Annual report: 2011 overall picture

 This represents the first time I have attempted to compile a reasonable overall report on birds observed in Carwoola in a year.  While I did have a broad picture in  mind before starting what follows has to some extent evolved during writing.  In particular the decision to adopt a multi-post approach was made (note: not taken - a snooze is taken, a wine is sipped and a decision is made!!) after finding some difficulty in analysis of the long term changes.  (For those that think the result is too long, the Canberra Ornithologists Group Annual Bird Report is 80 A5 pages - and 2Mb to download!)

This report will be a bit heavy on numbers but I will attempt to explain them in terms of their meaning rather rather than simply a barrage of percentages!  For those who wish to skip the statistics I have tried to highlight the main points in bold blue.

By the end of 2011 we had recorded, over a 5 year period, 167 species in the catchment area of the Gazette.  74 (43.8%) of these had been recorded undertaking some form of breeding activity. mas shown in the linked post,  5 species were observed for the first time in 2011 and 19 were recorded in every month.

It is interesting that over a 30 year period the Garden Bird Survey, run by the Canberra Ornithologists Group has recorded 239 species with 108 of these (46.2%) recorded as breeding.  Given the much shorter time span and far fewer observers I think we have, to quote Young Mister Grace, "...all done very well."


In 2011, 141 species were recorded in the study area.  This is 84% of those ever recorded in the area.  This graph shows the number of species recorded per year.

Some analysis of the growth in species recorded has already been posted on this blog.  However the decrease in number of species from 2010 to 2011 requires a further look!  Watch this blog!

In 2011 a somewhat lower than average 36.6% of the species recorded were observed undertaking some form of breeding activity.  It is tempting to ascribe this to some attribute of the year (eg the very high rainfall in January - March).

Links to other sections of this report
2010 cf other 4 years, 2010 cf 2011, Breeding

Annual report: 2011 compared to 2010

While analysing the results of this project over the full 5 years I found that the analysis was hampered by the differing numbers of observers in the various periods.   Was a difference due to a real change in the birds' behaviour or simply an artefact of observer 'X' not being active at a point in time?  An earlier post discusses the issues of observer effort.  To overcome this problem I have decided to compile this post contrasting 2011 with 2010 where the level of observer effort was broadly similar.

Of the  167 species recorded in this project 157 species were reported in one or both of the years covered by this analysis.  Of these 157 species:

• 16 were reported in 2010 but not in 2011;
• 11 were reported in 2011 but not in 2010; and 
• 130 species were reported in both years.

Looking at the entire 157 species there is a very strong correlation (correlation coefficient 0.9006) 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 species recorded in 2010 but not 2011, 15 were sighted in a single month while Red-capped Robin was seen in 2 months.  The species seen in 2011 but not 2011 include (of course) 5 species recorded for the first time in this project.  3 other species were seen once in 2011 after absence in 2010 while:

• Painted Button-quail were seen in 3 months (flushed from cover while walking our dog);
• Hardhead seen in 4 months; and
• Black-shouldered kite seen in 6 months.

The latter two observations show a return to more normal rates than 2010.

33 species were reported every month in both years.

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	2010	2011
1 Waterbirds	121	146
2 Birds of Prey	62	72
3 Parrots and Relatives	88	89
4 Kingfishers and other non-songbirds	125	131
5 Honeyeaters	97	90
6 Flycatchers and similar species	122	128
7 Thornbills, Finches and similar species	192	198
8 Other, smaller birds	109	114
9 Other, larger birds	95	94

The broad similarity of the results is clear, with the exception of:

• Waterbirds, reflecting the movement of many species in this group to the inland swamps in the wet of 2010 and their return in 2011; and
• Birds of Prey, reflecting the amount of 'action' on the Hoskinstown Plain in late 2011 due to the large amount of prey (such as mice).

The picture for the Honeyeater group is interesting since that is the only group in which 2010 exceeds 2011.  Of the 11 species in the group,

• 5 have the same (high) score in both years,
• Noisy Friarbird and (the relatively uncommon) White-plumed Honeyeater show 2011>2010; and
• the remaining 4 species (New Holland, Yellow-faced, White-plumed and Brown-headed Honeyeaters) show a higher reporting rate in 2010 than 2011.  The value for New Holland was unusually high in 2010 and I was surprised to see that none of us reported Yellow-faced in 2 months in 2011.

Links to other parts of the Annual Report
Overview, 2010 cf other 4 years; Breeding

Annual Report: Breeding Activity

It can be argued that recording breeding events is the most important aspect of bird study since if the birds do not breed they will soon be extinct!  It is however a more difficult task than simple observation as:

• many birds go to some lengths to conceal their nests; and
• it is necessary to be very cautious with most species to avoid frightening the birds away from the nest.

