This depends. If you are picking the bird up to place it back into a nest or putting it up on a limb so that a dog or cat can’t get to it - YES. Birds have terrible senses of smell and do not care about human scent. If you are picking it up to take it to somewhere else, the answer is NO. Most baby birds that are on the ground are very close to being on their own and they generally need only a few more bugs or worms from the adults to make it. Too often people pick them up and take them to a vet or nature center while mom and dad birds are going nuts looking for their baby. Let nature take its course.