Abandoned Ducklings Mistake Another Female for Their Mother: Urban Wildlife Behavior of Spot-Billed Duck Families

Abandoned Ducklings Mistake Another Female for Their Mother: Urban Wildlife Behavior of Spot-Billed Duck Families

Along an urban river in Japan, several Eastern Spot-billed Duck families were observed interacting within the same small stretch of water. The most remarkable event involved six temporarily unattended ducklings that approached an unfamiliar female duck as though she were their returning mother. After briefly following her, the ducklings apparently recognized the mistake and drove the female away.

The same field session also documented a newly discovered brood of four young ducklings, dragonfly predation by a duckling, alarm behavior possibly triggered by a large fish, parent–offspring vocal communication, family reunions, and signs of increasing independence among older juvenile ducks.

This nearly unedited wildlife footage provides a continuous behavioral record of Eastern Spot-billed Ducks, Great Cormorants, Carrion Crows, Azure-winged Magpies, dragonflies, and freshwater fish in an urban riparian ecosystem. It may be useful as stock footage and as reference material for searches relating to avian parental care, brood recognition, filial imprinting, alloparental behavior, duckling development, predator response, vocal communication, urban ecology, waterfowl behavior, and long-term wildlife monitoring.

Species Featured in This Observation

1. カルガモ — Eastern Spot-billed Duck
Scientific name: Anas zonorhyncha

The Eastern Spot-billed Duck is a dabbling duck native to East and Southeast Asia. In Japan, it commonly breeds along rivers, ponds, canals, rice fields, and other urban or suburban wetlands.

Female Spot-billed Ducks normally raise their broods without assistance from males. Newly hatched ducklings remain close to their mother and respond strongly to her movements and vocalizations. As they develop, however, they become increasingly capable of feeding, swimming, resting, and making short-distance decisions independently.

The families in this record were distinguished by individual identification codes based primarily on the females’ tertial and flight-feather patterns. These naturally occurring plumage differences make it possible to follow multiple broods living in the same area.

Observed family groups included:

スf4 — A newly discovered female with four ducklings, estimated to be approximately seven days old.

シf6 — A female with six ducklings, approximately sixteen days old. The ducklings had repeatedly been observed waiting without their mother.

アf3 — A female with three juveniles, approximately forty-six days old.

Tf8 — An older family approaching two months of age. The juveniles were beginning to spend more time apart from their mother and siblings.

ジf — An unidentified female that displayed mother-like behavior toward the unattended シf6 ducklings. She may have previously lost a brood, although this interpretation remains unconfirmed.

2. カワウ — Great Cormorant
Scientific name: Phalacrocorax carbo

The Great Cormorant is a large piscivorous waterbird found on rivers, lakes, reservoirs, estuaries, and coastal waters. It captures fish by swimming and pursuing prey underwater.

A resting cormorant was closely watched by one of the ducks during this observation. Later, a cormorant and a crow encountered each other directly above the ducklings. The cormorant vocalized, and the young ducks immediately reacted to the disturbance.

3. ハシボソガラス — Carrion Crow
Scientific name: Corvus corone

The Carrion Crow is an intelligent and adaptable corvid commonly found in Japanese agricultural land, river corridors, parks, and residential areas. It is an omnivorous opportunist and may feed on insects, seeds, fruit, carrion, eggs, and small animals.

A possible Carrion Crow family was observed during this session. Crows can represent a potential threat to very young waterfowl, so their presence may influence vigilance and alarm behavior in adult ducks and ducklings.

4. オナガ — Azure-winged Magpie
Scientific name: Cyanopica cyanus

The Azure-winged Magpie is a long-tailed social bird belonging to the crow family, Corvidae. It often lives in groups and inhabits woodland edges, parks, gardens, agricultural areas, and urban green spaces.

One Azure-winged Magpie was recorded balancing in strong wind near the end of the observation.

5. トンボ類 — Dragonflies
Taxonomic order: Odonata

Dragonflies are predatory insects associated with freshwater habitats. Their aquatic nymphs develop underwater, while the winged adults hunt other insects in flight.

