Heronrymap:Africa - Mapping the Distribution and Status of Breeding Sites of Ardeids and Other Colonial Waterbirds in Africa

Heronrymap:Africa - Mapping the Distribution and Status of Breeding Sites of Ardeids and Other Colonial Waterbirds in Africa

Copyright © 2019. Harebottle, D. M. 2019. HeronryMAP:Africa - Mapping the distribution and status of breeding sites of Ardeids and other colonial waterbirds in Africa. Journal of Heron Biology and Conservation 4:1 [online] www.HeronConservation.org/JHBC/vol04/ art01/ HeronryMAP:Africa - Mapping the distribution and status of breeding sites of Ardeids and other colonial waterbirds in Africa # Douglas M. Harebottle Department of Biological and Agricultural Sciences, School of Natural and Applied Sciences, Sol Plaatje University, Private Bag X5008, Kimberley, South Africa; [email protected] Abstract Heronries in Africa are poorly studied and many data gaps are evident in terms of occurrence, species composition and productivity of these colonial breeding sites. This paper introduces HeronryMAP:Africa, a citizen-science project started in 2014 that aims to systematically collect long-term data on location, size and composition, site fidelity, longevity and conflict scenarios of heronries in Africa. Preliminary results are presented for current and historical sites sourced over a three year period (2014-2016). Three hundred and thirty-six colony sites were identified and mapped in 14 (25.9%) African countries; 72.6% of sites have no formal protection, 18.8% were subject to at least one human conflict scenario with ‘cut- ting of trees’ and ‘removal of trees’ being the most common human disturbances. A first, but presumably grossly underestimated total of 35,000 breeding pairs of colonial waterbirds in Africa is provided from available data. No species-specific nest data are given due to the tendency to report total nest numbers in mixed colonies rather than species-specific numbers. The study revealed a general paucity of data for heronries in Africa (there was no response from 74.1% of African countries), but also the challenges faced in collecting adequate scientific data for these sites. It did, however, show how citizen-science can make significant contributions to research projects that are poorly funded or have limited resources. Human-wildlife conflicts were highlighted as an area that is poorly understood for heronries but has im- portant conservation outcomes. Future objectives include identification of species composition, assess- ment of priority sites, identification of conservation action for colonies under threat and production of an Atlas of African Heronries. Key words: Africa; colonial waterbirds; heronries; HeronryMAP:Africa; human-wildlife conflict; moni- toring. # This paper was presented at the 1st Herons of the World Symposium at the 40th Anniversary Meeting of the Waterbird So- ciety at New Bern, North Carolina, USA, 21-23 September 2016. Other papers from that Symposium have appeared in past (or will appear in future) issues of the Journal of Heron Biology and Conservation, and Waterbirds. Journal of Heron Biology and Conservation 4:1, page !2 Introduction 2002, Stier 2018, Yanosky 2018) and Australia (Maddock and Baxter 1991, Richardson et al. Waterbirds that breed communally in freshwater 2001, McKilligan 2005). However, gaps do exist or coastal systems are spread across eight bird and in Africa, information on the status and dis- families: Phalacrocoracidae, Anhingidae, Pele- tribution of heronries is severely lacking; it is canidae, Ardeidae, Ciconiidae, Threskiornithidae, limited mainly to Southern and Eastern Africa Phoenicopteridae and Laridae (Perennou et al. (Tarboton 1977, Underhill et al. 2009, Turner 1996, Clements et al. 2017). Most of these wa- 2011, Kopij 2014). Some data have been collect- terbirds breed in large colonies, either loosely or ed through atlas projects (Tanzania Bird Atlas; N. in close association; however, some species are Baker in litt.), waterbird surveys (Botswana; solitary nesters, e.g. Goliath Heron (Ardea go- Tyler 2001, Madagascar; Wetlands International liath) and White-backed Night Heron (Gorsachius 2012, Dodman 2014, Rabarisoa et al. (in review)) leuconotus) (Hancock and Kushlan 1984, del and some dedicated efforts of individual re- Hoyo et al. 1992). Colonies may be largely dis- searchers (Turner 2002, J. Agutu unpubl. data, C. crete (e.g., pelicans, gulls, terns and cormorants) Barlow in litt.). However, most of these studies or mixed (e.g., ibises, herons, egrets and spoon- were short-term or of an irregular nature. Cur- bills) (Hancock and Kushlan 1984, Perennou et rently, only a single long-term monitoring pro- al. 1996). However, some species such as the gram (1993 to present) for heronries in Africa is White-breasted Cormorant (Phalacrocorax luci- known to the author (Rabarisoa et al. (in da) and Reed Cormorant (Microcarbo africanus) review)). As a result, there is a gap in the knowl- are also known to frequently nest in extensively edge of the importance of these African sites in mixed flocks with Ardeids and Threskiornithids terms of location, species composition, abun- (DMH pers. obs.). The term ‘heronry’ usually dance, breeding productivity and site manage- refers to breeding sites where