David Riddell & Annette Taylor
Tuesday, 26 March 2013 5:07 p.m.
It was good to meet you at the Sumner street fair the other day. Have had a look at your website, it looks really good. Just a few comments (not criticisms at all, I think what you're doing is excellent!).
(Photo: Michael Eckstadt)
On colouration, females that are more than a couple of years old can be almost as bright as the males. The trouble is that most of the females that are around these days aren't old enough to achieve that full colour - they get picked off the nest in their first couple of years by some passing predator. But occasionally you do see a female (identifiable by call, or interaction with male) that's bright yellow. Most of the bird guides don't have this. The issue is further complicated by there usually being juvenile nest helpers around the nest site, who are duller, but are usually males, given the gender imbalance.
Regarding calls, females from Fiordland don't have the buzzing call that you get from eastern and northern birds. They have simple calls of only a few notes (which eastern and northern females also have), can sound a bit like bellbirds. This suggests they might be a distinct genetic stock, which could be something to bear in mind when considering translocations.
(Photo: Michael Eckstadt)
On distribution, there are probably more birds in western Southland and Fiordland than you've indicated - at least there were back in 1999-2000 when I was down there. Or maybe they've declined more than I realise in the meantime! We found mohua regularly at several locations through the Longwoods, though they weren't throughout the whole range - certainly they were recorded in 2000, rather than mid-1990s as stated. We also found quite a few in the Takitimus. Our main study and trapping areas were in the Rowallan Forest (above and below Otway's Clearing), and along Pig Creek behind Borland Lodge. Plenty of birds in both sites. We also surveyed around Lake Hauroko (including the start of the Dusky track and down the Wairaurahiri into the Waitutu Forest, as well as the Caroline Burn and Russet Burn) and found birds in most places. The same for Big River, upstream of Lake Hakapoua. West of Lake Poteriteri in the catchment below Lake Mouat (three main arms) they were a bit more patchy. They like beech, and areas with mainly kamahi or, particularly, bog pine (Halocarpus bidwillii) had few or no birds. You also get very few above about 700m.
Long-tailed cuckoos also go to the North Island, where they parasitise whiteheads.
Hope this is some help, best of luck with your future projects.