Table 1.
Direction of correlation (positive, negative or absent, see column 1) between concentrations of a particular hormone (column 2: T, testosterone; E, oestradiol; A4, androstenedione; DHT, dihydrotestosterone; B, corticosterone; T4, thyroxine) in maternal plasma and egg yolks in 11 studies on several bird species (column 3: B-h., black-headed; B-b., black-backed). The type of data are indicated in column 5: individual females, correlation based on data from individual females and their eggs; group level, comparison of the effect of a manipulation (social challenge and food provisioning during egg laying) and artificial selection for adult plasma hormone levels on female plasma and yolk hormone concentrations; laying sequence, comparing the patterns of change in plasma and yolk over the laying sequence of a clutch. The last column refers to sampling protocol; see also text.
| correlation | hormone | species | reference | kind of data | remarks |
|---|---|---|---|---|---|
| + | T | domestic canary | Schwabl (1996a) | individual females | females: faecal samples |
| + | T | house finch | Badyaev et al. (2005) | individual females | eggs: yolk rings |
| 0 | T | house sparrow | Egbert (2006) | individual females | eggs: yolk rings |
| 0 | T | domestic canary | Marshall et al. (2005) | group level: social challenge | plasma and yolk in different studies |
| 0 | T | Eurasian starling | Pilz et al. (2003) and Williams et al. (2004) | group level: laying sequence | plasma and yolk in different studies |
| − | T | house sparrow | Mazuk et al. (2003) | group level: social challenge | plasma at incubation |
| − | T | eastern bluebird | Navara et al. (2006) | group level: social challenge | |
| + | T | B-h. gull | Groothuis & Eising (in preparation) | Individual females | plasma at start of incubation |
| − | A4, T, DHT | B-b. gull | Verboven et al. (2003) | group level: food provisioning | plasma at incubation |
| − | E | Eurasian starling | Williams et al. (2005) | individual females | small sample size |
| + | B | Japanese quail | Hayward et al. (2005) | group level: selection lines | |
| + | B | Eurasian starling | Love et al. (2005) | individual females | data of controls and E treated together |
| +/0 | T4 | Japanese quail | Wilson & McNabb (1997) | individual females | weakly positive |