Journal of Natural Resources and Environmental Management http://dx.
org/10.
29244/jpsl.
RESEARCH ARTICLE
The Display Behavior of Sub-Adult Greater Bird-of-Paradise (Paradisaea apod.
A Learning Process from an Adult? Raka Aditya Pramunandyaa.
Ani Mardiastutib.
Yeni Ariati Mulyanib.
Vinoba Chandrac Tropical Biodiversity Conservation Study Program.
Graduate School.
IPB University.
IPB Darmaga Campus.
Bogor, 16680.
Indonesia Department of Forest Resource Conservation and Ecotourism.
Faculty of Forestry and Environment.
IPB University.
IPB Darmaga Campus.
Bogor, 16680.
Indonesia Inocin Abadi Ltd.
Korindo Group.
Boven Digoel.
Papua, 99611.
Indonesia Article History Received 27 December 2023 Revised 19 February 2024 Accepted 20 February 2024 Keywords display, learning behavior, lek tree.
Papua
ABSTRACT
The Greater Bird-of-Paradise (Paradisaea apod.
is a bird that performs a courtship display .
to attract females during the mating season.
The objective of this study was to examine the display behavior of adult and sub-adult males on lek trees as a learning process by a sub-adult and identify the lek trees.
The research was conducted in the Tunas Timber Lestari Ltd.
Production Forest in central mainland Papua, in a non-breeding season.
After a lek tree was found, a video recording was Analysis was performed from the video.
The lek tree was an emergent species with a dense canopy.
An adult male was observed to perform a dance display in front of sub-adult males, even in the absence of females.
When adult males performed display, the sub-adult were observed the adult males in an upside-down position.
The sub-adult also danced, but not as complete as the adult, suggesting that there was a learning process by the sub-adult.
This study revealed that the sub-adult/young males of the bird-of-paradise has the ability to dance inherit from their fathers, and then perfect the dance through practice and watching adults.
The lek tree surely need to be protected for the survival for this species.
Introduction The Greater Bird-of-Paradise (Paradisaea apoda.
Family: Paradisaeida.
is an endemic bird species on Papua Island.
It is distributed in the southern part of the Jayawijaya Mountain range, mostly in Indonesian Papua and on Aru Island, a satellite island in the western part of Papua .
As a member of the Paradisaeidae family, the Greater Bird-of-Paradise also performs a complex and fascinating display, a ritual dance conducted on a lek tree where males gather to do the lekking to mate with females .
The lek tree of the greater bird-ofparadise commonly consists of horizontal tree branches with an approximate diameter of 8 cm, positioned at an elevation more than 20 m from the ground, and situated beneath a moderately dense canopy .
The most well-known feature of the Greater Bird-of-Paradise is the extraordinary, magnificent plumage of the male bird, which is important for dancing and is fully developed during the breeding season.
In the nonbreeding season, the colorful, bright, and shiny plumage slowly molts .
The female Greater Bird-of-Paradise is strikingly different from that of males.
it has a plain brown color .
Research on the display behavior of this species in the last ten years is scarce, and thus, some older publications .
Ae.
are still used as references in this paper.
Some published papers were available for the closest kin of the genus Paradisaea .
, namely the Lesser Bird-of-Paradise (Paradisaea mino.
Ae.
, which is distributed along the northern coastal area of Papua, including small adjacent satellite islands .
Display behavior in the greater bird-of-paradise is typically associated with the breeding season, although previous research .
has suggested that this display behavior could occur throughout the year.
In general, display behavior is influenced by two factors, namely, internal factors .
, genetics, inherited by parent.
and Corresponding Author: Raka Aditya Pramunandya aditya95@gmail.
Graduate School.
IPB University.
IPB Darmaga Campus.
Bogor.
Indonesia.
Tropical Biodiversity Conservation Study Program.
A 2024 Pramunandya et al.
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC BY) license, allowing unrestricted use, distribution, and reproduction in any medium, provided proper credit is given to the original authors.
Think twice before printing this journal paper.
Save paper, trees, and Earth! external factors .
, environmental factors, obtained after birt.
