i'm happy to see one more of my clockwork creatures' illustrations in a natural history book!
This is a pair of Passenger pigeons featured in 'The Passenger Pigeon' by Errol Fuller.
At the start of the nineteenth century, Passenger Pigeons were perhaps
the most abundant birds on the planet, numbering literally in the
billions. The flocks were so large and so dense that they blackened the
skies, even blotting out the sun for days at a stretch. Yet by the end
of the century, the most common bird in North America had vanished from
the wild. In 1914, the last known representative of her species, Martha,
died in a cage at the Cincinnati Zoo.
Published in the centennial year of Martha's death, 'The Passenger Pigeon' features rare archival images and drawings and more regarding this lost species.
see here for more details