Duckling Independence at a River Weir: Kingfisher Mating, Crow Intelligence, and Little Egret Hunting
Young Eastern Spot-billed Ducks beginning to ignore their mother, a pair of Common Kingfishers mating beside the river, a crow testing prey in the water, and a Little Egret repeatedly hunting among aquatic vegetation—this field record captures several forms of bird behavior within the same urban river ecosystem.
The most striking scene involved five growing ducklings whose mother descended from a river weir and apparently expected them to follow. Instead, the ducklings remained above her for several minutes. Their delayed response may represent a small but visible stage in the gradual development of independence.
This article is based on footage recorded during a continuous daily wildlife observation project. The interpretations below are those of an amateur observer rather than a professional ornithologist. They are presented as field-based observations and questions, not as definitive scientific conclusions.
Field Observation Video
Next day’s observation:
https://youtu.be/_7GjCVR_jJc
Main Species Featured
カルガモ — Eastern Spot-billed Duck — Anas zonorhyncha
A common East Asian dabbling duck. The growing ducklings in this record showed increasing independence, although several families were still travelling and resting with their mothers.カワセミ — Common Kingfisher — Alcedo atthis
A small fish-eating bird known for rapid plunge-diving. Both mating behavior and successful hunting at the river weir were recorded.コサギ — Little Egret — Egretta garzetta
A small white heron that often disturbs vegetation or sediment with its feet to expose hidden prey.ハシボソガラス — Carrion Crow — Corvus corone
An adaptable and highly observant crow. One individual displayed an unusual sequence in which it placed a caterpillar-like animal in the water and watched it.ハシブトガラス — Large-billed Crow — Corvus macrorhynchos
A large crow common in Japanese urban environments. Parent–juvenile interaction, including gentle bill-touching behavior, was observed.コイ／ニシキゴイ — Common Carp / Ornamental Koi — Cyprinus carpio
Several unfamiliar ornamental-looking carp appeared in the river. Their sudden presence raised the possibility of recent human release, although this could not be confirmed from observation alone.
Growing Ducklings and the Gradual Development of Independence
The first duck family recorded was アf3, consisting of a mother and three ducklings estimated to be about 33 days old.
Two days earlier, I had only been able to locate the young ducks without their mother. On this occasion, the family was together again and resting quietly. At approximately 03:30, the ducks reacted slightly when a Little Egret arrived and called nearby.
The response was brief. The family did not flee, suggesting that the egret was noticed but not treated as an immediate threat.
Several young ducks were also sleeping elsewhere along the river. I had intended to identify their family group by observing them after they woke, but artificial feeding disrupted their natural movement. Once several ducks gathered around the food, family associations became difficult or impossible to determine.
This is one of the practical limitations of observing older ducklings. As they grow, their appearance becomes increasingly similar, they move more independently, and unrelated young ducks may temporarily gather in the same place.
Later, Gf mother was found resting with four young ducks. Identifying the mother was still possible from her plumage pattern, but the behavior of the young ducks suggested that they had begun spending more time apart.
At this stage, “independence” should not necessarily be understood as a single moment. It may be a gradual process in which young ducks alternate between staying with their mother, travelling with siblings, joining other ducks, and moving alone.
One solitary young duck was recorded at approximately 27:05. Seeing a growing duckling completely alone was unusual enough to attract attention. It approached a tunnel but did not pass through it. Because I had followed many of the local families since the ducklings were very small, even this ordinary-looking moment felt significant.
Little Egret Foot-Stirring and Successful Hunting
A Little Egret was filmed using its feet while searching for prey.
At approximately 04:11, the bird repeatedly moved its feet through the shallow water. This behavior appeared to disturb the riverbed or aquatic vegetation, potentially causing hidden animals to move into view.
The early attempts were unsuccessful. Later, however, the same or another Little Egret began catching prey repeatedly near an area with abundant algae or submerged vegetation.
At approximately 24:23, the hunting success increased noticeably. The captured animals looked somewhat like shrimp, although some appeared relatively large. Small crayfish are another possibility, but the footage does not provide enough detail for a reliable identification.
The concentration of prey near the vegetation may indicate that the algae provided shelter or feeding habitat for aquatic invertebrates. It is also possible that prey simply became easier to detect when disturbed by the egret’s foot movements.
These possibilities remain observational hypotheses rather than confirmed conclusions.