, with one common external factor being influenced by other individuals, including young and adult individuals .
During the culmination of the display, the female selects the preferred male .
resumably males with an appropriate danc.
for the copulation process .
After copulation, the female lays eggs, incubates, and raises the chicks by herself .
More detailed information on the nesting behavior of the greater birds-of-paradise .
ncluding the number of eggs, incubation period in the wild, and weaning perio.
is virtually almost not unavailable.
The only indirect information about nest selection by the female parent was on a large and dry fern plant that patches tall trees .
Certainly, in the lek breeding system, the female was responsible for raising the young, without the presence of the males .
Meanwhile, dancing behavior was conducted by males.
Some birds have the ability to AolearnAo behaviors from other individuals or events in their environment, especially those related to vocalizations and movements as adaptive responses .
This learning and observational process aids juveniles in acquiring and imitating display movements upon reaching maturity during the subsequent breeding seasons .
, which might also occur in the Greater Bird-of-Paradise.
The act of imitating movements from others is also called AocopyingAo .
The objectives of this study were to .
examine the display behavior of adult and subadult males of the Greater Bird-of-Paradise on lek trees as a learning process by a sub-adult, and .
identify lek trees and their characteristics.
The research also tried to reveal whether there was a learning and copying process by the male sub-adult through watching the adult male performing the ritual dance.
Materials and Methods Study Area The study was conducted in the production forest .
ogging concessio.
of Tunas Timber Lestari Limited Liability Company (Ltd.
Boven Digoel Regency.
South Papua Province, in December 2022, which corresponded to a rainy season.
The study area was a mixed dry forest with an altitude range of 25 to 100 m above sea level.
Tunas Timber Lestari Ltd.
holds a Timber Forest Product Utilization Business Permit for natural forests.
The company harvested timber by using a selective cutting system.
To locate the Greater Bird-of-ParadiseAos lek, a preliminary observation was conducted from December 10 to 14, 2022.
Figure 1.
Research map depicting the observation point located in the mixed dry forest of Tunas Timber Lestari Ltd.
concession area, bordering with Inocin Abadi Ltd.
This journal is A Pramunandya et al.
JPSL, 14.
| 506
The local people who had a good understanding of the forest conditions and lek tree location provided valuable information that aided in identifying observation points for birds and the locations of lek trees.
The difficulty in finding a lek tree was because the peak breeding season, which normally occurs from July to September, had already passed.
After four days of intensive searching through the forest, a lek tree was discovered in the Tunas Timber Lestari Ltd.
concession area, near the border of another concession area of Inocin Abadi Ltd.
(Figure .
The location of the lek tree was not too far from the Inocin Abadi Camp, where some employees of the company .
pproximately 200 household.
were accommodated.
The trees were identified and measured, including the tree species, height, diameter at breast height (DBH), bole .
height, tree canopy diameter, leaf density, dominant species, canopy layer, forest floor density, clumps, emergent large trees, non-emergent large trees, disturbances, and distance to the village and road.
Observation of Bird Behavior The first encounter with a group of bird parasites occurred on December 15, 2022, one day after the lek tree was discovered.
Ten Greater Bird-of-Paradise individuals were recorded, comprising four females and six males that were not displayed.
The following day, an observation blind was established at a distance of 15 m and a vision angle of approximately 45A from the eastern side of the lek tree.
The constructed blind was covered with a black raincoat and nibung palm (Oncosperma tigillariiu.
leaves to minimize any disruption to the Greater Bird-of-Paradise throughout the observation period (Figure .
Intensive observation of the behavior was conducted for two days, from 6:00 am to 11:00 am .
ocal tim.
, aligning with the peak display activity period in the morning until midday .
afternoon and evening observations were omitted considering the anthropogenic disturbances caused by various human activities in the study area.
On the second day, when the Greater Bird-of-Paradise was not observed within an hour, a playback recording of the lek call was initiated to attract the bird to the lek tree.
The playback recording stopped upon the bird's Individuals perched on the lek tree were documented through videographic recordings using a Sony Alpha 7 Mark II digital camera equipped with a Sony Gmaster FE 200Ae600 mm telephoto lens and a Sony 2x converter extension attached to a tripod.
