‘Aggressive Behavior and other associated behavior of plumed whistling duck’

A Research Paper

Presented in partial fulfillment of the

Requirements of the subjects

SB332.1 Ornithology

By

Jessica. Iropu

May 2014

Aggressive Behaviour and other associated Behaviours of Plumed Whistling duck (Dendrocygna eytoni)

ABSTRACT Plumed whistling duck is one of the 8 species of whistling duck species. Plumed

whistling duck only portrays aggression during the breeding season. It was found that plumed

whistling duck species are the most socialising type of birds. They only use Pacific Adventist

University as their resting ground. They are nocturnal birds that normally flew off high up to

grassland area for foraging and feeding purposes.

Key Words: Plumed Whistling Duck (dendrocygna Eytoni) Aggressive Behaviour, Resting

Behaviour, Feeding Behaviour, Social behaviour and reproductive behaviour.

Introduction Plumed whistling duck is a tall and long-necked bird that is closely associated with

tropical grassland where it lives and forages near edges of lagoons, marshes, swamps and

wetlands (Johnsgard, 2010:8). Plumed Whistling Duck has a pinkish bill and legs with

different shades of pale brown over its head, neck, breast and flank. It has long flank plumes

that are edged black and extend over its back. Its wings are brown above and a paler black

below. Both sexes have the same colour but males tend to be large and have longer plumes

than females. Plumed whistling duck have a body length of 40cm-60cm and body weight of

1kg and lays 10-12 eggs .It takes almost 30days to incubate the eggs before they are hatch.

However, having these facts about plumed whistling duck known this paper will take you

through to identify the aggressive behaviour of plumed whistling duck. Aggressive behaviour

in animals is a mechanism by which individuals compete for essential, and often limited,

resources (e.g., mates, food).

METHODOLOGY

Study Area

The study was carried out in 2014 at

Pacific Adventist University (PAU)

(S090 24.309’ E 1470 16.343’)

approximately 22.5km east of Port

Moresby, the capital city of Papua

New Guinea. This land was reclaimed

from a farming land (Cow paddock) to

build the institution. It was then

declared as a bird sanctuary in the

1980s by the Government of Papua

New Guinea a few years after its establishment. This study area is covered with the most

beautiful trees (Planted by man) and shrubs. The study area is very rich in avifauna

community which attracts many migratory and native birdlife a total of 196 bird species.

However the main study site which is the wetlands of PAU comprises of a number of ponds

Figure 1 and streams and is part of the tributary of the main Laloki River coastal plains

around the Port Moresby area. This wetland supports many water birds including three

species of Whistling ducks, Pacific Black ducks, Cormorants, Egrets, Herons, Grebes,

Jacanas, Swamp and Moore hens, Ibis, Darters, Kingfishers, plovers and Geese (Tarburton,

2008, Saguba, 2010). The wetlands are located at the foothills of the Owen Stanley Range

and has tropical wet and dry climate with the annual rainfall of 1,270 mm. The wet season

starts in December and ends in May and the dry season starts in June and ends in November

(Jones, 2010, a 10 year personal weather recordings and readings). The average area of the

wetlands is17650��.

Figure 1.Study site at PAU wetland Northern View of Pond one

Birds Species

There are 8 species of whistling ducks in which three of these 8 species are found in the

wetlands of Pacific Adventist

University. Of these 3 species

found in the study area, only the

plumed whistling duck was

observed from March to May

2014 which is the period of wet

season. Aquatic vegetation was

dominatedby floating waterlilies

(Nymphoides indica, Nymphaea

sp.), Azolla pinnata, Ipomoea

aquatic (as shown in figure 2) and Lemnaceae species. This study comprises only the

behavioural aspect of the plumed whistling duck specifically the aggressive behaviour.

