Underhill LG, Loftie-Eaton M and Navarro R. 2018. Dragonflies and damselflies of the Western Cape – OdonataMAP report, August 2018. Biodiversity Observations 9.7:1-21
Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701 South Africa; Biodiversity and Development Institute, 25 Old Farm Road, Rondebosch, 7700 South Africa
Megan Loftie-Eaton
Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701 South Africa; Biodiversity and Development Institute, 25 Old Farm Road, Rondebosch, 7700 South Africa
Rene Navarro
Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701 South Africa; FitzPatrick Institute of African Ornithology, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701 South Africa
What is this document about, and for whom was it written?
This paper is about the Odonata (dragonflies and damselflies) of the Western Cape. It contains a summary of the information in the combined database of the OdonataMAP project and the ODA initiative. It provides a species list for the province. It gives instructions that enable the reader to obtain up-to-date distribution maps for each species, and to obtain up-to-date lists of species for quarter degree grid cells in the Western Cape.
The main users will be the citizen scientists who collect photographic data of dragonflies and damselflies and submit it to OdonataMAP. We believe the information contained here will be useful for planning purposes, and to guide citizen scientists to the areas within the Western Cape where the data needs are greatest.
The paper also aims to provide a model for the presentation of biodiversity data in such a way that can be used by managers and policy makers, by researchers, and by conservation advocacy NGOs. For these groups of people it aims (1) to provide a snapshot, at a point in time, of the quality and volume of data available for the Western Cape, and (2) to provide links to the relevant databases, so that they have access to useful summaries of the ongoing data collection effort. The data can clearly be repackaged in many different formats (for example, species lists for individual sites, such as nature reserves). The aim here is to provide a broad brush overview at the provincial level.
What are the headlines?
In the two-year period 1 July 2016 to 30 June 2018, citizen scientists added seven species to the list of dragonflies and damselflies in the Western Cape, bringing the total to 76 species (Figure 1).
The database available for this report contained 11,267 records of dragonflies and damselflies. This includes the specimen record dating back to the start of the 20th century.
Of these records 2,433 records (22%) were added between July 2016 and June 2017, and 4,202 (37%) between July 2017 and June 2018.
Thus 59% of the entire Western Cape database of records of dragonflies and damselflies was contributed by citizen scientists in two years.
Where is the study area?
The Western Cape is a province of South Africa, situated on the southwestern section of the country (Figure 2). Of South Africa’s nine provinces, it is the fourth largest with an area of 129,449 km2. The Western Cape is the third most populated province, with an estimated 6.5 million inhabitants in 2017 (Statistics South Africa 2017).
The Western Cape Province is roughly L-shaped, extending northward and eastward from the Cape of Good Hope, in the southwestern corner of South Africa. It stretches 400 km northward along the Atlantic Ocean coast, about halfway to Namibia, and 500 km eastward along the south coast, ending at Natures Valley on the Indian Ocean. It is bordered on the north by the Northern Cape and on the east by the Eastern Cape.
The province has large variation in rainfall, with the eastern end, bordered by the warm Indian Ocean, being almost forest, and the northern end, bordered by the cold Atlantic Ocean, being semi-desert. This wet-dry gradient has a strong influence on the distribution of Odonata within the province. The other major factor in Odonata distribution is a series of almost linear ranges of mountains, roughly parallel to the coast, but at varying distances from it.
There are 262 quarter degree grid cells (Figure 2) which are entirely or partly within the Western Cape. 186 are entirely within the Western Cape. 76 are partly within the Western Cape; 52 are shared with the Northern Cape, 22 are shared with the Eastern Cape, and there are two which are shared between the three provinces (3124CA Winterhoekberge and 3124CC Winterhoek). This report is based on all 262 grid cells which are “in” the Western Cape.
What data are available for the dragonflies and damselflies in the Western Cape?
On 14 August 2018, there were 11,267 records of Odonata in the combined database of OdonataMAP and the Odonata Database of Africa (ODA), recorded since 1980 for Western Cape (Table 1). These were the records strictly within the boundaries of the Western Cape. Of these, 8,938 (80%) had been submitted by citizen scientists as photographic records and the balance were from ODA.
The Odonata Database of Africa (ODA) is an open access database developed by a JRS-funded project (Clausnitzer et al. 2012, Dijkstra 2016). It contains records of the distribution of dragonflies and damselflies across Africa and includes most of the museum specimen records for the region. It is available online as the African Dragonflies and Damselflies Online (ADDO) (http://addo.adu.org.za/). ADDO is a collaboration between the Department of Conservation Ecology and Entomology (University of Stellenbosch) and the ADU (University of Cape Town). Although the two databases are separate, search queries made to the OdonataMAP database can include a search of the Odonata Database of Africa. This was done for this report. This collaboration represents a major consolidation of data resources.
The records in the database are georeferenced, often to an accuracy of metres. But for the purposes of this report each record has been allocated to its “quarter degree grid cell”, a well-known mapping standard in South Africa, which has been used for many biodiversity atlases. The quarter degree grid cells are defined on a geographical grid, and are 15 minutes of latitude north to south, about 27 km, and 15 minutes of longitude east to west, about 25 km at the latitude of the Western Cape (Figure 2). Each quarter degree grid cell has a six-character code, and a name, usually that of a town (or farm) in the grid cell. Exact localities are not disclosed in this report, but are available to anyone with a bona fide need for them.
