2015 PLAINS-WANDERER REPORT
As in 2014, low and erratic rainfall put plains-wanderers under pressure in
the Wanganella district in 2015. Throughout the district, the rainfall was
again 50—100 mm below the long term average and crucially, this is the
fourth year in succession of below average rainfall.The rainfall varied
throughout the district, with Wanganella township recording 329.9 mm,
whereas out on the plains-wanderer property only 267.5 mm fell, a
difference of 62.4 mm in only about 40 km. Even within the combined
plains-wanderer properties, the rainfall varied by up to 75 mm in a short
distance. Over the past 15 years, 11 have been droughts or had well below
average rainfall, two have been a bit above average and two have been flood
years —in itself, problematic for plains-wanderers.
In such bleak conditions, no bird could be expected to thrive, nor can they
co-exist with livestock when cover is so scarce. This is reflected in the
fact that in 2015 the only paddock that still contains plains-wanderers has
had little or no stock in it over the past three years. As over the past 15
years, the irregular rainfall continued in 2015 with severe deficits in
February and March (no rain at all was recorded in March), May, September,
October and December. The September and October deficits were the most
crucial, coming in prime breeding time for plains-wanderers and most other
species. During the year we had three two-month periods of little rainfall:
February/March, September/October (except for 31 October), and after the
first week of November through to the end of December.
Despite all these hardships plains-wanderers still managed to breed
successfully in 2015 (much to the Nevinson family’s credit in these dry
years when feed is scarce). The year got off to a good start with well
above average rainfall in January, which triggered breeding. An adult male
with two small chicks was recorded in mid February and a courting pair on
23 February. Immature birds (three to five months old) were recorded in
January, March and April. During this period of time, we suspect we had at
least two adult females (each probably with two males) as well as up to
four immature birds present in the one paddock. By May, numbers had dropped
off considerably and only a single male could be located on 25 May. By late
July, when we next looked for plains-wanderers, they had seemingly
disappeared. Despite looking for them on four occasions in late July and in
August, only a single male was located in an area that appeared marginal at
best and it was not seen there again. With only minimal cover, the
situation appeared dire. After several nights’ reconnaissance, including
two nights searching a neighbouring property, with no positive result, we
were worried; then, on our last attempt in late August, a male with small
chicks was found. This meant he had been on eggs back in July as
plains-wanderers take 26 days to hatch. This was an amazing effort as there
was very little cover out on the plains at that time. On 18 September, an
adult female was located, the first seen since April. By mid October, there
was thought to be a second adult female present and probably each female
had two males each. By late November, a third female was possibly present
given where they were located in the paddock. However, it was difficult to
be certain as the maximum number of adult females seen in any one night was
two birds (29 November). As in the previous year’s low, erratic rainfall,
breeding was again attempted whenever conditions appeared even marginally
favourable. Breeding birds were detected in January, February, August (eggs
in July), September, October and November. One young female, about three
months of age, was recorded on 24 October, calling for a mate,
demonstrating that the species can breed at a very young age. Clutches of
chicks were seen in February (male with two chicks), late August (male with
two to three chicks), November (male with five chicks that subsequently
lost one, with only four chicks seen 12 December) and another in December
(male with one chick — different male/chick to 12 December sighting). In
early December some immature birds were seen that did not match up with any
of our known clutches so it was thought that another clutch had been raised
nearby that we had not detected. It seems likely that five clutches of
chicks have been raised in this paddock over the twelve-month period,
albeit, two of these clutches had only two and one chicks. It is also not
known how many chicks made it to independence. The clutch of five chicks
was a mighty effort in such bleak conditions and was in much the same
locality as the five chicks recorded in 2014; it’s possible the same
adults could be involved.
Quite a few of the earlier clutches have made it through to independence,
going by the number of immature birds recorded in October, November and
December. From September through to December 2015, up to 20
plains-wanderers including chicks and juveniles were estimated to have been
in the one paddock.
Climate change and associated extreme weather events are the overriding
causal factors limiting the plains-wanderer to very low numbers. The
species is hanging on but only just. The problem it has at present in the
Wanganella district is there is nowhere for population expansion, with all
the surrounding country too bare for them. Unless we have a reasonable
rainfall this year, plains-wanderers will again be restricted to small,
ungrazed or lightly grazed areas. Any surplus birds will have to move quite
some distance to find suitable habitat, if they can find any at all.
Stats
In 2015, Robert and/or I went out spotlighting for plains-wanderers with
clients on 56 nights (43 in 2014). The number of clients including
Australian and international birding tour leaders totalled 241 birders (196
in 2014). We had 50 successful outings with a total of 230 happy clients.
Six searches with a total of 11 clients failed to find a plains-wanderer,
the same number of search failures and disappointed clients as in 2014.
Four of these failed searches occurred in late July and August, and two in
October. Robert and/or I did three or four reconnaissance trips, of which
one was successful.
All plains-wanderer searches are documented on the Latest News page of our
website. http://www.philipmaher.com/LatestNews1htm.htm
Philip Maher
Australian Ornithological Services Pty Ltd
Deniliquin 2710
New South Wales
www.philipmaher.com[1]
Links:
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[1] http://www.philipmaher.com
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