At approximately 26:19, アf3 and the Little Egret came close to one another. The mother duck showed mild vigilance, but the encounter remained peaceful.
Common Kingfisher Mating and Hunting at the Weir
At approximately 08:58, a female Common Kingfisher was perched near the river. When a male arrived, her reaction and his approach suggested that mating might follow.
At 09:59, copulation was successfully recorded.
I had previously missed or poorly recorded a similar opportunity, so this sequence was especially valuable. The behavior developed quickly, and anticipating what might happen made it possible to maintain focus on the birds.
At approximately 11:50, a male kingfisher was also recorded hunting at the weir.
Kingfishers are frequently seen flying through the observation area, but obtaining clear evidence of a successful feeding event can be difficult. Their dives are fast, the bird may disappear behind concrete structures, and the prey is often swallowed within seconds.
This footage therefore provides useful visual documentation of both reproductive and feeding behavior within the same local river environment.
Unfamiliar Ornamental Carp and Possible Human Release
At approximately 16:58, an unfamiliar ornamental-looking carp was observed.
Another unfamiliar carp appeared shortly afterward, and additional individuals were present nearby. The sudden increase was unusual compared with previous observations at this location.
It is possible that these fish had been released by someone, but the footage alone cannot establish their origin. Natural movement from another part of the river or connected waterways should not be excluded.
Some of the fish appeared to have unusually swollen abdominal areas. This could reflect body shape, reproductive condition, feeding history, or the characteristics of a particular ornamental variety.
One darker golden carp with soot-like scale markings had already been present in the area before this observation. I have followed the movements of individual ornamental carp with interest, including their travel between upstream and downstream sections.
Although ornamental fish can be visually attractive, the deliberate release of captive animals into a river may affect the local ecosystem and should not be treated as harmless.
Xf5 at Approximately 41 Days Old
At approximately 19:13, a duck family appeared while I was observing a Little Egret. The family was identified as Xf5.
The five young ducks were estimated to be about 41 days old. Their bodies had become much larger and more developed, making their progress especially noticeable.
At this age, family identification becomes increasingly difficult. Several young ducks were present in nearby groups, but distinguishing whether they belonged to Ff, Gf, Df, or another family was no longer reliable.
For this reason, I record uncertainty rather than assigning a family code based on appearance alone.
エf5 Reaches and Descends the Weir
At approximately 28:55, エf5 was found above the river weir. The family consisted of the mother and five ducklings estimated to be about 27 days old.
Two days earlier, they had been unable to climb this weir. Their presence above it was therefore evidence that they had either succeeded later or reached the upper section by another route.
When I first saw the mother, I could not immediately see the ducklings. Moving leaves in the current briefly created the impression that small birds might be present. The ducklings then became visible, confirming the family’s identity.
At approximately 30:18, the family descended the weir.
After reaching the lower section, the mother became strongly focused on feeding. I had previously noticed that she often foraged intensively below the weir after descending.
The physical structure of a weir can create differences in water depth, flow speed, oxygenation, and prey concentration. These conditions may make the lower section attractive for feeding, although direct prey sampling would be required to test that idea.
A Crow Places a Caterpillar-Like Animal in Water
At approximately 33:15, a Carrion Crow was walking and foraging near the water.
Its relaxed movements were recorded while I also rested in the shade beneath a bridge.
At approximately 37:30, the crow displayed an especially interesting behavior. It appeared to place a caterpillar-like animal in the water and then watch it.
The exact purpose of this action is uncertain.
The crow may have been testing whether the animal was alive, attempting to clean it, softening it before eating, or reacting to defensive chemicals or hairs. Another possibility is that the prey was not a caterpillar at all, despite its appearance in the footage.
Crows are known for flexible problem-solving, but it would be inappropriate to assign a specific intention from a single observation. The value of the record lies in preserving the full sequence for later comparison with similar behavior.
At approximately 37:55, the crow’s jumping movement was also recorded clearly. I am particularly interested in how wild animals use their bodies—how they balance, jump, land, accelerate, and adjust their posture on uneven surfaces.
These details may appear minor, but repeated observation often reveals that each species has a distinctive way of moving through the same environment.
The crow then flew away because エf5 was approaching.
Ducklings Ignore Their Mother’s Descent
At approximately 42:02, エf5 reached a small step near the entrance to the fish passage.
