Year to date in the yard

Apart from keeping records of birds seen in the area generally I also maintain a COG Garden Bird Survey site.  The principle of this is to record:

1. the maximum number of birds of each species;
2. seen in a week;
3. within 100m of a house.

Practically the third criterion is a bit flexible since if a bird-attractive feature is nearby human nature will include the birds seen there.  So as long as the site is no larger than the area of a circle with radius 100m (ie 3.14 Ha) it is acceptable.  It is also helpful in maintaining some rigour if the boundaries are physically recognisable (eg fences, roads etc).  Birds overflying the site are included.

My site is shown below.

The polygon function of Google Earth shows the area as 2.8 Ha which is pretty close to the required limit.  Of course the area is not covered evenly: the section visible from my study window (see below) is monitored for 4 hours a day minimum while the dam and Whiskers Creek get checked for perhaps a couple of minutes every second day (depending on what I'm doing around the block).

The Survey operates on a year beginning 3 July so that breeding seasons falls within a single year.  It starts on 3rd July because the original proponents felt it important to keep the week numbers consistent with desk diaries (!!!! - but we are dealing with a Survey that starts before personal computers had been invented!) in which the the start of week 1 is January 1.

The reason for compiling this post is that the results for this GBS year so far are a bit strange in a number of ways. Since starting the site in February 2007 I have recorded 111 species within the site.  This chart shows the pattern through which that total has been arrived at.   

The dashed line is a logarithmic trend line which seems to be usual form of trend followed in such activities.  I added two species last GBS year:  Channel-billed Cuckoo (an unusual species in the Southern Tablelands) and Flame Robin (common on the Hoskinstown Plain but not up here - they are renowned colonisers after fire).  So far this year I have added one species: Rufous Songlark- again quite usual on the Plain but not so common up here.

One of the major unusual features of the year is the pattern of total diversity.  The next graph shows the cumulative total number of species seen as the current year progresses and the equivalent average over the 10 previous years..

We were seriously underperforming until the week ending 27 September, when 7 species were added to the tally.  The total got a further boost, of 6 species, in the first week of October.  Additional species have continued to be added.

I am currently at 81 species for the year.  I did an extrapolation of a trend line fitted to the data up to 16 January and that indicated about 85 species would be the total.  As there are 30 species seen in previous years which I have not yet recorded this year that seems to be quite achievable, and there are at least 10 MIAs which are regular in the Gazette area.

Another way of looking at the current year is that the number of species already recorded is equal to or greater than the number recorded in any full year except 2009-10.

Four species in particular had caught my attention as appearing more frequently than in the past.  To give a little rigour to the analysis I compiled a table of species seen by week compared this year (so far) with the average of other years.  This added a few more "interesting" species.

I have written a specific post about White-winged Triller so will not say more about them here.

The second species is Dusky Woodswallow.

So far this year I have recorded them in the GBS site in 19 weeks, whereas the average is 2.78 weeks per year.  In other years they have been very common on Whiskers Creek Road (about 300m away) but much less so this year.  They have also been very aggressive to other birds - including this Kookabura.

Note the hurtling Woodswallow  lower right in the photo.  (This image was rejected by ebird because the Kooburra dominated the depiction of the Woodswallow.)  They have also given Magpies similar treatment.  This made me wonder if they were nesting in the area and on 15 January I  saw a Dependent Young Woodswallow.

The third species is Red-rumped Parrot.  .

I had only recorded this species once before in the site, although they are very common on the (relatively) nearby Hoskinstown Plain.  This year I saw a flock of 4 fly over just after New Year's Day and since then have been seeing and hearing them almost daily.  It has been suggested that the bush fire has opened up the vegetation and allowed some plants attractive to the parrots to come to seed.

The fourth species is Tree Martin.  These are not widespread in the area but a remnant Brittle Gum Woodland - about 8km away - with lots of hollows is a common nesting site for the species.  This year I have recorded them in 6 weeks compared to an average of 3.2 weeks in other years.  Their call is distinctive and pretty much continual as they hawk overhead.

An addition thrown up by the quantitative analysis is Sacred Kingfisher.  I have recorded them in 7 weeks this year, which I thought "usual" but in fact I have only recorded them on average 2.3 weeks per year in the past.  They appeared to be trying to excavate a nest hollow at one point

but didn't pursue this endeavour.

I realised that only 29 weeks of the year had passed so then expanded the number of weeks seen by 52/29.  (This gave a few false positives for migrants as a much higher proportion of their period of presence has occurred, so I ignored them.)  The main additional species drawn to my attention by this step was Magpie Lark, which has been recorded 9 weeks (after adjustment 16 weeks) compared to an average of 6 weeks.