The Western Cape section of the database has seen spectacular growth over the past two years: 2,433 records were added between July 2016 and June 2017, and 4,202 between July 2017 and June 2018. The total for the six-year period from 2010 to June 2016 was 2,275 records (Loftie-Eaton et al. 2018). In percentages, 22% of the database was added in the 2016/17 year, and 37% in the 2017/18 year. Thus 59% of the 11,267 records in the Western Cape database was contributed by citizen scientists in two years.
Table 1: The 76 species of Odonata (dragonflies and damselflies) in the Western Cape based on the combined databases of OdonataMAP and ODA (see text). The species are sorted first by family, then genus and species names. The Red List (RL) classification of the species is that of Samways and Samaika (2016) and the eight species in threat categories are in boldface. The quantitative information is the number of quarter degree grid cells, in the parts strictly within the Western Cape each species has been recorded in since 1980 (QDGC), and the number of records of the species (N). The final column gives the last date on which the species was recorded, prior to 14 August 2018, when this table was created from the database.
Family
Species code
Scientific name
Common name
RL
QDGC
N
Last recorded
Aeshnidae
664070
Anaciaeschna triangulifera
Evening Hawker
LC
6
6
23/01/2017
Aeshnidae
664120
Anax ephippiger
Vagrant Emperor
LC
2
3
15/05/2017
Aeshnidae
664140
Anax imperator
Blue Emperor
LC
66
350
30/07/2018
Aeshnidae
664170
Anax speratus
(Eastern) Orange Emperor
LC
23
83
05/04/2018
Aeshnidae
664180
Anax tristis
Black Emperor
LC
1
2
01/01/2005
Aeshnidae
664470
Pinheyschna subpupillata
Stream Hawker
LC
27
126
18/03/2018
Aeshnidae
664510
Zosteraeschna minuscula
Friendly Hawker
LC
30
75
14/04/2018
Chlorocyphidae
661180
Platyypha caligata
Dancing Jewel
LC
2
2
12/03/2018
Chlorocyphidae
661210
Platycypha fitzsimonsi
Boulder Jewel
LC
13
100
27/02/2018
Coenagrionidae
662330
Africallagma glaucum
Swamp Bluet
LC
45
202
27/07/2018
Coenagrionidae
662370
Africallagma sapphirinum
Sapphire Bluet
LC
2
3
20/12/2013
Coenagrionidae
662470
Agriocnemis falcifera
White-masked Wisp
LC
6
12
16/12/2017
Coenagrionidae
662630
Azuragrion nigridorsum
Sailing Bluet
LC
21
72
04/05/2018
Coenagrionidae
662720
Ceriagrion glabrum
Common Citril
LC
41
301
15/05/2018
Coenagrionidae
663100
Ischnura senegalensis
Tropical Bluetail
LC
87
859
08/08/2018
Coenagrionidae
663160
Proischnura polychromatica
Mauve Bluet
EN
3
45
21/10/2017
Coenagrionidae
663260
Pseudagrion citricola
Yellow-faced Sprite
LC
11
21
06/02/2018
Coenagrionidae
663300
Pseudagrion draconis
Mountain Sprite
LC
38
254
01/04/2018
Coenagrionidae
663350
Pseudagrion furcigerum
Palmiet Sprite
LC
36
329
30/04/2018
Coenagrionidae
663410
Pseudagrion hageni
Painted Sprite
LC
5
48
26/03/2018
Coenagrionidae
663460
Pseudagrion kersteni
Powder-faced Sprite
LC
43
245
05/06/2018
Coenagrionidae
663820
Pseudagrion massaicum
Masai Sprite
LC
28
160
29/05/2018
Coenagrionidae
663560
Pseudagrion salisburyense
Slate Sprite
LC
3
3
03/12/2009
Coenagrionidae
663880
Pseudagrion sublacteum
Cherry-eye Sprite
LC
1
1
04/05/2018
Gomphidae
664550
Ceratogomphus pictus
Common Thorntail
LC
31
121
08/04/2018
Gomphidae
664560
Ceratogomphus triceraticus
Cape Thorntail
NT
20
58
14/02/2018
Gomphidae
665740
Paragomphus cognatus
Rock Hooktail
LC
38
202
12/03/2018
Gomphidae
665790
Paragomphus genei
Common Hooktail
LC
11
18
21/04/2018
Lestidae
660360
Lestes plagiatus
Highland Spreadwing
LC
7
35
04/05/2018
Lestidae
660330
Lestes tridens
Spotted Spreadwing
LC
3
4
08/04/2018
Lestidae
660300
Lestes virgatus
Smoky Spreadwing
LC
5
21
06/06/2018
Libellulidae
667030
Brachythemis leucosticta
Southern Banded Groundling
LC
1
1
30/04/2017
Libellulidae
667130
Crocothemis erythraea
Broad Scarlet
LC
83
712
06/07/2018
Libellulidae
667140
Crocothemis sanguinolenta
Little Scarlet
LC
46
259
05/06/2018
Libellulidae
667200
Diplacodes lefebvrii
