Raptor’s View residents Chris Hines, Derek Solomon and Jeremy Brown (all +/- in the middle section of the estate) joined forces to conduct a 21-day lockdown bird count around their individual homes and submitted their findings to The Hornbill, BirdLife Lowveld’s newsletter due for publication soon. Their report follows – we then asked RV residents to submit their bird lists for the extended lockdown 5 week period to look for similarities, differences and anything else of interest.
The Report – The general idea was to see how many species we could record on the reserve over the initial 21-day lockdown period (27 March – 16 April) and to see what the differences were between the 3 sites. Could we use the data to determine how many species could be expected on Raptor’s View? Between the 3 observers 105 species were seen. This is a good total for the time of year and given the restricted movement – we were limited to our own properties (about 1 ha) each. There were few records of migrant species, with those on the list (e.g. European Bee- eater, Levaillant’s Cuckoo) being seen in the first few days of the lockdown – late leaving migrants.
Limiting our sampling area excluded observations in other diverse habitats within the whole reserve and so it is hard to extrapolate to a total for Raptor’s View – we know we missed species such as African Goshawk and Tambourine Dove both of which we know occur on Raptor’s. We also acknowledge that our sampling was not done using a structured or common protocol – we collected data when we could in an ad hoc manner.
This accounts for most of the variance in the species seen as most of the differences are of species that were observed flying – for example, eagles, waterbirds (none of us have any water body on our properties) and aerial feeders such as swifts and swallows. If the observer happened to look up at the right time the list grew!
By doing some basic analysis of the data (and this is not statistical by any stretch of the imagination) we were surprised by the differences between the 3 sites. Only 54 species were common to all three sites – about 51% overlap – which is surprisingly low, given that the habitats are fairly similar Combretum-Acacia woodlands. Again, this is probably a result of observer bias and styles. Derek mainly used sound recordings, Chris tended to spend a lot of time birding in the early morning and late afternoon in between the house maintenance and helping with children’s education. Jeremy scanned the skies and surrounding bush on frequent occasions each day, as well as keeping a keen ear out for calls.
We tried a simple analysis of the similarity of the three sites. Derek and Jeremy (about 1.4 km apart) were the most similar with 64 species in common. They had 8 species (Derek) and 17 species (Jeremy) that one saw but the other did not. This gave a similarity index of around 0.84 – pretty high (using a simple measure called Sorensen’s Coefficient). Chris was about 1.05 km north of Derek and they had 60 species in common, with differences of 11 (Derek) and 15 (Chris) species. The least similar where Jeremy and Chris – about 2.5 km apart – they shared 57 species but had 23 (Jeremy) and 21 (Chris) not found in the other persons list (SC of 0.73). It is difficult to be certain of why there are these differences – but as with most endeavors of this type most differences are generally accounted for by observer bias and the way the data was collected.
Species totals by two observers over the 21 day lockdown period:
The broad trends are similar showing a decline in totals during a period of cool, wet and windy weather around Day 12 – 14. The highest totals for both observers was on the same day following a positive change in the weather – we all know birds respond like this and so in this case did the observers – “thank goodness that miserable weather is over, let’s get out there!”
The surprising thing for all three observers was the paucity of birds of prey over the 21 days. We all missed African Hawk Eagle even though they breed near Derek’s house (were they hiding or is Derek just sleeping longer than he admits to?!), no Dark Chanting Goshawk, only 1 accipiter was seen (Shikra) and we never really got good thermals in nearly 3 weeks (blame the weather!).
So back to the original question – how many species are there on Raptor’s View Estate? The list for the estate is 262 – and our current total accounts for about 40% of that. Our observations include very few migrants, no regional rarities and no vagrants. We cannot start to extrapolate the current data but we can get a reasonable idea of what happens on the estate at this time of the year.
The daily totals can be used to give an indication of relative abundance with the commonest species such as Southern Red-billed Hornbill, Laughing Dove, Ring-necked Dove and Blue Waxbill observed on 85-100% of the days.
However, the observations of the rarer species (the one-offs) are not really indicative of much other than the fact that the species occurs here. For example, seeing a small group of Yellow-billed Stork flying overhead does not tell us how often they might be in Raptor’s View at suitable habitat. Actual numbers of individual species over a period of time would give a far better indication of abundance (and hence setting conservation goals and priorities) – and could be a great way to spend our time during the next lockdown!
See the list HERE.
Extended Lockdown Birding
Needless to say, the extended period of recording (another 2 weeks up to the end of April) combined with records from other residents helps to paint a new picture and many thanks to the 11 residents who submitted their records for this lock down period. Despite the limitations of only recording birds seen or heard around each homestead, 158 species of birds were recorded during this 5 week period. This represents 60% of the 262 species on the estate checklist. Jeremy Brown ended with 92 species, Chris Hines 105 species, but Joel Roerig, overlooking Osprey Dam, topped this with a whopping 111.
