Possible Clues:

• Small bird that builds floating nests
• 105 Across that's spelled out by the first letters of this puzzle's unclued Down answers
• Flier essential to meagre beginnings
• Water creature carried westward by icebergs
• Aquatic bird, nests on floating plant material
• __ tissue, in which 16 is stored
• Small aquatic bird that builds floating nests
• Flier taken over Eastern mountain
• The little ____ is an aquatic bird also called “dabchick”
• Bird in boiling rebellion