Black Percher
LC
16
60
27/04/2018
Libellulidae
667690
Nesciothemis farinosa
Eastern Blacktail
LC
21
154
01/04/2018
Libellulidae
667780
Orthetrum abbotti
Little Skimmer
LC
1
1
01/01/2004
Libellulidae
667860
Orthetrum caffrum
Two-striped Skimmer
LC
49
244
15/05/2018
Libellulidae
667890
Orthetrum capicola
Cape Skimmer
LC
61
1002
03/08/2018
Libellulidae
667900
Orthetrum chrysostigma
Epaulet Skimmer
LC
22
31
22/06/2018
Libellulidae
667950
Orthetrum julia
Julia Skimmer
LC
40
125
23/03/2018
Libellulidae
668000
Orthetrum machadoi
Highland Skimmer
LC
1
1
01/01/1991
Libellulidae
668120
Orthetrum trinacria
Long Skimmer
LC
37
150
22/04/2018
Libellulidae
668180
Palpopleura deceptor
Deceptive Widow
LC
1
1
23/03/2017
Libellulidae
668190
Palpopleura jucunda
Yellow-veined Widow
LC
13
25
12/03/2018
Libellulidae
668230
Pantala flavescens
Wandering Glider
LC
15
32
22/06/2018
Libellulidae
668370
Rhyothemis semihyalina
Phantom Flutterer
LC
5
11
14/03/2018
Libellulidae
668420
Sympetrum fonscolombii
Red-veined Darter or Nomad
LC
77
531
09/08/2018
Libellulidae
668540
Tetrathemis polleni
Black-splashed Elf
LC
2
2
01/04/2018
Libellulidae
668620
Tramea basilaris
Keyhole Glider
LC
3
3
21/03/2014
Libellulidae
668630
Tramea limbata
Ferruginous Glider
LC
27
106
22/06/2018
Libellulidae
668660
Trithemis annulata
Violet Dropwing
LC
6
31
06/07/2018
Libellulidae
668670
Trithemis arteriosa
Red-veined Dropwing
LC
81
963
31/05/2018
Libellulidae
668800
Trithemis donaldsoni
Denim Dropwing
LC
2
3
05/01/2017
Libellulidae
668870
Trithemis dorsalis
Highland Dropwing
LC
31
104
18/05/2018
Libellulidae
668890
Trithemis furva
Navy Dropwing
LC
58
370
05/06/2018
Libellulidae
669120
Trithemis kirbyi
Orange-winged Dropwing
LC
44
103
30/06/2018
Libellulidae
668900
Trithemis pluvialis
Russet Dropwing
LC
10
79
09/04/2018
Libellulidae
669080
Trithemis stictica
Jaunty Dropwing
LC
40
286
05/05/2018
Libellulidae
669180
Urothemis assignata
Red Basker
LC
1
8
03/05/2018
Libellulidae
669390
Zygonyx natalensis
Blue Cascader
LC
20
63
27/02/2018
Libellulidae
669420
Zygonyx torridus
Ringed Cascader
LC
1
1
18/01/2018
Libelluloidea incertae
666270
Syncordulia gracilis
Yellow Presba
VU
7
82
19/11/2017
Libelluloidea incertae
666280
Syncordulia legator
Gilded Presba
VU
7
28
21/10/2017
Libelluloidea incertae
666290
Syncordulia serendipator
Rustic Presba
VU
3
13
28/03/2016
Libelluloidea incertae
666300
Syncordulia venator
Mahogany Presba
VU
10
34
22/02/2018
Macromiidae
666620
Phyllomacromia picta
Darting Cruiser
LC
6
10
18/11/2012
Platycnemididae
661480
Allocnemis leucosticta
Goldtail
LC
23
162
05/04/2018
Platycnemididae
661790
Elattoneura frenulata
Sooty Threadtail
LC
28
240
18/03/2018
Platycnemididae
661810
Elattoneura glauca
Common Threadtail
LC
31
85
27/02/2018
Platycnemididae
662140
Spesbona angusta
Ceres Streamjack
EN
4
71
30/11/2017
Synlestidae
660070
Chlorolestes conspicuus
Conspicuous Malachite
LC
19
135
22/04/2018
Synlestidae
660120
Chlorolestes fasciatus
Mountain Malachite
LC
5
5
30/03/2018
Synlestidae
660130
Chlorolestes tessellatus
Forest Malachite
LC
12
118
14/05/2018
Synlestidae
660080
Chlorolestes umbratus
White Malachite
LC
23
305
03/08/2018
Synlestidae
660150
Ecchlorolestes nylephtha
Queen Malachite
NT
12
67
06/06/2018
Synlestidae
660160
Ecchlorolestes peringueyi
Rock Malachite
NT
10
99
21/03/2018
Table 2: The number of records of Odonata for each of 157 quarter degree grid cells in the Western Cape, South Africa. The six-character codes for the grid cells are given and the official names of the 1:50,000 map sheets for the grid cell. The final column gives the total number of records available for the grid cell for which identifications have been made at species, genus or family level. The third column gives the number of species in each grid cell, and the fourth column the number of records that were identified to species level. The fifth column provides a count of the overall number of taxa, including species, genus and family.
