In 2022, a male Pallid Harrier was recorded in farmland in the province of Groningen on 19 June when transferring a prey to a male Marsh Harrier. This bird had been colour-ringed as a chick in a nest of Pallid Harriers in 2019, less than two km away from the harrier’s presence in 2022. The Marsh Harriers had a nest in a wheat field. The nest was observed from a hide on 7 July, when five chicks of 1-12 days old were present. Between 8:45 and 13:30, a total of 22 prey deliveries were recorded (of which 18 were brought to the nest), five by Pallid Harrier, six by female Marsh Harrier and eleven by male Marsh Harrier. Except two birds, all prey were voles, presumably Microtus arvalis. Taking prey mass into account (25 g for Common Voles, 50 g for birds), each chick received 35 g of food per 100 minutes, of which the male Pallid Harrier contributed 10.4 g (30%). Furthermore, the Pallid Harrier was also frequently recorded chasing potential predators away from the nest site, including attacks on Marsh Harriers (other than the nesting pair), Buzzards Buteo buteo, Kestrels Falco tinnunculus, Carrion Crows Corvus corone and a Goshawk Accipiter gentilis. The nest eventually fledged four chicks. It is unknown whether extrapair copulations of female Marsh and male Pallid Harrier had taken place, which might have explained the Pallid male’s investment in the Marsh Harrier brood.

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R. Ubels, & R. G. Bijlsma. (2023). Mannetje Steppekiekendief Circus macrourus als helper bij het nest van een Bruine Kiekendief C. aeruginosus. De Takkeling, 31(1), 78–85.