| These waterfowl migrate early in spring and move northward from their wintering grounds as soon as wetlands become ice-free. |
| Weather data were collected during the ice-free season from a meteorological station situated in a central location on the study area. |
| We headed back north of Bridgeman Island in hopes of getting to the relatively ice-free waters of the eastern Bransfield Basin. |
| The extra shelter from the riverside developments saw the walkways stay ice-free last week. |
| The animals spend most of the winter on pack ice and invariably return to their birthplace to breed in ice-free coastal areas in summer. |
| With less krill to go around during the ice-free years, fewer penguins survive to adulthood. |
