Fragile ground: Peregrine falcon chicks nesting at a limestone hill in Ipoh. — Photo courtesy of Perak Malaysian Nature Society branch.
IPOH: The presence of peregrine falcons in Peninsular Malaysia is closely tied to one critical and increasingly threatened habitat –tall limestone cliffs.
Swiss ornithologist Dr Marc Kery said surveys conducted by the Perak branch of the Malaysian Nature Society (MNS) since 2017, with his assistance, have focused on six states not because the country’s rarest breeding falcon is found there, but because these areas have the steep, vertical cliffs needed for nesting.
Surveys conducted between 2017 and 2025 – with the latest currently underway from Jan 27 to Feb 8 – covered Perak, Perlis, Kedah, Kelantan, Pahang and Selangor.
Trained as a biologist and now a statistical modeller at the Swiss Ornithological Institute, he has spent decades studying peregrine falcons, from Europe’s limestone cliffs to Malaysia’s karst hills.
Kery said suitable nesting sites for the Malaysian subspecies Falco peregrinus ernesti are extremely limited, making the habitat highly specialised and rare, and that identifying nesting locations is the first step towards conservation.
“Only when we know where they are located can we potentially do something to protect them.
“The peregrine falcon, the fastest animal on earth, is being used as a flagship species to highlight the ecological importance of limestone karst hills,” he said in an interview on Tuesday.
Kery said limestone hills in Peninsular Malaysia cover only about 5% of the land area, making them a rare natural resource, and described the peregrine as a charismatic and highly conspicuous species.
While acknowledging limestone’s economic value for cement and development, he stressed that natural heritage must also be considered, as karst hills are highly specialised habitats, with quarrying among the main pressures affecting cliff-nesting species.
He said falco peregrinus ernesti is the darkest of all peregrine subspecies and looks strikingly different from those in Europe, with nearly 20 recognised peregrine subspecies globally.
Kery said the local population is sedentary and breeds in Malaysia, although a small number of northern peregrines from Japan and eastern Siberia migrate south between October and April.
While Switzerland also has limestone cliffs, he said Malaysia’s tropical karst formations are unique, with dense vegetation, cave-like structures and towering vertical faces that provide ideal nesting habitats.
Before the coordinated surveys began, only about 20 breeding sites were known, a figure that has since increased to 42.
Notably, the 2024 survey failed to detect the birds at nine previously recorded sites, signalling potential localised declines, although survey timing, weather and breeding behaviour can affect detectability.
“When the female is on eggs, the birds are much less conspicuous, with less calling and fewer display flights.”
He added that while there is no clear overall decline, limestone quarrying remains a serious threat.
The ongoing survey will revisit known sites to track population trends and explore new areas to identify undiscovered habitats.
Perak MNS committee member Robert Percival said falcons are elusive birds and tend to keep to high limestone hills and seldom come down to the ground.
“With the help of Dr Kery, we are now studying falcons to determine their population, breeding factors and habitat conditions,” he said, stressing that protecting limestone hills is vital for falcons and many other species as well.