QDGC
QDGC Name
Species
Records
Taxa
Total
3118AD
Kliphoek
1
1
2
2
3118BB
Douse The Glim
2
2
2
2
3118BC
Wolwenes
1
1
1
1
3118BD
Grootdrif
1
2
1
2
3118CA
Papendorp
1
1
1
1
3118CB
Lutzville
8
9
8
9
3118CC
Doringbaai
1
1
1
1
3118DA
Van Rhynsdorp
7
14
7
14
3118DB
Urionskraal
8
27
9
28
3118DC
Klawer
7
11
7
11
3118DD
Bulshoek
11
15
13
18
3119AC
Nieuwoudtville
13
45
17
53
3119CA
Lokenburg
1
2
2
3
3119CC
Doringbos
4
6
4
6
3124CC
Winterhoek
4
4
4
4
3217DD
Vredenburg
1
1
1
1
3218AB
Lambert’s Bay
2
2
2
2
3218AD
Elandsbaai
6
6
6
6
3218BA
Graafwater
1
1
1
1
3218BB
Clanwilliam
21
39
22
41
3218BC
Redelinghuys
1
1
1
1
3218BD
Oliewenboskraal
12
18
15
24
3218CB
Aurora
2
2
2
2
3218CC
Velddrif
3
3
3
3
3218CD
Bergrivier
2
4
2
4
3218DA
Goergap
4
4
4
4
3218DB
Eendekuil
1
1
1
1
3218DC
Moravia
1
1
1
1
3218DD
Piketberg
8
19
9
20
3219AA
Pakhuis
26
154
31
166
3219AB
Uitspankraal
6
9
6
9
3219AC
Wuppertal
28
103
31
110
3219AD
Grootberg
25
39
25
39
3219BC
Elandsvlei
7
7
7
7
3219BD
Middeldrif
1
1
1
1
3219CA
Citrusdal
23
48
24
51
3219CB
Grootrivier
23
76
24
77
3219CC
Keerom
21
38
21
38
3219CD
De Meul
5
6
7
8
3219DC
Groenfontein
5
7
5
7
3219DD
Kareekolk
2
3
2
3
3220DB
Komsberg
1
1
1
1
3220DC
Kruispad
4
6
4
6
3221DD
Fraserburg Road
1
1
1
1
3222AB
Rosedene
1
1
1
1
3222AC
Paalhuis
3
3
3
3
3222AD
Klipbank
4
4
4
4
3222BA
Kuilspoort
1
1
1
1
3222BB
Renosterkop
3
4
4
5
3222BC
Beaufort West
8
18
8
18
3223AA
Nelspoort
1
1
1
1
3223AD
Oorlogspoort
1
1
2
3
3223BA
Toorfontein
15
26
20
32
3224AA
Toorberg
0
0
1
1
3318AA
Saldanha Bay
5
12
6
13
3318AC
Yzerfontein
2
2
2
2
3318AD
Darling
2
4
2
4
3318BA
Mooreesburg
6
11
7
12
3318BB
Porterville
6
7
6
7
3318BC
Malmesbury
7
10
7
10
3318BD
Riebeek-Kasteel
20
42
21
43
3318CB
Melkbosstrand
7
15
7
15
3318CD
Cape Town
27
377
30
404
3318DA
Philadelphia
5
10
5
10
3318DB
Paarl
26
77
29
80
3318DC
Bellville
25
182
30
193
3318DD
Stellenbosch
42
357
48
382
3319AA
Groot-Winterhoek
22
70
23
71
3319AB
Gydopas
4
4
5
5
3319AC
Tulbagh
27
43
28
44
3319AD
Ceres
39
155
40
156
3319BA
Baviaanshoek
2
4
2
4
3319BB
Inverdoorn
8
10
8
10
3319BC
De Doorns
11
14
11
14
3319CA
Bain’s Kloof
43
573
49
591
3319CB
Worcester
35
109
37
111
3319CC
Franschhoek
38
389
43
396
3319CD
Villiersdorp
33
134
34
135
3319DA
Nuy
9
10
9
10
3319DB
Koo
10
17
10
17
3319DC
Langvlei
5
7
5
7
3319DD
Robertson
19
43
19
43
3320AC
Touwsrivier
1
1
1
1
3320AD
Bloutoring
5
6
5
6
3320BA
Matjiesfontein
2
2
2
2
3320BC
Fisantekraal
1
2
1
2
3320CB
Allemorgens
4
6
4
6
3320CC
Montagu
10
13
10
13
3320CD
Scheepersrus
10
28
10
28
3320DA
Kareevlakte
3
3
3
3
3320DB
Plathuis
2
2
2
2
3320DC
Barrydale
17
25
19
27
3320DD
Warmwaterberg
7
10
8
11
3321AC
Vleiland
4
4
5
5
3321AD
Ladismith
33
85
33
85
3321BC
Matjiesvlei
14
22
17
26
3321BD
Kruisrivier
1
1
1
1
3321CA
Algerynskraal
4
4
4
4
3321CB
Van Wyksdorp
1
1
1
1
3321CC
Muiskraal
1
1
1
1
3321DA
Calitzdorp
7
7
9
13
3321DB
Vleirivier
1
1
1
1
3321DC
Langberg
5
6
5
6
3321DD
Attakwaskloof
1
1
1
1
3322AA
Prince Albert
1
1
1
1
3322AC
Kangogrotte
15
54
19
62
3322AD
Rosselerf
7
11
9
15
3322BA
Seekoegat
1
1
1
1
3322BC
De Rust
3
4
3
4
3322CA
Oudtshoorn
8
11
8
11
3322CB
Dysselsdorp
14
41
15
44
3322CC
Jonkersberg
22
60
26
65
3322CD
George
27
144
31
170
3322DA
Stompdrift
18
49
21
58
3322DB
Buffelsdrif
1
1
1
1
3322DC
The Wilderness
41
594
48
633
3322DD
Karatara
39
354
42
377
3323AC
Barandas
10
15
10
15
3323AD
Willowmore
5
7
5
7
3323BC
Willowmore (East)
4
4
4
4
3323CA
Uniondale
4
4
4
4
3323CC
Kruisvallei
40
383
47
422
3323CD
The Crags
32
111
36
115
3323DA
Voorkloof
1
1
1
1
3323DC
