"Least bitterns are the smallest members of the heron family and are one of the
most inconspicuous of all marsh birds (Weller 1961; Gibbs et al. 1992)."
"In general, least bitterns occupy freshwater and brackish marshes with dense, tall
growths of emergent vegetation interspersed with clumps of woody vegetation
and open water (Gibbs et al. 1992)."
"The least bittern’s small size, highly compressed trunk, and ability to grasp with
its feet enable it to move through dense vegetation. They forage by clinging to
emergent vegetation over open water and extending their long necks, wading
along the edge of open water, and using small constructed foraging platforms at
rich feeding sites (Eastwood 1932; Sutton 1936; Weller 1961; Gibbs et al. 1992)."
These three quotes were taken from a PDF file available from
Lower Colorado River
Multi-Species Conservation Program
Balancing Resource Use and Conservation
https://www.lcrmscp.gov/species/least_bittern.html
The following images illustrate some of the points mentioned above.