To ameliorate these problems a wide definition of breeding is employed with the core events of "nest with eggs" and "nest with young" supported by a range of other, indirect, measures of breeding activity ranging from breeding display to dependent young.  To be rated as dependent young the fledglings must be out of the nest and generally be seen being fed by the parents or, in the case of waterbirds, be incapable of flight.  An exception is made for the Tawny Frogmouths where the fledglings are fed at night and it isn't possible to determine how this is achieved.  In that case the young are considered dependent until they move away from the parents some 10 weeks or so after leaving the nest.

(In other countries such as Canada studies are undertaken which assume all birds seen or heard  during the breeding season are in fact breeding.)

The number of records of each type over the 5 years of the project is in the table below.

Type of breeding activity	Number of  records
not coded	108
carry food	5
copulate	3
display	12
dependent young	90
Inspect hollow	1
nest building	16
nest with eggs	5
nest with young	33
bird on nest	28

Since this project commenced 303 breeding records have been noted. The decision to use the COG Breeding codes was made in late 2009 and thus approximately 1/3rd of the records are not coded to type of activity.  Such is life!  With respect to the analysis of the months where codes are available, the high proportion of records of dependent young is typical: note that this may not mean that the nest site was in the area.

7 species have been recorded breeding in 10 or more periods (year/month combination) accounting for 95 records (31.3% of all records) in total.  At the other extreme 23 species have a single breeding record and 12 species have been recorded twice as showing breeding activity.

A difficulty with analysis of breeding records is that the peak breeding period in the Southern Hemisphere is split by the change of year.  This is illustrated in the following chart.

 To overcome this I commenced, in mid 2009, recording the month in which observations were made and it is possible from that point on to re-categorise observations to a "breeding year" (running from July to June).  It might be noted that 78% of the records after December are coded as dependent young.

Following from this, the next section mostly covers 2 breeding seasons ending on 30 June 2011: the 2011-12 season will, inshallah, be reported on next year.

The records for 2009-10 show 58 breeding records whilst in 2010 -11 123 breeding events have been recorded.  In view of the number of events recorded in the first half of 2011-12  I believe this reflects extra effort by myself in recording information from 2010 onwards rather than an increase in amorousness of the
birds.  I shall endeavour to keep up the work moving forward but in view of the better effort in 2010-11 will restrict what follows to that breeding season.

In 2010-11 50 species were recorded as breeding and have been indicated as such in the monthly reports.  The number of months in which breeding was recorded, by the number of species performing this way, is shown in the following table.

# months breeding	# species
1	22
2	14
3	5
4	5
5	3
7	1

Australian Magpie was recorded as breeding in 7 months: 'on nest' in August and September 2010 and then dependent young until February 2011.  (I sometime times feel that a new code is needed for "indolent young" when the Magpie chicks are clearly able to fend for themselves but would rather bludge off their parents.)

The three species with breeding behaviour recorded in 5 months are Yellow-rumped Thornbill, Red Wattlebird and Willie Wagtail.  Again the dependent young category extends the breeding season for each species although one Willie Wagtail family appears to have attempted a second brood in February.

Links to Other sections of this report.
Overview; 2011 cf other 4 years; 2011 cf 2010

Annual report: 2011 compared to 4 previous years

Links to other sections of this report are at the end of this page.

The following table summarises the number of species reported by month and year.

month	2007	2008	2009	2010	2011
Jan		69	84	87	95
Feb	59	74	69	87	89
Mar	69	72	78	72	87
Apr		65	70	77	76
May	61	65	83	80	80
June	51	69	64	77	65
July	54	59	62	77	78
Aug	57	72	73	80	90
Sep	67	77	86	86	101
Oct	67	84	91	97	99
Nov	73	84	106	96	108
Dec	60	83	94	95	94

Looking at the 141 species which were recorded in the area in 2011 in comparison with  the previous 4 years a first comment is that 5 species were observed for the first time in 2011.  These were

• Yellow-billed Spoonbill, Cattle Egret, Silver Gull, Black Falcon and Horsfield's Bushlark.  

Of the 136 species for which comparison is possible, 19 have been recorded in every month throughout the 5 years (obviously including every month of 2011) These are:

• Australian Wood Duck; Galah; Sulphur-crested cockatoo; Crimson Rosella; Eastern Rosella; Laughing Kookaburra; White-eared Honeyeater; Noisy Miner; Willie wagtail; Magpie-lark; Welcome swallow; Yellow-rumped thornbill; White-throated treecreeper; Common starling; Grey butcherbird; Australian Magpie; Pied Currawong; Australian Raven; Little Raven.

