A pair of ducklings calling repeatedly from dense riverside vegetation led to an unexpected reunion with a mother duck that had not been observed for fifteen days. The family was eventually identified as an Eastern Spot-billed Duck brood previously recorded moving through the same river system.
This field record documents duckling distress calls, temporary separation from the mother, maternal return, family recognition through plumage patterns, and the difficulty of detecting duck families in heavily vegetated urban waterways. It also includes observations of older juvenile ducks, bathing birds, family dispersal, and a mother waiting for a separated duckling.
Field Observation Video
Next day’s record:
https://youtu.be/BPpwk5rBYl0
Main Species Featured
カルガモ — Eastern Spot-billed Duck — Anas zonorhyncha
A common East Asian dabbling duck. Males and females have similar plumage, so individual mothers in this project are identified mainly by stable patterns in their tertial and wing feathers.ハクセキレイ — White Wagtail — Motacilla alba
A small, active bird commonly seen along rivers, roads, and other open areas. Its constantly moving tail and ground-foraging behavior make it relatively easy to recognize.スズメ — Eurasian Tree Sparrow — Passer montanus
A familiar small bird that often lives close to people. In this record, one individual visited the riverbank to bathe.ヒヨドリ — Brown-eared Bulbul — Hypsipetes amaurotis
A vocal East Asian songbird that feeds on fruit, nectar, and insects. Its bathing behavior can be surprisingly direct, with the bird sometimes dropping almost vertically into the water.
A Duck Family Found by Sound
At 04:28, faint duckling calls could be heard from vegetation beside a tributary. Duck families had recently become unusually difficult to locate in this area, and the calls provided the first clear sign that ducklings were hidden nearby.
Two ducklings were eventually seen in the vegetation. They appeared to be separated from their mother and called intermittently while remaining in approximately the same place.
At 05:54, one duckling produced a distinctive, sharply rising call. I usually hear this type of vocalization during sudden danger, alarm, or intense distress. In this case, however, the cause was unclear. The duckling may have been startled by something beneath its feet or by movement inside the vegetation.
This interpretation is based only on repeated personal observations. I am not a specialist in avian vocal communication, and the precise function of the call cannot be determined from this recording alone.
Two Ducklings Left Waiting
By 06:23, the two ducklings were still without an adult. They occasionally called, but no mother appeared immediately.
Several Eastern Spot-billed Duck families of similar age were active in the area, making identification difficult. At first, I suspected that the ducklings belonged to the ケf family or possibly the キf family. Both broods were approximately fourteen days old, and their ducklings were similar in size.
Because the mother’s wing pattern could not yet be seen, I continued observing rather than assigning a definite identification.
At 09:05, an adult duck flew into the riverside vegetation. Grass moved near the center of the area, but the bird itself remained largely hidden. The ducklings could still be heard, suggesting that they had not yet completed their reunion.
At 09:50, the adult finally emerged.
The two ducklings were with her.
An Unexpected Reunion After Fifteen Days
The mother’s wing markings did not match the ケf mother. Closer comparison showed that this was the オf family, recorded here as オf2-19.
The discovery was unexpected because this family had not been confirmed for fifteen days.
On July 9, the family had moved into the area with eight ducklings. On July 10, the mother descended at a small sluice structure while the ducklings remained above her. After that incident, the family disappeared from regular observation and was thought to have moved farther downstream.
Their reappearance suggests that they may instead have remained in a poorly visible section of the tributary, entered nearby rice-field habitat, or moved upstream through the sluice area.
These possibilities remain speculative. The continuous video archive provides chronological evidence of when and where the family was observed, but it does not show their movements during the missing fifteen-day period.
The brood had declined from seven ducklings in the most recent confirmed count to two. The causes of the losses are unknown. Predation, separation, injury, environmental obstacles, and other factors are all possible, but no specific explanation can be supported by the available footage.
At 11:37, the mother led both surviving ducklings back into dense vegetation.
Why Duck Families Were So Difficult to Find
At 17:25, the イf4-53 family emerged from riverside vegetation. Shortly afterward, the mother disappeared from view behind what appeared to be only a small patch of grass.
This simple moment helped explain a major difficulty encountered throughout the season.
Eastern Spot-billed Duck families are often visible beside vegetation, beneath overhanging plants, or along shaded banks. In previous years, even resting families were usually detectable because some part of the mother or ducklings remained exposed.
In this season, however, vegetation had grown densely in many narrow strips along the river. Even relatively small patches were sufficient to conceal an entire family. The river remained open on both sides, yet the ducks could disappear almost completely within a short distance.
This means that an apparent absence does not necessarily indicate that a family has left the area. A mother and several ducklings may remain nearby while producing little movement, sound, or visible disturbance.
It also creates an identification problem. Even when ducklings can be seen, the mother’s tertial feathers may remain hidden. Without those markings, several families of similar age can be extremely difficult to distinguish.
