Buzzard Mobbing Behaviour – June 2015

During the breeding season many animals defend their territories and breeding sites from potential danger and birds of prey are no exception. Birds of prey will ‘alarm call’ at any perceived threat that comes too close to their nest site. On rarer occasions they may dive at the threat if it persists, and even make contact with it. This is a natural response which can be observed by many different types of wildlife. For example, many of us are familiar with being ‘dive-bombed’ by gulls.

Alarm-calling is usually enough to deter the threat, but for those of us who are not familiar with the sounds of birds of prey may not realise what is happening and continue merrily on our way, getting closer and closer to the nest. It is rare for a bird to actually make contact but it does happen and NIRSG get a few reports every year at sites where a bird is repeatedly disturbed and aggressive mobbing or ‘attacks’ may occur.

We can provide information if required and ask people to stay clear of the area for a few weeks until the height of the breeding season is over. However, this year, the media have picked up on a small number of nest sites in particular where buzzards are particularly aggressive and are making contact with people who are oblivious to the early warning signs that they are approaching an active nest site. In these cases the buzzards have unfortunately nested very close to active pathways or roads and as a result are being frequently disturbed each day. The buzzard nesting season typically extends from March through to July or early August each year but young are only typically in their nests between May and late June or early July.

‘Attacks’ or mobbing behaviours may increase in ferocity throughout the season as a learned behaviour which you get with any bird – if it makes contact and it is successful in making the threat leave then it learns to perhaps do this quicker and harder next time so the threat will leave quicker. The more birds are disturbed the more aggressive they may become, and this goes for most nesting birds, including gulls, terns and waders. Every individual bird may be totally different in their response to disturbance and the majority will perhaps alarm call and then fly high overhead calling continuously and it is important for people to try and understand what these behaviours and calls might mean and minimise such negative impacts on our wildlife.

Birds of prey in Northern Ireland are protected under the Wildlife (Northern Ireland) Order 1985, as amended by the Wildlife & Natural Environment Act (NI) 2011 and it is illegal to disturb them at, in, on or near their nests. Such offences may be subject to a custodial sentence and/or £5,000 fine per offence. There is a reason for this. Birds of prey sit at the top of their food chain and thus are very sensitive to changes in the environment. This leaves them as very vulnerable species whose populations are unstable. The success of their breeding attempts can be affected by disturbance, with eggs and chicks at risk from chilling, predation and starvation when the adults are responding to perceived threats. One or two successive poor breeding years is enough to cause radical declines in some species.

What can you do?

If you are aware of a bird of prey calling when you are out an about, take a few seconds to think, am I disturbing this bird and could it be calling at me? If so, please find an alternative route for the next number of weeks. We would therefore advocate avoidance as the means to prevent such disturbance to the buzzards and their nests and thereby also avoid any associated mobbing and defensive behaviours.

Buzzard chicks are generally large enough to be left alone by the adults by mid-late June and they leave the nest around the first week of July. Over this time the defensive behaviour of the adults will decrease and the mobbing behaviour will not then typically occur. These birds are only protecting their young.

You can let NIRSG know whereabouts you are witnessing this protective behaviour and we can take action by putting up signage asking people to find an alternative route until the end of the breeding season (email: info@nirsg.com or raptorofficerni@gmail.com).

Finally, if you witness any bird of prey being antagonised or disturbed you can call PSNI on ‘101’ or anonymously at Crimestoppers ‘0800 555 111’. This disturbance may, after all, be a crime, and should be reported.