webbed
He has recorded a dramatic decline in the numbers of semipalmated sandpipers.
Semipalmated and western sandpipers are so difficult to identify that they could almost drive you to give up birdwatching.
A separate branch of waders developed semipalmated feet in many species.

SMART Vocabulary: related words and phrases

The legs & feet of non-human animals
bipedal
clawed
cloven
cloven hoof
foot
forefoot
hooves
leg
limb
member
pad
paw
shank
talon
toe
trotter
web-footed
webbed
webby
zygodactyl