Annual Report 2015: 2015 compared with 2014

I have indicated in the overview that the number of observers was restored in  2014.  

Of the  191 species recorded in this project 168 species (87.9% - a trivial decrease on the 88.1% given by a similar analysis last year) were reported in one or both of the years covered by this report.  Of these 168 species:

• ·         11 were reported in 2014 but not in 2015;
• ·         17 were reported in 2015 but not in 2014 (of which 5 were reported for the first time in 2015); and 
• ·         140 species were reported in both years.

##Looking at the entire 168 species there is a very strong correlation (correlation coefficient =  0.90) 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 11 species recorded in 2013 but not 2014, 8 were sighted in a single month 1 was seen in 2 months; 3 in 3 months and 1 (Horsfield’s Bronze-Cuckoo) in 5 months.   The absence of this Cuckoo was most intriguing as other Cuckoo species have been very evident.

For those seen in 2015 but not reported in 2014:

• 13 species (4 additions to the area list) were seen in a single month;
• 2 species (no additions) were seen in 2 months in 2014;  
• 1 species (an addition to the list) seen in 4 months;  and ·         
• 1 species seen in 5 months.

The ‘4 month species’ is White-fronted Chat.  This species was seen in pasture near Hoskinstown and was first noticed as "by-catch" when monitoring the outbreak of Banded Lapwings in the area.  They are very localised in Canberra, mainly around the vicinity of Stromlo Forest Park.  I suspect (hope?) they will continue to be found as people continue to monitor the Banded Lapwing site.

The '5 month species' is Horsfield's Bronze-Cuckoo.  This is a puzzle as the species has been reported in 4 - 6 months every year except 2014.  The species is often identified by a distinctive call so is easy to pick up.  My summary of the reasons for the disappearance in 2014 is "Ain't nature interesting?" 

 34 species were reported every month in both years: a similar comparison last year showed 35 species (and 2 years ago 38) – effectively the same outcome. 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.

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

Category 2014 2015 1  Waterbirds 196 231 2 Birds of Prey 59 66 3 Parrots and Relatives 92 94 4 Kingfishers and other non-songbirds 98 120 5 Honeyeaters 95 102 6 Flycatchers and similar species 136 132 7 Thornbills, Finches and similar species 185 192 8 Other, smaller birds 120 125 9 Other, larger birds 89 94

The similarity of results between the two years is readily apparent.  When expressed as a percentage of total species-months the correlation coefficient is 0.98.

The group with the largest percentage increase were Waterbirds.  Within that group most species were very similar in the number of months recorded (typically +/- 1 month).  Theer were no large decreases  and of the species showing larger increases:

• At a site in Hoskinstown Banded Lapwing were observed in 5 months in 2015 rather than the single observation at Wanna Wanna Rd in 2014.  They were also present in good numbers with more than 10 birds present on occasion, and a chick was observed in one month.  A high proportion of the Canberra birding community came out to look at these birds.
• Nankeen Night-Heron also increased from 1 observation to 5.  In this case it involved 1 or 2 observations at several sites, mainly along the Molonglo.  On one occasion 5 birds - all in adult plumage were seen simultaneously.
• Australian Darter rose from 1 month to 4.  This may be an indicator of a wide dispersal, following destruction of some of the willows in Canberra, in which they used to breed.
• Pink-eared Duck rose from 2 months to 5, mainly on small dams between Mills Cross and the Foxlow bridge.  This species has returned to its usual haunts in the ACT after being very scarce for a couple of years.
• Australasian Shoveler rose from 6 months to 9, and Hoary-headed Grebe from 4 months to 7.

The largest percentage decline was in Flycatchers and similar species.  This is almost entirely attributable to:

• Red-capped Robin, seen for several months on the Plain in 2014 but largely absent in 2015; and 
• Flame Robin, seen every month of the year in 2014 but only in Winter in 2015.  This is a case of 2014 being the unusual year and 2015 a return to traditional values.
• There is a slight counterbalance with Satin Flycatcher appearing for 2 months after being absent in 2014.

Links to other sections of this report

Overall picture

Breeding

Comparison with previous 8 years