For the species recorded in 2011 which changed the proportion of months in which recorded 87 (61.7%) showed an increase in the number of months in which they were recorded and 30 (21.3%) showed a decrease.  I shall return to an analysis of those numbers below.

There are thus 25 species recorded in the prior 4 years which did not appear in 2001.  They are:

• Chestnut Teal; Darter; Royal Spoonbill; Black-winged Stilt; Latham's snipe; White-bellied Sea-eagle; Grey Goshawk; Scaly-breasted Lorikeet; Spotted Dove; Black-eared Cuckoo; Powerful owl; Superb lyrebird; Yellow-tufted honeyeater; Scarlet Honeyeater;Crescent Honeyeater; Rufous Fantail; Satin Flycatcher; Jacky Winter,Red-capped Robin; Zebra Finch; Brown Treecreeper;White-winged triller; Masked Woodswallow; Brown Songlark .

Most of these birds are not common in the Canberra region.  The possible exceptions are:

• Superb Lyrebird (the omission of which probably reflects my not having explored the gullies of Cuumbeun or Yanununbeeyan when the birds were vocalising) and
• White-winged Triller, for which I cannot offer an explanation.

Increasing species
There are 23 species recorded every month in 2011 which have been omitted at least once in earlier months.   With a 5 year series of observations I regard the 10 species only omitted once or twice as observer error (in most cases the missing period is early in the life of the project).   Most of the other species in this group of 23 are cases where the increased number of observers in recent years has added to the completeness of reports.  This is particularly the case for Eurasian Coot now seen every month at a site on Widgiewa Rd.  A second species with an obvious explanation is Tawny Frogmouth, now reported every month from Whiskers Creek Rd since I am specifically searching for a resident family, while in the past observing these birds was serendipity.

At the other end of the spectrum 11 species were recorded in a single month in 2011 and appear in the list of 'increasers' as a statistical quirk since 1/12 > 1/46!  They are clearly unusual in the area and will not be considered further.

A group seen in  at least 6 months in 2011 for which an increase has been noted amounts to 31 species.  I can't offer a comment about all of these so what follows is 'picking the yes out' of the list.

• Common Myna: the rat with wings appears to have established a presence in Hoskinstown and has been reported half of the months in 2011.  A pity.
• Stubble Quail are not unusual n the area but are difficult to see.  However the paddocks of tall grass in early 2011 provided great breeding habitat for them and their calls were very easy to record.
• Eastern Yellow Robin is usually thought of as a bird of the damp gullies.  The wet conditions of late 2010 and early 2011 led to a pair taking up residence at Whiskers Creek Rd.  They have since disappeared.
  
• Black-shouldered Kites: have re-appeared (in astonishing numbers) after disappearing almost completely for a couple of years.  This phenomenon, plus the increase in Brown Falcons is thought to be due to a mouse plague.  (Towards the end of the year Eastern Barn Owls were reported frequently, and sometimes in large numbers.  This was also related to the mouse plague, but they were not seen in 6 months.)
• Musk Ducks and Black Swans were often recorded when looking from the road down into Foxlow Lagoon but nowhere else in the area.  The increase in 2011 reflects the Lagoon filling again as a result of the rain in 2010 and early 2011.
• A number of species regarded as migrants (Shining Bronze-cuckoo, Leaden Flycatcher, White-throated Gerygone,Noisy Friarbird, Fan-tailed Cuckoo, Rufous Whistler, Black-faced Cuckoo-shrike) were recorded more frequently than usual.  Most of these are generally thought to have some 'opportunists who try to survive in the area through Winter and their presence is thus probably not a result of climate change.
• The preceding comment may be strengthened by the increased presence of two species which I regard as winter in-migrants: Golden Whistler and Scarlet Robin.

Decreasing Species
There is relatively little "big picture" material in this category.  In most cases the decrease is a reflection of the wider rage of fractions possible with a 46 month range rather than a 12 year range.  By way of example,

• in 2011 Brown Goshawk was recorded 7 of 12 months (7/12 = 0.58);
• in the previous 4 years it was recorded 27 of 46 months (27/46 = 0.59;
• had the Brown Goshawk been recorded 8 months in 2011 (8/12 = 0.67) or only recorded in 26 months in the previous periods (26/46 = 0.57) it would have shown as an increase.

Overall the proportion of months reported in 2011 and the 4 previous years gives a correlation coefficient of 0.986 - very similar patterns.

The possible exception is Straw-necked Ibis  where the rate of reporting in 2011 was roughly half that of the longer period.  This reflects the Straw-necked Ibises departing for the inland in the deluge of 2010 and (unlike most other waterbirds) not yet returning to Carwoola.
Links to other sections.
Overview report, Comparison with 2010; Breeding

December 2011

The biggest news from me this month is the addition of a new species to the list.  This was a Horsfields Bushlark (previously known as the Singing Bushlark) which I saw while riding my bike along Bungendore Rd, Hoskinstown, near the Mills Cross facility.  I mainly recognised the bird by its song: in appearance it is somewhat like a female House Sparrow.

