'Monster' bird reveals dark side

Shoebill chick is filmed attacking its younger sibling

Aggressive bullying between bizarre-looking shoebill

chicks has been filmed for the first time.

The encounter was captured at Bangweulu wetlands, near Kasanka, in northern

Zambia for the BBC One series Africa.

Wildlife filmmakers were surprised to witness an older chick attacking its

younger sibling while their mother was foraging away from the nest.

The birds are rare subjects for study because their swamp breeding grounds

are very difficult to access.

The team's aim was to shed light on the species by documenting intimate

behaviour of shoebill parents and young at the nest.

Siblicide, the phenomenon of offspring killing their siblings, is common

among many larger birds.

"This behaviour had previously been recorded in

shoebills (Balaeniceps rex) but we hadn't planned on seeing it,"

explained director Alex Lanchester, who describes the shoebill as

"prehistoric-looking".

The film, which is at times disturbing, provides intimate footage taken using

three mini-cameras fitted to the nest.

The shoebill chicks were approximately three weeks old at the time of

filming, with one chick a few days older than the other.