One シf6 duckling was observed capturing and eating a dragonfly. Young dabbling ducks consume a varied diet that can include aquatic invertebrates, terrestrial insects, seeds, vegetation, and other small food items. This event provides useful footage of opportunistic insectivory and juvenile foraging behavior.

The exact dragonfly species could not be determined from the available footage.

6. コイ — Common Carp or Carp Species
Likely scientific name: Cyprinus carpio

The Common Carp is a large freshwater fish widely established in Japanese rivers, ponds, canals, and reservoirs. Large fish moving near the surface may surprise small ducklings even when they are not actively attempting to prey on them.

The newly discovered スf4 family entered an intense state of vigilance, possibly after being startled by a carp beneath or beside them. Because the fish itself was not clearly identified, the cause of the alarm remains a field interpretation rather than a confirmed conclusion.

Video




Next day:
https://youtu.be/8ZH2dr4ZesA

Field Observation Log

00:00 — Edited Highlight Sequence

The opening three minutes present a short selection of notable scenes in non-chronological order. The continuous observation footage begins at 03:01.

03:01 — An Unexpected Duck Family Appears

A mother duck and several small ducklings were found immediately after arriving at the observation area.

At first, I suspected that they might be one of two previously recorded families, because they were swimming near a familiar resting structure. A closer look revealed four ducklings, however, and the female’s appearance did not match the mothers I already knew.

03:17 — Discovery of a New Brood: スf4

The ducklings were noticeably small, and the mother was unfamiliar. I therefore recorded them as a newly discovered family, スf4.

The four ducklings appeared to be approximately one week old. An age of around ten days was also possible, but their relatively small size, slow movements, and calm swimming style suggested that they were slightly younger.

They also behaved as though they had only recently entered this section of the river. I had monitored the area almost daily and had not previously seen them there.

05:56 — Slow-Moving Ducklings and Female Identification

The スf4 family continued moving at an unusually relaxed pace.

Because this was my first encounter with the female, I attempted to document the plumage of both wings, especially the tertial and flight-feather patterns used for individual identification. She repeatedly kept her right wing out of view, making a complete record difficult.

12:26 — Passing the Resting Platform Beneath the Bridge

The family reached a platform beneath a bridge but did not stop to rest.

Many ducks had recently gathered in the shaded area, but on this occasion the スf4 family was almost alone. The usually crowded site appeared unusually quiet.

13:53 — The Mother Stops and Reverses Direction

While traveling downstream, the スf4 female suddenly stopped and turned back upstream.

Abrupt directional changes can be associated with environmental assessment, disturbance avoidance, brood management, or a decision to seek a different feeding or resting area.

14:49 — A Duck Watches a Resting Great Cormorant

A duck stared intently at a resting Great Cormorant as another duck approached it.

Calls suggesting a recent dispute had been heard shortly beforehand. The cormorant’s size and movements appeared to attract the duck’s attention.

15:44 — Four Ducklings Swim Close to Their Mother

The four スf4 ducklings followed directly beside and behind their mother.

Close formation is especially important for very young ducklings. Staying near the female may assist with directional guidance, social cohesion, thermoregulation during rest, and rapid responses to threats.

17:50 — シf6 Found Without Their Mother Again

Farther away, the six シf6 ducklings were visible without their mother.

This was the seventh consecutive day on which some form of maternal absence or temporary abandonment had been recorded for this brood. By this stage, waiting without their mother appeared to have become a familiar part of their daily behavior.

Several unrelated ducks were gathered around the nearby resting board.

18:12 — A Duckling Captures and Eats a Dragonfly

One シf6 duckling successfully caught and consumed a dragonfly.

This scene documents active animal prey capture by a juvenile Eastern Spot-billed Duck. Although these ducks are often seen feeding on plant material and small aquatic organisms, growing ducklings also exploit insects and other protein-rich invertebrates.

19:13 — An Unfamiliar Round Stone

A round object resembling a stone had appeared in the area. It may have been placed there by a person, although its origin could not be confirmed.

19:38 — The スf4 Mother Detects the Other Brood

The スf4 female abruptly changed direction after apparently detecting the シf6 ducklings.

The scene is difficult to see clearly because the six ducklings were positioned among the concrete tetrapods.

