• The main idea in this project is invite the starling (Sturnus vulgaris) to settle on golf courses. It preys upon larvae of insects such as cranefly on lawns and fields. Thus it may help the greenkeeper by performing biological control to remove larvae from the golf course.
• This pilot project aims to study which parts of the golf course and surrounding habitat are most used by foraging adult starlings during the breeding period.
• High-precision GPS-loggers will be fitted to around five starlings, to learn which habitat they prefer and at what distances from the nest site they forage.
The project “Invite the starling to help the greenkeeper” was initiated as a collaborative work between Sydsjællands Golfklub, Dansk Golf Union and DOF (Dansk Ornitologisk Forening)-Birdlife Denmark in 2018. We prepared and erected ~100 nest boxes, and placed them all over the golf course. All were numbered and georeferenced via the Turfgrass app. We recorded all breeding birds and ringed juvenile starlings and found that 45 successful clutches in 2019 produced on average 5.0 nestlings per clutch. This proves that the golf course provides conditions that are sufficient for the starling to produce successful clutches, with an estimated more than 100 kg prey removed from the grass. We found marked differences between the number of foraging starling in different parts of the golf course and its surroundings where they foraged during the season. They foraged mainly on the fairway and often also in the semi-rough (there is no rough on this golf course), but rarely on the greens.
In 2019, Sydsjællands Golf Club hosted a successful guided bird trip “Birds at golf courses” for local people on one evening in May. This was led by ornithologists from the local branch of DOF-Birdlife Denmark (DOF Storstrøm). Besides birdwatching, the event gave the opportunity for interaction between members of the two organisations, to talk about the new initiatives at the golf course. In order to study invertebrates in the turf layer, an additional project was included: “What do starlings eat at the golf course?” To see what the starlings preyed upon, samples of the turf were extracted in transects from the green to the semi-rough. A large number of different invertebrates were found, but only earthworms and cranefly larvae were present in sufficient biomass to be of importance for starlings.
The number of prey items decreased during the breeding season, but the items present increased in size at the same time, so the biomass for starlings increased. The number of earthworms per m2 of the fairway was more than twice that in the semi-rough, with none in the greens. The number of larvae was lower than expected in 2019. Despite no comparable data, the problem with larvae was assessed to have been reduced significantly due to the help from the starlings.
| 2018 | 2019 | Total | |
|---|---|---|---|
| STERF | 90 | 10 | 100 |
| Other sources | 90 | 0 | 90 |
| Total | 180 | 10 | 190 |
