A Forest foray in search of the Forest-king...
During the course of 2017 we learnt about the presence of the Western Forest-king Charaxes (Charaxes xiphares occidentalis) in the Grootvadersbos Forest, near Heidelberg in the Western Cape. Hours were spent pouring over our “Conservation Assessment of Butterflies of South Africa, Lesotho and Swaziland” that evening, and the Bionerds.co.za team was excited to have the opportunity to head off on an ecoexploration in search of this range restricted beauty.
We had to wait till the height of breeding season… which meant our first opportunity at finding the butterfly would be February 2018.
We set reminders and early in January this year – after planning our booked Biosurveys, we contacted Aileen Anderson in regards to accommodation for our trip. Aileen, and her partner Walter, own and manage Strawberry Hill Farm, which is part of the Grootvadersbos Conservancy. A spectacular property that has been in Aileen’s family for 3 generations, sections of the most south-westerly indigenous Afromontane Forest in Africa are present on their property.
Aileen kindly accommodated Bionerds, and our date was set with this spectacular and gaudy butterfly.
We arrived on Saturday, 4th February 2018, and wasted no time in getting our gear ready and headed into the forest in the search of a large blue butterfly… we were barely inside the forest when we sighted our first ones! They were flying about 7m from the forest floor, in the canopy at high speed. We were ecstatic, but we were both silently hoping that this was not going to be the only way we were going to see them!
We kept on hiking deeper into the forest, over little forest streams, and muddy spots on the pathway. Birdlasser was working overtime as we logged our bird sightings. Birding in this patch of indigenous forest has always been productive, and this time was no exception. We had a small party of Forest Canaries that was escorting us along the pathway, feeding on the Num-num bushes along the trails edge. The ever present Sombre Greenbuls were inviting everyone to “Come out and play” and the Cape Batis’ contact calls is the coffee of the forest, warm and welcomingly announcing the approach of a bird party, almost invariable followed by the unmistakeable call of the Blue-mantled Crested Flycatcher. The Terrestrial Brownbul’s sounded like a bunch of teenagers mumbling their opinions just outside of earshot, and a distant Narina Trogon was barking its elusive presence from deep within the forest.
We also saw other small butterflies, little Coppers and Browns – but our eyes was mostly scanning the canopy overhead for movement – and each time one would do a fly-by we sounded like over excited toddlers. Not our proudest moments…
We eventually found a small forest glade, lined with ferns and bisected by a small little running stream. The edges were lined with Cat-Thorn (Scutia myrtina), which is the larval food for this butterfly. It definitely looked promising. I watched as Keir put our gear against a tree… AND CHASED UP TWO WESTERN FOREST-KING’s!!!!
We stood gawking at them flying away… we were either very lucky, or very unlucky… we chose the perfect site – but did we chase them off permanently?
Our concerns soon abated, as the first Forest-king flew up overhead, circled the tree where we chased the others from – slowly spiralling downwards, until it settled on a scar in the trees trunk. We could not believe it! We had chanced upon one of their feeding sites! How lucky can one be.
Whilst we sat down, just observing them, we managed to identify the three main activities of the Western Forest-kings described by Crous et al (2015), a paper we had read in preparation for our trip.
We observed them touring high in the canopy, flying very fast and not doing anything in particular. Once it appeared that they decided to come to feed they would tour overhead, then dip and start a short patrol of the area. Patrolling entails flying low above the vegetation at a slow speed. While patrolling, if they found another butterfly on the wing, they would engage and chase the ‘opponent’ off. If they did not find any other butterflies they would come in towards the Black Ironwood (Olea capensis) and circle it a few times, settle high on the mossy trunk above the sap scar, and walk down to the feeding site. Then they would start feeding on the sweet, lemony sap (yes, we tasted it!) oozing from the scar in the tree…
The sexes in this butterfly subspecies are strongly dimorphic, but the underwings look very similar - although the females upperwings do not have the strong royal blue that is so attractive in the males, they are definitely not drab.
Our first observation was of a female, who can have a wingspan of up to 80mm. We managed to photograph not only her underwings, but also her striking upperwings.
This time of year – January to March – is the breeding season for this single brood subspecies.
Whilst we were photographing her we saw two more Charaxes patrolling the glade, we settled and watched them as they chased each other, and then one approached the feeding site… we were in awe, the blue on this butterfly is very inconspicuous when flying, just enough of it is visible to catch your attention, but it was unmistakeable… it was a male.
He came in low, settled about 20cm above the scar on the moss, and slowly ‘walked’ (OK, that sounds a bit more gracious than it actually was…stumbling would describe it better) down towards the feeding site. His wings were closed throughout this process, but we had wonderful views of him unfurling his proboscis and sucking up the sap.
Another butterfly settled at the scar… and the next moment they were facing each other, and sizing each other up… with their wings open! Our jaws dropped, we had not expected to be treated to such a display by this endemic, range restricted subspecies.
The males faced off for about 30 seconds, opening and closing their wings systematically, after which they both settled at opposite spots of the feeding site and sipped the sap.
Before we knew it we had spent 4 ½ hours observing the Western Forest-kings in their natural habitat, and our lives was so much richer for it.
What was the most spectacular of the whole experience was not just the fact that we saw both a male and female, but that we actually got to observe so much of the behaviour of these butterflies.
We will definitely be heading back to this forest soon…
* Crous, C.J., Pryke, J.S. & Samways, M.J., 2015, ‘Conserving a geographically isolated Charaxes butterfly in response to habitat fragmentation and invasive alien plants’, Koedoe 57(1), Art. #1297, 9 pages. http:// dx.doi.org/10.4102/koedoe. v57i1.1297
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