There are DIY articles available for building a camera system to get
pictures of deer (so you can decide which game trails to hunt, I guess -
I've never been a terribly serious deer hunter) based on motion sensors
from lighting systems and modifications to cameras. Tends to keep going
out of date as the specific models that someone has figured out where to
hook up to keep changing, but might be a lot simpler to do in this case.

You can also purchase non-DIY versions of the same thing based on motion
sensors, for about 10X the cost of the DIY setup.

I suspect the "wire-break" sensor someone mentioned would be a lot
better for this purpose (no/less false alarms), and the availability
(presumably) of power in your front yard makes some aspects simpler. Put
a bunch of lights where they shine on the yard, and set those off when
the wire breaks.

At the low end, without camera modification, a small circuit to punch a
solenoid that triggered the camera (via cable release, or directly if
it's a cheap camera with no cable release) a few times at intervals
after the wire broke would do - could even be a film camera, rather than
a digital, so long as it has autowind. One which put a time/date stamp
on would be a nice touch, if the camera clock was set correctly. Use a
camera with no flash and enough lights to still get good pictures, so
the camera flash is not giving the camera away. If you're fiddling with
a camera you don't mind modifying, you might be able to skip the
solenoid and access the shutter release contacts electrically. Might
also be able to get rid of the camera batteries and make it plug in to
the wall, so that you don't have to make sure the batteries are still
good if nobody crashes into your yard for a few months.

At the high end, some sort of digital video setup which continuously
recorded a loop of 2-5 minutes or so and had a means of getting
information from the sensor wire to know that it should now save the
recorded loop (thus getting them even before they hit the wire) and
anything else that will fit (at least another 5 minutes) on its disk
would be nice. More work, probably far more cost, unless you have the
right toys in the junkbox.

Hide the camera (or cameras) well, in any case.

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