This location resembled a previous incident in which one duckling was carried into the fish passage by the current. At that earlier age, the family had struggled with the same small elevation difference.
On this occasion, the young ducks crossed the area much more confidently. Their improved ability provided a clear visual indication of growth.
The ducklings also made several short dives. Their compact underwater movements were both functional and unexpectedly playful in appearance.
At approximately 44:02, the mother descended to the lower side of the weir.
The five ducklings did not immediately follow her.
Instead, they remained above the drop while the mother moved through an area she seemed to prefer. Similar behavior may previously have occurred with this family, and I have also wondered whether mothers such as Of and ケf showed comparable preferences for particular feeding locations below weirs.
The delay was striking because much younger ducklings usually respond quickly when their mother changes position. These older ducklings appeared less controlled by her immediate movement.
One duckling eventually reacted at approximately 48:14, but the group still took time to commit to the descent.
At approximately 49:35, the ducklings finally followed.
They then travelled directly toward a resting place and settled beneath filtered sunlight.
The scene may represent an intermediate stage between dependence and independence. The ducklings had not abandoned the mother, but neither did they respond automatically. They appeared capable of evaluating the route and delaying their decision.
It is also possible that they were simply resting, distracted, or reluctant to descend the structure. Continued observation of the same family would be needed before interpreting the behavior more strongly.
Parent–Juvenile Interaction in a Large-billed Crow
At approximately 57:54, a Large-billed Crow family was recorded.
An adult gently touched or pecked around the young crow’s bill. The movement appeared delicate and may have been related to feeding solicitation, food transfer, bill inspection, or social interaction.
Because the exact contents of the adult’s bill were not visible, the function of the behavior remains uncertain.
The scene nevertheless provides a useful contrast with the crow’s public image as a harsh or aggressive urban bird. Like many intelligent social animals, crows also display attentive parental behavior.
イf4 at Approximately 49 Days Old
At approximately 59:24, イf4 was found in an area that had once contained several actively growing duck families.
The four young ducks were estimated to be about 49 days old.
The location now felt much quieter than it had earlier in the breeding season. This seasonal change is gradual but unmistakable. Families disappear from familiar resting places, older ducklings become harder to distinguish, and some groups begin moving beyond the routes where they were first recorded.
The reduction in visible family groups does not always mean that the birds have died or permanently left the river. Older young ducks can move farther, rest in hidden vegetation, or merge visually with other ducks.
Cf Family Revisited at Approximately 70 Days
Near the end of the observation, several ducks were found in a field after the grain harvest, together with pigeons.
At approximately 1:02:10, one group was identified as the Cf family.
The young ducks were approximately 70 days old. The mother was accompanied by only two visible young ducks.
I had hoped to see all three together, but the encounter was still significant. It was the first time I had clearly documented this family returning with grown young ducks to forage in this type of field environment.
The ducks were covered with floating aquatic plants, suggesting that they had recently travelled through a rice field or another vegetation-rich water channel.
At this age, the relationship between mother and offspring can be difficult to interpret. They may still associate temporarily even after the young are capable of independent feeding and movement.
Tf Family at Approximately 45 Days
At approximately 1:03:46, the Tf family was located.
The young ducks were estimated to be about 45 days old, but the group entered dense vegetation before useful footage could be recorded.
Several other families, including ケf2 and キf4, were searched for later but could not be found. Sf9, which had not been observed recently, was also not located.
Failure to find a family on one day should not be treated as evidence of disappearance. Visibility changes with vegetation, water level, shadows, sunlight, resting location, and the direction of the river.
I have noticed that there are periods each year when the changing angle of sunlight makes certain parts of the river unusually difficult to observe. The orientation of the river and the seasonal position of the sun may create recurring weeks in which glare and deep shadows reduce detection.
Artificial Feeding and the Loss of Behavioral Evidence
Artificial feeding affected part of this day’s observation.
Food was thrown near a step in a way that caused the ducks to repeatedly climb and descend the structure. This changed their movement and brought unrelated individuals together.
Although the ducks were not very young, the event still prevented reliable family identification and interrupted the natural behavioral sequence I had intended to document.
Feeding can make wildlife easier to see, but it also creates observational bias. Birds may gather in unnatural numbers, abandon normal foraging, compete with one another, or repeatedly use structures they would otherwise avoid.