On the same ride I saw 1 Brown Falcon, 2 Black-shouldered Kites and a Nankeen Kestrel.  The numbers of Brown Falcons and Black-shouldered Kites appears to have dropped to more normal levels.  The property owner concerned has indicated that this reflects a decline in mouse numbers to more normal levels.

On the last day of the month/year I was alerted to a possible Spotted Harrier visible from Plains Rd.  I was able to find the bird and agree with the identification.  This is the second observation of this species in the area.  Interestingly there has not been a single record of the closely related Swamp Harrier in the area covered by this blog.  They are much more common than the Spotted Harrier in the ACT.

In total this month we have recorded 97 species.  This is 11 fewer than the extraordinary diversity of November 2011 but 2 more than December 2010.  Here is the graph of long term numbers.

Of the 97 species, 21 were recorded undertaking some form of breeding activity.   This is one more (and a different mix of species) than  in November 2011 and more than double the number recorded in the very rainy December 2010.

Getting back to current events, many thanks to observers in Widgiewa Road, Hoskinstown, Plains Road, Radcliffe, Woolcara Lane and Molonglo River Park for their reports and records.

Here follows the list of species observed.  It is now possible to link to photographs of the birds in the pages towards the end of the blog.  Of the 164 species recorded since I started these reports 62 have associated photographs.  In the list this is  indicated by the name, in blue or purple type, being underlined.  Migrants are in italics and species for which breeding activity has been recorded in the month are in bold type.

1  Waterbirds:  Musk Duck;  Australian Wood Duck; Grey Teal;  Pacific Black Duck; Hardhead; Australasian Grebe; Little Pied Cormorant; White‑necked Heron; White‑faced Heron; Australian White Ibis;  Purple Swamphen; Dusky Moorhen;  Eurasian Coot; Black‑fronted Dotterel; Masked Lapwing; 

2 Birds of Prey:  Black-shouldered Kite; Whistling Kite, Brown Goshawk; Collared Sparrowhawk; Spotted Harrier; Wedge-tailed Eagle; Little Eagle; Nankeen Kestrel; Brown Falcon;

3 Parrots and Relatives:   Glossy Black-Cockatoo; Yellow-tailed Black-cockatoo; Gang‑gang Cockatoo; Galah;  Sulphur‑crested Cockatoo;  Superb Parrot; Crimson Rosella; Eastern Rosella; Red-rumped parrot  

4 Kingfishers and other non-songbirds: Stubble Quail; Brown quail; Common Bronzewing; Crested Pigeon; Tawny Frogmouth; Australian Owlet-nightjar; Shining Bronze‑cuckoo; Pallid Cuckoo; Fan‑tailed Cuckoo; Eastern Barn Owl;  Laughing Kookaburra;Sacred Kingfisher; Rainbow Bee‑eater.

5 Honeyeaters: Eastern Spinebill; Yellow-faced Honeyeater; White-eared Honeyeater; Noisy Miner; Red Wattlebird; Brown‑headed Honeyeater; Noisy Friarbird

6 Flycatchers and similar species: ;Rufous Whistler; Grey Shrike-thrush; Grey Fantail; WillieWagtail; Leaden Flycatcher;  Magpie-lark;  Scarlet Robin; Flame Robin; Welcome Swallow; Fairy Martin; Tree Martin

7 Thornbills, Finches and similar species:  Superb Fairy-wren; White-browed Scrubwren; Speckled warbler; White-throated Gerygone; Weebill; Striated Thornbill;  Yellow‑rumped Thornbill; Buff‑rumped Thornbill; Brown Thornbill;  Spotted Pardalote; Striated Pardalote; Silvereye;  Double‑barred Finch; Red‑browedFinch; House Sparrow; European Goldfinch

8 Other, smaller birds:  White-throated Treecreeper; Black-faced Cuckoo-shrike; Olive‑backed Oriole; Dusky Woodswallow; Horsefields Bushlark, Skylark; Australian Reed-warbler;  Common Blackbird; Common Starling; Mistletoebird; Australasian  Pipit;

9  Other, larger birds: Satin Bowerbird; Grey Butcherbird; Australian Magpie; Pied Currawong; Grey Currawong; Australian Raven; Little Raven; White-winged Chough

A further report, analysing 2011 as a whole, both in its own right and in comparison with the earlier years will be prepared over the next week.  Watch this blog!

As well as this report a couple of ad-hoc reports of birds in the general area, but outside the Catchment of the Gazette have been generated .  Readers may wish to peruse them.