Black-thighed Falconet

Black-thighed Falconet  (in Malay, Helang Belalang meaning ‘Grasshopper Eagle’)

Falconets are the smallest birds of prey, not much bigger than a sparrow.   Female falconets are on average larger and have longer tails than the males.  Such sexual dimorphism is generally true of birds of prey.

	Eurasian Tree Sparrow	Falconet
Weight (grams)	24	35
Length (cm)	14-15	15-18 cm.
Wingspan (cm)	21	30

 

This is another bird with disruptive camouflage.  It is more difficult to see than my cropped photos would suggest.  Listen for its call: either a high-pitched shiew (https://www.xeno-canto.org/317255) or a repeated kli-kli-kli-kli (https://macaulaylibrary.org/asset/203918251)

The falconet’s original habitat would have been open woods, forest edges, fields, and beside streams.  In our time it is frequently found around villages, paddy fields and slash and burn clearances.

As its Malay name suggests, it mainly eats insects such as grasshoppers, butterflies, dragonflies, and winged termites.  It has also been known to prey upon small vertebrates including other birds and lizards. The falconet is a sortie hunter: it sits on a high perch and makes quick short flights.  Flying insects are locally abundant but widely dispersed.  Hence, feeding behaviour is often social, in groups of up to ten birds. 

Falconets nest on small sheltered ledges on cliff surfaces or in cavities in trees, generally abandoned woodpecker or barbet nests.  They do not ‘improve’ the nest; there might be some insect exoskeletons lying around, but no moss or leaves to line the cavity.  The female lays two to five eggs.  Juveniles are cared for by the breeding pair and, on occasion, helper sub-adult(s) from the previous brood. Falconets can breed at any time of the year but generally February to June.  The falconets also sleep at night in nest cavities, so seeing a bird enter or leave at presumed nest is not proof of breeding.  Instead you need to look for courtship behaviour: allopreening, presenting gifts of dragonflies, locking claws whilst in flight- and hence losing altitude rapidly!