For a long-term behavioral record, it is important to distinguish between spontaneous movement and behavior caused by human intervention.
A Daily Record of an Urban River Ecosystem
This observation day included duckling development, kingfisher reproduction, egret hunting, crow foraging, parental care, possible fish release, artificial feeding, and the seasonal dispersal of growing duck families.
No single event explains the ecosystem as a whole.
Instead, the value of the record comes from the coexistence of many small events within the same place and time. A weir is simultaneously a feeding site for a kingfisher, an obstacle for ducklings, a hunting area for an egret, and a boundary through which fish and other aquatic animals must move.
The observations are documented with minimal editing using Nikon P1100 and P950 superzoom cameras. The first three minutes of the video contain an edited digest, while the remaining footage is presented primarily as a chronological field record with natural sound.
Some nesting locations of popular bird species may be omitted to reduce the risk of disturbance or attracting large numbers of photographers.
Advance footage is sometimes shared with channel members, while general publication may be delayed when revealing the immediate location of sensitive wildlife could create unnecessary pressure.
Notes on Interpretation and Evidence
I am not a professional ornithologist, ecologist, or animal behavior researcher.
The behavioral interpretations in this article are personal observations developed through repeated filming of the same river, individual mother ducks, and family groups. They should be treated as questions and field impressions rather than verified scientific conclusions.
At the same time, the project preserves daily footage across consecutive dates. Publication dates, recording codes, family identification codes, plumage comparisons, and next-day observations provide chronological evidence that can be checked across multiple videos.
This is especially useful when documenting gradual changes such as:
the growth and dispersal of ducklings;
repeated use of the same weir or resting place;
changes in mother–duckling responsiveness;
injuries and later recovery;
movement between upstream and downstream areas;
the arrival or disappearance of individual birds and fish;
behavior observed before and after a specific event.
Not every family can be found every day, and not every individual can be identified with certainty. When the evidence is insufficient, the record intentionally preserves that uncertainty.
Observation Codes
The recording code for this observation is 【0721F】.
In this system:
0721 represents July 21;
F represents the 2025 observation year.
Duck family codes combine the individual identification of the mother, the observation year, the number of young ducks, and their estimated age.
Examples from this record include:
アf3: mother アf with three young ducks;
Xf5-41: mother Xf with five young ducks at approximately 41 days old;
エf5-27: mother エf with five young ducks at approximately 27 days old;
イf4-49: mother イf with four young ducks at approximately 49 days old.
The katakana identifiers, such as アf, イf, エf, ケf, and キf, are independent identification symbols. They are not English alphabet codes and must not be converted into Af, If, Ef, Kf, or other Roman-letter forms.
A detailed explanation of the recording-date codes, mother-duck identification system, family codes, and the purpose of this long-term observation project is available here:
https://okasinaikimono.blogspot.com/p/welcome-to-wild-duck-diaries.html
A reference table comparing mother ducks by the patterns of their tertial feathers is available here:
https://okasinaikimono.blogspot.com/2025/07/0721f.html
Observation Continuity
The next day’s video can be viewed here:
This day-by-day continuity is an essential part of the project. Each video is not intended to stand only as entertainment; it also functions as dated supporting evidence within a longer record of wild birds, individual duck families, and ecological change in an urban river.
