STGF Gouldian Finch Count – Results for 2019

Results of the Save the Gouldian Fund Gouldian Count 2019

Gary Fitt, Brisbane  (November 2019)

Early September 2019 saw a happy band of 21 volunteers assemble in the town of Wyndham in the east Kimberley region of WA to conduct the annual count of Gouldian finches in the Save the Gouldian Funds long term study site around Wyndham.

The Gouldian count was first done in 2008 and was completed every year to 2013. Unfortunately there was then a gap of four years before STGF recommenced the count in September 2018. This long-term monitoring of Gouldian finches using a well-defined protocol is critically important in understanding the population status of the Gouldian. As the Gouldian is a declared Endangered species we need to know how the population is trending. Is it increasing, static or decreasing?

The 2019 count followed a very poor 2018/19 wet season which saw the region receive only 60% of an average rainfall. Undoubtedly the biomass of annual sorghum, on which Gouldians depend for breeding from January through to about June, was very much reduced and by the time we got there in late August there was very little surface water remaining and many of the locations where we had counted in the past were totally dry. So our expectations were that numbers overall might be down, but we might see more concentrated numbers because there were fewer places they could drink.

The count depends on the fact that all finches need to drink regularly and all the population will come in for a drink early each morning before going off to forage. From previous work by Sarah Pryke we know that Gouldians come in to water during quite a tight time window between 6am and 7am, have a big drink and then leave.

By contrast some other finches (eg Doublebars) come to water repeatedly through the day. So for the Gouldians if we have counters at all the potential water points across the landscape early each morning we can get a reasonable snapshot of the local population.

How did we count?

We conduct the count for two hours from 0530 to 0730 for five consecutive mornings always in the first week of September when the dry season is well advanced and the only natural sources of water are reduced to small springs and “permanent’ pools. At each site we count all the finch species but record only those birds which actually drink during 15 minute recording periods. For the Gouldians we record head colours and sex for the adults and count all the juveniles. For the other species (Longtails, Masks, Crimsons, Doublebars, Zebras, Chestnuts, Pictorellas or Yellowrumps) we record numbers only. Counters are rotated around all the sites, so everyone gets to see birds at different sites and we spread the variation in expertise around sites.

Where did we count?

Over the 10 years of STGF research around the Wyndham region, Sarah Pryke and her team identified all the “permanent” water points where Gouldians and other finches might find water late in the dry season.

There are about 20 such sites within about 20km of Wyndham town.  Some are artificial water points in the town (in homes, gardens, parks and anywhere there is a dripping tap!), while others are natural water points varying from tiny springs up to substantial water bodies (see right).

This year many of our former count sites were totally dry and we added a couple of new ones in town.

Overall we had counters at 7 locations and a total of 15 sites across those locations.

What did we find?

Over the five days we counted an average total of 200 adult Gouldians and 270 juveniles per day. So 57% of the birds were juveniles. The number of Gouldians counted is about 60% of the population we counted in 2018 when the daily average was 330 adults and 456 juveniles per day (58% juveniles). Not surprisingly there was much variability among count sites as birds travel from feeding locations to watering points. The figure below shows this variation – some sites with consistent numbers, some with none, some with an occasional few. Some with a noticeably higher proportion of juvenile birds than others – for example compare Site 5 and Site 11.

Among the Gouldians counted in 2019 which were fully coloured we recorded 81.9% Black-headed birds, 16.8% Red-headed and 1.3% Yellow Headed. These would have been the breeding population for the previous breeding season as none of the juvenile were yet coloured, though some had started to moult. This ratio of head colours is a little different to 2018 when we had 75.8% Black Headed, 23.7% Red Headed and 0.6% Yellow-Headed.

Sex ratio of birds across the head colours was highly variable. Black-headed birds were slightly female dominant – 46% male: 54% female. By contrast the Red-headed birds were strongly male biased – 81% male and only 19% female. Seeing a Yellow-Headed bird in the wild is always a special occasion and there were small numbers of Orange/Yellow headed birds seen at 3 of the sites – these were all males. Clearly female Red-heads and Yellow-heads are being selected against.

A striking feature of the 2019 results was the variability in numbers counted across days and across sites. Through the week we saw a distinct increase in number of birds across all sites from a total of 200-300 birds on the first three days to 700-800 birds on the last two days.

Even more striking was the variability in numbers over time at some individual sites. The figure below shows the numbers of Gouldians counted at one site. There were none on two days and over 300 on another day. We saw the same variability at a few other sites. This scale of day to day variation has not been seen in previous counts. Clearly the birds which appeared at this site on Day 4 had been finding water elsewhere on previous days and their fidelity to one water point was low. The results suggest that in extremely dry times where the birds are struggling to find food and water they will be utilising multiple water sources and travelling each morning to the site closest to where they have been feeding.

This spatial and temporal variability highlights why the count needs to be done over multiple days. One morning of casual counts could give a very misleading assessment of Gouldian populations! If we went to this site on Monday or Wednesday we would think there were no Gouldians, but on Thursday we would think there were plenty.

Numbers of other finches

Our count of Gouldians showed a significant reduction in numbers compared to 2018 and we might rationalise this as being due to the extremely dry season and lack of food resources to support breeding and survival. So what did the other species show? We counted substantial numbers of other finch species.  The table below shows the average total per day and number of sites out of 15 for each species.

The data shows that Longtails were the most abundant species and were present almost everywhere. Doublebars and Masked were likewise present at most count sites, whereas Crimsons and Pictorellas were seen only at specific sites. Gouldians were counted at 73% of our sites.

Curiously the numbers of Longtails and Masks were both substantially increased compared to 2018 counts. So they appeared not to have suffered with the excessively dry conditions and it was noticeable that we saw several clutches of newly fledged Longtails, Masks and Zebras still being fed by their parents. These species were still breeding late into the dry season.

Note that Pictorellas were much more common elsewhere in the region and had been seen “in their thousands” at water holes just outside our area and at sites back towards and around Kununurra. Likewise of course Gouldians are being seen at several locations around Kununurra and at multiple locations along the Victoria Highway across to Katherine in the NT. Just before the count we also observed adult and juvenile Gouldians at El Questro Resort on the other side of the Cockburn Range.

Conclusions

Overall this was another successful STGF Gouldian Count. The counts conducted from 2008 to 2013 showed Gouldians were slowly increasing in numbers in the Wyndham study area.  Although we can’t conclude much from just two years of data since the count recommenced in 2018, it was clear that Gouldians were substantially less abundant this year. We will continue with the count for another 3 or 4 years and see where the population is trending.

It is important to thank all those who generously donated their time and quite a bit of expense to get to Wyndham to be part of the count.  So, many thanks to Jason and Amanda, Sue and Neil, Barry and Anne, Elisabeth and Mike, Cheryl and Gary, Dave and Hazel, Barry and Irene, Bushy, Steve and Jenny, Michelle (unfortunately hidden) and Ian, Tony and Strop. STGF couldn’t do this work without your involvement. We also need to thank Michelle Brown who was the custodian of our data sheets and entered all the data on the computer. That helped a great deal. Thanks also to Cheryl Mares for some excellent photographs.

We were all inspired by the commitment of Mike and Elisabeth Fidler to the Gouldian finch and their love of the Kimberley environment. All of us, but particularly those who hadn’t been there before, were likewise captivated despite it being very dry.

We always welcome new volunteers to help with the Gouldian Count which happens in the first half of September each year. Contact Gary Fitt at naturallyforbirds@gmail.com if you’re interested.