Older Juveniles and Continuing Family Associations
At 03:01, the Cf family was observed with two well-grown juveniles at approximately 74 days old.
Two juveniles had also been seen with the mother in a rice field several days earlier. Their continued association at this age may represent a relatively prolonged family bond, although brief encounters alone are not enough to determine how dependent the juveniles still were.
Later, at 13:44, another similarly named family, Of2-54, was observed. The similarity between the codes Of2 and オf2 illustrates why the Japanese katakana symbols must remain distinct from Roman letters.
The Of mother bathed and rested while her older juveniles swam away from her. Their increasing independence contrasted with the much younger オf ducklings, which remained close to their mother after the reunion.
Bathing Behavior of Riverside Birds
At 16:14, a Eurasian Tree Sparrow came to the water to bathe.
At 19:15, a Brown-eared Bulbul also approached the river. Its feathers appeared fluffed, suggesting a strong intention to bathe, but it repeatedly changed position without immediately entering the water.
At 19:48, the bulbul suddenly descended directly onto the water.
This type of rapid, direct bathing entry may be more common in Brown-eared Bulbuls than the cautious approach first suggested. I have seen similar behavior on other occasions, but it is often difficult to record because the bird’s landing point is unpredictable.
At 20:26, the bird briefly hovered without fully bathing. The moment was short, but it provided an additional example of the species’ agile movement near the water surface.
A Mother Waiting for a Separated Duckling
At 21:57, eight large juvenile ducks belonging to the Tf family were observed near the river.
At 22:25, one juvenile had become separated from the others. The mother remained nearby and appeared to watch the isolated bird until it returned to the group.
A similar separation had been recorded the previous day beneath the weir, where vegetation divided the family. On that occasion, the mother also remained positioned in a way that appeared to support reunion.
The scene was visually subtle, but it may provide useful behavioral evidence. The mother did not simply continue with the nearest juveniles. Instead, she remained attentive to the separated individual and waited until contact was restored.
Care is required when interpreting intention in wild animals. It is not possible to know exactly what the mother perceived or decided. Nevertheless, repeated observations of similar waiting behavior suggest that the position and calls of separated offspring can influence a mother’s movement.
At 23:06, all eight juveniles crossed the river together before spreading out again.
The Tf mother’s forehead injury also appeared to be improving. Feathers were growing back over the previously damaged area. Earlier in the season, she had been highly aggressive toward nearby ducks, including members of the Cf family. More recently, she appeared to engage in fewer confrontations, although this may reflect changing family circumstances rather than a permanent behavioral change.
A Single Survivor from a Pond-born Family
At 24:52, Uf1-45 was confirmed alive.
This individual originated from the fifth brood recorded at a nearby pond. The family had been difficult to relocate after moving away from the pond, even when its likely location was known.
The duck appeared to favor quiet, poorly observed sections of the waterway. Such locations may reduce disturbance, but they also make repeated confirmation difficult.
Among three pond-born families recorded during the same period—Uf5, Vf8, and Wf2—the Uf individual was the only survivor still being observed. Its continued presence therefore carries particular importance within the season’s chronological record.
What This Day Revealed
The most significant discovery was the return of the オf family after fifteen days without confirmation.
Only two ducklings remained, but their calls made it possible to locate them, observe their temporary separation, and document their reunion with the mother. Because I initially misidentified the family during filming, the final identification depended on later comparison of the mother’s wing pattern, the ducklings’ size, and the family’s previous records.
The observation also demonstrated how easily duck families can remain undetected in dense riverside vegetation. Several families that appeared to have disappeared may have been using concealed habitat only a short distance from regularly searched areas.
At the same time, some families genuinely remained unconfirmed. The ケf2 family was still missing, as was the キf family. The Lf mother had recently been seen alone, but the status of her offspring was uncertain. They may have dispersed unusually early, moved outside the observation area, or remained hidden.
The older Cf juveniles, the separated Tf juvenile, and the surviving Uf individual also showed that family relationships and habitat use continue to vary greatly as young ducks approach independence.
About This Observation Record
This article is based on continuous day-by-day field observations and nearly unedited video records collected along the same river system.
I am an independent wildlife observer, not a professional ornithologist. Behavioral explanations in this article should therefore be understood as personal interpretations based on repeated observation, video comparison, and chronological field records rather than formal scientific conclusions.
The project attempts to preserve every filming day, including ordinary periods, failed searches, temporary disappearances, uncertain identifications, and later reunions. Records from adjacent dates are compared to establish chronological context and provide evidence of changes that cannot always be understood from a single encounter.
The recording date also functions as part of the evidence. Most footage is published with minimal editing, although public release may be delayed when sensitive nesting sites or heavily visited wildlife locations are involved.
Observation Codes
The date code for this record is 0725F.
0725 indicates July 25.
F indicates the year 2025.
Duck family codes combine an individual mother identifier, the observation year, the number of surviving ducklings, and their estimated age in days.
For example:
オf2-19 indicates mother オf, two ducklings, approximately 19 days old.
