Answers are grounded in this paper and cite their sources.
The main biases of the studies included selection bias, non-response bias, measurement bias and biases associated with length of sampling time. Careful design and planning of studies is a necessity before executing a study to estimate pet populations.
No takes yet. Share an insight, caveat, or question.
Downes et al. (2013) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: