Could I please seek chat line subscribers’ indulgence to copy below the rather long but relevant Section on this issue from my summary of the rise and rise of the Eastern
Koel (CBN 46, 105-118 (2021), as to my knowledge this remains the most recent literature discussion of the issue of any interaction between adult and juvenile Eastern Koels.
Jack Holland
4.2. Interaction of adult Koels with fledglings, especially late in the season
As noted in Section 4.8 in (Holland 2021; this issue), in the 2020-2021 season Christine D.’s was the only example I am aware of adult Koels being close to juveniles
in March. While on 15 Jan John Harris posted that he was making similar observations to those he made last season (Harris 2020), these observations were made in mid January, well before the end of the season. It is not known how long John’s observations continued
beyond that.
Interestingly Maller and Jones (2001) comment that ‘there are persistent reports, which are difficult to verify, of possible parent-fledgling interactions’ (R Nattrass,
unpublished). Jones and Nattrass (2001) discuss this in more detail, i.e. whether the examples of Koels calling in February as detailed by Maller and Jones (2001) were produced by the young Koel’s biological parents having returned to the vicinity of nests
they may have parasitised earlier. If so, they suggest these visits may provide the fledglings with an opportunity for auditory imprinting prior to the northward migration. While this is one of the theories last discussed in Section 5.4 of Holland (2020),
and by Harris (2020), unfortunately the reference they cite (Brooker and Brooker 1994) does not contain this statement.
In contrast, based on their observations Abernathy and Langmore (2016), citing Jones and Nattrass (2001), state: ‘While this has never been confirmed and could simply
be a function of male territorial behaviour (males could be calling near parasitised nests to defend their nesting territories from other Koels), the fact that males do sometimes call close to Koel young may allow the young to imprint on the proper vocalisations.’
On 13 Jan Geoffrey Dabb drew my attention to the very interesting comments on post fledging behaviour posted by Chris King on birding-aus that morning: ‘Alan Morris
posted this response recently to a Facebook photo of a Koel, and I confirmed with him that it is Ok to post it. The parent Koels usually re-connect with their young at this time when they wean them off the largely insect diet of the Wattlebird and Friarbird
hosts and onto the fruit diet of figs, berries, cherry tomatoes and other fruits! They then depart northwards with their families.’
This information extends well beyond the observations we have made so far in Canberra, so I e-mailed Alan seeking further details. Unfortunately, while Alan acknowledged
my e-mail, the promised further information was never forthcoming. Christine D. has indicated that she has watched the young begging Koels arrive in her fig tree and they seem to work out for themselves that they can eat the figs. They also do it when their
Red Wattlebird (Anthochaera carunculata; RWB hereafter) host is away searching for food for them, and gradually eat more on their own, and soon do not need to be fed by the RWB. So, from her observations no help from an adult Koel has been seen or was
needed.
A search of the literature reveals very few examples of adult Koels feeding their own fledglings.
Brooker and Brooker (1989) note that Chisholm and Cayley (1929) recorded adult Koels ‘in attendance’ on a young bird fostered by Olive-backed Orioles (Oriolus sagittatus).
I note the latter authors’ comments under Eudynamys orientalis: ‘Koel. – A pair visited the back yard of the boarding house every morning during our stay and made the welkin ring with their weird calls. They were in attendance on a young bird whose
foster-parents were a pair of Orioles.’ Steve Read also alerted me to a couple of examples in the literature of Asian Koels (a different species, or at least sub-species) doing the same, as well as other cuckoos, in particular the Pallid Cuckoo (see Lorenzana
and Sealy 1998; Monga 2007).
So, there is at least one precedent, though Ruth’s male in Theodore (see Section 4.3 of Holland 2021; this issue) is the first local observation for an adult Eastern
Koel seen to adopt and feed a Koel fledgling.
In summary, despite the bumper Koel fledgling season there is very little new information on the interaction of adult Koels with fledglings beyond that summarised in
Section 5.4 of Holland (2020). This is a very interesting area, and the questions cannot be answered by the “Citizen Science” study I have been co-ordinating.
From: Canberrabirds <>
On Behalf Of Philip Veerman via Canberrabirds
Sent: Saturday, 5 October 2024 11:15 AM
To: 'calyptorhynchus' <>;
Subject: Re: [Canberrabirds] Koel
There is nothing at all to suggest that young Koels travel north with parents. The young Koels have zero connection to their parents. We can see that even here.
They are raised by foster parents and leave them as soon as the foster parents’ role is done. The parents have often left before the young are mature enough to start the journey. Even so, if young Koels had any connection to their parents it is even stranger
to think that they would hang around long enough to make the return journey months later.
In general with birds there is not a lot to suggest that young birds migrate specifically with parents. Some do, like some storks (or is it cranes) or both groups,
or very social birds that just maintain big collectives anyway…….
I also looked at HANAB book yesterday as Jack quoted, but then I have gone through the same exercise before as the question gets raised every couple of years.
Philip
From: Canberrabirds [
On Behalf Of calyptorhynchus via Canberrabirds
Sent: Saturday, 5 October, 2024 10:07 AM
To:
Subject: Re: [Canberrabirds] Koel
If young birds travel north with parents, then I guess younger birds might travel south with older birds in the spring.
On Sat, 5 Oct 2024 at 8:13 am jandaholland--- via Canberrabirds <> wrote:
Thanks Brian, I’ve had a look through HANZAB online which only contains “Suggested that migrate singly, in pairs or in small groups”.
The references to this statement are quite old, but I am not aware of any more recent information, the main question that has come up in the past 10 years is “do adults travel together with juveniles (escort) on the outward migration?”.
Certainly, the reports of first Koels in at least 9 different locations (both N and S side) over the past 2 days (including 3 birds
in Rivett yesterday afternoon) would suggest they were all travelling at much the same time, though not necessarily very close together.
Jack Holland
With all these birds appearing at the same time, I wonder whether migrating Koels travel as a group then disperse at their destination.
On Oct 4, 2024, at 4:44 PM, jandaholland--- via Canberrabirds <>
wrote:
And certainly in W Rivett today too. After a brief set of “ko-els” this morning, one was ko-eling (with some short stops) there very
loudly for at least 25 minutes around 15:00, and again when walking dogs after 16:10, around which time I also heard at least 4 brief sets of the female “kek kek kek” call, and also briefly a few of the male’s alternative “whoas”, in one case answering the
female call. Jack Holland
