Can a ground shockwave affect something mid-air? Let's say if something were to hit the ground very fast and hard with no explosion just force, would it affect something mid-air like a bird that is not touching the ground?
 A: Yes.
Impacts create shock waves - waves of high pressure and high kinetic energy (which is energy in the forms of temperature and net, bulk flows of gas) as they propagate. The gas’ kinetic energy itself (think “temperature”, explained below) may cause damage to the bird, the pressure itself may, and the gust of air may (maybe the gust would be enough to break a wing for example). The combination of course would be harder to deal with.
To disentangle what I meant by kinetic energy being in the forms of both gusts and temperature, consider what temperature is, in this diversion (between the lines):

Room air particles are full of energy: Temperature is actually the kinetic energy of the molecules. For example, in an ideal gas model, the relationship between pressure and temperature is determined by modeling it as many tiny particles. Pressure comes from the particles colliding with a wall at the point we are determining pressure, in a perfectly elastic collision, transferring an impulse to the wall. Many particles do that in a given time $t$: $F= \sum \tfrac{m \cdot \Delta v_{rms} }{t}$. And this aspect of the model (particularly velocity) matches perfectly with the temperature model of the same particles: a temperature model where internal energy in the gas comes from its kinetic energy $\sum \tfrac{1}{2}mv_{rms}^2$, where $m$ is the mass of a single molecule.
How Fast are the molecules moving
And a good guesstimate is $$v_{rms} = \sqrt { \tfrac{3RT}{M_m}} \approx \sqrt { \tfrac{3 \cdot 10 \cdot 300}{0.03}} \approx 500 m/s$$
We would have to be around mach-1.5 for the air’s net velocity to match the average particle speed of room air. When you touch something hot, it’s vibrating molecules make yours vibrate. The bird has this aspect as part of it.

In our case, because it is a highly dynamic, non-equilibrium situation, it can be a little (not a ton though) unclear what aspect of the gas’ kinetic energy would be temperature versus gusts in rapidly evolving shock waves. As you see pressure is differential concentrations of energetic air molecules as well (pressure being net molecular impacts per the force equation above). These all combine into a wave of nasty air molecules with differing densities (and hence $\Delta p$’s), temperatures, and flows (gusts).
Five minute video What are shockwaves https://youtu.be/pCcAN_MAlLQ
