A young Eastern Spot-billed Duck became separated from its family and was bitten during a tense encounter with another duck. Elsewhere along the same river system, a mother unexpectedly flew away from seven resting ducklings, while another newly discovered family became divided between dense riverside vegetation and an adjacent rice field. This continuous wildlife observation documents aggression, temporary abandonment, reunion, territorial defence, and parent–young communication among urban duck families.
Observation Video
Main Species Featured
カルガモ — Eastern Spot-billed Duck — Anas zonorhyncha
A resident dabbling duck widely found in East Asia. Females raise their young without help from males, and family groups must navigate predators, territorial adults, artificial river structures, strong currents, and frequent encounters with unrelated ducks.スズメ — Eurasian Tree Sparrow — Passer montanus
A small bird closely associated with human settlements in Japan. During this observation, an adult collected duck feathers while a recently fledged juvenile continued begging for food.
Field Conditions and Scope of the Record
This observation was recorded during a period of strong wind associated with an approaching typhoon. The survey covered the main river, tributaries, riverside vegetation, weirs, and nearby rice fields.
The footage forms part of a continuous, day-by-day record of urban wildlife. I am not a professional ornithologist, and the interpretations presented here are those of an amateur observer based on repeated field encounters, video evidence, family identification patterns, and comparisons with observations made on preceding and following days.
Whenever visibility was poor or identification remained uncertain, I have preserved that uncertainty rather than presenting an assumption as fact. The upload date also corresponds to the filming date, allowing the videos to function as chronological evidence across multiple days.
The Missing カf Duckling Was Reunited With Its Mother
The first priority of the day was to search downstream for カf1, a single young duckling that had been found without its mother during the previous day’s observation.
At 03:37, the カf mother was located. The duckling was not immediately visible, but at 03:52 it appeared beside her. The family was recorded as カf1-15, confirming that the missing duckling had successfully reunited with its mother sometime after the preceding observation ended.
This is an important limitation of field observation. A camera can document separation and later reunion, but it does not necessarily capture the process that occurs between those two events. Nevertheless, the consecutive daily records provide circumstantial evidence that the duckling survived the night and found, or was found by, its mother.
Later in the day, the カf family rested among dense vegetation near several unrelated ducks. The duckling was frequently hidden, making the pair difficult to recognise as a family. The mother eventually drove the surrounding ducks away, demonstrating that she remained attentive and capable of defending the area around her offspring.
Mf1-47: An Older Duckling That Sometimes Leads Its Mother
The Mf family, consisting of one approximately 47-day-old juvenile and its mother, was first observed sleeping together.
This was reassuring because the two had also been seen apart on the previous day. At this age the young duck was already large and increasingly independent, so the earlier separation had not appeared as immediately dangerous as the separation of a very young duckling.
After waking, the Mf juvenile approached and drove away another duck. The behaviour appeared aggressive, although its purpose could not be determined from the footage alone. It may have involved defence of space, competition, or a reaction to proximity to its mother.
Interestingly, this juvenile has often appeared to choose the family’s direction while the mother follows. At 14:34 the mother briefly moved in front, but the juvenile soon resumed the leading position. This reversal of the typical visual image of a mother leading small ducklings may reflect the increasing autonomy of an older offspring.
The juvenile’s aggression was also selective. It challenged some ducks but moved away from a mother accompanied by small ducklings. A single observation cannot establish a consistent social rule, but the contrast was notable.
A Solitary Duckling Was Bitten by an Older Duck
At approximately 16:29, one of the most serious encounters of the day occurred.
A small duckling believed to belong to the キf family approached an older reddish-toned duck. The other duck had just returned after threatening a group of four young ducks believed to be Df捨4-59.
The older duck did not initially appear to be actively hunting or pursuing the small duckling. However, the duckling showed little avoidance and approached closely. After an intense threat display, the larger duck bit the duckling.
The young duck escaped and was subsequently seen alone. Its isolation suggested that it had become separated from the キf family. It wandered for some time before sleeping alone near the resting site used by the same family on the previous day.
This event illustrates how temporary separation may expose a duckling to risks beyond predation. Encounters with unrelated ducks can include displacement, pecking, biting, or territorial aggression. A lone duckling lacks both the protective presence of its mother and the collective movement of its siblings.
The footage does not prove that the attack caused an injury, and no obvious lasting physical damage was confirmed. The duckling was later reunited with its family.
キf7-4: Seven Ducklings Reunited After Another Separation
After the isolated duckling entered vegetation, calls were heard and an adult female approached from deeper within the area. Visibility was poor, and the number of accompanying ducklings could not immediately be confirmed.
At 26:10, several ducklings emerged. By 28:11, all seven could be counted, confirming the family as キf7-4. The solitary duckling that had been bitten was therefore back with its mother and siblings.
This was the second consecutive day in which one member of the キf brood had remained separated for an extended period. Both incidents ended in reunion, but the repetition may indicate that this family was moving through particularly complex habitat, or that one duckling was more prone to losing contact with the group.
Individual differences among siblings are often visible in the field. Some follow closely, while others stop to feed, explore vegetation, hesitate at obstacles, or move independently. It is difficult to determine whether repeated separation reflects temperament, physical condition, chance, or the structure of the habitat.
The Mother Suddenly Flew to a Rice Field
Soon after the seven ducklings settled at their resting site, the キf mother bathed and then unexpectedly flew away at 29:12.
The ducklings remained behind, scattered across the resting area. They did not immediately follow, and because they were still very young, they could not accompany their mother by flight.
One isolated duckling eventually moved toward its siblings, forming a compact resting shape resembling a small water dumpling. The behaviour may simply have reflected a preference for physical contact, shelter, or warmth, although loneliness cannot be objectively determined from appearance alone.
The mother could not initially be found. She was later seen emerging from a rice field, suggesting that she may have flown there to feed. She then returned toward the ducklings.
Surprisingly, the young did not immediately rush toward her. When the brood was divided to the left and right, the mother moved toward one side and the ducklings gradually followed.
Temporary maternal absence can easily resemble abandonment when observed only briefly. Continuous recording is therefore important. In this case, the mother returned, resumed contact with the brood, and repeatedly defended the area from other ducks.
Territorial Defence Around the Resting Site
The resting area attracted several unrelated ducks throughout the observation.
A group believed to be Df捨4 approached the キf family’s sleeping place, and the キf mother drove them away. She later reacted aggressively again when the same or another nearby duck returned.
At 40:25, one キf duckling left the resting area alone. After travelling some distance, it appeared to realise that it was separated and began calling. The mother responded and approached it. The remaining siblings did not follow, and the wandering duckling eventually returned quietly to the resting site.
This short event showed the importance of vocal contact. Although the exact calls and responses cannot be translated into human terms, the timing suggests that sound helped the separated pair locate one another.
The mother continued to drive away other ducks at several points later in the day. Her willingness to leave briefly for the rice field therefore coexisted with strong defensive responses when unrelated ducks entered the brood’s immediate space.
Rather than classifying her simply as attentive or inattentive, the record suggests a more complicated balance between feeding, spatial defence, movement, and maintaining contact with seven young.
Two Duck Families Shared the Same Dense Riverside Area
At 42:44, another adult female moved cautiously through the same vegetation. Her movement along the edge of the plants resembled that of a mother guiding a hidden duckling.
At 43:26, a young duck appeared behind her. This was the カf1 family observed earlier in the day.
The reddish duck that had bitten the isolated キf duckling was also present nearby, but this encounter remained peaceful. Additional ducks entered the site, and the vegetation frequently concealed the young duckling.
At one point the カf mother was visible while her offspring remained completely hidden, making the two appear unrelated unless their earlier movements had been followed. This demonstrates why brief observations can produce misleading conclusions about family composition.
The キf7 family later departed toward a tributary. The カf1 family also entered the same general area, but the families appeared to pass one another without conflict. Shortly afterward, the キf family emerged, suggesting that both broods had used the vegetation without a serious encounter.
The キf mother later avoided the particular thicket where a duckling had become separated on the preceding day. It is impossible to establish whether this represented memory or deliberate avoidance, but the changed route was worth recording.
Possible Identification of Df捨4-59
A group of four young ducks was seen below the weir and was repeatedly threatened by other ducks.
Their exact identity could not be proven. Af was considered as an alternative, but Df捨4 appeared more likely because four individuals remained together, their behaviour resembled earlier observations of that group, and their location below the weir was consistent with their recent absence upstream.
A prolonged wing-flapping display at 20:33 also supported the Df interpretation, although this remains a field identification rather than a confirmed result.
Such uncertainty is unavoidable when following numerous similar-looking ducks. Individual recognition is based on a combination of the mothers’ tertial feather patterns, family size, age estimates, habitual locations, behaviour, and continuity from previous observations.
Strong Wind and a Duck With a Damaged Wing
A duck previously observed with a damaged or abnormally positioned wing was recorded again at 10:34.
Strong gusts affected the river throughout the day, apparently linked to the approaching typhoon. At 23:31, a young duck performing a wing-flapping movement was visibly disturbed by the wind.
The footage does not establish how the injured duck’s wing was damaged or whether the condition was improving. It is included because repeated documentation may later reveal changes in mobility, survival, or behaviour.
Hf2-55 and Other Older Families
The Hf2 family was encountered again after an interval. The two young ducks, approximately 55 days old, had developed substantially.
Their approach toward the observer may have been associated with food-conditioning by people. I cannot confirm the cause, but movements that appear to anticipate feeding are personally troubling because habituation can alter normal avoidance behaviour and increase dependence or risk.
Other established families were also observed:
イf4-43 resting together.
Lf4-47, with the mother calling repeatedly.
