population dynamics

Population decline and extinction are often driven by multiple stressors. Since AD 1500, the predicted global extinction rates for birds is estimated to be at least 80-times higher than the long-term background average. Pāteke/brown teal (Anas chlorotis) is a threatened waterfowl endemic to Aotearoa New Zealand, with a current population of c. 2500, spread across two remnant populations and a handful of reintroduction sites. The decline of pāteke since the arrival of humans results from habitat loss and fragmentation, predation, and other anthropogenic interactions.

In New Zealand, intensive, site-based conservation management of bird species is often focused on controlling threats from invasive species at a local scale. Such management may benefit species resident within the site but may be insufficient for mobile taxa whose movements extend beyond it through annual migrations, irregular nomadic movements, or exchanges of dispersing individuals in metapopulation networks.