Data Collection

I used focal sampling method to

study the behavioural pattern of

the plumed whistling duck. Daily

observations were done from three

locations (Pond 1, 2 &3) from the

same spot using binoculars as the

pond is small and clear of much

aquatic vegetation due to occasional cleaning of the pond. In addition, the birds were mostly

Figure 2: Plumed Whistling Duck Spotted at PAU Pond Two

Figure 3: Bird watching using Binocular

feeding, resting and moving around in the same sport and were most often feeding together.

No distinctions were made between the sexes. A 3 hours study each day for (1 hour each:

early morning 6am-7am, mid-day 12pm-1pm and late afternoon 5:30pm-6:30pm) preliminary

observations helped categorise the behaviour of the plumed whistling duck: The behaviours

observed were (1). Feeding, (2). Resting and or alert, (3) Aggression, (4) Preening. The

detailed descriptions of each behaviour categories are given in the result section of this

report.

Results

DAY

Date

TIME

No. of birds observed

Types of behaviour observed

location

Thursday

27/03/14

6am-7am

22

Aggressive

Pond Three

Thursday

27/03/14

10am-11am

22

Resting but awake

Pond Three

Thursday

27/03/14

5:30pm-6:30pm

22

feeding

Pond Three

Wednesday

2/04/14

5:30pm-6:30pm

40

Aggressive (Chasing only one )

Pond Two

Thursday

3/04/14

6am-7am

22

Resting

Pond one

Thursday

3/04/14

5:30pm-6:30pm

20

Moving around and standing still looking aggressive

Pond two

Monday

7/04/14

6am-7am

40

Resting but alert

Pond Two

Tuesday

8/04/14

5:30pm-6:30pm

22

(Preening)Moving around socialising

Pond three

SUNDAY

27/04/14

5:30pm-6:30pm

40 Resting

Pond Two

Monday

28/04/14

5:30pm-6:30pm

20

(Preening)Flapping & moving around

Pond Two

Tuesday

6/05/14

5:30pm-6:30pm

70

Moving around under the shade of the trees in the edge of the pond one next to the church

Pond one

Tuesday

29/04/14

10am-11am

55

Resting

Pond one

Tuesday

29/04/14

5:30pm 6:30pm

61

Resting

Pond Two

Thursday

8/05/14

6: am-7am

70

Resting

Pond Two

Thursday

8/05/14

5:30pm-6:30pm

70

Resting but awake (Alert)

Pond one

Friday

9/05/14

5:30pm-6:30pm

70

Resting but flew off to Easterly maybe up to Mt Eriama

Pond One

�� ��� ���� � ��� � Types of Behaviour

Specific Location

Time of day (Morning or Afternoon)

Days observed

Number of Plumed whistling duck

Mean for each time of day

Percentage of plumed whistling duck

Aggressive

Pond 3 Early Morning

27th March

22 22 0.04 %

Pond 2

Late Afternoon

2nd April 40 �����

�= 30 6.39%

3rd April 20 3.19%

Resting and Alert

Pond 3 Mid-Morning

27th March

22 22 + 55

2= 38.5

0.04 %

Pond 1 29th April

55

8.79%

Pond 1

Early Morning

3rd April 22 22 + 40 + 70

3

= 44

0.04 % 7th April 40 6.39%

Pond 2 8th May 70 11.18%

Pond 2

Late Afternoon

27th April 40 40 + 61

2

= 50.5

40 + 61 + 70 + 70

4

= 39.5

6.39% 29th April 61 9.74%

Pond 1

8th May 70 11.18% 9th May 70 11.18%

Feeding

Pond 3 Late Afternoon

27th March

22 22 0.04 %

Preening

Pond 3 Late Afternoon

8th April 22 22 + 20 + 70

3

= 22.67

0.04 % Pond 2 28th April 20 3.19% Pond 1 6th May 70 11.18%

TOTAL BIRDS OBSERVED NUMBER= 626

Discussion

Birds can get angry or aggressive for many reasons. Some birds get angry to defend

their young or a possible mate while some birds get angry to defend their territory and

resources. According to Mayntz (2014) she stated that birds get angry for many reasons all to

do with their survival. Brown (1975) and Alexandra (1978) identifies that ‘Because of

aggressive behaviour there is frequently an unequal disposition of resources, with dominant

individuals having priority of access .Moreover, some researchers indicate that dominant

individuals have greater survival probabilities than subordinates.