Nature’s Valley
46
594
52
612
3418AB
Cape Peninsula (central)
21
239
26
269
3418AD
Cape Peninsula (Cape Point)
16
42
16
42
3418BA
Mitchells Plain
16
38
16
38
3418BB
Somerset West
36
2166
49
2230
3418BD
Hangklip
42
1212
51
1268
3419AA
Grabouw
36
116
38
118
3419AB
Caledon
16
39
17
40
3419AC
Hermanus
21
52
22
53
3419AD
Stanford
22
117
25
122
3419BA
Greyton
33
179
39
195
3419BB
Riviersonderend
10
21
11
23
3419BC
Jongensklip
2
2
2
2
3419BD
Napier
6
6
6
6
3419CB
Gansbaai
15
82
18
89
3419DA
Baardskeerdersbos
7
9
8
10
3419DD
Elim
2
2
2
2
3420AA
Stormsvlei
1
1
1
1
3420AB
Swellendam
40
177
44
184
3420AD
Wydgelee
3
6
3
6
3420BB
Heidelberg
15
23
15
23
3420BC
Malgas
6
11
6
11
3420CA
Bredasdorp
11
14
11
14
3421AB
Riversdale
1
1
1
1
3421AC
Vermaaklikheid
9
10
9
10
3421AD
Stilbaai
16
51
16
51
3421BA
Albertinia
1
1
1
1
3421BB
Herbertsdale
2
2
2
2
3422AA
Mosselbaai
27
219
32
269
3422AB
Pacaltsdorp
6
12
6
12
3422BB
Sedgefield
18
122
22
130
3423AA
Knysna
22
86
23
88
3423AB
Plettenberg Bay
21
59
22
60
Of the 262 quarter degree grid cells “in” the Western Cape, there is at least one species of dragonfly or damselfly for 157 (60%) of them (Table 1, Figure 3). The total number of records submitted for these grid cells was 11,885 (Table 2), reflecting the fact that there were 618 records in the sections of the 74 grid cells which were part of the Northern Cape or Eastern Cape.
From this database, a total of 76 Odonata species were recorded in the Western Cape (Table 1). The Cape Skimmer Orthetrum capicola had the most, 1002, records; the most recent observation was on 3 August 2018, 11 days prior to the data extraction for this report (Table 1). The second most abundant species was Red-veined Dropwing Trithemis arteriosa with 963 records, followed by Tropical Bluetail Ischnura senegalensis (859), Broad Scarlet Crocothemis erythraea (712) and Red-veined Darter Sympetrum fonscolombii (531). There were 26 species with between 100 and 500 records, and 23 with between 20 and 99 records. The five species with between 10 and 18 records, and the 18 species with fewer than 10 records were all given careful consideration, with checks to confirm identifications. Eight of the 76 species recorded in the Western Cape were in IUCN Threat Categories (Table 1).
Two quarter degree grid cells had more than a thousand records: 3418BB Somerset West had 2,230 and 3418BD Hangklip had 1,268 (Table 2), both on the eastern side of False Bay. There were 25 grid cells with 100 or more records, and 57 with between 10 and 99 records.
How many new species been added to the Western Cape list recently?
Amazingly, seven species of Odonata were added to the Western Cape list in the most recent two years, 2016/17 and 2017/18.
There are three records of the Vagrant Emperor Anax ephippiger in the Western Cape. They come from two quarter degree grid cells: two records, in April and May 2017, from distinct sites within 3219AA Pakhuis in the northern Cederberg range; one record, in May 2017, in quarter degree grid cell 3418BB Somerset West (Figure 1). The nearest record to these is in the Great Karoo in the Northern Cape, from quarter degree grid cell 3022CA Garskolk near Carnarvon, made in December 2016. There are five records in the Eastern Cape in three quarter degree grid cells: from west to east these are from 3324DD Hankey in March 2017, three from 3325DC Port Elizabeth in May 2017, November 2017 and February 2018, and from 3237CB Stutterheim, an older record from March 2006.