It is not surprising that three species of dove (Ring-necked or Cape Turtle, Laughing and Emerald-spotted Wood Dove) together with Southern Red-billed and Yellow-billed Hornbill were amongst the most commonly recorded. Grey Hornbill was recorded several times; and Joel saw a Trumpeter Hornbill flying over Osprey Dam. An uncommon record for the estate was Hugh Marshall’s Ground Hornbill recorded near the fenceline towards the bottom end of the estate. Woodpeckers were well represented with regular sightings of Bearded, Cardinal and Golden-tailed on most properties.
In many cases both Bearded Scrub Robin and White-browed Scrub Robin dominated the dawn chorus and there were a few records of White-throated Robin-Chat in the riverine habitats. A Red-capped Robin-Chat next to Osprey Dam seen by Joel was an unusual record although over the years he has occasionally recorded it in the same habitat. It must have moved in from the forested areas close to the mountain.
Red-capped Robin Chat
(photo not taken on RV)
Both Retz’s and White-crested Helmetshrike were fairly regular visitors and at Derek’s home Retz’s was recorded almost every day with White-crested only appearing every 5-7days.
Several late migrants were recorded including Barn Swallow, House Martin, European Bee-eater, Alpine Swift, African Paradise Flycatcher, Wahlberg’s Eagle, Woodland Kingfisher, Jacobin Cuckoo and surprising numbers of Levaillant’s Cuckoo.
Birds of Prey
As mentioned in the 21-day report, diurnal raptors were generally scarce but other observers found both African Hawk Eagle and African Fish Eagle, the latter being quite vocal on various occasions. Neil and Nicky Swart hit the jackpot with 8 diurnal raptors – Black-chested Snake Eagle, Brown Snake Eagle, Bateleur, Martial Eagle with juvenile, Tawny Eagle, Dark Chanting Goshawk and the first records for the estate of Ovambo Sparrowhawk and Peregrine Falcon. Another great record was Black Sparrowhawk seen by Chris Gregory. Wahlberg’s Eagle, African and Gabar Goshawk, Shikra and African Harrier Hawk plus Cape, Hooded, Lappet-faced and White-backed Vulture brought this total to 20 species.
Peregrine Falcon – N&N Swart
Black-chested Snake Eagle – N&N Swart
Most nightbirds were recorded by sound with Fiery-necked Nightjar common at all sites. 7 species of owls included Verreaux’s and Spotted Eagle Owl, Southern White-faced Owl, African Scops Owl, African Barred Owlet and Pearl-spotted Owlet with records of Western Barn Owl by two observers. Bronze-winged Courser was another exciting record with several residents hearing them on various occasions.
Common Buttonquail (male)
L Gutteridge (not taken on RV)
Although not a nightbird, the hooting sound of the Common Buttonquail was recorded on various occasions – they were most vocal in the early evening or at dawn. It was interesting to observe the crepuscular behaviour of certain species with Fork-tailed Drongo and Southern White-crowned Shrike calling actively most evenings until almost completely dark, and let’s not forget the Ring-necked Dove that calls regularly in the dark, particularly on moonlit nights.
Listen to the Common Buttonquail:
Spotted Eagle Owl – N&N Swart
Bronze-winged Courser – L Gutteridge
(not taken on RV)
Ali Joy living on the edge of Hamerkop Dam and Joel Roerig on Osprey Dam kept a close eye on the various birds associated with these habitats, recording 24 water or water-associated species. Several other residents also submitted records for some of these species recorded mainly when flying overhead. African Spoonbill were seen at both Osprey and Hamerkop Dam.
African Black Duck – D Solomon
Seven species of duck included a Hottentot Teal and the African Black Duck that has been hanging around Osprey Dam for some time, an interesting sighting as it is mainly a duck of rivers and fast flowing streams.
Storks were well represented with records of Saddle-billed, Woolly-necked, Yellow-billed, and most importantly Black Stork, the latter an uncommon species now regarded as vulnerable in South Africa. Probably the most exciting record was Joel’s sighting of a female Painted Snipe at Osprey Dam that spent most of the day hiding under branches or exposed roots.
Black Stork – A Joy
African Spoonbill – A Joy
See the Extended Lockdown Bird List HERE.
With thanks to Jeremy Brown, Chris Hines, Derek Solomon, Chris Gregory, Pam Zirkel, Neil & Nicky Swart, Joel Roerig, Hugh & Julie Marshall, Ali Joy, Martin & Lynne Hopkins and Mirjam Albertse.