Ardeid species nest ment (Perennou et al.1996, Kushlan et al. 2002). in mixed colonies (British Trust for Ornithology 2018); however, for the purpose of this paper, I HeronryMAP:Africa was born out of a heron will use this term to refer to breeding colonies for banding project that started in 2002 in Cape the colonial species concerned. Town, South Africa (Harebottle and Gibbs 2004, 2006) and the general paucity and limited nature Due to their conspicuous behavior, abundance of information on heronries in South Africa (Tar- and often socio-economic and ecological im- boton 1977, Perennou et al. 1996, Veen et al. pacts, the general distribution and basic biology 2011). The project was officially launched on 1 of most of these taxa have been well studied August 2014 through social media with the cre- globally (Hancock and Kushlan 1984, Brooke ation of a web page via Facebook - ‘HeronryMAP: and Birkhead 1991, Kushlan and Hafner 2000, Africa’. Kushlan and Hancock 2005). Continentally, stud- ies are generally well distributed: in Europe The objective of this paper is to introduce Heron- (Hafner and Fasola 1997, Marchant et al. 2004, ryMAP:Africa as a continent-wide, citizen-sci- British Trust for Ornithology 2018), Asia (Hong ence based monitoring project for African heron- Kong Bird Watching Society 2016, Mashiko and ries; preliminary results on the status and distrib- Toquenaga 2018, Matsunaga 2018) North Ameri- ution of current and historical heronries in Africa ca (Gawlik et al. 1998, Spies and Weingartner are presented for 31 species (Appendix 1) and 2007, Maccarone et al. 2010, Rush et al. 2015, gaps in research and conservation interventions Cox et al. 2017), South America (Kushlan et al. are identified and discussed. Journal of Heron Biology and Conservation 4:1, page !3 Methods or human-related conflict issues were sourced by the author where these were not or could not be The study area for this paper was the entire con- provided by the respondent or observer. tinent of Africa, the island of Madagascar and smaller offshore islands including Cape Verde, Madeira Islands, Zanzibar, Comoros, Sao Tome Results and Principe. Data were collected from various sources including surveys from ornithologists, Spatial distribution and numbers heron researchers and bird club members; addi- A total of 336 heronry sites was mapped from 14 tional information was sourced from nest record countries across Africa (Table 1, Fig. 1); no dis- cards (Animal Demography Unit, University of tinction was made between colonies being mixed Cape Town; unpubl. data), academic or popular or discrete. Most records (n=238, 70.8%) were literature and from personal observations. The from southern Africa. Almost a quarter of the HeronryMAP:Africa web page was used exten- sites (n=73, 21.7%) were located in East Africa sively to request data and collate records and in- (including Madagascar), while 24 sites (7.1%) formation about heronries throughout Africa, es- occurred in West Africa, including the Cape pecially South Africa; all researchers and ob- Verde Islands. Only one site (0.3%) was reported servers were encouraged to post records and up- for Northern Africa (Mauritania, Table 1). No load images of active heronries. Standardized data were received from central Africa. Nearly datasheets, available on the site, were provided half (45.8%) of localities (154/336) were record- for participants to use in uploading their data in a ed from South Africa; the next largest representa- standardized format (Appendix 2). Any incidental tions were from Kenya (32 sites), Uganda (29), information relating to breeding sites that was Botswana (26), Lesotho (22), Zimbabwe (21) and posted directly on the page was transferred to a The Gambia (21) (Table 1, Appendix 3). database. Based on available data from submitted and Data were grouped into current sites, 2012-2016, sourced records for active heronries, a prelimi- which had census data and historical sites, nary estimate of 35,000 breeding pairs was calcu- pre-2012 which included sites with census data lated from the 319 sites (out of 336 total sites) for and those which were reported as active but lack- which there were numerical data (Table 1); the ing census data. The reason for selecting 2012 as estimate assumes that all historical sites (i.e. prior a cut-off to separate ‘current’ from ‘historical’ to 2012; n=162) have remained active with simi- heronries is based on heronry dynamics; natural lar colony sizes that were initially reported. Sev- heronry sites generally persist for a few (2-3) enteen sites were shown to be active prior to years (due to natural variable landscape fluctua- 2012 but lacked actual nest data. Most survey tions or changes) before being abandoned responders did not indicate any species specific (Perennou 1996, Underhill et al. 2009), therefore numbers within a heronry; unfortunately, no veri- five years (prior to the final year of data gather- fied species-specific breeding numbers are yet ing for this study, 2016) would be a reasonable available in this study. amount of time to isolate recent, active colonies from older colonies that may have abandoned Protection status preferred sites and moved to other optimal sites.

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