The impact of roads on the densities of four bird species in an open field habitat—evidence of a long-distance effect

• Published in: Biological conservation Vol. 18; no. 4; pp. 299 - 321
• Main Authors: van der Zande, A.N., ter Keurs, W.J., van der Weijden, W.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.1980
• ISSN: 0006-3207
• DOI: 10.1016/0006-3207(80)90006-3

Roads may effect animal communities in various ways. One such way is ‘di sturbance’, i.e. emission of stimuli to which animals may respond by avoiding the vicinity of the road. The extent, intensity and mechanism of this effect is almost entirely unknown. Veen (1973), studying the bird species lapwing Vanellus vanellus, black-tailed godwit Limosa limosa, oystercatcher Haematopus ostralegus, redshank Tringa totanus and ruff Philomachus pugnax in open grassland areas, found disturbance over surprisingly long distances, ranging from 500–600 m for a quiet rural road to 1600–1800m for a busy highway. However, his approach has met with serious methodological criticism. The validity of Veen's conclusions was tested by critically reanalysing bird distribution in one of his study plots. It is inferred that his conclusions do hold for the lapwing, the godwit and possibly the redshank, though not for the oystercatcher. An additional field study in four areas yielded similar results, with comparable disturbance distances. The total population loss over this distance may amount to 60%. Rough indications were obtained that the distance-density graph is a logistic one, while the relation between traffic volume and total population loss is possibly logarithmic. In addition confirmation was obtained of the general impression that, apart from roads, disturbance may also be caused by farms, other buildings and plantations, suggesting that disturbance caused by a road is not easily eliminated by planting trees alongside. It is recommended that extra care be taken in planning new roads, while impact statements concerning roads which disregard disturbance and other long-distance effects on the fauna should be rejected.