I have a Bushnell Trophy Cam HD Max that I have been quite pleased with. You can set it to do stills OR video and works day and night. Night pix/vids are in monochrome, day in colour. Can also be set to take images at a certain time of day/night without the sensor being triggered. Takes 12 AA batts. for longterm performance although will work on 4.
You'll no doubt get a number of recommendations. Check out the specs of each and decide what you want or need, e.g. sensor range, before coughing up your hard-earned.
If it's a short-term need you may be able to hire one.