イf and Lf mothers apparently reacting to one another’s presence across the river.
Tf8-39 sleeping in a dispersed group and later waking, stretching, and flapping their wings.
All eight Tf juveniles were eventually counted.
A Eurasian Tree Sparrow Collected Duck Feathers
At 1:14:52, a Eurasian Tree Sparrow family created a smaller but notable observation.
An adult sparrow collected duck feathers, apparently as nesting material, while a nearby juvenile begged for food. The juvenile did not receive food during the recorded moment. The adult later returned to collect another feather.
The coexistence of fledged young and active nest-material collection raises the possibility of another nesting attempt, nest maintenance, or replacement of lining material. However, a direct conclusion cannot be drawn from this brief sequence.
Duck feathers are light, insulating, and readily available around communal resting sites. Their use by small birds shows how materials produced by one species can become resources for another within the same urban ecosystem.
A Newly Recorded Family: クf5-5
At 1:22:11, five small ducklings were discovered moving without an adult.
They called while travelling and eventually entered dense vegetation, apparently waiting there. At first, they were suspected to belong to another known family, possibly オf, but an adult female soon flew into the area.
The mother appeared to be searching for the young. She landed near a place the ducklings had recently occupied, called, moved again, and repeatedly failed to locate them. Meanwhile, the ducklings had apparently continued farther along the vegetation line.
For several minutes, the mother and young were both present in the same general landscape but separated by distance, plants, and movement. The mother searched near the rice field while the ducklings remained difficult to see.
At 1:36:40 the five ducklings were located again. Seconds later, the mother flew toward them and the family reunited.
Because this female did not match the expected known family, the group was provisionally recorded as a newly observed family: クf5-5.
The ducklings may have been slightly older than five days, but their size did not appear consistent with an estimate as high as seven days. Age estimation from body size is imperfect because growth rates, posture, distance, lighting, and individual variation can all influence appearance.
For consistency, the provisional age of five days was retained rather than repeatedly adjusting the estimate to match uncertain visual impressions.
Why Parent–Young Separation Is Difficult to Interpret
Several distinct forms of separation occurred during this single observation:
A duckling that had been missing on the previous day was confirmed reunited with its mother.
A キf duckling became isolated, was bitten by another duck, and later rejoined its family.
The キf mother flew to a rice field while all seven ducklings remained behind.
One キf duckling briefly wandered away and called until its mother approached.
The newly identified クf mother and her five ducklings searched for one another from different parts of the same habitat.
Older juveniles such as Mf1 were also sometimes physically separated from their mothers, but at a developmental stage when such distance appeared less dangerous.
These cases should not all be described simply as abandonment.
Some separations may result from feeding, vegetation, rapid movement, disturbance, sibling differences, or the inability of young ducklings to follow a flying adult. Others may create genuine danger even when they last only a short time.
The camera records visible behaviour, but not intention. For that reason, terms such as “searching,” “waiting,” or “defending” are used as observational interpretations rather than definitive statements about the birds’ mental states.
A River Becoming Increasingly Crowded With Duck Families
By the end of the survey, both キf7 and カf1 remained alive and reunited with their mothers. The newly observed クf5 family had also reunited after a prolonged search.
At the same time, the day revealed several sources of risk: aggressive encounters with unrelated ducks, dense vegetation that separated family members, strong wind, repeated maternal departures, and a growing concentration of families within the same limited spaces.
The arrival of クf5 marked the second consecutive day in which a previously unrecorded family was discovered. As the number of broods increased, it became more difficult to survey the full river system. Following one separated family often meant being unable to inspect another upstream area.
This is one reason the daily record is valuable. No single observation provides a complete picture, but consecutive records can reveal survival, disappearance, reunion, changes in family size, movement across weirs, and repeated use of particular resting or feeding sites.
Observation Codes
The filming date code for this record is 0715F:
0715 indicates July 15.
F represents the year 2025.
Duck family codes identify the mother, the observed brood size, and the estimated age of the young.
For example:
キf7-4 indicates the mother identified as キf, seven ducklings, and an estimated age of four days.
カf1-15 indicates the mother identified as カf, one duckling, and an estimated age of 15 days.
クf5-5 indicates the newly recorded クf mother, five ducklings, and an estimated age of five days.
The Japanese katakana characters used in codes such as カf, キf, and クf are individual identification symbols. They are not interchangeable with Roman alphabet letters and must remain in their original form.
A full explanation of the date codes, duck family identification system, and purpose of this long-term observation project is available here:
https://okasinaikimono.blogspot.com/p/welcome-to-wild-duck-diaries.html
This article is based on continuous daily field observations and minimally edited video records. The behavioural comments are personal interpretations by a long-term wildlife observer, not conclusions from controlled scientific research. By preserving each day’s footage and comparing events across consecutive dates, the project aims to create an honest chronological record of urban wildlife behaviour and the changing lives of individual duck families.
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