The Spotted Spreadwing Lestes tridens also has four Western Cape records, all at the eastern end of the Western Cape, with a scattering of records in the adjacent part of the Eastern Cape. The Western Cape records, arranged from west to east are in three quarter degree grid cells 3322CD George in April 2018, 3322DC The Wilderness in December 2016 (two records), and 3423AB Plettenberg Bay in January 2018 (Figure 4). Over the border in the Eastern Cape, there are six records from quarter degree grid cell 3424BA Kruisfontein (with Oyster Bay as a more well-known locality within the grid cell) dated between January and April 2017, one record from the adjacent quarter degree grid cell 3424BB Humansdorp in September 2014, six records from quarter degree grid cell 3325CC Loerie dated between December 2017 and April 2018. There are four more records between Port Elizabeth and East London, then a gap to the KwaZulu-Natal border, and many records in the start of the core of the distribution, along the KwaZulu-Natal coast.
There are eight records of Red Basker Urothemis assignata in the Western Cape, all made in the quarter degree grid cell 3322DD Karatara, immediately north of Sedgefield (Figure 5). The eight records were made by three observers at two localities between February and May 2018. There is a single record in the Eastern Cape (quarter degree grid cell 3325DC Port Elizabeth) made in May 2017. There are multiple records in coastal KwaZulu-Natal.
The Denim Dropwing Trithemis donaldsoni has three Western Cape records from two quarter degree grid cells, which are both in the interior: 3119CC Doringbos, north of the Cederberg range, in November 2016, and 3321BC Matijesvlei, north of Calitzdorp (two records in January in 2017). There are no records for the Eastern Cape and a single record for the Northern Cape in 2823DA Danielskuil, northwest of Kimberley, in January 2017. This record is itself vastly out of the known range, in the savanna biome in the northeast of South Africa.
The first Western Cape record of the Cherry-eye Sprite Pseudagrion sublacteum was made in January 2018 in quarter degree grid cell 3323DC Nature’s Valley, close to the border with the Eastern Cape. There are seven records of Cherry-eye Sprite from five quarter degree grid cells in the western half of the Eastern Cape in the database, all dated 2014 or later; the suggestion is that the distribution of this species is moving westwards from KwaZulu-Natal through the Eastern Cape and has recently reached the Western Cape.
The single record of Southern Banded Groundling Brachythemis leucosticta for the Western Cape was made in April 2017, in quarter degree grid cell 3320CC Montagu (Figure 6). The nearest records are in the western Eastern Cape, with four records in quarter degree grid cell 3325CD Uitenhage, west of Port Elizabeth. There is a thin scattering of records along the Eastern Cape coast, all dating from 2012 or later, suggesting that the distribution of Southern Banded Groundling is expanding westwards along the coast from KwaZulu-Natal.
The single record of Deceptive Widow Palpopleura deceptor for the Western Cape was made in March 2017, in quarter degree grid cell 3319BB Inverdoorn, south of the Cederberg range, north of Ceres. There is a single record for the Eastern Cape, from quarter degree grid cell 3129CB Tombo (near Port St Johns) and there are eight records, from four quarter degree grid cells for KwaZulu-Natal.
There are two alternative explanations of the occurrence of these species in the Western Cape. They have been present for decades, but have been overlooked until the proliferation of citizen science observers and observations associated with OdonataMAP. Alternatively, these are genuine range expansions. Many bird species have, during various decades of the past 50 years, extended their ranges westwards into the Western Cape. Well known examples are Hadeda Ibis Bostrychia hagadash and Fork-tailed Drongo Dicrurus adsimilis (Ainsley et al. 2016, Second Southern African Bird Atlas Project unpubl. data). Perrisnotti et al. (2011) reported on range expansions in South Africa between 1980s and the 2002 of some conspicuous insects: fruit chafers (Coleoptera, Scarabaeidae, Cetoniinae), longhorn beetles (Coleoptera, Cerambycidae) and butterflies (Lepidoptera, Rhopalocera). All except one of the eight species they considered showed range expansions of the order of 500-800 km from KwaZulu-Natal in the direction of the Western Cape along the coastline. Although the evidence is anecdotal, it seems that the Golden Orb-web Spider (or Black-legged Nephila) Nephila fenestra expanded its range westwards reaching the Cape Peninsula in the first 10 years of the 21st century, and have become abundant.
How do I obtain lists of species for quarter degree grid cells?
Up-to-date lists of the species recorded in a quarter degree grid cell can be obtained from the following link: https://www.slideshare.net/Animal_Demography_Unit/how-to-create-a-species-list-from-the-virtual-museum-data The list of grid cell codes is provided in Table 1. In the link below, replace the “locus” with the code for the QDGC required (consult also Figure 2). The link below provides the species list for the quarter degree grid cell 3219AA Pakhuis, in the northern Cederberg:
This link provides a map of the quarter degree grid cell, a list of the species recorded in it, the number of records for each species and the date of the most recent record. In addition, you can look at all the details for all the individual records of a species. It is also possible to get the list of all the records for the quarter degree grid cell. These are presented in batches of 30 records. This feature is particularly useful if there is a relative handful of records for a grid cell, and you want to see the details for all of them at once.
How up-to-date is the database?
In Table 1, the most recent date on which each of the 77 species has been recorded in the Western Cape is provided in the last column. The median of these dates was 5 April 2018; in other words, half of the species recorded in the Western Cape have been recorded there since 5 April, in the most recent four months prior to the download of the database for this. Of the 77 species, 59 species had last been recorded in the Western Cape during 2018 and a further 10 during 2017 (Table 1). This is a remarkable achievement. Seven of the eight species in IUCN threat categories had most recently been recorded in 2017 or 2018, and one Rustic Presba Syncordulia serendipator was last recorded in March 2016 (Table 1, Figure 8).
