I have birds in the eaves of my house!

I regularly receive calls in April or May from people complaining they have birds nesting in the eaves of their homes. This is a common complaint as starlings and house sparrows take up residence for the nesting period. They are often associated with people and commonly found in or near buildings.


They can become a significant pest of the food industry causing problems in supermarkets, food processing plants and warehouses. They will take advantage of any food spillage. They will even peck holes in stored food products – bagged or boxed packaging. Produce can become contaminated by heavy fouling.


House sparrows (Passer domesticus) only mate for a season and have a lifespan of 1-2 years. Incubation is mainly by the female, lasting 12-15 days, laying four to six eggs. The young are fed by both parents and fledge after about 15 days. The breeding season normally extents from April to August when two or three broods may be reared. They scavenge on a wide variety of foods but mainly cereals in urban areas.


Starlings (Sturnus vulgaris) can be seen in both rural and urban areas. Populations consist of manywinter immigrants from Northern Europe and North West Russia. Generally, roost communally in large numbers in woods or reed beds. During Autumn/Winter they form conspicuous flocking at dusk called a ‘murmuration of starlings’- a swooping mass of thousands of birds whirling acrobatically in the sky above. A fascination sight to any naturalist or nature lover.


Both species are difficult to proof and keep out of buildings. Roofing comb in one metre strips is very effective for eaves proofing of domestic homes. Outside of this the only other satisfactory proofing option is to install 19mm wire mesh (House Sparrows) or 28mm (Starlings).


Visual or audio scaring does not seem to be a realistic option in many sparrow infestations. Managed scaring systems have been found to be effective at dispersing summer resident starlings from daytime feeding areas. Predator birds of prey have been used successfully to disperse them from structures such as buildings or pylons. However, scaring devices are likely to be limited unless they are very well managed with other scaring techniques.


Removal of sparrows can be difficult and is often the only option available. However, house sparrows are quick to avoid traps and will soon associate the shape of a person with danger so will dive for cover and disappear into the fabric of the building. I have seen this behaviour on my garden bird table during the winter months when it was visited on a few occasions by a passing Sparrow Hawk. The House Sparrows later became flighty when feeding and would often disperse to the nearby hedgerow.


I would recommend proofing jobs to commence from September to March in any year. Don’t call me during the nesting season! Birds on the nest are protected and cannot be disturbed during this period. Habit modification is a very effective means of relocating sparrows combined with proofing. Simply put up nest boxes in a suitable location to re-home the birds you are evicting from your home.


Mervyn Walsh, Field Conservation Biologist

Ecologica Environmental