WILD LIFE OF ORCHARD AND FIELD 



and weak, but those which stay there through the 

 winter fatten rapidly, and in March or April begin 

 to prepare for departure. " They can be seen dur- 

 ing the day, at this time/' says an authority, ''tak- 

 ing long or short flights out at sea and returning 

 again to the island. This exercise is undoubtedly 

 for the purpose of strengthening themselves for the 

 final effort — their muscles, during their winter's 

 life of luxury and ease, having become flabbj^ 

 and feeble.'' This scene is repeated every spring 

 in the North Island of New Zealand, when the cur- 

 lews gather in flocks on the utmost headlands at 

 sunset, and with plaintive gathering cries rise into 

 the air, circling higher and higher until at last 

 they turn and speed away across the twelve hun- 

 dred miles of restless waves that separate them 

 from the nearest resting-place. 



But these feats of flight are by no means con- 

 fined to sea -fowl. Land birds constantly travel 

 between the mainland and such distant islands 

 as Madagascar, the Canaries, and Bermuda— 

 from the last-named even the ruby-throated hum- 

 ming-bird goes and comes with the changing sea- 

 sons. In Oceanica migration-habits are observa- 

 ble that seem to have no part in the general equa- 

 torial-polar movement — the case, for instance, of 



115 



