Hello again dear readers. Well, field work has begun in earnest Boorowa. Besides having now submitted a second PhD proposal titled ‘The effects of single-handedly opening thirty paddock gates per day on long-term mental integrity’, over the past three weeks I’ve managed to squeeze in 96 bird surveys at 54 sites (27 treatment and control sites pairs) across dozens of properties owned by some very welcoming and accomodating folks. This small but important progress comes despite valiant attempts by the gods (plural intended) to assault both myself and my feathered subjects with wind, rain and pestilence – well wind and rain at least. Fuelled by superb coffee at the Pantry on Pudman, and well rested after a solid sleep at the excellent Boorowa Hotel, surveys kick off just before sunrise, stopping mid-morning to resume a couple hours before sunset.
The amount of restoration work that has been undertaken in the area, and continues to be through key groups such as Greening Australia, Landcare and the CMA, as well as landholders planting trees and fencing woodland remnants ‘off their own bats’, is extremely encouraging. It is also promising to see several less common species as well as those recognised as declining in the region using the revegetation sites despite their relatively ‘young’ age. Southern whiteface, Speckled warblers, Red-capped robins and White-browed babblers have been observed at multiple sites. The key is whether they are found in sites with particular characteristics (eg. dense vs. sparse, uniform vs. varied habitat structure, narrow strips vs block-shaped plantings etc), and whether those characteristics attract a different cost that will influence the cost-effectiveness. While it is obviously too early to draw conclusions, I will draw several. 1) All sites are not created equal: revegetated sites that were planted in the same year, with the same method, and even in the same paddock, can differ dramatically in the structure and composition of the vegetation. Some are patchy with greater proportion of eucalypts, others are basically dense hedgerows of multi-stemmed Acacia species. This will make unpacking of the effects of different restoration approaches difficult, given the wide variation within each approach. It also means several additional variables will need to be measured to undertand what is driving the variation. Guess it’s not meant to be easy; if it was there would be too many PhD’s out there wouldn’t there. 2) Stem density matters: an early observation is that the more dense sites have less species, less individuals and different species. Again this is only an observation but is not surprising at all given the needs of species that require open space in which to hunt prey (eg. robins) can’t be met in such sites. This will however create an interesting dynamic when economic data is thrown into the mix as these sites are almost exclusively direct-seeded, a technique that is much more cost-effective per unit area than tubestock planting. 3) Bird communities differ between revegetation and remnant protection sites (fenced patches of woodland): again, just an observation and the most spurious as I’ve surveyed much fewer of these sites, but still a no-brainer given the obvious differences in the composition and structure of the vegetation. Others have shown this (several studies coming from the Fenner School among them, too many to list). Those of you still reading (ie. those that haven’t drifted off or opened a new window to google “what is twerking?”) might ask ‘How can you compare the effectiveness of restoration between revegetation and remnant protection sites when the habitat structure and bird communities differ so much? ‘. Well there in lies the rub – my intent in determining cost-effectiveness is not to compare the birds at the revegetation sites to those at remnant protection sites, but rather to compare the size of the gain that each approach has generated (by surveying the birds at nearby control or unrestored sites), and to compare the costs to achieve those gains. Got it? Good, now don’t ask any more rude questions. Enough for now. Next time, I start using paragraphs, and introduce you to the term cheeseheads.