Invloed van havikenpredatie op postduivenbestanden Haviken in Zuid-Twente (3)

In the period 1986 until 1993 mr. PT. Koopmans and the author researched the effects of goshawkpredation on homing-pigeonpopulations. The locations researched consist of seven goshawk territories in the neighbouring muncipalities of Haaksbergen and Enschede. All data and conclusions given are based on 603 rings, from homing-pigeons, that were collected by the two researchers. The data led to the following conclusions: Half of the pigeons were juvenile. 50% of the distances between ring-spot and find-spot is between 7 and 30 km and spread concentrically. The other 50% show radii from 31 up to 625 km around the nest-woods. Diagonally seen, the pigeons came from Newcastle (U K.) to Czechia and from Schleswig-Holstein (G.) to Flanders (B.). For four nest-woods researched, throughout the years the pattern of ring-spots of the predated homing-pigeons is consistently star-shaped showing densities inverse with range to the nestwoods. For a very small part mortality among homing-pigeons is caused by goshawkpredation. Homing-pigeon losses due to goshawkpredation, as measured by ringrecoveries is only 0.1%. Almost all homing-pigeons predated apparently wandered solitary; they had uncorrelated owners from 231 Westeuropean cities and villages. Goshawk breeding pairs did not visit pigeon houses in the neighbourhood. Tot slot een woord van dank aan mevrouw Vera Visser voor het vertalen van de samenvatting.