Masai Giraffe (Giraffa Camelopardalis Ssp. Tippelskirchi)
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Masai Giraffe (Giraffa camelopardalis ssp. tippelskirchi) Appendix 1. Masai Giraffe Range and Population Estimates (Historic through Current) KENYA For Kenya there are data from the counties that encompass the majority of the range of the Masai Giraffe: Kajiado County which includes Amboseli, Chyulu Hills, and Nairobi National Parks and adjoining pastoral lands, Narok County including the Masai Mara National Reserve and surrounding pastoral lands, Taita Taveta including Tsavo National Park, Kilifi, Kitui, Kwale, Tana River, Machakos/Makeuni Counties, and the Nakuru Wildlife Conservancy (NWC) - a collection of 33 wildlife holdings including three national parks (Hell’s Gate, Mt. Longonot and Lake Nakuru) and private reserves (Ogutu et al. 2017). Most data are from aerial sample counts from the Directorateof Resource Surveys and Remote Sensing of Kenya (DRSRS). Time periods covered were 1977 to 2015 (2014 for Taita Taveta, Tana River,Kajiado and Narok, 2015 for Kitui and Machakos/Makueni, and 2013 for Kilifi and Kwale). Data from NWC are bi-annual ground counts, conducted in all units of the conservancy by Kenya Wildlife Service (KWS) and the conservancy members from 1996 to 2015.Data were compiled, analysed and provided to us by Joseph O. Ogutu, University of Hohenheim, Germany. Masai Giraffe declines have been dramatic in most regions of Kenya in recent decades (Table 1). Giraffes in Narok, Kilifi, Kitui, Tana River and Machakos/Makeuni County declined by 76-88% (Figures 3, 6, 7, 9, 10), Kajiado and Kwale Counties experienced roughly 50% declines (Figures 1, 8), and Giraffe numbers in Taita Taveta County declined by 5.2% (Fig. 4). Only in the NWC were Giraffe numbers stable or increasing, in total increasing by 190% from approximately 280 to 811 in the period 1996 to 2015 (Table 1, Fig. 5). All told Masai Giraffe numbers in these regions of Kenya declined from approximately 32,000 to 12,000, a 63% reduction, in approximately 38 years, a reduction of nearly two-thirds of its Masai Giraffes since 1977 (Table 1). THE IUCN RED LIST OF THREATENED SPECIES™ Table 1. Masai Giraffe numbers in areas of southern Kenya mean mean County 1977-80 2011-2014 Change % change Taita Taveta 2,407 2,282 -125 -5.2 Narok 7,982 1,925 -6,057 -75.9 Kajiado 9,613 4,678 -4,935 -51.3 Kilifi 1,163 136 -1,027 -88.3 Kitui 3,387 393 -2,994 -88.4 Kwale 517 261 -256 -49.5 Tana River 5,751 1,155 -4,596 -79.9 Machados/Makeuni 511 114 -397 -77.7 1996-98 2013-15 Nakuru Wildlife 280 811 531 189.9 Conservancy Kenya Totals 31,611 11,755 -19,856 -62.8 Data source: Jospeh O. Ogutu For several of these regions there are recent published analyses describing substantial land-use change and human population growth in recent decades. Kajiado County. Wildlife in Kajiado reside in the protected areas and the much larger area of Maasai group ranches. Ogutu et al. (2014 and references therein) describe broad changes in land use and population within the group ranches. Human population has increased from 85,903 in 1969 to 406,054 in 1999 and to 687,312 in 2009; an annual rate of increase of ~4% (Ogutu et al. 2014). These include increases in cultivation, particularly in wetlands, fencing, sedenterization and individual land tenure among pastoralist Maasai. These changes have led to a more uniform human presence across the landscape as bomas disaggregate. The result is that livestock numbers have generally declined, but their spatial distribution has increased. This corresponds with the decreasing population size (Fig. 1) and spatial distribution of Masai Giraffes and most other wild ungulates in the county (Ogutu et al. 2014). The trends within specific areas of the county have been even more dramatic. Ogutu et al. (2013) analysed data for the Athi-Kaputiei ecosystem that includes Nairobi National Park and the plains to the south. There Giraffe numbers have declined by 84% from 1977 to 2011 (602 to 94 estimated individuals; Fig. 2). Interestingly, Giraffe numbers within the national park have remained reasonably stable at approximately 100 individuals. A photographic mark-recapture survey in March 2014 estimated the park population at 119 +/- 48 (Wildlife Direct 2014).Reid et al. (2008) and Said et al. (2016) have described in detail the habitat loss and fragmentation in this system. Narok County. This includes the Kenyan portion of the Serengeti-Mara Ecosystem and includes the Masai Mara National Reserve and the Maasai group ranches to the north on the Mara, Siana and Loita Plains. In the northern Loita Plains, the high end of the regional rainfall gradient, extensive areas have been leased for large-scale mechanized wheat farming. In the remaining group ranch areas similar changes are occurring as in other areas