Bokmakierie Newsletter of the Witwatersrand Bird Club April 2015 No 242 ND RA S R E T B A U L W T C I W D IR B BirdLife SOUTH AFRICA Giving Conservation Wings Ernst Retief, Regional Conservation Manager BLSA, received the beaded Bearded Vulture award at the 2015 AGM - photo by Lia Steen Barbi Forsyth receiving the Diamond award at the AGM- photo by Lia Steen WITWATERSRAND P O Box 641 BIRD CLUB Cresta 2118 Tel: 011 782 7267 ISSUE NO 242 Fax: 086 512 7696 APRIL 2015 Email: [email protected] Web: www.witsbirdclub.org.za Inside this issue: 30 Birding in the Hawaan Forest by Anthony Cavanagh 2 Letter from the Chair 32 Rare pipits return following rat erad- 3 A Murder of Crows by Arjan Amur ication on South Georgia – Wildlife Extra 5 Pied Crows are Brill by Leslie 34 Birding by calls by Peter and Sandra Cornish Greaves 6 Jy kan help om aasvoëls van uitwiss- 36 Nylsvley 2015 Woodland Census, 16th ing te red deur VulPro Year by Warwick Tarboton 8 An Anecdote on Ringing by Arie Wl- 38 Rarities and unusual sightings report: liams December 2014 compiled by André 8 A Nesting Log in Waverley by Freda Marx Kirschner 9 A Christmas Holiday in Germany by Anthony Cavanagh 2015 Committee: 13 South Africa’s Favourite Bird by Mark Anderson Honorary President Lance Robinson 14 Counting Birds by Rolf Wiesler Chairman Andy Featherstone 16 Letter to the Editor and John Camp- Vice-Chairman Lia Steen bell’s Observations on Birds in 1820 Treasurer Leanne Webster by Desmond Cole Courses Janice Isom 20 Trackers show Vultures on decline by Kamcilla Pillay Conservation Lance Robinson 23 Carrion Crows in Spain thrive when Evening Meetings Lia Steen they have a cuckoo in the nest - Website Thinie v d Merwe Wildlife Extra Programme Ginny Mes 25 Four Tswana bird tales by Des- mond Cole Club Secretary Lauraine Leigh 29 Extracts from the Korsman Conserv- ancy Member’s Newsletter Febru- ary 2015 Cover Photo: Blue Crane Chick by Cover Design: Philip Tarboton Albert Froneman 1 Letter Lia Steen will be this year’s Vice-Chairman. Murrie Slotar was given a warm farewell From at the Marievale outing and braai or- ganised in her honour. As a parting gift The Murrie was given an original painting of a Bokmakierie by Graeme Arnott. We wish Chair her all the best in her new life in Durban. Thank you Barbi Forsyth, Ginny Mes and Dear Members, Lance Robinson for all the hard work in or- Although it seems a long time ago, I trust ganising and catering for the day. everyone had a relaxing break over the As many of you are aware we decided to holiday period and perhaps managed to try a new venue for our evening meetings fit in a little birding activity of some kind. and held our first one at St Stithian’s School. I had family visiting from the UK and we The security and parking are much supiri- spent a very enjoyable week in Cape or to Delta Park which has sadly been a Town in early January with the obligatory little neglected of late. There will be chal- visit to the penguins for the visitors. Whilst at lenges to overcome at St Stithians but I the penguin colony in Betty’s Bay we wit- would like to urge you to come and try nessed the release of a number of young the venue and see what it is like. It was not fledglings that had been rescued from par- ideal changing during the course of our first ents who had stopped feeding them due Programme and this led to some people to the onset of their moult. It seems that going to the wrong venue despite it being when penguins breed late in the season widely publisized in our Weekly Reminder. there is a danger of this happening and For those of you who were affested by this, these young birds would normally die. please accept my apologies. As our 2015 Calendar Competition proved popular and the calendar well received, we have decided to run another competi- tion this year for a 2016 version. So all you budding Albert Fronemans dust of your cameras and start snapping!, Full details of the competition will be circulated shortly. It is always interesting to receive letters and articles from our members and it was The AGM has been and gone and the 2015 a real pleasure to recieve two submissions Committee duly elected. Janice Isom and from one of our elder statesmen, Desmond Thinie van Der Mewre have joined the Cole. A recent new member to the club Committee taking over the courses and is cartoonist Alastair Findlay who has sent website portfolios respectively. Lance Rob- in an example of his humour. Keep them inson was duly elected as Honorary Pres- coming everybody! ident taking over from Murrie Slotar and Andy Featherstone 2 eating their defenceless chicks,” said study A Murder of Crows? co-author Dr Arjun Amar [note 2] from By Dr Arjun Amar the Percy FitzPatrick Institute of African Ornithology [note 3]. “Although this pre- dation is entirely natural, these observa- tions can be upsetting to witness and often leave people wondering if these pred- ators might be reducing bird numbers.” “Our review suggests that we should be cautious before jumping to conclusions over the impacts these species may have. Just because a predator eats something occa- sionally does not always mean that they have an impact,” Dr Amar said. However, Pied Crow he cautioned that there was no informa- tion for the southern hemisphere, where The Pied Crow population has increased songbirds raise fewer chicks each year. in many parts of South Africa, and with The study, the first of its kind, reviewed this increase has come concern over their all published evidence on whether pre- potential impact on other native wildlife. dation by corvids actually reduces the A new study by researchers at the Uni- overall breeding performance of birds or, versity of Cape Town suggests that, more importantly from a conservation at least for bird species, the unpopular perspective, reduces their numbers. Data crow may not be as big a menace as were collated from 42 studies of cor- people think. Their review found that vid predation conducted in Europe and crows – along with their avian cous- North America over the last sixty years. ins the Eurasian Magpie and Northern Not only were corvids unlikely to have Raven – have surprisingly little impact any impact on their potential prey spe- on the abundance of other bird species. cies, if there was an impact it most of- Collectively known as corvids, these ten affected the breeding success of birds are in fact being menaced by the prey species rather than their sub- mankind in the mistaken belief that re- sequent numbers. Half of cases found moving them is good for conservation. that corvids reduced breeding success whereas less than 10% found that they Published this week in the leading or- nithological journal Ibis (note 1), the study reduced prey numbers in the long term. found that in the vast majority of cas- The review analysed the impact of six cor- es (82 percent), corvids had no impact vid species on prey species including game- at all on their potential prey species. birds, songbirds, waders, herons, cranes, sea “Many nature lovers have been distressed birds, waterfowl and raptors. The 42 stud- to witness a crow or magpie raiding the ies used in the review included 326 cases of nests of songbirds, stealing their eggs or corvid–bird prey interaction The impacts 3 were determined partly by comparing 3. The Percy FitzPatrick Institute bird counts before and after corvids were for African Ornithology is a re- either removed or their numbers reduced. search institute situated in the Bi- ological Sciences Department of Mistaken assumptions about corvid pre- Cape Town University. It is one of dation were possibly explained by the the world’s leading ornithological birds’ diurnal nature and the fact that research institutes and is a South they are conspicuous nest predators: “Their African Department of Science importance in prey population regula- and Technology-National Research tion is often assumed prior to any assess- Foundation Centre of Excellence. ment of the evidence,” the study warned. 4. Chrissie Madden is the lead au- Chrissie Madden [note 4], the lead au- thor of the paper. The research was thor on the paper, hoped that the re- undertaken as part of her Conser- view would challenge the perception vation Biology Masters research that all corvids were bad, thereby pre- at the University of Cape Town. venting needless killing: “Our results sug- gest that this is a mistaken belief and • The full paper is freely avail- that generally speaking people would able via open access.The full ref- be wasting their time killing corvids to in- erence for the paper is: Madden, crease the numbers of other bird species”. C.F., Arroyo, B. & Amar, A. (in press) A review of the impact of Editor’s notes: corvids on bird productivity and 1. The Ibis is a peer reviewed sci- abundance, Ibis. doi: 10.1111/ibi.12223 entific journal published by the • http://onlinelibrary.wiley.com/ British Ornithological Union. It has journal/10.1111/%28ISSN%291474-919X/ been published since 1859 and is earlyview one of the highest ranked interna- tional Ornithological journals in the world. http://www.bou.org.uk/ibis/ DEADLINE FOR AUGUST 2015 2. Dr Arjun Amar is a Senior Lectur- ISSUE - 1st JULY 2015 er at the Percy FitzPatrick Institute Contributions, addressed to the Editor, and was the lead supervisor of this can be: research project.