrong, of course.
Yesterday I wasn't so sure that the visitor was actually a female. I remember the rattling of the beak.

Today, however, Kergu's reactions were very clear. And the female visitor reacted accordingly. But now it's getting very late for mating.

We'll see if the female will be a regular visitor. And perhaps we will be surprised how things continue.

[brofasa]

Thank you for the detailed reply, Swenja.

I still have hope that the female joins Kergu. You are right, it is quite late for successful breeding, although our Janika joined Jan in May as well and they had chicks. So, who knows?

She may come to his nest yet. Like Kaia did to Karl II. Even if the eggs did not hatch, she made his nest her home and returned next year early to Karl II.

[Anne7]

Hello Brofasa.

My guess is also that the visitor was a female. But I can't be entirely sure of that.

Although behaviour can help us determine gender, as Swenja rightly points out, we should (often) speak with some reservations.

I think the only way to really be 100% sure of the gender of a BS observed in nature is DNA testing. Except of course in a breeding pair, where one is laying eggs.

I read a while back that birds (even in case —according to us humans!— there is no external difference between the sexes) can easily see whether there is a male or female nearby.
I think it was in a book written by Tim Birkhead. The author emphasises that birds' eyes and brains are very different from those of humans. Partly because birds can see UV light, but also because there are major differences in the structure of the eyes themselves, birds undoubtedly perceive colours differently from humans. They see things (details) and colours we cannot see.


An interesting article says that homosexual behaviour also occurs in birds.
It may in some cases (like maybe lone BS males?) reduce stress, reduce social tension, and increase mating opportunities

"MOTHER NATURE NETWORK"
Evolution of homosexuality in birds explained
"A new study published this week may mark the end of the theory that homosexuality only has evolutionary disadvantages, according to Nature*.
The findings, based on observations of 93 bird species that are known to engage in homosexual activity, revealed that the amount of time males or females put toward parental care was proportional to how often they engage in homosexual behavior.
This means that homosexuality may not be costly for birds that have plenty of mating opportunities because of lower parenting demands, said Geoff MacFarlane, one of the study's principal researchers.
In other words, since some animals can devote more energy toward mating behavior than to raising offspring, there is wiggle room for homosexuality to become a common behavior without sacrificing evolutionary efficiency.
Previously, biologists struggled to explain how homosexuality could have evolved since it distracts animals from sexual activity that directly produces offspring. The fact that it had evolved was difficult to deny: more than 130 species of birds participate in homosexual activity. For example, among Laysan albatrosses, as many as 31 percent of all pairings are female-female. Among graylag geese, one in five pairings are male-male.
The research team reached its conclusion by scoring each bird species based upon the relative contribution of males and females to parental chores. They found that male homosexuality is more prevalent among bird species in which the female is more heavily devoted to parenting tasks (such as tending the nest or feeding and caring for chicks). Similarly, when females had more free time, female homosexuality was more frequently witnessed.
Overall, the research discovered that 38 percent of the species studied display female–female sexual behavior and 82 percent participate in male–male behavior. In total, 5 percent of all sexual encounters among all the species was homosexual in nature.
"This is one of the few studies that explains homosexual behavior from the evolutionary point of view," said Vincent Savolainen, a biologist at Imperial College London.
Although the study dispels of the theory that homosexuality is evolutionarily disadvantageous or unnatural, it cannot determine what the ultimate explanation for homosexuality is. As evolutionary geneticist Allen Moore points out, "this study suggests that when there's no cost, homosexuality can persist, which isn't the same as saying it's adaptive. It may be that when there's no parental care involved, it's like having a hobby." [ ]
Researchers have speculated, though, that homosexual behavior in birds may help them to practice courtship displays, form alliances, reduce social tension or solidify dominance."
https://www.mnn.com/earth-matters/anima ... -explained

* https://www.nature.com/articles/news.20 ... 0offspring.


And another article
Homosexual behaviour in birds: Frequency of expression is related to parental care disparity between the sexes
Homosexual behaviour occurs in over 130 species of birds, yet explaining its maintenance in evolutionary terms appears problematic at face value, as such sexual behaviours do not seem in immediate pursuit of reproductive goals. Parental care sexual conflict theory predicts that release from parental care translates to an increased propensity towards polygamous sexual behaviour. We hypothesized that homosexual behaviour(s) may be expected to increase in frequency for the sex that invests less in parental care and potentially enjoys increased mating opportunities. Consistent with our predictions, lower relative contribution to parental care for a particular sex is related to increased frequency of occurrence of homosexual behaviour. For males, highly polygynous species with minimal male parental investment exhibit higher frequencies of male homosexual behaviour, including male–male mounting and especially courtship. In socially monogamous species, male parental investment is greater, and the expression of male homosexual behaviour is lower. Similarly, among pair-bonding species, frequencies of male–male pair bonding increase with decreases in male contribution to care relative to females. When females of socially monogamous species provide less care than males, they exhibit higher frequencies of homosexual behaviour, namely pair bonding and courtship activities. Conversely, when females of polygynous species provide the bulk of parental care, female–female sexual behaviour is infrequently expressed. Homosexual behaviour in birds is more likely to occur under scenarios of enhanced mating opportunity without necessarily influencing reproductive success and thus may exist neutrally, or alternatively provide a behavioural template co-opted for adaptive design.
https://www.researchgate.net/publicatio ... _the_sexes

[Swenja]

21:02 Kergu is at home.

[Swenja]

May 9

Kergu continued to build his nest this morning.
He also fetched nesting material.



He occasionally sang his song.

Kergu sat down in his beautiful nest for a while two times.

[Swenja]

Kergu sings. He is looking for a female.



nice stretching


Kergu has not yet gone in search of food today. Looks like he has a date? He stands and waits.



11:22 Kergu flies away.

[Swenja]

11:26/27 He is back with moss.



11:31 He sings. But there doesn't seem to be anyone around.



11:33 He flies away.

[Swenja]

14:00 Kergu is back. He sings.



He is resting and preening.

15:44 Kergu flies away.

[Swenja]

19:41 Kergu is at home.
He sings two times when he arrives.