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Glutz von Blotzheim, U. N.

Die Bedeutung der Blattlaus Rhopalosiphum padi (L., 1758) und der Traubenkirsche Prunus padus L., 1753 für Vögel.

2004

101

89–98

Key words
(von 1994 bis 2006 vergeben)

Bird cherry, Prunus padus, bird cherry-oat aphid, Rhopalosiphum padi, stopover in migrating birds, feeding ecology, energy storage, hedges, woodland edges

Zugrast, Nahrungssuchverhalten, Nahrungsangebot, Energiespeicherung, Siedlungsökologie, Hecke, Waldränder

Schlagwort_Vogelart
(wissenschaftlich)

Troglodytes troglodytes, Prunella modularis, Erithacus rubecula, Phoenicurus ochruros, Phoenicurus phoenicurus, Acrocephalus scirpaceus, Sylvia curruca, Sylvia communis, Sylvia borin, Sylvia atricapilla, Phylloscopus sibilatrix, Phylloscopus collybita, Phylloscopus trochilus, Regulus regulus, Ficedula hypoleuca, Aegithalos caudatus, Parus palustris, Parus ater, Parus caeruleus, Parus major, Sitta europaea, Certhia brachydactyla, Passer domesticus, Passer montanus, Fringilla coelebs, Fringilla montifringilla, Carduelis chloris, Carduelis carduelis, Carduelis spinus, Loxia curvirostra

Schlagwort_Vogelart
(deutsch)

Zaunkönig, Heckenbraunelle, Rotkehlchen, Hausrotschwanz, Gartenrotschwanz, Teichrohrsänger, Klappergrasmücke, Dorngrasmücke, Gartengrasmücke, Mönchsgrasmücke, Waldlaubsänger, Zilpzalp, Fitis, Wintergoldhähnchen, Trauerschnäpper, Schwanzmeise, Sumpfmeise, Tannenmeise, Blaumeise, Kohlmeise, Kleiber, Gartenbaumläufer, Haussperling, Feldsperling, Buchfink, Bergfink, Grünfink, Distelfink, Erlenzeisig, Fichtenkreuzschnabel

Schweiz, Sempach, Schwyz, Luzern

deutsch

Abhandlung

The significance of the bird cherry-oat aphid Rhopalosiphum padi (L., 1758) and its primary host, the bird cherry Prunus padus L., 1753, for birds. – Emigrants of the host-alternating bird cherry-oat aphid fly from the primary host to various grasses in June. In September alate gynoparae arrive on bird cherry and give birth to oviparae. The arrival of the males coincides with the maturation of the first oviparae. Mating takes place and the oviparae lay their eggs mainly on the current year’s twigs around the bases of the buds. During some 20 autumns we noted 30 species of birds feeding on these aphids (no disturbance by mist-netting). The 7 most frequent avian predator species are summarized in table 1. Blackcap Sylvia atricapilla and Common Chiffchaff Phylloscopus collybita are the most numerous predators and those feeding most intensively. As other species too, they feed alternatively on aphids and fruits or on other insects. Feeding on aphids begins at a very low level during the second half of August, intensifies in mid-September, reaches its peak from 23 September to 7 October in Garden Warbler Sylvia borin, Blackcap and Willow Warbler Phylloscopus trochilus, from 13 to 17 October in Chiffchaff, tits Parus sp. and Common Chaffinch Fringilla coelebs and declines rapidly at the beginning of November. During the peak of harvesting up to 13 individual birds of 7 to 8 different species may gather simultaneously in one bird cherry, or at least 11 to 20 Chiffchaffs may be present in bird cherry and nearby other bushes and trees (these figures may show the carrying capacity of one bush or one small clump of bird cherry bushes). In 2003 a Reed Warbler Acrocephalus scirpaceus stayed for at least 23 days in our garden just to feed on this aphid. In this autumn we estimated at least 99 540 presumed prey captures (pecks) by the one Reed Warbler, at least 50 240 pecks by Blackcaps and more than 1000000 pecks by Chiffchaffs. The total harvest on only two bird cherry bushes may be estimated at 1.5 to 3 million aphids during this autumn, representing 3000 – 6000 g or 20160 – 40330 kJ (attempt to give a rough idea of the amount of aphids eaten by birds). Feeding superabundant aphids is easy (joining behaviour, short search), efficient (no handling time, high digestibility) and of high reward in carbohydrates – an important complement to berries and fruits and probably a remunerative method of optimal foraging. Bird cherry is an attractive, flowering wild tree. It offers a variety of insects early in spring, fruits or seeds in advance of most other bushes and trees in early summer, and a high amount of aphids favourable for re-fuelling autumn migrants. In addition, the honeydew, excreted by aphids, attracts a number of insects. The all-year-round environmental contribution of bird cherry should be reason enough not to remove this bush from woodland edges and hedges. In fact this should be an encouragement to plant it more often in parks and gardens.