A total of 311 s of video recording was captured, but only 116 s .
3%) contained the most important information and were used to analyze the behavior.
Figure 2.
The observation blind was covered by a raincoat .
and point of view from inside the observation blind .
Data Analysis After emitting unnecessary sounds, the video data obtained were interpreted descriptively by examining individual morphology, timing of certain displays, interactions between individuals, and movements during displays and non-displays.
The display movements of the Greater Bird-of-Paradise were categorized as wing pose, pump, bow, and dance .
(Table .
http://dx.
org/10.
29244/jpsl.
JPSL, 14.
| 507
Table 1.
Display lek behavior of the Great Bird-of-Paradise .
Display Wing pose Pump Bow Dance Description Uphold the wings and tail for a couple of seconds and chirp AuwaukAy.
The body is lowered, wings are extended, the head is slightly lowered, legs are stretched out, the tail is moved rapidly, and movement from one branch to another is repeated.
The head is lowered, the rear is arched, wings almost embrace the branch.
It emits a 'baa' sound, the body remains stiff for up to a minute.
this position marks the end of courtship.
Females are not always present during this stage.
Jumps and flapping wings, repeated.
Results and Discussion Lek Tree A Syzygium sp.
amily: Myrtacea.
, located at coordinate 6A40'xx"S, 140A35'xx"E .
xact location was hidden for a security reaso.
was identified as the lek tree for the bird-of-paradise in the study area (Figure This tree emerged, although its diameter was not too large (Table .
and the canopy had a moderately dense cover, allowing sunlight to penetrate.
Despite its proximity to a residential area, the Syzygium sp.
serving as a lek site, was considered relatively safe because of its height.
The presence of numerous large trees and shrubs around lek trees created a lush environment.
Figure 3.
Syzygium sp.
was used as a lek tree by two individuals: .
tree structure, .
forest canopy, and .
dense leaves of Syzygium sp.
Table 2.
Description of the lek tree of the Greater Bird-of-Paradise located in the concession area of Tunas Timber Lestari Ltd.
Variable Description Location Forest type Lek tree species Diameter at breast high Tree height Branch-tree section Tree canopy diameter Leaf bushiness Dominant species Canopy layer Floor forest density Clumps Emergent big tree Tunas Timber Lestari Ltd.
Annual Logging Plan (Rencana Kerja Tahuna.
2021 Dry mix forest Jambu (Syzigium sp.
30 cm Medium Jambu (Syzigium sp.
Dense Not much Many This journal is A Pramunandya et al.
JPSL, 14.
| 508
Variable Description Non-emergent big tree Disturbance Not many Close to the village, many footpaths, the sound of logging traffic can be heard, close to the daily activities of the local people.
Distance to the nearest Distance to the nearest The lek tree was located at a short distance from the residential area of Inocin Abadi Camp.
However, the residents in that area generally did not disturb the Greater Bird-of-Paradise or the lek trees.
Their activities mainly involved gathering firewood and hunting small animals such as wild chickens and Columbidae birds.
Additionally, there was a small hut on the edge of the forest where residents received a signal in the evening.
The lek tree was also relatively close to the main road.
therefore, when logging vehicles passed by, noise and vibrations could be detected from the lek tree.
Despite some disturbances in the surrounding area, the activity of the Greater Bird-of-Paradise seemed to continue.
Morphology of Bird Being Observed The two Greater Birds of Paradise exhibited yellow heads with green throats, brown bodies, and wings, indicating that they were both male.
Furthermore, the two focal birds could be differentiated by the color of their head feathers and the presence of ornamental feathers on their tails.
One of the males had a dense feather coloring around his neck and body, complete head feathering, and two elongated ornamental tail feathers .
r AowiresA.
measuring around 30 cm, which are the physical characteristics of an adult bird.
However, the lack of side feathers indicates that the bird is not yet fully developed, and this male appears to be an older individual sub-adult.