20:06 — Two Broods Visible in the Same Frame

The older シf6 ducklings were visible in the upper-left portion of the frame, while the younger スf4 family occupied the lower-right.

The difference in body size between the approximately sixteen-day-old and approximately seven-day-old ducklings was clearly visible.

The シf6 brood moved toward the resting board but appeared reluctant to climb onto it because other ducks were already present.

22:29 — Possible Carrion Crow Family

Several crows were observed together and may have been an adult Carrion Crow accompanied by young birds.

24:07 — The Ducklings Cannot Access the Resting Board

The シf6 ducklings remained unable to climb onto their usual resting place because it was occupied by other ducks.

Access to secure resting structures can influence the movement, spacing, and waiting behavior of young waterfowl.

24:27 — A Female Duck Arrives and Calls

A duck flew into the area and vocalized in a manner resembling a mother contacting her brood.

The unattended ducklings immediately reacted to the arrival and the calls.

25:46 — Apparent Mutual Recognition

The female and the ducklings appeared to notice each other and began moving together.

At first, the interaction strongly resembled a reunion between a mother and her offspring.

26:26 — The Ducklings Join the Female, but Something Is Wrong

The six シf6 ducklings reached the female and briefly joined her.

On closer inspection, however, the bird did not appear to be the known シf6 mother. The actual mother was believed to be missing flight feathers from her left wing, while this female’s wing pattern appeared different.

Despite this mismatch, the newcomer’s calls, posture, and movements strongly resembled maternal behavior.

26:37 — The Ducklings Attack the Unfamiliar Female

The interaction changed abruptly. One or more ducklings appeared to attack or drive away the female, possibly after recognizing that she was not their mother.

The unfamiliar female then joined another adult duck that had been accompanying the brood. The シf6 ducklings continued following the adults toward the resting board.

This is an unusual behavioral sequence involving possible mistaken maternal recognition followed by rejection. The footage may be relevant to discussions of parent–offspring recognition, vocal recognition, visual discrimination, filial imprinting, brood mixing, adoption attempts, and alloparental behavior in waterfowl.

The exact motivation cannot be confirmed from the footage alone. The ducklings may have recognized an incorrect vocal, visual, olfactory, or behavioral cue, or the apparent aggression may have had another social cause.

27:37 — The Ducklings Finally Reach the Resting Board

The six ducklings successfully climbed onto the board after the ducks occupying it moved aside.

Their access to a resting location provided a brief resolution after the confusing interaction.

28:23 — The Unfamiliar Female Had Approached Them Before

The unknown female had also been seen near the シf6 ducklings on a previous day.

Her distinctive wing pattern made her comparatively easy to recognize, so I began recording her provisionally as the ジf female.

Her behavior during the apparent reunion closely resembled that of a mother responding to her own young. One possibility is that she had recently lost a brood and was still responding to duckling calls. This remains speculative and should not be regarded as a confirmed history.

28:59 — The New スf4 Family Enters an Alarm State

The newly discovered family suddenly showed signs of an emergency response.

A large fish, probably a carp, may have startled them. The mother became highly vigilant, and the brood’s relaxed movement changed immediately.

29:36 — The Mother Accelerates Upstream

The スf4 female rapidly swam away, and all four ducklings followed her.

The family continued upstream and disappeared from the main observation area. Their coordinated escape illustrates how quickly a brood can transition from slow foraging travel to urgent directional movement.

31:23 — The シf6 Ducklings Continue Waiting

The シf6 mother had still not returned.

The six ducklings remained together with the composed behavior of young birds that had experienced repeated maternal absences.

32:40 — Ducklings React to a Crow–Cormorant Encounter

A crow and a Great Cormorant encountered each other directly above the ducklings.

The cormorant vocalized, and the brood reacted immediately. Their response shows the sensitivity of young ducks to sudden calls, wing movements, and overhead disturbances.

33:59 — The ジf Female Remains Nearby

The unidentified female continued circling the area and appeared persistently interested in the unattended ducklings.

Her repeated proximity strengthens the impression that her response was not a momentary coincidence, although her precise motivation remains unknown.

