Thursday, January 4, 2018

Annual Report: 2017 compared with 2016

During 2017 I received reports from more members of the community than in the past. These have often been single sightings of birds of interest to the observer, but are very welcome as they often fill gaps. Please keep them coming! If anyone wants to keep regular records I can provide them with a FREE! Easy to use! EXCEL spreadsheet template! Drop me an email!

Of the  195 species recorded in this project 167 species (85.1% - a slight decrease on the percentages achieved by a similar analysis last year) were reported in one or both of the years covered by this report.  Of these 167 species:
  • ·         10 were reported in 2016 but not in 2017;
  • ·         15 were reported in 2017 but not in 2016 (of which 1 was reported for the first time in 2017); and 
  • ·         142 species were reported in both years.
Looking at the entire 167 species there is a very strong correlation (correlation coefficient =  0.926) between the number of months each species was reported in the two years.  Thus it can be concluded that the two data sets are reasonably consistent.

Of the 10 species recorded in 2016 but not 2017, 
  • 7 were sighted in a single month of 2016, 
  • 2 were seen in 2 months; 
  • 1(Brown Quail) was seen in 3 months.  Tend to be seen irregularly in the area: they are skulkers so it isn't surprising that they go missing at times.
For those seen in 2017 but not reported in 2016:
  • 10 species (1 addition to the area list) were seen in a single month;
  • 3 species were seen in two months: Rufous Songlark - only seen/heard in last two months of the year;  Masked Woodswallow - an irruption in Spring; and Grey Goshawk seen at two sites more or less along the Molonglo.
  • 2 species seen in 3 months;  
    • Red-capped Robin has been very unusual in the area.  They have been reported much more in the ACT this year than the past so it isn't surprising we also got some.
    • White-bellied Sea-Eagle: Clearly seen lurking over Foxlow Lagoon, which at the time was one of the few large water features in the area.
 42 species were reported every month in both years: Last year was 43 while a similar comparisons in other recent years have shown 34 -38 species.  I am unsure what has caused the increase but see it as a Good Thing. I noted in the overview post that the set of species seen every month of the project has been very stable sitting at 19 species until last year when Willie Wagtail went walkabout for a year.  No species went AWOL this year - and willie wagtail was back at 12 months!

The following table shows the aggregate number of months in which members of the broad groups of species were seen in the two years.

1 Waterbirds203207
2 Birds of Prey6777
3 Parrots and Relatives100101
4 Kingfishers and other non-songbirds107116
5 Honeyeaters9290
6 Flycatchers and similar species125119
7 Thornbills, Finches and similar species189176
8 Other, smaller birds123130
9 Other, larger birds9696
The similarity of results between the two years is readily apparent.  When expressed as a percentage of total species-months the correlation coefficient is 0.99.

There is no large increase in any group.
  • The most surprising entry in the table is the small increase in the number of species-months for Waterbirds.  This is , as would be expected a balance, specifically between:
    • the larger number of species seen in January - February (when the marsh on the plain was well endowed with water) and 
    • the situation in December (when 12 less Waterbird species were seen, reflecting these species heading for the flooded areas of Victoria).
  • For Birds of prey the main difference was in July, reflecting most observers (including me) being absent in July 2016.  
  • For kingfishers etc significantly more species were reported in January and May but I can't suggest a reason!
  • Honeyeaters, Flycatchers etc and Thornbills etc show lower numbers of species in all months (notably June at 8 species less) except for July where observer effort was very low in 2016.
  • The group covered by Other smaller species were reported more frequently in the majority of months with 4 months reporting 3 or 4 additional species.
  • 8 species are included in Other larger species and they are usually reported in all months (as was the case in these two years).
The species with the largest increases in number of months-recorded have been:
  • Hardhead (going from 4 months to 12). Recovering to normal after a very low year in 2016.  (Last year it was a big decliner!)
  • Southern Boobook (from 4 months to 10).  I have no idea why this is so.  Mainly reported from Hoskinstown.
  • Straw-necked Ibis (from 1 month to 5) A very variable reporting rate for this species.  They all went West in 2016.  Again in 2016 it was a big decliner.
  • Australian King-parrot (from 9 to 12)  The species appears to be spreading from areas near Tallaganda into the Eastern part of the study region.
  • Collared Sparrowhawk (from 6 to 9)  a pair took up residence in our block for most of the year (but I couldn't find the nest).

The species with the greatest decline were:

  • New Holland Honeyeater (from 6 to 1).  Almost entirely as a result of the departure of an observer from Widgiewa Rd who used to have a small resident flock.  In 2015 it was seen 11 months!
  • Black-shouldered kite (7 to 2)  The dry start to the year meant very little prey around on the Hoskinstown Plain.  Its peak period (2012-13 it was reported nearly every month.
  • Little Corella (8 months to 5)  Last year was a big increaser.  I suspect the decline reflects us doing less dog walks to Captains Flat Rd, where most records were made.
  • Eastern Yellow Robin (12 months to 9).  For the first 4 years of this project the species was very unusual.  A pair then took up residence in our yard and were recorded almost every day.  However since September 2017 they have not been sighted or heard.  No idea why.

    Links to other sections of this report

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