“I have been watching Purple Swamphens (Porphyrio porphyrio viridis) at this location for a number of years, occasionally seeing new young. In the past 3 years their population has started to grow and last weekend I saw 7 adults in the same area, 6 were together. This location is an ex-mining pool adjacent to limestone hills, now used for some fish farming (fortunately not aggressively) but has a lot of Water Hyacinth (Eichhornia crassipes) growth, which the Purple Swamphens love to walk and feed on (above).
“I have seldom seen such numbers, usually 2-3 in an area. Was pleasantly surprised to read (David R Wells. The birds of the Thai-Malay Peninsula, Volume 1) that there are records of up to 200 in Thailand. Another source (Robinson & Chasen, Birds of Malay Peninsula Vol 3, 1936) notes them as being ‘numerous’ in the past but declining with time.
“The distance from my location and the birds was significant so that their behaviour could be observed undisturbed. I was walking light as usual and did not have a tripod to do video. The 6 adults that were together were rather ‘noisy’. I saw numerous episodes of adults ‘chasing’ other adults. One would ‘fly in’ or raise the wings vertically to ‘threaten’ another bird. It would then move in and a chase would ensue (above). During this activity the white lower tail-coverts
would be flirted frequently with loud calls. A lot of ‘strutting’ around with white lower tail-coverts exposed and wings partially elevated.
“I considered a number of possibilities for this activity: (1) Courting behaviour – but it looked too ‘aggressive’ for this and I saw no mating; (2) Territorial breeding behaviour for a mate – i.e. an adult male chasing other adult males for access to females; (3) Territorial feeding behaviour – i.e. fights for food locations. I thought (3) was most likely but this area ex-mining pool is vast with lots of space. Six out of 7 were ‘crowded’ in a small location. Despite the ‘chasing’ they did continue feeding within a few meters of each other. So perhaps (2) is more likely. I thought I also saw some nipping of individuals but not captured on camera.
“There are some lovely territorial disputes posted in OBI database: HERE and HERE.
“Apart from the loud single calls, there were also a lot of prolonged calls that I managed to record despite the distance … which may have a bearing on this behaviour. The calls are very loud and carry some distance, hence I was able to record some. I have amplified the calls in the recordings.
“Audio 1 is stripped from a hand-held video recording: This adult heard a series of calls from another adult in the group – note the beginning of the recording 5 calls in a series. It appeared to be affected – turned to look and bent the head with beak open. It then responded with a series of 5 calls – second half of recording. When making the calls it turned the neck to the side of the body, lowered the head and opened the beak to make the calls (a video grab of the bird making the call HERE).
“If you listen carefully (or use a good audio pgm like Audacity to see waveform) you will note that each call in the series, by the bird replying, has two separate parts (crescendo, decrescendo).
“A YouTube video of the bird here (note truncated and audio recording is full, as shaky, handheld)
“In all these series of calls I heard and recorded, the calls seem to pick up in volume and then wind down. Most had 4-7 calls in a stretch.”
Dato’ Dr Amar-Singh HSS
Tambun, Ipoh, Perak, Malaysia
Ex-mining pool adjacent to limestone hills and secondary growth
19th December 2010
Sun Chong Hong
I am a bit confused by the description for the sound file calls-2a.mp3. I heard and saw, with Audacity, 7 calls @ 0.4″, 1.3″, 2″, 3″, 4.6″, 6″, & 7.5″.
And yes, it takes a pair of keen ears and attention to details to notice the crescendo and diminuendo especially at such long intervals between calls. I would not have realised it. Kudos to Dato.