In the same way as the up-to-dateness of the provincial database can be assessed using the median of the most recent date for each species, this same approach can be applied to individual quarter degree grid cells. This median date is calculated and presented whenever the species list for a grid cell is downloaded (see section above). Special fieldwork attention needs to be paid to quarter degree grid cells for which the median date is more than three years from the present. For example, quarter degree grid cell 3223BA Toorfontein, in the Great Karoo near Murraysburg, contains 15 species, but their median date is 24 January 2013, more than five years ago. The species list for this grid cell can be downloaded using http://vmus.adu.org.za/vm_locus_map.php?vm=OdonataMAP&locus=3223BA
Are there species which have not been recorded in recent years?
For four species, the most recent record was prior to 2010. All these records come from the Odonata Database for Africa, and are supported by specimens, mostly curated in the Stellenbosch University Entomology Collection.
The Highland Skimmer Orthetrum machadoi has been recorded only once in the Western Cape, in 1991, in quarter degree grid cell 3219CB Grootrivier, in the southern Cederberg range. Until 2017, the nearest records to this one were in KwaZulu-Natal. However, in February 2017, Highland Skimmer was recorded in the western Eastern Cape, in QDGC 3325CB Uitenhage North (http://vmus.adu.org.za/?vm=OdonataMAP-30854), and seven further records have been made from this locality.
There is a single record of Little Skimmer Orthetrum abbotti for the Western Cape, made in 2004 in quarter degree grid cell 3421AC Vermaaklikheid, along the south coast. There are OdonataMAP records for this species in five grid cells of the Eastern Cape, two of which are near Port Elizabeth (3325CC Loerie, four records in May 2018, and 3325CB Uitenhage North, 16 records between November 2017 and April 2018).
Both Western Cape records of the Black Emperor Anax tristis were made in 2005 in quarter degree grid cell 3418BD Hangklip, which includes the village of Bettys Bay. The nearest record was made in quarter degree grid cell 2930CB Pietermaritzburg in KwaZulu-Natal in 1991, with recent records slightly to the northeast (2830DA Collessie in November 2012 and 2831DA Nkwalini in January 2018).
There are three records of the Slate Sprite Pseudagrion salisburyense in the eastern half of the Western Cape: in quarter degree grid cells 3321AD Ladismith in 2005, in 3322CA Oudtshoorn in December 2009 and in 3323DC Nature’s Valley in April 2008. There is a scattering of records throughout the Eastern Cape.
The continued occurrence of these four species in the Western Cape needs confirmation. The first place to search is at the location of the original discovery.
What are the priority areas for data collection in the Western Cape?
There were 156 quarter degree grid cells in, or partially in, the Western Cape with at least one species of dragonfly or damselfly identified to species level (Table 2, Figure 3). The largest number of species record in a quarter degree grid cell was 46 (in 3323DC Nature’s Valley, at the eastern limit of the province (Figure 2). 13 quarter degree grid cells had 36 or more species, and are shaded brown in Figure 3, and a further 12 had between 24 and 35 species, and were shaded dark green-brown in Figure 3.
These 25 quarter degree grid cells are characterised by areas of rugged and mountainous terrain. The grid cells of the mountains of the Boland, immediately east of Cape Town, show consistently large species richness, as do the mountains along the Garden Route in the eastern edge of the Western Cape. The intervening mountain ranges have patchy coverage. In simplistic terms, there are ranges of mountains to the south and the north of the Little Karoo. The main range to the south is the Langeberg; the quarter degree cell 3420AB Swellendam which lies along this axis has 40 species. The range to the north is known as the Groot Swartberge; within this range, quarter degree grid cell 3321AD Ladismith has 33 species. This gap, between the eastern and western ends of the Western Cape, probably represents the biggest challenge of fieldwork in the province, in the summer of 2018/19.
The second biggest challenge lies north of the mountains of the Boland, towards the Cederberg, and northwards along the Escarpment immediately inland of Vanrhynsdorp.
The third challenge is the Great Karoo, where the majority of the quarter degree grid cells without any coverage lie. The fact that quarter degree grid cell 3223BA Toorfontein, south of Murraysberg, has a list of 15 species (Table 2) is indicative of what is achievable in the Great Karoo.
The fourth coverage challenge lies in the Swartland and Overberg regions north and east of Cape Town, respectively. Large parts of these regions are almost totally transformed to agriculture, with complete loss of natural habitats to fields of wheat and canola, to vineyards and to orchards. A sensible strategy in these areas would be to increase the number of records per quarter degree grid cell to at least 50, and preferably 100, and to examine the species accumulation curves. Three candidate quarter degree grid cells in the Swartland, chosen only because they are conveniently close to Cape Town, are 3318DA Philadelphia (five species, 10 records), 3318BC Malmesbury (seven species, 10 records) and 3318BA Moorreesburg (six species, 12 records) (Table 2).