The other bird was identified as a younger sub-adult, with incomplete head feathering, less-developed elongated tail feathers, and a lack of clear separation between his neck and back feathers (Figure .
Figure 4.
Young sub-adult male Greater Bird-of-Paradise Paradisaea apoda (A), indicated by incomplete yellow nape feathers .
hite arro.
, and sub-adult birds (B), with characteristics by fully yellow nape feathers .
ellow arro.
and ornamental tail feathers .
ed arro.
http://dx.
org/10.
29244/jpsl.
JPSL, 14.
| 509
Dance Behaviour Two display behavior events were observed in this study.
The first display was composed of a solitary young subadult male on a lek tree, whereas the second display event involved an AoolderAo subadult individual dancing in the presence of a young subadult male (Table .
No females were present during the display behaviors of the young sub-adult and sub-adult birds.
In this study, differences in display behavior between young subadult and sub-adult birds were also observed, particularly in terms of the completeness of display movements and the duration of each movement.
All four display movements .
ing pose, pump, bow, and danc.
were observed in sub-adults, whereas only two display movements .
ing pose and danc.
were observed in young adults (Table .
Table 3.
Two Displays of the behavior of two males of the Greater Bird-of-Paradise on a lek tree in the concession area managed by Tunas Timber Lestari Ltd.
Time Seconds Individual Display Description 0Ae17 Young subadult Wing pose Perch facing the 12 o'clock direction by spreading its wings and flapping them 8 times.
Move the legs for 6 steps while the body moves in a circular motion forming the number 8, making the sound 'khaak' 7 times.
Facing the 3 o'clock direction while spreading the wings 38 times.
Facing to the right, the body faces 12 oAoclock.
Nodding the head.
Facing the right.
Head facing left, body faces the 12 oAoclock.
Look around before flee.
First, look upwards, then fly and perch on the branch above.
Look to the right and left, the body faces 6 oAoclock.
Rubbing the feathers using a beak.
Perching, facing the 6 o'clock.
Fly from the top branch of the tree.
Look at the adult male and glance around twice, body facing the 6 o'clock direction.
Jump three times towards the young male, gaze directed towards the young male.
Stay still and bow down for about 3 seconds, facing 2 oAoclock.
The body bows down faces 5 oAoclock, beak rubbed against the side of the branch 6 times.
The body bows down face, legs spread open, head pointing downward, moving by hopping downward.
Seeing an adult male with an upside position.
18Ae21 Dance 22Ae50 51Ae59 0Ae9 0Ae35 Wing pose Perch Perch Perch Perch Take of Perch Perch Grooming Perch Perch Perch 0Ae4 5Ae25 26Ae29 30Ae39 40Ae42 40Ae51 43Ae46 Sub-adult Young subadult Sub-adult Jump 47Ae49 50Ae51 Bow Rubbed beak 52Ae54 Pump 52Ae91 Young subadult Young subadult 52Ae54 55Ae56 57Ae58 59Ae60 1Ae34 32Ae33 35Ae42 43Ae50 51Ae54 55Ae56 Young subadult Sub-adult Inverted Dance Pump, wing pose, bow Dance Young subadult Sub-adult Take off Perch Jump Jump Take off Wings flapped, legs spread open, and tail raised.
The body bows down facing the 6 o'clock direction, legs spread open, head pointing downward, moving by hopping slowly uphill 3 times, and making the sound 'choagh' 2 times.
The head bows down, slowly flapping wings 40 times, then hopping 30 times and making the sound 'choagh' 13 times.
Look at the adult male and the surroundings, then fly.
Looking around, take a rest with fast breathing.
Hoop to branch above.
Move to the smaller branch below, unexpected another individual is passing by.
Fly and glide downwards with another individual on the left side.
*interaction between young sub-adult and sub-adult of the Greater Bird-of-Paradise From 08:39:40Ae51, the sub-adult Greater Bird-of-Paradise landed on the same branch as the young sub-adult After landing, the sub-adult male immediately displayed in front of the young sub-adult male who promptly observed the sub-adult male.
At the same time .
:39:52Ae.
, the sub-adult male danced and the young sub-adult male perched upside down .
