Max, its an organised tour around the various national parks (Andasibe, Ramanofara, Isalo, Andringitra) including stops at private reserves and wildlife parks. The focus will be on nature and wildlife. Also, I some relaxation is planned at a lodge (Anjajavy) at the end of the trip which is in a private reserve. The duration of the trip is three weeks. At the national parks I expect we will be walking 3-5 hours a day in hot conditions. At least in the rainforests the ground is undulating and hard work to trek around. So weight would be a consideration. In the smaller parks and private reserves we might not need to do very much walking.Do you mind asking how did you get the organized tour?
AJ, that's an approach that makes sense and is certainly another way to go about it. Did you feel that you sacrificed much in the way of IQ? Also, did you often find yourself at the end of the zoom range when photographing wildlife? To get the equivalent range of 300mm on a 7D, I would need 480mm on my 6D. How did your set up cope with taking shots in the rainforests? 5 weeks must have been quite the trip, which areas of Madagascar did you visit?
April in Madagascar is still rainy green period (as opposed to October). I would focus on either macro or wildlife. You could shoot both but with a focus mainly on one - Just a suggestion. The 100mm L will do really well if you are a macro fan. I envy you, shooting macro with a full frame in that country during the rainy period! I am planning, but in two years.
300mm on a full frame could be too short, unless you take an extender. Try not to be too heavy.