Any quarter degree grid cell in the Western Cape with fewer than 100 records should be regarded as a priority. That excludes only 25 grid cells (Table 2). Even for the grid cells with large volumes of data, every record should be submitted to the OdonataMAP database. There are three reasons for this: (1) it “refreshes” the record for the species, confirming the continued presence of the species in the grid cell; (2) it is only in the grid cells with the most data that studies of changes in species composition through time are going to be feasible; (3) every record contributes to our understanding of the “phenology” (the flight period) of the species. Studies of phenology require large data volumes.
How do I go about participating in data collection for this project?
In a nutshell, the protocol is simple. Take photos of dragonflies and damselflies, and upload them to the OdonataMAP section of the Virtual Museum website. There is no need to identify the species in the photograph. This gets done by an expert panel.
There is a slideshow entitled “How to shoot your dragon” at https://www.slideshare.net/Animal_Demography_Unit/how-to-shoot-your-dragon
Taking photographs of dragonflies and damselflies is less challenging than most people anticipate. Most individuals have a perch which they return to routinely after each foraging flight and generally remain on the perch for long enough for several photographs to be taken, from different angles. The foraging flights seldom last for more than a few minutes, so a measure of patience is required. Each time they land, they tend to perch differently, so this provides an opportunity to take photographs at several angles. The entire spectrum of cameras are in use; the most versatile for this type of photography are the new generation of “compact” cameras
Before you can upload into the Virtual Museum you need to register as a citizen scientist. The procedure for doing this is described here: https://www.slideshare.net/Animal_Demography_Unit/how-to-register-as-a-citizen-scientist-with-the-animal-demography-unit
Once you are registered you logon to the website using your email address and password. A “Data upload” section now becomes visible. The critical information that needs to be uploaded into the database is date, place and a series of one to three photographs of a single species, usually different angles on the same individual. Guidance on the upload process is provided in this slideshow: https://www.slideshare.net/Animal_Demography_Unit/how-to-submit-records-to-the-virtual-museums
The expert panels for each project consists of taxon experts and the most experienced citizen scientists. For OdonataMAP, many records get confirmed identifications within a week. Some records take longer, and for some photographs a positive identification to species level is not possible. Records are sometimes identified to genus or family level. Some species can readily be identified from a poor, even partially blurred photograph. At the other extreme a few species can only be identified in the hand. As a beginner participant, the best strategy for a positive confirmed identification is to submit the best one, two or three photographs, preferably from different angles. The most important parts of the dragonfly or damselfly to get in sharp focus are the thorax and a wing.
There is an exceptional fieldguide to the dragonflies and damselflies of South Africa. It was written by Warwick and Michèle Tarboton. It is called A Guide to the Dragonfllies and Damselflies of South Africa, and published by Struik Nature. It describes and illustrates 164 species of Odonata recorded in South Africa at the time of publication (Tarboton & Tarboton 2015). It is widely available in good bookshops, and an ebook version is also available (see https://www.warwicktarboton.co.za/Dragonfly%20Book.html).
Acknowledgements
Many friends and colleagues made helpful suggestions which improved this report: Sharon Stanton, Eugene Moll, John Wilkinson, Alan Manson, Warwick Tarboton and Lappies Labuschagne. Pete Laver prepared the maps. We acknowledge funding from the JRS Biodiversity Foundation, Seattle, USA. But above all, we celebrate the amazing contributions made by the citizen scientists responsible for 80% of the data upon which this report is based.
References
Ainsley J, Underhill LG, López Gómez M, Brooks M 2016. Bird distribution dynamics 8 – Hadeda Ibis Bostrychia hagedash in South Africa, Lesotho and Swaziland. Biodiversity Observations 8.6: 1-10. Available online at https://journals.uct.ac.za/index.php/BO/article/view/404Clausnitzer V, Dijkstra K-DB, Koch R, Boudot J-P, Darwall WRT, Kipping J, Samraoui B, Samways MJ, Simaika JP, Suhling F 2012. Focus on African freshwaters: hotspots of dragonfly diversity and conservation concern. Frontiers in Ecology and the Environment 10: 129-134.
Dijkstra, K-DB 2016. African Dragonflies and Damselflies Online. (Version 1 July 2016). Available online at http://addo.adu.org.za .
Loftie-Eaton M, Underhill LG, Navarro R 2018. OdonataMAP: progress report on the atlas of the dragonflies and damselflies of Africa, 2016/17 and 2017/18. Biodiversity Observations.
Perissinotto R, Pringle EL, Giliomee JH 2011. Southward expansion in beetle and butterfly ranges in South Africa. African Entomology 19: 61-69.
Samways MJ, Simaika JP 2016. Manual of Freshwater Assessment for South Africa: Dragonfly Biotic Index. Suricata 2. South African National Biodiversity Institute, Pretoria.
Statistics South Africa 2017. Mid- year population estimates. Available online at http://www.statssa.gov.za/publications/P0302/P03022017.pdfTarboton W, Tarboton M 2015. A Guide to Dragonflies and Damselflies of South Africa. Struik Nature, Cape Town.
Underhill LG, Navarro R, Manson AD, Labuschagne JP, Tarboton WR 2016. OdonataMAP: progress report on the atlas of the dragonflies and damselflies of Africa, 2010-2016. Biodiversity Observations 7.47: 1-10. Available online at https://journals.uct.ac.za/index.php/BO/article/view/340