37:48 — The Unidentified Female Flies Toward the Rice Fields

The ジf female left the river and flew toward nearby rice paddies.

A later search of the fields did not locate her or any accompanying ducklings.

38:02 — The Unattended Ducklings Begin Moving

Shortly after the unidentified female departed, the シf6 ducklings began to move.

One duckling appeared to pause for another, producing a scene in which a young duck seemed to be waiting for its sibling.

The timing suggested a possible connection with the departure of the ジf female, although this could not be demonstrated conclusively.

43:15 — Another Duck Arrives

A second adult duck flew into the area.

This time, the wing pattern and behavior suggested that the true シf6 mother might finally have returned.

43:28 — The Real Mother Returns

The arriving female was confirmed as the シf6 mother.

The six ducklings immediately reunited with her after their prolonged period of waiting and the earlier interaction with the wrong female.

This reunion provides a useful comparison with the false reunion. Differences in approach, following behavior, spacing, vocal response, and social stability may offer clues about how ducklings distinguish their actual mother from other adult females.

45:41 — The Mother Attempts to Rest

The シf6 female climbed onto the sleeping platform.

The ducklings had apparently only recently awakened and did not seem ready to rest again. The difference between the mother’s intended schedule and the juveniles’ activity level created a brief family conflict.

47:46 — Only Two アf3 Juveniles Are Visible

Two fast-swimming juvenile ducks from the アf3 family traveled upstream.

Only two of the expected three young birds were visible, and they appeared to be moving urgently.

48:59 — The Mother Stops and Calls

The アf3 mother suddenly stopped and vocalized.

A juvenile’s call could be heard from downstream, indicating that one family member had become separated from the others.

49:32 — The Missing Juvenile Reappears

The third juvenile was located and successfully rejoined the family.

The reunion was coordinated through movement and vocal contact. This scene demonstrates the importance of contact calls in maintaining brood cohesion when older juveniles are traveling over longer distances.

50:48 — The Complete Family Moves Upstream

With all three juveniles reunited, the アf3 family continued upstream.

Their speed suggested purposeful travel rather than relaxed feeding.

52:02 — Older Juveniles Rest Without Their Mother in View

Five juvenile ducks, probably members of the Tf8 family at approximately fifty-eight days old, were sleeping together.

The adult female was not visible.

At this age, the young ducks were approaching fledging and showing increased independence in their choice of companions and resting positions.

52:50 — Green Appearance of the Speculum

The wing speculum of one approximately fifty-eight-day-old juvenile appeared green under the available lighting conditions.

Structural feather colors can change in appearance depending on the angle of observation, sunlight, feather condition, and camera exposure.

After this scene, I searched nearby rice paddies during a short break. The unidentified ジf female was not found. I also searched likely resting locations because the repeated absences of the シf6 mother raised the possibility that additional ducklings might occasionally remain elsewhere. No further brood was discovered.

53:44 — Tf Family Members Return to a Familiar Resting Site

The Tf mother and two juveniles moved toward their usual sleeping area.

Other juveniles were resting separately, indicating that the gradual process of family dispersal and independence had begun.

54:28 — The アf3 Family Rests Together

The adult female was initially visible without an obvious view of her young.

A closer look revealed all three juveniles clustered tightly together like three small sleeping dumplings.

56:07 — Azure-winged Magpie in the Wind

An Azure-winged Magpie was filmed balancing as its feathers and long tail were moved by the wind.

End of Recorded Timestamps

After the documented sequence, I repeatedly searched upstream for the new スf4 family but could not relocate them.

They were probably still present within the area, but two major resting locations were occupied by members of the Tf family. The young brood may therefore have entered a concealed bank, shaded structure, vegetation patch, or another resting place that was difficult to observe.

Field Summary

This observation unexpectedly produced several valuable behavioral records.

The newly discovered スf4 brood added another active Spot-billed Duck family to an already crowded urban river system. The young ducklings’ slow travel, close formation, sudden alarm response, and rapid upstream escape provided a compact record of early brood behavior.

The シf6 family produced the most unusual event. After being left without their mother, the ducklings responded to another female, approached her, and appeared to join her. They then apparently recognized that she was not their mother and drove her away.

