Hi All,
This is my fifth attempt to post this message to BA. Yesterday I asked Russell
to forward it. It looks to me like all that came through was the header. As
such I will now expunge the tail I formerly had included, being the message
from David Geering and others. That seems to have made the combined thing too
long or had formatting that has prevented it going through. Sorry about that.
Enough of the irrelevance, down to the message and I hope this goes through now.
It should be taken in the context of those messages of last week.
As for the similarity of the Regent Honeyeater calls and mimicry. When I first
encountered a Regent Honeyeater (RH) I noted that the only call this bird was
making was indistinguishable (apart from lesser volume and some lesser
hoarseness) from the Red Wattlebird (RW). In my then very limited
understanding of evolutionary processes, I thought it peculiar and interpreted
this as evidence of relationship. This was in 1974 when I was in final year of
school. It was only years later that I realised (from reading) that the Regent
Honeyeater had other calls, that are different from those of wattlebirds.
Remember in 1974 the only books available describing the honeyeaters were
Cayley's, Leach's & Hugh Officer's. I didn't think of it again for years,
until there was a lot of attention devoted to the species (for its declining
status). Following this attention, more reports of its mimicry came in.
The mimicry idea was not only mine (but it was me who wrote it up). It was Don
Franklin who suggested it to me in a letter dated 19-11-1987, writing: "Your
note describing a call resembling a RW I found particularly intriguing and I
suggest you reconsider the possibility of vocal mimicry. Apparent
vocal mimicry has been described 3 times before" (and then listed the records
he had). He was replying to a letter I had sent to Peter Menkhorst about this
behaviour, that Peter had sent to him. I appreciated his suggestion. As what
struck me was the very unusual circumstances in which all the examples
occurred, I sought further evidence and developed the idea. Experts in vocal
mimicry from outside Australia have since then been very interested in this
behaviour. The top of page 189 of my first ABW article on the subject (1992)
?Vocal mimicry of larger honeyeaters by the Regent Honeyeater Xanthomyza
phrygia?, Australian Bird Watcher 14: 180?189) clearly postulates a close
evolutionary relationship as one possible basis for the use of wattlebird and
friarbird calls by this species. Especially with this further evidence, I
believe both aspects are involved, or it adds an extra dimension to what I
am still sure is true mimicry. I am not a bit surprised at stronger evidence
than previously available, that the RH is genetically close to the RW (but
closer than the LW is to the RW is a little hard to believe). I guess it
depends a bit on the relative importance of the particular genetic loci being
looked at. The behaviour is consistent with and appears to be elicited as
functional mimicry. It is also very likely based on a deeper inherited
capacity. It is very different from typical random copying mimicry of other
birds in the way done by lyrebirds, bowerbirds, orioles, etc. (Yes I know
lyrebirds learn from other lyrebirds.) It is the context of the mimicry that is
really odd, that it is invoked in particular circumstances: being winter-time
association of solitary Regent Honeyeaters among groups of wattlebirds, and not
at all whilst breeding. The question arises as to why they do the same with
friarbirds (although I have not personally observed that). Notwithstanding that
alarm calls of many Meliphaga honeyeaters are
very close, it is not just a phenomenon of a similar call from related species.
Birds of other species do not spontaneously make calls of closely related
species when surrounded by them, in the same context as done by the RH.
The Regent Honeyeater is big in colour, if not in size, compared to the RW.
As for the Blue-faced HE being aligned to the Melithreptus group, well I always
thought that was obvious. They look so similar and sound in some ways similar.
Nothing terribly special about gigantism, it is one of them, grown bigger.
Philip
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