Final answer:
Elephant densities might vary among different transects due to their complex social structures and habitat preferences, as well as potential methodological issues with the survey design, such as placement and timing of line transect surveys and the expertise of personnel conducting the surveys.
Step-by-step explanation:
There are multiple factors that might result in variation in elephant densities among different transects of a habitat stratum. One reason related to elephant behavior is territoriality and social structure. Elephants are known to have complex social structures and may prefer certain habitat types that meet their needs for food, water, and security. They could also be influenced by historical patterns of range use or by the presence of other elephant groups, leading to uneven distribution across transects.
From the survey design perspective, the variation in density estimates could result from methodological challenges. For example, a line transect survey carried out with limited resources and perhaps non-professional personnel might not evenly sample the stratum, leading to biased density estimates. Incorrectly placed transects or timings that do not account for elephant movements and activity patterns could also affect the data collected, making some areas look more or less densely populated than they truly are.