Because the female had approached the same brood before and displayed behavior strongly resembling maternal care, her actions raise several possibilities. She may have been responding instinctively to the ducklings’ calls, attempting to associate with them, seeking her own missing young, or simply participating in an interaction that looked maternal from the camera’s perspective.

The later return of the true シf6 mother provides an important behavioral contrast and confirms that the first female was not the brood’s regular parent.

The アf3 reunion also showed how older juveniles and their mother use vocalizations to locate a temporarily separated family member. Meanwhile, the Tf juveniles appeared to be entering a new developmental stage in which siblings and the mother no longer remained continuously together.

I had originally intended to spend less time observing the frequently unattended シf6 brood and to search for another family farther downstream. The discovery of the new スf4 brood in the same area changed the entire plan.

Long-term wildlife observation repeatedly demonstrates that even a familiar river can produce unexpected behavior without warning.

Individual Identification of Duck Families

Because many Spot-billed Duck families occupy the river simultaneously, I identify adult females by comparing their tertial and flight-feather patterns.

Reference images and identification notes for the females recorded during this period are available here:

https://okasinaikimono.blogspot.com/2025/08/0803f.html

Purpose of This Unedited Wildlife Record

My YouTube Shorts primarily feature Eastern Spot-billed Duck families and other remarkable moments of urban wildlife.

Short-form videos, however, often use background music, sound effects, selective cuts, slow motion, captions, and narrative editing. Those techniques can make an event easier to understand and more emotionally engaging, but they can also make it difficult to evaluate what actually happened in the field.

I personally approach heavily edited wildlife footage with caution. A short sequence may omit the events that came immediately before or after it, and editing can unintentionally alter the apparent timing, motivation, or meaning of animal behavior.

The scenes used in my short videos are always extracted from longer recordings like this one. These minimally edited records document the animals continuously and provide the evidence behind the shorter stories.

For more than 1,000 days, I have recorded wildlife by date and preserved long stretches of ordinary activity alongside rare events. A single day’s footage may seem uneventful or inconvenient to watch, but a chronological archive can reveal changes that isolated highlight clips cannot show.

These records may help document:

• The growth and survival of individual duck broods  
• Changes in brood size  
• Maternal absences and reunions  
• Feeding and resting behavior  
• Predator and disturbance responses  
• Seasonal changes in river conditions  
• Juvenile development and independence  
• Repeated use of specific resting sites  
• Interactions among multiple duck families  
• Changes in urban biodiversity over time  

I understand that long, nearly unedited footage is not convenient for every viewer. Nevertheless, I believe that the accumulated archive has value as field documentation, behavioral reference footage, stock wildlife material, and evidence of daily ecological change.

I hope these records will be useful to researchers, educators, filmmakers, birdwatchers, wildlife enthusiasts, and anyone who enjoys observing the lives of animals as they unfold naturally.

🦆 Raw Bird & Wildlife Footage | No BGM 🌍️

https://www.youtube.com/playlist?list=PLL7dTQKKqrPzZpmfSA98tn9tXWfkp1jBB

 00:00 Highlights (unordered)

