Green plants in starling nests: effects on nestlings

Green nesting material has a function in mate attraction in the European starling

“…3, Table 2). The scab scores we found were within the range of the average scab scores on starling nestlings in herb (green) and dried grass (control) nests found by Gwinner et al (2000) (Fig. 3).…”

“…Previous studies also found that the use of green plants in starling nests had no effect on ectoparasite numbers (Gwinner et al 2000) and nestling condition (Clark & Mason 1988;Fauth et al 1991), even though the green plant species that were used contained high levels of volatile compounds (Clark & Mason 1985;Gwinner 1997;Lambert 1997). However, some of these studies found that nestlings from nests where greenery was added during the incubation stage had a higher immune response (measured as haematocrit level; Clark & Mason 1988;Gwinner et al 2000) and a higher first-year survival (Gwinner et al Table 2; N Z number of nestlings). As a comparison, the scab scores on starling nestlings in herb (green) and dried grass (control) nests as found by Gwinner et al (2000) are given.…”

“…Only male starlings carry green plant material into their nests (Kessel 1957;Feare 1984;Clark & Mason 1985;Gwinner 1997), some of which is rich in volatile compounds (Clark & Mason 1985). Some studies found that these plants impair the development of bloodsucking mites and bacteria in nests (Clark & Mason 1985, 1988Clark 1991), but others found no effect (Fauth et al 1991;Gwinner et al 2000). Furthermore, a reduction in blood-sucking parasites did not improve the growth or survival of nestlings (Powlesland 1977;Clark & Mason 1985, 1988Walter & Hudde 1987;Fauth et al 1991) nor did this result in increased blood haemoglobin levels (Clark & Mason 1988).…”

“…Furthermore, collecting mites from the nesting material would influence their numbers. The percentage of a nestling's abdomen covered with scabs is a reliable measure of mite numbers present (Spearman rank correlation between total number of mites on nestlings and average scab score of all nestlings per nestbox: r S Z0:850, NZ8, PZ0:007; see also Gwinner et al 2000). The scabs on the abdomen of each nestling were scored five times, at 3, 6, 9, 12 and 15 days of age, using a 0e2 scale (0: no scabs; 1: less than 50%; 2: more than 50% of the abdomen covered with scabs (as defined by Gwinner et al 2000; see also Fauth et al 1991)).…”

“…However, some of these studies found that nestlings from nests where greenery was added during the incubation stage had a higher immune response (measured as haematocrit level; Clark & Mason 1988;Gwinner et al 2000) and a higher first-year survival (Gwinner et al Table 2; N Z number of nestlings). As a comparison, the scab scores on starling nestlings in herb (green) and dried grass (control) nests as found by Gwinner et al (2000) are given. 2000) than nestlings from nests where no greenery was added.…”