Document ID: chunk:federal_register_of_legislation:F2023L01713:body:0:p27
Version: federal_register_of_legislation:F2023L01713
Segment Type: other
Provision Reference: 
Character Range: 145145–147949

to eight individuals of all ages and sexes, but with no more than one adult male (Van Dyck 1996). An average of two occupants was recorded in permanent shelters monitored with cameras along the Maroochy River (Kaluza et al. 2016).
There is no recorded information about water mouse shelters in freshwater habitats where large, complex structures may not be required due to an absence of daily fluctuations in water height (Gynther 2011). In these areas, the water mouse may use simple tunnels in banks around the margins of wetlands, or surface debris, for shelter and nest sites (Gynther et al. 2011).
Male and female water mice can be detected in breeding condition throughout most of the year in southeast Queensland and camera monitoring of shelters suggests they breed up to twice per year (Van Dyck 1996; Kaluza 2021 pers. comm.). A nest of four hairless young was detected in a shelter on Minjerribah/North Stradbroke Island (Van Dyck 1996).

3.6                  Diet and foraging
The water mouse feeds primarily on sesarmid and grapsid crabs across its distribution (Magnusson 1976; Van Dyck 1996; Burnham 2000; Ball 2004; Ball & Mitchell 2018). In southeast Queensland, where it has been studied intensively, the water mouse also feeds on other crustaceans, as well as marine pulmonates, bivalves and polyclad flatworms within intertidal systems (Van Dyck 1996). It is likely that the water mouse has a diverse carnivorous diet across its range. It is reluctant to consume vegetables in captivity (Magnusson et al. 1976) and gut and scat analyses support a carnivorous diet (Van Dyck 1996). There is speculation that a high density of crab prey may be required for water mouse to occur and persist along the central Queensland coast (Ball 2004).
The water mouse is only known to forage at night and when the tide does not cover intertidal feeding areas (Van Dyck 1994). Food items are consumed under cover in sheltered locations (Van Dyck 1996, Ball 2004). Nocturnal foraging is likely to be unconstrained in areas without tidal influence such as the subcoastal lagoons, floodplains, and freshwater wetlands (Gynther 2011).
Low trap rates and a lack of feeding activity by radio-tracked water mice in freshwater habitat (Van Dyck 1996) suggest they may only forage in these areas when resources elsewhere are in short supply such as during flooding events (Gynther 2011). The diet, shelter and activity patterns of water mouse in freshwater environments are not known (Gynther 2011), although freshwater crabs may be a significant prey item on the extensive floodplains of the Northern Territory (Woinarski et al. 2000).
Figure 15: Abundant crabs in mangroves that are occupied by the water mouse.
Source: © Melissa Bruton (Cairns in 2022).

3.7                  Movement
Recorded minimum water