16 RUDOLF SÖDERBERG, STUDIES OF THE BIRDS IN NORTH WEST AUSTRALIA. 
The ebbzone. The tide was of the greatest importance for the wading birds 
of the islands. For these islands are never surrounded by sandy shores, but the 
rocks fall directly to the sea. Only in small and scattered places do the glens run 
out to the water-line, and then even in spring-tide a real shore is formed, which is 
lacking elsewhere. Instead the enormous ebb (14—17 yards) lays bare large stretches of 
the seabottom, which here is firm, though soft, level ground, drenched with salt water. 
Outside the openings of the glens, but also elsewhere, is found the mongrove-wood, 
this region is otherwise without vegetation. In some places, where the bottom is 
very shallow, stretches are bared, on which it is possible to walk as far as 2'/2 miles 
from the water-line of the spring-tide. 
It is this important winning of land in the ebb-tide, that is the condition for 
the presence of a good many waders, the existence of which would otherwise be 
rendered impossible in these islands. The ebbzone and the mangrove-vegetation 
accordingly have their special birds, distinguished from the specific inland-fauna of 
the islands, to which nevertheless certain birds of the latter also belong, as is seen 
in the special part of this work. 
Beagle bay 
situated on the northern point of Dampier land, was characterized by the richest 
vegetation which was met with at any place on the continent, visited by the expedi- 
tion. Close Eucalyptus-vegetation of bushes covered great areas together with the 
usual large-trunked, thinner wood, here besides interspersed with Malaleuca leucaden- 
dron trees. In some places there was a real greensward of a low but matted grass 
and in some places broaklets traversed the ground. 
Characteristic were the springs we found here and there round the missionary 
station of Beagle bay. Around them were found Pandanus-palms. The ground 
rose to a cone about 20 m. in cireumference at the base and about one meter in height. 
At the top of the cone clear and relatively cold water was found, and it was evident, 
also because of the considerable depth, that the wells reached down to subsoil water. 
A very high (more than height of man), knolly grass enwreathed them. 
Also the difference in temperature in the course of twentyfour hours, which 
WiDELL and I had to experience here in July, was remarkable. Thus in the middle 
of the day we had more than 40” C. in the shade, but on the night of the 6th of 
July the thermometer fell below freezing-point, so that we had —3” C. On the 
water-pools ice had formed and on the ground lay a thin hoar-frost. This low tem- 
perature, however, prevailed only some nights, but the nights were cold all the month, 
and towards the evening the open places in the wood grew very foggy. We were 
told that Beagle Bay would be the coldest place as far as was known in the part 
of North West Australia that we visited. 
