HUSTINGS F (2002) Recent breeding of Firecrest Regulus ignicapillus in the Netherlands. LIMOSA 75 (3): 85-90.

Being one of the more unobtrusive songbirds, breeding Firecrests have long been underestimated in The Netherlands. After breeding was first confirmed, in 1928 near Breda, province of Noord-Brabant (see Pellinkhof 1928, elsewhere in this volume), it took several decades before identification skills among ornithologists revealed a detailed pattern of the species' distribution and numbers. More or less casual records suggest a very limited distribution in low numbers throughout the eastern and southern Netherlands until the 1950s, followed by an expansion of breeding distribution and a strong population increase in the 1960s and, especially, the 1970s. As this coincides with an increase in birdwatching activities, however, the true magnitude of the increase may have been overestimated. The first national breeding bird atlas, fieldwork for which was conducted in the mid-1970s, revealed a rather evenly distribution over the wellwooded parts of the higher grounds; 22% of all 5x5 km-squares were occupied (Goldcrest R. regulus: 45%) and the population estimate of 1750-3000 breeding pairs was certainly too low. In the 1980s and 1990s, the distribution expanded slightly, resulting in a presence as a breeding bird in 30% of all atlas-squares in 1998-2000 (Goldcrest 51%). In fact, the species nowadays inhabits nearly all atlassquares holding at least 10 ha of spruce. As Firecrests prefer trees at an age of at least some tens of years, the species is most numerous in regions holding large areas of older spruce plantations (Drenthe, Veluwe), although it may occur widely as well in deciduous forests with lanes or small pockets of spruce (Twente, Zuid-Limburg). Breeding in purely deciduous forests is restricted to the utmost southeast of the country (Zuid-Limburg).
      Although breeding numbers during recent fieldwork for the second national breeding bird atlas in 1998-2000 have been estimated at some 5000-7000 pairs, much more than in the mid-1970s, detailed studies suggest that in some long occupied regions numbers have stabilised or even slightly decreased since the 1980s. Changes in forestry practices, expressed by a replacement of coniferous plantations by inland deciduous trees, may account for part of this stagnation in population growth, but decreasing tree vitality due to atmospheric deposition cannot be excluded.

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