Which drone are you considering? From an operational perspective, fixed-wing platforms are less flexible than VTOL (quadcopter-style), and are arguably harder to operate. VTOLs obviously have much shorter loiter time and are noisy, though the noise shouldn't be a problem as long as you don't immediately turn up with guns every time you spot a sounder (if you do, the boars will make the connection ... they're smart). But they will let you position to see through gaps in the plantation's canopy, and a high frame rate isn't as important if the platform isn't moving.
Whichever platform you use, you will need a stabilised gimbal mount and a telephoto optic for the thermal camera, plus a regular lens for the visible/IR navigation camera. There are two-in-one cameras like the FLIR Duo Pro R that may make this easier for VTOL as long as the telephoto lens doesn't block a large part of your field of view.
Fixed-wing you pretty much have to use the thermal in a side-view configuration, with a fixed, forward-looking navigation camera. You will need aerodynamic fairings in front of and behind the thermal. Consider how long the thermal and its optic will be ... it might be difficult to fit within the fuselage ...