In birds, aggressive behaviour is a common phenomenon associated with the

reproductive period when males establish territories and compete for mates. As observed

during the months of March and april the birds showed an aggressive behaviour. This shows

that during these months the plumed whistling duck competes for possible mate for breeding.

Lack (1954) and Fret well (1972) quoted in Mayntz (2014), however, have suggested that, in

terms of survival, the nonbreeding period is the more critical portion of the annual cycle.

Lack (1966) further suggested that many bird populations are regulated by food supply

during the nonbreeding period. In most bird species, a post breeding tendency to form flocks

generates a situation in which aggression is common (quoted in Marler 1971, Jenkins et al.

1975, and Patterson 1977). Often times this aggression involves asymmetric contests where

males dominate females in competition for food (Brown 1963, Sayler and Afton 1981, Grubb

1982), although the opposite sometimes occurs (quoted in Thompson 1960, Samson 1977).

The study showed that the plumed whistling duck species are one of the nocturnal

birds who rest most of the time during the day. This is further supported by Johnsgard (2010)

he stated that the species is relatively nocturnal in its foraging behaviour, spending the day in

large roosting flocks near shorelines, and flying out in late afternoon or evening to foraging

grounds that may be nearly 20 miles away. The study showed that during the month of May

the number of the whistling ducks increased relatively and during most of the afternoons the

birds were seen flying off easterly up towards Mount Eriama. This clearly shows that

attractive foraging areas are visited nightly until the food supply is exhausted, when the birds

move to a new area.

In waterfowl, behavioural dominance has been studied in plumed whistling ducks

(Paulus 1983, Hepp and Hair 1984), but is poorly understood in diving ducks. The species

was rarely seen swimming. However, only when outside disturbances like kids playing and

disturbing their habitat the birds flew into the ponds. The study also showed that the birds

were preening most of their time especially when they were alert. When studying this species

one thing you come across is they are found to be socialising with each other wether in their

own races of species or with different species. These species however were generally found

to be friendlier than any other bird species. Though at times they may be aggressive they are

still regarded as one of the friendliest and sociable group of birds of the whistling duck

family.

Conclusion

In conclusion, we view the aggression behaviour of plumed whistling duck as a suite

of secondary adaptations for protection of young, defense of food resources from marginal

competitors, and sexually selected ritualized behavior for assessment of males by females

especially during the breeding season. This time of the year is more crucial to them for their

survival. They defend the mates and in doing so they show aggression wether towards their

own race or towards other species around them.

Reference List

Alexander, W. C. (1987). ‘Aggressive Behavior of Wintering Diving Ducks (Aythyini).’ The

Wilson Bulletin. 99(1):38-49.

Howard, L. (1953) Bird as Individuals. London: Union Ltd.

Johnsgard ,A.P. (2010) ‘Ducks, Geese, and Swans of the World’: Tribe Dendrocygnini

(Whistling or Tree Ducks). University of Nebraska-Lincol

Jones, R. (2010). Monthly Rainfall reading at PAU from 2000 to 2010 (Unpublished).

Mayntz, M. (Online). (2014, May 11). ‘Angry Bird Behavior.’

http://birding.about.com/od/birdbehavior/a/Angry-Bird-Behavior.htm

McCray,J. (2008, February) Husbandary Guidelines for Plumed Whistling Ducks. 31-34

Pettingill, O.S. 1985. Ornithology in Laboratory and Field. 5th Edition. Academic Press.

Saguba, K. P. (2010). Ecological Impact assessment of the PAU wetland area, Port Moresby,

PNG: Pacific Adventist University.

Tarburton, M. (2008). PAU Bird Book. Port Moresby, PNG: Pacific Adventist University