23. Potential role in research? Yes – but only if you’re asking the right questions Can TERN support it better? Yes – but don’t give us a new survey method
24.
Notes de l'éditeur
I haven’t given a talk in a long time – so please yell at me if I mumble. I also apologise in advance if the slides are hard to read. So this talk comes in under regional monitoring, which to me is immediately interesting, because the Atlas is usually regarded as a national monitoring project. But it MAY be that this session is where this project truly belongs - but we’ll get to that later
A very quick overview – and I’m assuming many to most of you don’t already know a lot about the Atlas. Apologies to those of you who basically invented the atlas, I know there’s one or two in the room.
This talk is really about the Atlas project proper which began in 1977, although we also have a pre-atlas database, which we call the Historical Atlas, and that goes back decades. We also have a bunch of other volunteer collected datasets, some of which go back even further, and I’ll mention them later if there’s time.
Just a quick indication of data volume over the past ten years, peaked during the middle years of the ‘Second Atlas’, and now fairly stable at over 400,000 records per year, although some of you may see a slight decline.
Another version of the same thing – surveys coming in at a little over 2000 per month.
To me a really important graph, which shows we currently have about 600 active atlassers, from a peak of about 28 hundred in 1999. It shows what the potential is if we can engage people in a meaningful monitoring project. These people were fired up about something – and the basic message that fired them up in the second atlas was the idea that we could take another snapshot and compare the status of our birds with what was going on about twenty years ago.
This is what we are basically working towards. Tow snapshots was good, but we really need ongoing data collection to give us population trends we can have some confidence in. The two snapshots were very difficult to interpret for a number of reasons - very different rainfall conditions was widely cited as one major problem. It’s not often mentioned as a major aim of this project, but community engagement is key – I’ll get to that in a minute.
Some other aims here: In 2002, the Convention of Biological Diversity (CBD) adopted a target of significantly reducing the rate of biodiversity loss by 2010. In October next year, the international community will review whether the target has been met, when they convene in Nagoya, Japan for the 10th meeting of the Conference of the Parties to the CBD. Birds score very highly on many of the broad criteria defined for selecting indicator taxa. Their most significant advantage is that we have, relatively speaking, so much information about them, and their biology and life-histories are so well understood. Birds are also taxonomically well-known and stable, and their populations are readily surveyed and manipulated. Bird families and genera often occupy a breadth of habitats and have broad geographical ranges, yet many individual species are specialised in their requirements and have narrow distributions. Birds are mobile and responsive to environmental changes and there are enough bird species to show meaningful patterns, yet not so many as to make identification itself a challenge. Birds have real economic importance in their own right - a useful attribute in an indicator. Besides highlighting the limited development of indicators, the review also raises questions over whether the current suite of indicators will provide all the right answers. For example, the indicators do not include any measure of the impacts of climate change on biodiversity, and few that shine a light on the benefits, the goods and services, that we gain from biodiversity and natural ecosystems. "Biodiversity monitoring and indicators will only be successful if they help to answer the questions that decision makers are asking"
The basic survey techniques, all very user friendly – note that the first two are not search-effort quantifiable, while the remainder are. I won’t go on about these, except to note that the area searches and 2ha surveys have been around since the start of the second atlas, while fixed route surveys and group atlassing are relatively new variations on the search area theme.
So there is a lot of ad hoc data collection going on – we don’t tell people where and when to survey, although we gently encourage them. That gentle encouragement has gradually become more insistent over the past decade – and we are starting to see the results.
Th e ACRIS project was a pass at the existing unstructured data to see what story it could tell. It illustrates some of the challenges facing continent-wide reporting of population trends, and some of the strengths of regional reporting. The unit were the IBRAs. The interim biogeographical regions of Australia – are they still interim?
This shows the IBRAs that had sufficient data for Ross to analyse
An example of the results Ross generated: this is Grey-Crowned Babbler, which showed an overall decline, although you can see that this wasn’t consistent across IBRAs: most Overall, 45 species (75%) showed significant heterogeneity in trends (p-value <0.05), and 15 species showed consistent trends across regions. Top left Observed and smoothed reporting rates (%) aggregated over Year by Month, all IBRAs included Top right Observed and smoothed reporting rates (%) aggregated over Year by Month; only IBRAs where the bird was observed at least once are included. Bottom Left Smoothed reporting rates for each IBRA where at least one bird seen in 40 or more months, excluding IBRA where no bird was observed. Stats tests Key for IBRAs displayed in bottom left graph Significance test for heterogeneity of trends between IBRAs: low p-value indicates heterogeneity Estimated reporting rates at points near the beginning and end of the analysis period The magnitude and direction by which reporting rate has changed over the reporting period, based on the smoothed spline The magnitude and direction by which reporting rate has changed over the reporting period, based on the linear trend Significance test for linear trend: divergence from a zero gradient over the reporting period. Low p-values indicate a significant divergence (caveat)
An increaser – note significant divergence in trends across IBRAs. You can also see a trough around 2003.
Another increaser, this time with consistent trends across IBRAs.
Another example of a species showing fairly consistent trends across IBRAs, and one which exhibits a feature of many of the species graphs, a marked hump in the period around 2000-2001. We got a few people to eyeball the graphs independently and came up with a consensus approach to qualifying the graphs as exhibiting distinct peaks and troughs:
Some attempt at aggregation was made. The temporal distribution in the number of peaks and troughs in relative abundance among 60 bird species in the Rangelands. Many species showed peaks in occurrence in 2000 and 2001, followed by a less distinct period of troughs in 2003-2005. This broadly corresponds of high rainfall (1998-2001), and the beginning of drought (2001 onwards).