When the young sub-adult male perched in an inverted position, his entire body was not visible because of the thickness of the foliage, but he continued to This journal is A Pramunandya et al.
JPSL, 14.
| 510
gaze at the displayed sub-adult male.
The lek movements of the young sub-adult male were fewer than those of the sub-adult male, with no pump and bow movements observed in the sub-adult male (Figure .
However, in the wing pose movements, young males had more sessions and longer movement durations.
There were distinct differences in movement between the young subadult and subadult males, where the subadult males had more refined display abilities (Table .
Table 4.
Differences in display behavior by young sub-adult and sub-adult males of the Greater Bird-of-Paradise in the study area Display behavior Wing pose Pump Bow Dance Young sub-adult male Observed 2 times, total duration 40 seconds Did not observe Did not observe Observed 1 time, total duration 3 seconds Sub-adult male Once, for 1 second Once, for 6 seconds Twice, total duration 2 seconds Twice, total duration 36 seconds Figure 5.
Display of sub-adult male Greater Bird-of-Paradise: wing pose (A) and bow (B).
Learning the Dance Steps from An Adult Bird This study is the first to report the behavior of the younger sub-adult Greater Bird-of-Paradise, which learned and imitated a display dance from an AoolderAo sub-adult male bird in a non-breeding season.
There was a hypothesis that Auyoung malesAy .
f the bird-of-paradis.
inherit those dance steps from their fathers, and then refine them through practice and watching adults .
(Figure .
Although the hypothesis for the bird-ofparadise has not yet been written in a scientific paper, the process of watching and practicing ritual dance has been reported in some other bird species, such as in Java sparrow (Lonchura oryzivor.
in captivity .
, cranes .
, and golden-collared manakin (Manacus vitellinu.
In the Java sparrow observed in captivity, the young bird repeatedly practiced courtship dance from early life, a practice that was needed for motor learning and vocal-motional coordination .
Similar to the Java sparrow, the bird-of-paradise may have learned to display because it was released from its mother's care or during its juvenile phase.
In another bird group, cranes .
amily Gruida.
, it was found that the sub-adult bird also dances as a play behavior when performed in a non-breeding season .
Meanwhile, in the Goldencollared manakin, adults initially provided examples of behavior that were subsequently imitated by a young bird .
In the Greater Bird-of-Paradise, chicks were raised by their mothers without any interference from the father .
Therefore, the ability to dance, at least in some important steps, is an innate behaviour inherited from fathers.
To perfect ritual dance, the sub-adult bird needs to learn and practice from the adult.
http://dx.
org/10.
29244/jpsl.
JPSL, 14.
| 511
Figure 6.
Young sub-adult male Greater Bird-of-Paradise .
n the righ.
observing the dance of the 'older' sub-adult male P.
n the lef.
The young sub-adult-male served in an inverted position .
ighlight by a red circl.
As mentioned previously, the behavior of the young/sub-adult male observing the adult male's dancing or singing is a part of learning .
In this study, the young sub-adult male had the opportunity to watch the dance from a short distance.
The AoolderAo sub-adult male was also seen to provide an example of dance steps to the young sub-adult, like the report of the manakin study, using the adultAos incomplete breeding plumage .
The inverted position is a common behavior in bird-of-paradise species .
However, the behavior of observing another male display in an inverted pose has not been recorded previously.
The behavior of the young male, both upright and upside-down, suggests that he was actively observing the adult male's display, which might be closely linked to learning.
Earlier research McDonald and Potts .
revealed that young individuals naturally tend to pay attention to other males doing something like singing or searching for food, as well as display.
This was evident during the breeding season when displays occurred at the lek site, and all adults and subadults gathered for both display and observing .
There was no information on the watching, learning, and practice of the sub-adult Greater Bird-of-Paradise on a lek tree during the non-breeding season.
There is a good possibility that the sub-adult might be present in the lek tree during the breeding season, watching, and learning from adults from a distance .
ot on the main lekking branch, possibly practicing by himsel.
, but did not participate in the dance aiming for copulation.
