I can now confirm that North Island robins definitely do eat peanut butter.
We had suspected this at one of the sites where I volunteer, having found inky bird footprints on tracking cards and (sadly) the occasional pile of feathers below an A24 trap, but were uncertain whether robins were eating the PB, eating the insects on/in the PB, or simply exploring. However, today I was reluring an A24 with peanut butter and kept having to shoo away an overly interested robin. As soon as I stood up the robin flew down right by my feet and started stuffing its beak with the peanut butter I’d just blazed onto the tree.
My current plan to attract rodents not robins is to avoid putting the blaze directly under the trap and instead blaze the peanut butter around the side of the tree, beside/above the trap if on a slope, or on an adjacent tree. Runny peanut butter that drips through the trap could also be a problem (and may cause the gas canisters to go flat early if it sticks on the A24 trigger wire). I don’t want to eliminate the blaze entirely, or use a less attractive lure, as these particular traps are part of a defensive perimeter line and need to be more attractive to any passing rodents than all those tasty native species inside the forest.
Any other tips for making traps unattractive to robins while keeping the rodents interested?