Cf2-74 indicates mother Cf, two juveniles, approximately 74 days old.
Tf8-49 indicates mother Tf, eight juveniles, approximately 49 days old.
Uf1-45 indicates mother Uf, one juvenile, approximately 45 days old.
Katakana identifiers such as オf are separate from Roman-letter identifiers such as Of. They must not be converted into one another.
A detailed explanation of the date codes, duck family identification system, and the purpose of the Wild Duck Diaries project is available here:
https://okasinaikimono.blogspot.com/p/welcome-to-wild-duck-diaries.html
The family identification chart and the original Japanese field notes for this date are available here:
https://okasinaikimono.blogspot.com/2025/07/0725f.html
00:00 Highlights (unordered)
03:01 Mother duck with well-grown juveniles – Cf family, 74 days old
* The other day in the rice paddies she also had 2 ducklings with her; still 2 today. Maybe they’re clingy?
04:19 White wagtail
04:28 I hear duckling calls somewhere… there they are!
* In the tributary bushes. Lately I haven’t been able to find many duck families; while walking near the weir… ケf maybe!?
05:54 A special duckling call—usually used in emergencies—but the cause was unknown.
* A single “Pyu↑ii” cry. Usually a panic call, but maybe they bumped into something underfoot?
06:23 Two ducklings left behind… calling occasionally, but the mother isn’t returning.
* Likely ケf2, but キf and ケf are both around 14 days old so I can’t tell. I’ll wait.
09:05 A duck flew in and went into the bushes! Is it the mother? Grass in the center moved occasionally but I couldn’t see.
* The ducklings were in there too; I could hear their calls so they probably hadn’t reunited yet…
09:50 They came out! Did they reunite with the ducklings? Yes!! It’s the mother!
* The feathers aren’t キf!!! It’s ケf2!! …Or so I thought until now.
10:00 オf2-19 – Unbelievably, the オf family returned after 15 days! Ducklings reduced from 7→2…
* Turns out it was オf母. They moved with 8 ducklings on 0709F, and on 0710F the mother fell with the ducklings at the small floodgate.
After that they vanished, assumed to have gone downstream—but apparently not. Likely either climbed into the rice paddies or up the small floodgate to the upper tributary. Given the reduction in ducklings, probably the latter.
* Compared with ケf2母 to be sure—definitely a different mother. Ducklings are also a different size.
11:37 Mother led the two ducklings back into the bushes – オf2
13:44 Of2-54 – other ducks around, making it confusing. Of2 and オf2 are so easy to mix up 
14:50 Of mother bathing and resting; ducklings swam off
16:14 Sparrow came to bathe
17:25 イf4-53 emerging from the bushes
18:00 イf mother vanished into a small patch of bushes…
* This is it! The reason duck families are so hard to find this year! Usually, even in shade or near grass, they stay visible—but lately it’s been baffling not seeing them. This year’s slightly thicker patches of grass are apparently enough to hide them completely (even when the sides are open).
* Amazing how even this much cover makes them invisible. Even when spotted, often you can’t see enough feathers to tell if it’s a family.
18:39 This year the tall grass makes duck families hard to spot
18:54 This one was easy to see… but it turned out to be a molting adult
19:15 Brown-eared bulbul came to bathe—can’t decide on a spot?
* Its fluffed-up feathers ready for bathing were cute, but it wouldn’t start.
19:48 Surprise direct water entry
* Actually, this is probably the more common bulbul bathing style. Even when I see it, I rarely catch the entry point on film.
20:26 ★ Didn’t bathe… hovered for a moment!
20:32 The many ducks suddenly became fewer, but still some scattered around
21:57 Larger ducklings… Tf8, but where’s the mother?
22:25 ★ The mother duck was waiting for the straggler! Watched over them until they reunited.
* Tf8 also split at the weirside bushes yesterday, and I filmed the mother bringing them back together. A subtle scene, but a great example of maternal care.
23:06 Tf8-49 – all 8 ducklings crossed the river together, then scattered again
23:58 Tf mother’s forehead injury—feathers growing back nicely
* Early on Tf母 was fierce and reliable but scary (even attacked Cf ducklings).
Since calming down, she seems less aggressive.
24:52 Uf1-45 safe! Fifth family born in the pond
▲▲▲ End of timestamps
*
So… an unexpected reunion with the オf family!
It’s sad that 5 ducklings were lost, but so happy to see them again.
Unfortunately, at the time I mistook them for ケf2 and didn’t realize… and now ケf2 itself is missing.
キf3 also wasn’t found this time—mysterious. Lf family too: I saw the mother solo recently, so I think they’re around, maybe an early fledging pattern?
On the bright side, I was happy to meet the Cf family at 74 days old.
Uf1 also has a special place in my heart since I saw their relocation—they’re the only survivors out of the pond’s 5th, 6th, and 7th families (Uf5, Vf8, Wf2). I really hope they make it.
* 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/2025/07/0725f.html
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