Guillemots are a bird that can be found around the world. They are fishers and breed in colonies nestled among sea rocks and cliffs.

Some of those colonies have turned into killing grounds as the birds attempt to find a way to deal with their collapsing food supply.

At risk are their young.

A colony in the Firth of Forth in the North Sea off the coast of England has seen a sudden rise of infanticide. This disturbing unprecedented breakdown of the birds social order has been described as a “catastrophe” that could eventually see the whole colony dying out.

The Guillemots are very tough birds that form close colonies to protect themselves from marauding gulls who try and feed on their eggs and young.

Mating pairs produce only one chick, with the parents taking turns minding their young while the other hunts.

In 2005 Biologists at the Center for Ecology and Hydrology, near Edinburgh discovered that as a result of depleting fish supply both parents were forced to hunt at the same time leaving their chick unattended.

Before 2005 chicks left alone were often looked after by their neighbors until their parents returned.

Recent video footage taken by Leeds University shows that lone chicks are often brutally attacked by their neighbors and even pushed off the cliffs to the rocks below.

“When the chicks are unattended, they wander off to find shelter or food from a neighbor, and that’s when they end up being attacked,” said Kate Ashbrook, of Leeds University.

While it is extremely rare for Guillemots to leave a chick unsupervised. Ashbrook said that 60 percent of the chicks were left alone last year. Of 99 chicks born between late May and early August, 60 percent died – almost 70 percent of them as a result of direct attacks by their neighbors.

“It is one of the most extraordinary behaviors I have ever heard about and it really flags up that something monumental is happening out at sea,” said Tim Birkhead, of Sheffield University.

He added: “All one can do is watch in despair as this catastrophe unfolds.”