03:01 Oh, a duck family already! Is it キf3 or シf6...? Hmm? * It’s near the mystery board, so likely one of them—but there are only 4 ducklings... 03:17 Small ducklings… unknown mother duck… could it be a new family!? Looks like スf4, around 7 days old? * Surprising! I debated calling them 10 days old, but they seemed slightly younger and moved very slowly—so I’m setting them at about 1 week. * Seems like it’s their first time coming here (I’ve been checking this area daily lately). 05:56 Very slow-moving スf4 * I want to record the mother’s feather pattern on first sighting, but she won’t show her right wing 12:26 They reached the footing under the bridge but didn’t rest. * Recently, many ducks gathered in the shadows, but now it’s just スf4—feels a bit lonely. 13:53 スf母 stopped and turned back upstream. 14:49 She stared hard at a resting cormorant that approached. * Sounded like a scuffle just before—heard agitated calls. 15:44 スf4 swimming right beside their mother. 17:50 In the distance—シf6-16. Another motherless day... * At this point, it’s just a given. That’s 7 straight days of abandonment. * Several other ducks were at the mystery board. 18:12 ★ One of the シf6 ducklings caught a dragonfly! 19:13 Mysterious round stone… did someone place it there? 19:38 スf母 suddenly turned sharply—perhaps sensing シf6 nearby? (シf6 was on the tetrapod, hard to see) 20:06 シf6 on the upper left, スf4 on the lower right—duckling sizes clearly different! * シf6 headed toward the mystery board but seemed to hold back due to others already there. 22:29 Possibly a Carrion Crow parent and chick? 24:07 シf6 couldn't land on the mystery board. 24:27 ★ A duck flew in! Looks like a mother, calling out! Ducklings respond! 25:46 ★ Did the ducklings and the mother notice each other? 26:26 ★ シf duckling reunited! …Wait, doesn’t look like シf母... * シf母 is missing left primaries… but this one acts motherly… hmm? 26:37 ★ Duckling attacks… did it realize it’s not their mother!? * The fake mother joined another duck (had been trailing シf6 ducklings) and headed toward the mystery board. シf6 ducklings followed... 27:37 ★ シf6 ducklings landed on the mystery board! The previous occupants gave them space—phew! 28:23 The fake mother is a female I saw the other day… (she approached シf6 ducklings then too) * Her calls and behavior during that "reunion" were completely mother-like… hard to say, but I feel like she might be a mother searching for lost ducklings. Since she’s identifiable by feather pattern, I’ll record her as ジf母 for now. 28:59 ★ Emergency? スf4 suddenly on high alert—probably startled by a koi fish. 29:36 ★ スf母 dashed off, ducklings followed, heading upstream. 31:23 シf6 still left alone. Totally composed as usual. 32:40 ★ Ducklings reacted—a crow and a cormorant crossed paths right above; cormorant called. 33:59 Mysterious female (ジf母) still lingering around シf6 ducklings. 37:48 Mysterious female flew off toward the rice fields. 38:02 ★ シf6 started moving. One duckling waited for another * The timing lines up with ジf母 flying off—might be related. 43:15 ★ A duck flew in… is it the real mother this time!? 43:28 ★ It’s シf母! Finally returned and reunited! 45:41 シf母 landed at the bed site. But the ducklings just woke up—don’t want to nap yet 47:46 ★ アf3-46 with just 2 ducklings… swimming fast, heading upstream quickly. 48:59 ★ アf母 suddenly stopped and called! Heard duckling calls from downstream! 49:32 ★ There it is!! The duckling! アf3 reunited—so glad. 50:48 アf3 family heading upstream together. They seem to be in a hurry. 52:02 Probably Tf8-58. 5 ducklings sleeping, mother not in sight. 52:50 Wing speculum looked green. 58-day-old ducklings. * After this, I searched the rice field during a break. No sign of ジf母. If there are families there, the napping spots are limited, so I checked thoroughly… found nothing. (I suspect some シf6 ducklings may be left behind there due to frequent abandonment.) 53:44 Tf mother and 2 ducklings at their usual bed site. The ducklings are starting to go independent. 54:28 Looks like a mother… where are the ducklings? …Found them Adorable dango trio アf3 56:07 Azure-winged magpie blowing in the wind. ▲▲▲ End of timestamps. Afterword: I couldn’t find スf4 again despite carefully searching upstream. I believe they’re still around but probably slipped into a hard-to-see place—two key Tf sites were already occupied, so likely somewhere hidden. So, today brought the unexpected encounter with a **new duck family スf4**! And シf6 ducklings mistook another female for their mother—but then realized and drove her off, a rare scene. The reunion between a possibly lost duckling and アf3 was also very touching. Originally, I had planned to check in on オf2 downstream and give シf6 a rest (given her daily abandonments), but スf4 showing up near シf6 changed everything—I ended up staying in that one area all day. Tf8 is approaching 2 months old, and upstream Sf9 is a peer I haven’t seen in a while— I hope to search upstream again soon. Truly… you never know what will happen each day. * To keep track of the many duck families, I use the mother duck’s tertial feather pattern and code system. [Reference List ↓] https://okasinaikimono.blogspot.com/2025/08/0803f.html