Agricultural training and birds
Kluijver studied tropical agriculture at Wageningen and initially intended to work in sugar cultivation, a plan altered by the economic crisis. His starling research subsequently supplied the material for an agricultural doctorate.
At the plant-protection service he investigated whether insect-eating birds attracted to nest boxes could assist pest control. The practical question developed into long-term work on breeding and population changes.
References: [1]
Repeated nest-box records
Kluijver continued earlier nest-box work and made great tits a principal study organism. Repeated records enabled comparison of breeding, survival and numbers between years.
Attracting insectivorous birds was not itself proof of comprehensive pest control. Subsequent research by a close colleague also examined limits to that practical expectation.
References: [1]
Homing and acoustic experiments
His starling work included homing experiments in which cages were rotated during transport, introducing an experimental treatment rather than recording flight directions alone.
He also tested acoustic deterrence in cherry orchards before the Second World War. The professional obituary identifies contemporary sound technology as a constraint on that work.
References: [1]
Institutes and international influence
Kluijver directed the Royal Netherlands Academy’s Institute for Ecological Research. Established at Arnhem in 1954, it emphasized bird population and grassland ecology.
His Dutch tit investigations helped inspire Gibb and Lack’s Wytham project in 1947. Repeated individual records connected these research traditions and supported comparisons of bird populations.