Carcass is now a skeleton, with clean white bones and in wet areas no skin. Skeletons are difficult to see from the air. Carcass breakdown depends greatly on local conditions and can vary tremendously from year to year. Local conditions greatly affect the results of aerial surveys for elephants and carcasses. In particular, there is a great difference between wet and dry seasons in savannah habitats.
Aerial surveys have to be carried out in the dry season.
In hot seasons elephants will seek out shade earlier in the morning and remain in it for longer in the afternoon, thus reducing the amount of time that they are easily visible. Distribution Elephants may clump in response to seasonal resource availability. In very dry areas, they may concentrate along watercourses during the height of hot dry seasons in response to water scarcity. In wetter areas herds may actually become more clumped in the wet season. This paradox is explained by the fact that elephants are very sociable animals, and if food is readily availabile they may congregate in larger herds.