Threatened fauna of the Canterbury Region Colin F J O’Donnell Southern Regional Science Centre Department of Conservation PO Box 13049, Christchurch

Threatened fauna

Proportion of national total in Canterbury - fauna taxa

Wetlands/lowland rivers >90% drained

Canterbury Mudfish Aquatic vegetation/ overgrown springs and margins of wetlands Can cope with short periods of drying – form burrows Solitary

Lowland longjaw galaxias Kakanui (Kauru River) Hakataramea (1989) Twizel area (e.g. Fraser Stream) Open braided cobble/gravel river Shallow riffle habitat ? Spawning requirements

Badly designed culverts, weirs, and dams Pollution and sedimentation Changes in water levels/drainage Stock damage to margins Predation & competition Loss of habitat Reduced flows Overfishing Weed encroachment Threats

Braided rivers

–Multiple channels –Flow instability –High gradients –High levels of sediment supply and movement –Constant channel movements –Seasonally rich food supplies These processes provide outstanding feeding and nesting habitat for wetland birds & other fauna

Distribution of braided rivers nationally 163 rivers

O’Donnell & Moore (1983), Robertson et al. (1984), Maloney (1999) Number of wetland birds from index counts on rivers > 80 bird species

Trends in wrybill numbers Hay (1979), Davies (1997), Riegen & Dowding (2001)

c.1900

1979

2007

Trends in wrybill numbers

Edwards Stream – Scree Skink habitat

Threats: weed encroachment

Proportions of major rivers with weed encroachment After Wilson (2001)

Loss of water: Increased demand for irrigation water

Loss of water: Each species has a different requirement

The ‘moat’ effect – islands separated from the mainland by large flows appear to limit predation Predation by introduced mammals

What can be done?

Rules for habitat protection Rules for habitat protection Legal protection of waterways Firewood cutting rules

Adequate environmental flows to sustain fauna Assured environmental flows and water levels in rivers/wetlands/coastal lagoonsAssured environmental flows and water levels in rivers/wetlands/coastal lagoons

Protected areas networks Focus on lowlands where >90% lossFocus on lowlands where >90% loss For example: Protect a representative range of riversFor example: Protect a representative range of rivers –Braided rivers are not represented in our reserve network (though the waters of some are now protected with Conservation Orders) Most riverbeds are classed as “unoccupied crown land” or are council/private landMost riverbeds are classed as “unoccupied crown land” or are council/private land

Sustained predator control Poison laid 80% dead within 2 days

Community conservation initiatives: Community conservation initiatives: bat houses in South Canterbury

Species translocations: Species translocations: Quail Island using wooden disc technique for beetles…

Recreation management Black-fronted tern chick crushed by vehicle

Education

Conclusions: Huge challenges Most threatened biodiversity does NOT occur in reserves or on DOC landMost threatened biodiversity does NOT occur in reserves or on DOC land Need good inventories of what still remainsNeed good inventories of what still remains Regional action plans (Canterbury Biodiversity Strategy first step)Regional action plans (Canterbury Biodiversity Strategy first step) Need to turn the strategy into action to halt the lossNeed to turn the strategy into action to halt the loss