Introduction
In Victoria we have four indigenous members of the crow genus Corvus,
and the fifth species (House Crow Corvus splendens) is a south Asian
blow-in that has been recorded from time to time (ship assisted).
Though the Victorian species by common name are made up of three ravens
and one crow, none are closely related to the true ravens of the
northern Hemisphere. All the Australian Corvus species are most closely
related to each other and a few other Australasian regional species; so
in reality they’re all crows!
The Victorian crows are subtly distinct on various features of external
morphology, but to all intents and purposes can usually only be reliably
identified from their calls. Luckily, crows call frequently, and thus
are relatively easily identified using this feature. Many of the
Victorian crow records in state and national atlas databases, and
particularly from southern Victoria, are I believe quite unreliable.
This was identified as a problem back in the Victorian bird atlas of
1987 (Emison et al. 1987), and some misconceptions were perpetuated by
statements such as those in the first national atlas (1977-1981)
(Blakers et al. 1984) and Pizzey & Knight (1999) about the Forest Raven
being the only ‘corvid’ on the tip of Wilsons Promontory and at Cape
Otway. [References to ‘corvids’ here are strictly referring to members
of the genus Corvus, not the expanded Corvidae of latter day taxonomy.]
The Little Crow Corvus bennetti is confined to far north-west Victoria,
mostly contained within the Murray Scroll Belt, northern Murray Mallee
and northern Lowan Mallee bioregions. Typical habitats occupied in that
area include farmland and surrounding open mallee and Pine-Belah
woodlands, and it is well known from the Mildura landfill.
In southern Victoria, largely confined to the Glenelg Plain, Dundas
Tablelands, Greater Grampians, Warrnambool Plains, Otway Plain, Otway
Ranges, Strzeleckii Ranges, Wilson's Promontory and Gippsland Plain
bioregions, is the Forest Raven C. tasmanicus. It also occurs
marginally in the Bridgewater, Wimmera and Victorian Volcanic Plain
bioregions. It also occurs in contiguous parts of SE South Australia,
is the only crow in Tasmania proper, and has an isolated relict
subspecies in NE New South Wales sometimes known as the Relict Raven C.
tasmanicus boreus. Though mainly occurring in forest and woodland
habitats, the Forest Raven can also be found on open, treeless farmland.
Though there are probably numerous erroneous records of this species
from the core areas due to an uncritical geographic assumption by many
observers, the range is relatively well known except in the north, where
the precise upper boundary from the Grampians across to the Little
Desert needs further resolution. Emison et al. (1987) believed that
observers were more discriminating in their identification of this
species, and I believe to some extent they are right, except that there
is undoubtedly still confusion with the other two southern crows.
Both the Australian Raven C. coronoides and Little Raven C. mellori are
very widespread in Victoria, and both are found in virtually all
terrestrial bioregions. The Little Raven is the common town crow in
much of Victoria, unlike in Canberra, Sydney and Perth where that niche
is filled by the Australian Raven. In contrast Australian Ravens seldom
hold territories in built-up areas in Victoria, and I believe that many
town records of this species are in error.
In other areas such as the Otway Ranges and Otway Plain, all three
southern species occur, and the crow records in databases from there are
quite confused. In towns along the Otway coastline, Little Ravens
occupy their typical urban niche but are often presumed to be Forest
Ravens by uncritical observers. Australian Ravens are relatively rare
in the Otway Ranges, and many crows in the interior of this range are
most likely to be Forest Ravens. Forest Ravens do also occur alongside,
or in replacement of, Little Ravens in some of these coastal towns.
Along the northern fringe where the foothills meet the Victorian
Volcanic Plain, all three species are probably equally likely to occur.
The distribution of the three species in this area is probably not
static (with Little Ravens probably colonising farmland and settlements
throughout the area), and needs a complete review based on reliable
field records.
So what?
In a part of Australia with the highest density of bird observers, and
in an era where we have had two national atlas projects since the 1970s
(Blakers et al. 1984; Barrett et al. 2003), and a Victorian state
wildlife atlas ongoing from that time, we still have an incomplete or
misleading picture of the distribution of three of the commonest birds
in the state! The art of crow identification on the whole hasn’t
progressed much past the educated guess for many bird observers. One
regional organiser (vetting records) from the second national atlas
project related the answer given more than once when a SW Victorian crow
record was queried "It looked pretty big, so I though it was an
Australian Raven". Many observers also seem to mistake the attenuated
last note of the call sometimes given by Little Ravens as the
characteristic falsetto "death rattle" of the Australian Raven; hence
the numerous erroneous Australian Raven records from inner suburban
Melbourne! In reality the calls of Little and Forest Ravens are more
similar, given as they are somewhat more slowly and in a deeper register
than the Australian Raven.
This raises many corollary questions about how or whether these species
have partitioned niches when they are sympatric; are erroneous records
masking some kind of fine-grained micro-distributional separation; are
there seasonal movements of any or all these species; etc. Little
Ravens are known altitudinal migrants in the Australian Alps (Rowley
1971), but such movements of the other species are not known or are
poorly understood.
What can we do?
I’m keen to start collecting precisely located records of these species,
identified by experienced and competent observers, and coupled with some
basic habitat usage data. Naturally I want to contribute records, but I
also want to coordinate others' efforts. We can then accumulate this
body of accurate data, analyse and publish it; to assist birders and
others to better deal with crow identification, biogeography and ecology
in southern Victoria.
The basic data will be something like this:
# Observer (graded for crow ID skill level)
# Date, time
# Where was the record made (GPS waypoint and written locality
description)?
# How many birds?
# How were the crows identified?
# What was the surrounding habitat, and which part of it were the crows
using?
# What were they doing there (feeding, roosting, etc.)?
The best areas to target I think are those relatively easily accessed
parts of the state where the three crow species at issue are well known
to occur:
# SW Victoria - the area between Portland, the Grampians and Little
Desert; and
# The Otway Ranges and Otway Plain.
When do we start?
How soon can you get ready? All interested observers can contact me to
register their interest, preferably by e-mail for starters, at
and then we can start planning the field work.
References
Barrett, G., Silcocks, A., Barry, S., Cunningham, R. & Poulter, R.
(2003). The new atlas of Australian birds. Royal Australasian
Ornithologists Union, Hawthorn East.
Blakers, M., Davies, S.J.J.F. & Reilly, P.N. (1984). Atlas of
Australian Birds. Melbourne University Press, Melbourne.
Emison, W.B., Beardsell, C.M., Norman, F.I., Loyn, R.H. & Bennett, S.C.
(1987). Atlas of Victorian Birds. Department of Conservation, Forests
& Lands, and Royal Australasian Ornithologists Union, Melbourne.
Pizzey, G. & Knight, F. (1999). The field guide to the birds of
Australia. Angus & Robertson, Sydney.
Rowley, I. (1971). Movement and longevity of ravens in southeastern
Australia. CSIRO Wildlife Research 16, 49-72.
Lawrie Conole
17 Stafford Street
Northcote, Victoria 3070
15 July 2004
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