The analysis also drew my attention to some species which have dropped significantly in their reporting rate.  The two most obvious, before adjustment, were Eastern Yellow Robin (average 28 weeks and even after adjustment only 5 weeks) and White-eared Honeyeater (average 34 weeks. 3.5 weeks after adjustment).  The adjustment process also drew attention to reduced recording of Common Blackbird, Yellow-rumped Thornbill and Common Bronzewing.  For the last species, they are commonly attracted by the fallen seed of Acacia dealbata which shrubs largely got incinerated in the fires.  I have not yet come up with a theory about the reason for the disappearance of the other species.

Birds after the inferno

We were not much in Carwoola for the first few days after the fires tore across our block.  We actually moved back home on 24 February.  So here are my recent observations

From the first 24 hours we were back.

Around the house we have had a surprising number of the smaller birds.  The most obvious, and in greatest numbers have been Superb Fairy-wrens.  They and the thornbills and scrubwrens seem to be finding plenty to glean on the ground and we are providing water for them.  Quite a few bushes still have leaves so they have had shade on the hot days.

Medium-sized birds, especially nectivores have been thin on the ground.  The only honeyeaters seen or heard have been Red Wattlebirds and, up the top of the block, Noisy Miners.  No Yellow-faced Honeyeaters, Noisy Friarbirds nor Eastern Spinebills.  Two Rufous Whistlers were calling this morning and a couple of Black-faced Cuckoo-shrikes were seen on Widgiewa Rd.  Grey Fantails are evident as always.

I assume these latter species are dining on the dead insects around the area.  There are plenty of former grasshoppers (and still a surprising number of live ones: how did they survive?)  Also I have just removed the leaves from our gutters and it seemed that dead Christmas Beetles made a significant contribution to the biomass.

Parrots and their relatives have not been around much.  I have heard a few Galahs and some Yellow-tailed Black-Cockatoos have been the only participants from this family group.

The dominant species generally appears to be Little Ravens.  As we finished the dog walk this morning a flock of 50 of these raucous birds were carrying on alarmingly by the Creek.  Other large birds seen have been several family (? - I didn't check their DNA)  groups of Australian Ravens; good numbers of Australian Magpies; a pair of Magpie Larks; a Collared Sparrowhawk and a Kestrel were the contributions form the raptor family.  Finally while on the roof a clan of about 6 White-winged Choughs went by.

Not a bad haul in the circumstances.

Later sightings

The next morning 5 Australian White Ibis flew over: great scavengers (a common name in Sydney is Bin-chook) they'd undoubtedly got the word that grasshoppers were easier to spot!  Masked Lapwings were down at a dam.  Noisy Friarbirds made their presence known and a flock of 12 Dusky Woodswallows were hawking off the power lines.  The latter species have been thin of the ground this season.

Subsequently Grey Shrike-thrushes have been everywhere.  A Sacred Kingfisher flew across our block and a pair (OK, two) of Grey Currawongs were grazing on our lawn.  The choughs are patrolling every day (and causing hypertension when they kick up a cloud of smoky dust).

The biggest surprise was a juvenile Nankeen Night Heron perching briefly in a tree outside our sun room,  As I commented in a message to the COG chatline "I had to check the bottle of Shiraz to make sure I had only had one glass!"

Other eyes

A number of other folk in the area report birds they have seen to me, which helps keep tabs on what is happening.  

Since the fire one neighbour reported, through Facebook, a quail on their lawn.  This resolved to a Painted Buttonquail.  The observer commented that they knew there were quail in the paddock but hadn't seen them at the house before.

Another observer commented :

I have seen copious magpies, ravens, crimson rosellas, superb blue wrens and red browed finches….but none of our white browed scrubwrens (we had HEAPS) and it is noticeably quieter :-(   I can’t hear any of our usual wattle birds, honeyeaters or noisy friars…it’s really quite depressing :-(

I have seen quite a few raptors since the fires though - brown goshawk, wedgies and what I think was actually an Australian Hobby….I can’t think what else it could have been. I haven’t seen one here before!  

Lastly, put me down for a white faced heron from the other day and a black faced cuckooshrike as well - just saw it this morning.  Oh and a bunch of maned ducks - there’s a family group at the end of Widgiewa that I’ve had to wait numerous times whilst they waddle across the road.  One was hit the other day by a car in front of me and I got out and moved it to the side of the road - was hard watching the family try and process what had happened when they got to the body :-(

Comparisons

A Canberra friend commented that soon after the 2003 bushfires he visited the Bullen Range (across the 'bidgee from Kambah) and the only bird he saw was a Superb Lyrebird.  Several months later when I returned to Australia and visited the Brindabellas the only birds in numbers were Flame Robins: I think we counted 25 in 1km of Warks Rd.