Another possibility is that learning and dancing also occur during the non-breeding season, as revealed in this study.
The differences in display movements, in which the sub-adult male did not perform a complete display, could be because the young male had not yet fully mastered the display movements.
This suggests that the male's dancing ability was influenced by external factors, such as learning.
The display behaviors exhibited by both This journal is A Pramunandya et al.
JPSL, 14.
| 512
males indicate a tendency among males of the Greater Bird-of-Paradise to engage in the display, especially during the mating season.
Meanwhile, display or sexual activities outside the mating season are believed to be triggered by other factors such as hormones and calling .
The Selection and Safety of Lek Tree The dance site of the Greater Bird-of-Paradise was near the Inocin Abadi Camp, which is frequently used by locals for various activities.
There have been some reports .
, that the bird-of-paradise shows a reasonable tolerance to habitat changes and disturbances.
This means that the Greater Bird-of-Paradise is relatively easy to hunt illegally from plumage.
The trees used by the Greater Bird-of-Paradise lekking in Tunas Timber Lestari Ltd.
concession area were relatively dense.
However, video footage from camera traps at Inocin Abadi Ltd.
djacent to Tunas Timber Lestari Ltd.
) captured images of the Greater Bird-of-Paradise performing lek displays in the sparse tree canopy.
Another footage shot on Aru Island also indicated that open lek trees engage in display behaviors, including copulation .
Information about the lek preferences of the Greater Bird-of-Paradise remains limited, and it is suspected that canopy density may not be the primary factor determining display site selection.
At the same time, it is possible that the practice exhibition will be held in a partially closed lek tree, as opposed to an open main lek tree.
This might occur because dense lek trees are safe from disturbances and threats, but are not exposed in the event of a female's presence nearby.
In some areas where birds dance in an open environment, safety against illegal hunting must be maintained.
Furthermore, in contrast to this study, a study on Aru Island identified three lek tree species: Canarium vulgare.
Myristica fragrans, and Pometia pinnata .
All three species possessed a DBH > 30 cm and a height > 30 m, with relatively open canopies.
This closely aligns with the characteristics of lek trees observed in this study.
It is inferred that the selection of a lek tree by the Greater Bird-of-Paradise is not primarily based on its species but rather on its structural Conclusions The display behavior of the Greater Bird-of-Paradise in mainland central Papua (Indonesi.
revealed that the display might have occurred during the non-breeding season.
The behavior of young sub-adult male through watching a dancing AoolderAo sub-adult male reported in this study indicated that there was a learning, copying, and practicing process of the young/sub-adult in performing dance steps.
This study strengthened the earlier hypothesis that young males of the bird-of-paradise have the ability to dance inherited from their fathers and still need to perfect the ritual dance through practice and watching the older male.
Lek trees for practice tended to be more closed, indicating that safety was a priority.
In contrast, the main lek tree was more open, prioritizing the possibility of mating.
As the lek tree is crucial for the dance ritual and survival of this bird, its protection of the lek tree is necessary.
Author Contributions RAP: Conceptualization.
Formal Analysis.
Methodology.
Software.
Visualization.
Investigation.
Writing Ae original draft.
AM: Project administration.
Supervision.
Validation.
Writing -review and editing.
YAM:
Supervision.
Validation.
Writing -review and editing VC: Resources.
Funding acquisition.
Conflicts of Interest There are no conflicts to declare.
Acknowledgments We wish to convey our sincere appreciation to Mr.
Kim Nam Hong and Mr.
Ishok of the Korindo Group for their generous sponsorships.
We also extend our gratitude to Inocin Abadi Ltd.
and Tunas Timber Lestari Ltd.
for their invaluable assistance and permission to facilitate this research within their designated areas.
Our deep gratitude also goes to the Inocin Abadi Camp community and its staff, who extended the warm welcome to our team.
We would like to thank Mr.
Benyamin Warenkukli for his invaluable field assistance.
We also thank Firman Heru Kurniawan, an artist who produced sketches from video footage.
http://dx.
org/10.
29244/jpsl.
JPSL, 14.
| 513
References