00:00 Highlights (unordered)
03:01 Af3 is resting (Duck family Af: 3 ducklings, around 33 days old) * The day before yesterday, I could only film them without the mother, but today I finally saw them together again. 03:30 Af3 reacts slightly to the arrival and call of a little egret 04:11 A clear shot of the egret hunting with its feet (unsuccessful hunt) 05:46 Young ducks sleeping * I had planned to identify the family group afterward, but feeding by people ruined the chance. 08:58 Female kingfisher. A male appears, and she reacts—flies close… Looks like they’re going to mate! 09:59 Kingfisher mating * I learned from last time and got a great shot today. 11:50 Male kingfisher feeding at the weir * Finally got a proper recording as evidence! 13:08 Af3 wakes up but heads into the bushes 14:17 Ducks gather—after being fed * The young ones that were sleeping earlier joined in, and I couldn’t tell which belonged to which family. It was the type of person who throws food on a slope to make the ducks go up and down. Sad… but at least it wasn’t aimed at very young families. 16:58 A koi I don’t recognize was there… 18:02 Another unfamiliar koi showed up… there were several. Someone probably released them… * I don’t like releases, but I do enjoy watching the colorful koi… I’m interested in how they move upstream/downstream. But this sudden increase is sad. Their body shape and slightly swollen bellies also seemed odd—maybe it's the breed, or the feeding conditions? Will they slim down over time? The gold koi with sooty scales has been here for a while. 19:13 While watching the egret, a duck family appeared—Xf5! 20:27 Xf5-41 – looking great! 21:11 Several young ducks were around—but I can’t tell them apart anymore. * Some young ducks were in that group earlier too—maybe from Ff, Gf, or Df… but they’re so scattered it’s impossible to identify them. 21:44 Gf mother! Found resting with 4 young ducks * I can’t believe I found Gf mother! But the ducklings seem to be becoming independent already. 22:44 Af3 wakes up and moves. Egret is also hunting nearby. 23:58 Egret seems to be failing at catching prey... 24:23 ★ Egret’s hunting is on fire! More prey in the weedy area? * Looks like shrimp, but could be small crayfish—it looked pretty big. 26:19 Af3 and the egret get close. The mother duck seemed a little cautious but peaceful. 27:05 A lone young duck * Quite rare. It didn’t go through the tunnel… probably a juvenile from a familiar family, so it felt heartwarming. 28:55 Ef5-27. On top of the weir that they couldn’t climb two days ago! * At first, I thought I was mistaken—it looked like flowing leaves. But no, it was a duckling! 30:18 ★ Ef5 goes down the weir! 31:10 After going down the weir, Ef mother focused intensely on foraging downstream (as before) 32:33 Other ducks sleeping (Ef disrupted the roost two days ago. Today was peaceful) 33:15 Carrion crow foraging or strolling along the water * I rested in the bridge’s shade too… their slow movements were relaxing to watch. 37:30 ★ Rare crow behavior while feeding. Floated a caterpillar to test the waters. 37:55 Observed the crow’s jumping motion. * I love watching how wild animals use their bodies. I try to imitate them (probably poorly). 38:18 Reason the crow flew—Ef5 had arrived
42:02 Ef5 reaches the small step before the fishway
* This is similar to the scene where one duckling was swept away before. They used to struggle with this step—what growth!
42:55 Duckling diving—so cute
44:02 ★ Mother duck goes down, but the ducklings ignore her
* The mother likes this kind of area below the weir.
* I've seen this pattern with Ef before—and also with Of and Kef mothers, maybe?
48:14 Some ducklings finally react—but still taking their time…
49:35 ★ Ducklings finally go down! Then head to their sleeping spot
53:16 Enjoying a cute sun-dappled nap 
* After this, I searched downstream for Kef2 and Kf4, but couldn’t find any sign…
57:54 Jungle crow raising its young pecking gently at its chick’s beak
59:24 If4-49 – the parenting area feels quite lonely now
1:00:51 Lots of ducks in the bridge’s shadow
1:01:41 Ducks hanging out with pigeons behind the former wheat field
1:02:10 That’s the Cf family! 70 days old—only 2 ducklings with the mother
* I hoped all 3 would be there, but still, what a happy reunion! It’s my first time documenting them foraging together after growing up.
1:02:40 On closer look—dense floating plants must have come via the rice paddies lol
1:03:46 Tf family—ducklings 45 days old—entered the bushes and couldn’t be filmed
▲▲▲ End of timestamps
*
So… upstream Ef5 moved around a lot again today, and the log got quite long I forgot to note this in the memo, but I looked for Sf9, which I haven’t seen recently, but couldn’t find it. I also didn’t see much of the downstream families. I feel like there have been a lot of days this year when I can’t find them—probably due to sunlight. I remember that certain times of the year make visibility worse depending on the river's angle and sunlight.
Personally, I’m glad I got a kingfisher revenge shot and was able to observe both crows and egrets.
Oh, and I’ve decided to stop making these “quick update videos” next year (I’ll still film, but won’t edit/upload this type of video). I may not actually follow through, knowing my personality, but I’m writing it here for now.
I’d love to brainstorm with the viewers sometime… but for now, I’m fully focused on duck tracking and pushing forward!
* To keep track of the many duck families, I use the mother duck’s wing (tertial feather) patterns and code system. [List here ↓] https://okasinaikimono.blogspot.com/2025/07/0721f.html
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