June 2005 — Dry Season, and Heron Nesting at Tasek Putri


Concerns about climate change persuaded me to get a rain gauge and I have been tracking precipitation since March. June is always a dry month and this was no exception with a total rainfall of only 59mm. Rain fell on just 6 days, compared with 14, 15 and 16 of the previous three months, and it was concentrated in two of those days when we had 16mm and 37mm. The garden dried out, many trees shed their leaves, but they did not all respond in sync with others of the same species. Only one of the ten Intsia palembanica, a merbau timber tree of the Dipterocarpaceae family, shed its leaves, and the photo on the right shows the new red growth.

Reasons for this typical coloration of new leaves in the tropics vary, but it is plausible that because red leaves have a higher surface temperature than green, the rate of evapo-transpiration and the deposition of nutrients in the new growth is faster, thus ensuring more rapid growth when the leaves are most vulnerable.

The nesting season is well underway in the heronry at Bandar Tasek Putri to the north of Rimbun Dahan, and west of Rawang. The photo below shows a nest of the black-crowned night heron, one of 39 species identified at the swamp to the left of the access road to the Bandar Tasek Putri housing estate. The developers have built a viewing platform at the roadside for the public to view the birds just meters away, but Selayang Council continues to dump rubbish on the opposite side of this unprotected wetland. Damage to the pandans by the huge numbers of birds is considerable compared with last year, and ultimately the birds will have to move.

The Selangor State government needs to protect similar wetlands to ensure that the birds have alternative sites where they can nest en masse. Birds that nest in isolation, rather than with the huge numbers and species mix at Bandar Tasek Putri, are more vulnerable to predators, hence this preference to nest together. This heronry is believed to be the largest in Peninsula Malaysia and is well worth a visit.