KOOIJ H VAN DER (1995) Does Red Fox Vulpes vulpes get Purple Heron Ardea purpurea into a tight spot?. LIMOSA 68 (4): 137-142.

Purple Heron Ardea purpurea Red Foxes have settled in Dutch Purple Heron colonies at the end of the 1970s and the beginning of the 1980s. Although predation of clutches has occurred in a few cases, the direct impact of predation is probably negligible. However, there might be an indirect influence through e.g. disturbance of breeding birds. To investigate this, data on nest-site and nest-height have been analysed, with emphasis on the major Nieuwkoop colony. In colonies in reedland, Purple Herons showed a reaction to the appearance of Red Foxes by breeding more dispersed and in wetter vegetations than before. In colonies in shrubs, average nest height increased (Figs. 1, 2) and higher shrub or tree species were preferred (Fig. 3). In both habitats, Purple Herons quickly and successfully adapted to the new situation, thereby avoiding high predation risk. As the Dutch breeding population did not decrease after settlement of Red Foxes in colonies and as the significance of the most important colonies remained unaltered (Fig. 4), it is concluded that, until now, Purple Herons have not suffered directly or indirectly from this predator. The Dutch breeding population, however, remains vulnerable and future conflicts cannot be ruled out. Some suggestions for habitat management and creation of fox-free zones are presented..

[free pdf] [dutch summary]