In the “Pāteke survival guide”
Pāteke are most obvious during the summer non-breeding period, when large numbers can congregate during the day at permanent water bodies. These summer “flock sites” are commonly located at the head of estuaries and at stream pools, livestock ponds and drains.
Typically these sites have easily accessible banks, tree roots or partially submerged logs on which the birds roost and from which they can drop onto the water if danger threatens. Flock sites often have overhead cover such as trees and vines which give some protection from predatory birds, in combination with surrounding open areas which afford some view of approaching threats.
Pre-breeding body moult occurs at the flock sites in January–February. Not all birds are present at the flock site, with many adults staying in their breeding territory year round, particularly in wet years. Consequently, sub-adults frequently comprise the bulk of the flocking birds.
In the early autumn, most birds are still using flock sites for diurnal (daytime) roosts. However, during the autumn birds increasingly move to and fro between the flock sites and prospective breeding grounds, particularly after significant rain.
Pāteke breed mainly in winter and spring, although nests can occur in any month. Each pair defends a territory of variable size against other pāteke . The ideal territory provides for several needs:
- Ground-cover for nests which are nearly always on the ground, e.g. sedges (Cyperus, Carex, etc), long grass, undercut/overhanging banks, logs.
- A water body for rearing ducklings—stream, scoop pond, drain etc. Ideal sites are those which provide dense cover on the banks close to the water onto which ducklings can escape if a predator arrives. Often nests are found close to these water bodies and pairs take their broods to them soon after hatching, staying close to water during daylight.
- Good feeding for adults and ducklings, either in the territory or close by. Optimal feeding conditions for pāteke are poorly known, but anywhere with lots of invertebrates, seeds and fruits are likely to be good. Adults with broods are often found beside seepage areas, swamps, drains and shallow margins of ponds and streams. Slow moving waterways provide some feeding, including drains, seeps, estuaries, mudflats, muddy backwashes and associated wetlands, and they can provide valuable daytime refugia if sufficient cover is available.
- Pasture—closely cropped (short) pasture is used extensively during winter and in damp conditions where they glean invertebrates from the grass and they sometimes also eat clover.
Adults undergo a complete body moult beginning in late spring when birds are often still at breeding grounds. Birds are flightless during the height of this moult and therefore even more vulnerable to predators.