of Kenya. Lamprey and Reid (2004) estimate human populations on Koyiaki group ranch, one of the larger and more important wildlife ranches, increased at an annual rate of 4.4%. Related, livestock per capita has declined and the number of households has increased, as has the spatial distribution of permanent settlements. Individual land tenure has increased as has subsistence agriculture among the Maasai. Estimates of Masai Giraffe population size have declined from 7,982 to 1,925 during the period 1977 to 2014 (Fig. 3 and Ogutu et al. 2011 and Ogutu et al. 2016). Taita Taveta County. All of Tsavo West and much of Tsavo East National Parks are within this county. This region has received much less attention from researchers than has Narok and Kajiado counties, however, Mbau (2013) recently analysed land use change in the wildlife dispersal area to the west of Tsavo West NP over the period 1987- 2011. She found an approximate tripling of agricultural land during this period and a reduction of forest by 11%, woodland by 55% and shrublands by 17%. Human population growth was 3% annually to a density of 105 individuals/km2. However, Giraffe decline has been less severe in this region declining 5%, from 2407 to 2282 over the period 1977-2014 (Fig. 4). Nakuru Wildlife Conservancy.NWC is a collection of 33 wildlife holdings including three national parks (Hell’s Gate, Mt. Longonot and Lake Nakuru) and private reserves totaling 1,417 km2. Wildlife management in the conservancy occurs under the umbrella of the Nakuru Wildlife Forum. The region has experienced rapid population growth, urbanization and expansion of commercial flower farms, the latter kicking off in the early 1980’s. The human population of Nakuru County increased more than three times in the period 1969-1999 and a further 74% from 1999 to 2009 (Ogutu et al. 2017). Human population density was 41/km2 in 1969, 158/km2 in 1999, and 214/km2 in 2009. Despite similar changes in land use and human population growth this was the only region that showed an increase in Masai Giraffe numbers in recent decades, from 280 to 811 individuals over the period 1996 to 2015 (Fig. 5).It is important to note that the time series from NWC begins much later than for the other areas (1996 versus 1977) and is likely that much of the wildlife of this region had been lost prior to the period of data collection due to expanding agriculture and urbanization. Reports from the first half of the 20th century (summarized in Ogutu et al. 2017) describe “one of the richest wildlife assemblages in East Africa.” The increases in Masai Giraffes and a number of other ungulate species (Ogutu et al. 2017) probably represents a degree of population recovery from lower levels that were reached in the late 1980’s early 90’s due to land use change and human population increase. Ogutu et al. (2017) conclude the recovery “has largely been due to the coordination and support provided to the landholders and land users by governmental, international and local non-governmental organizations operating under the umbrella of the Nakuru Wildlife Forum.” [note: Three of the NWC members Lake Nakuru National Park, Kigio and Soysambu Conservancy support the Rothschild’s Giraffe rather than the Masai Giraffe. Counts for these three areas are not included in the NWC totals presented in Table 1. However, the numbers presented in Fig. 5 from Ogutu et al. 2017, do include the Kigio and Soysambu Conservancy counts but not those from Lake Nakuru National Park.] Figure 1. Estimated Masai Giraffe numbers in Kajiado County, Kenya. Figure from Ogutu et al. 2014. In this figure and figures 3, 4, 6-10 the trend line and point-wise 95% CI (shaded band) are derived from an analysis of the time series of individual population estimates from aerial counts (see text for details of aerial counts).The points represent the individual population estimate for that survey. The trend was estimated with a multivariate semiparametric generalized linear mixed model with a negative binomial error distribution, a log link function and penalized cubic B-spline smoothing with a third order difference penalty. The modeled trend is based on the Giraffe counts but also reflects the covariance with the counts of other non-migratory, wild ungulates in the surveys. This multivariate trend estimation produces more precise estimates of the focal species trend because it allows for a trend component common to all species, which may be due to all species responding in a similar way to environmental trends such as land-use change or climatic variability (Ruppert et al. 2003), and a trend component specific to each species. The model is very flexible and allows for potentially curvilinear trends, irregularly spaced surveys, non-normality of the counts and variation in the variance of the counts with their mean.