Blank is an appropriate method to monitor a population of swallows, while blank is an appropriate method to monitor a population of tortoises

Point count is an appropriate method to monitor a population of swallows while line-transect  distance sampling is an appropriate method to monitor a population of tortoises.

Explanation:

Point counts are widely used to count or keep track of birds. An observer can record the birds from a single point for a certain standardized amount of time

While line-transect distance sampling will help in the monitoring of tortoise population. It can show how some individuals are missed and also at the same time establish a method for controlling those number of individuals missed.