Table 1.
Site and sample data for the five subspecies of red knot, with predicted TRCs (W;±s.e.), average digestive prey quality (kJ g−1 DMshell;±s.e.), expected satisficing and net rate-maximizing gizzard masses (g; s.e.-confidence interval in brackets), the number of gizzards sampled and the observed gizzard masses (g; mean±s.e.).
| subspecies | migratory phase | site | month | TRC (W) | prey quality (kJ g−1 DMshell) | exp. satisficing gizzard mass (g) | exp. net rate-maximizing gizzard mass (g) | N gizzards sampled | obs. mean gizzard mass±s.e. (g) | reference |
|---|---|---|---|---|---|---|---|---|---|---|
| canutus | wintering | Banc d'Arguin, Mauritania | December | 1.49±0.27 | 0.89±0.07 | 10.51 (9.70–11.38) | 16.64 (15.71–17.67) | 6 | 9.89±0.53 | this study |
| canutus | stopover | Wadden Sea, NW-Europe | May | 1.99±0.03 | 3.74±0.03 | 5.73 (5.68–5.78) | 8.14 (7.93–8.34) | 2 | 8.00±0.30 | Van Gils et al. (2003) |
| islandica | wintering | Wadden Sea, NW-Europe | January | 2.93±0.02 | 2.10±0.03 | 8.49 (8.40–8.58) | 10.86 (10.55–11.17) | 60 | 8.75±0.18 | Van Gils et al. (2003) |
| islandica | stopover | Selvogur, SW-Iceland | May | 2.26±0.04 | 2.35±0.31 | 6.33 (5.91–6.85) | 9.45 (8.70–10.35) | 8 | 7.95±0.48 | Piersma et al. (1999), Alerstam et al. (1992) |
| rufa | wintering | Tierra del Fuego, S-Argentina | February | 1.82±0.06 | 2.03±0.14 | 7.21 (6.92–7.53) | 11.04 (10.47–11.66) | 13 | 8.09±0.20 | this study |
| rufa | stopover | San Antonio Oeste, E-Argentina | March | 1.35±0.05 | 3.50±0.23 | 5.09 (4.89–5.31) | 8.41 (7.97–8.87) | 7 | 8.17±0.20 | González et al. (1996) |
| rogersi | wintering | Northern New Zealand | March | 1.30±0.03 | 0.82±0.04 | 9.55 (9.29–9.84) | 15.49 (14.82–16.20) | 5 | 9.31±0.64 | Battley & Piersma (1997) |
| piersmai | wintering | Roebuck Bay, NW-Australia | January–April | 0.67±0.04 | 2.22±0.30 | 5.91 (5.53–6.39) | 10.55 (9.70–11.59) | 24 | 5.94±0.36 | this study |
References are to detailed studies at the particular site.