The capercaillie lekking season is upon us. Capercaillie Project Officer, Gareth Marshall gives us an insight into these extraordinary birds.

A clattering in the branches, a capercaillie male comes down to face his opponent in the lek. ©Pete Cairns/2020VISION

Deep in the pre-dawn darkness of a spring-time pine forest, something is stirring. It’s still too dark to make out any shapes, but above the sound of the wind blowing through the canopy there’s something else: a clattering in the branches, fluttering wingbeats and then…click…click…click.  An eery wheezing, rasping cough punctuated by clicks and pops comes out of the darkness.  More clattering wingbeats.  Click…click…click.  As dawn light eventually starts seeping through the wood the sounds increase, coming from several directions at once. The shapes of the forest begin to emerge from the gloom. The clattering begins again and two dark shapes move toward each other through the heather, tails fanned, chests puffed, necks out-stretched; two male capercaillie square up, the lek has begun.

An adult male capercaillie displaying in a pine forest. ©Mark Hamblin/2020VISION

Capercaillie, the giant grouse of the pinewoods, begin their breeding season at the lek (‘lek’ is an old Norse word that means ‘play’), where the males come together early in the morning at traditional sites to display and fight for their place in the pecking order. This happens throughout the Spring but the females, for whom the display is intended, only attend the lek for a few crucial days in mid to late April.  They perch on a branch with a good view of proceedings until it’s clear who the dominant male is and then fly down to the ground to mate with him.  In capercaillie populations, the dominant male gets to mate with all the females and the subordinates go away with nothing, so if they want to pass on their genes it’s vital that they’re the top dog.  For this reason male capercaillie expend a huge amount of energy during the lek and it’s not uncommon for a few to die from exhaustion or wounds inflicted by their rivals each year.

A female capercaillie. ©Danny Green

In Scotland, capercaillie numbers declined by about 90% between the 1970s and 1990s and there are now just between 1000 and 2000 birds left. The decline was caused by a combination of factors: changes to the way their forest habitat is managed, increased use of deer fencing (a killer if they fly into it), a changing climate and predation pressure.  On top of all that, in recent years there has been growing evidence that human disturbance is also having a negative impact.  If the lek is disturbed, particularly on one of the few mornings when the hens are there to be mated, there might be no breeding at all.

For this reason capercaillie are legally protected during the breeding season, so unless a licence has been granted by SNH it’s illegal for anyone to disturb them, either intentionally or recklessly, while they’re displaying. Despite making for an incredible wildlife spectacle, we urge the public to act responsibly and not go out looking for lekking capercaillie.

This protection also extends beyond the ‘traditional’ leks and breeding season. Every year a few birds show atypical behaviour such as losing their fear of people, vehicles or dogs. They can attract significant attention as they may seem like an easy and low-risk opportunity to see a capercaillie, but if encountered, the responsible course of action is to withdraw immediately and not share the location. This avoids causing unnecessary stress to a bird that’s already fighting for survival, not to mention disturbing other wildlife nearby.

If you do want a chance of a view of lekking capercaillie without risking disturbance, the RSPB runs Caper Watch at the Loch Garten Osprey Centre throughout April. For more details go the RSPB website.

Gareth Marshall is RSPB’s Capercaillie Project Officer. The project is joint funded by RSPB, Forestry Commission Scotland and Scottish Natural Heritage.