Among the nine sub-species of giraffes, the Maasai giraffe is the most widespread and common in Northern and Southern Kenya. Although it’s considered by the IUCN to be a species of no conservation concern, they have been reported to have declined in some of their range areas mostly due to bush meat activities, habitat fragmentation and loss. There are also concerns recent climatic changes especially prevalence of droughts is increasingly becoming another threat to their survival. In this regard, this study examined the status and trend of the Maasai giraffe in the Kenya-Tanzania border after the 2007 to 2009 drought. Amboseli had the highest giraffe number (averaging 2, 062.5 ± 534.7 giraffes), followed by a distant Lake Natron area (725.8 ± 129.4 giraffes), Magadi/Namanga (669.5 ± 198.0 giraffes), and lastly West Kilimanjaro area (236.5 ± 47.8 giraffes). Further, the proportion of giraffes were highest in Amboseli (55.09% ± 5.65%) followed by Lake Natron area (20.98% ± 3.42%), Magadi/Namanga area (16.35% ± 3.83%), and lastly West Kilimanjaro (7.58% ± 2.12%). But in terms of population growth after droughts, giraffe had positive growth in all locations in the borderland, with Magadi leading (+339.82 ± 329.99) followed Lake Natron area (+37.62 ± 83.27), Amboseli area (+38.11 ± 7.09), and lastly West Kilimanjaro (+3.21 ± 57.95.27). Their wet season population and density was much higher than that of the dry season. However, though the species was widely spread in the borderland, they seemed to avoid the region between Lake Magadi and Amboseli which is traversed by the Nairobi-Namanga highway both in wet and dry season. There is a need to develop a collaborative management framework for cross-border conservation to enhance their protection, conservation and genetic linkage.
In Africa, giraffes are found widespread south of the Sahara Desert particularly in eastern, southern and central parts of the continent [
Giraffes are exclusive browsers, mainly focusing on nutritious young and new tree and shrub shoots, but Acacia trees are their favorite source of forage [
There are nine different sub-species of giraffes living in various parts of Africa ([
The Maasai Giraffe (Giraffa camelopardalis tippelskirchi) which is the focus of this article was formerly widespread in the arid and drier regions of the Southern and Northern Savanna of Africa [
Although the population of the Maasai Giraffe is considered by the IUCN (International Union for Conservation of Nature) to be stable compared to other sub-species, they have been eliminated in most of their former range in the last century [
Thus, this research focused on the population status and distribution of the Maasai Giraffe in Northern Tanzania and Southern Kenya borderland as a result of the 2007 to 2009 drought. Although, the sub-species occupies a niche which gives it an ecological advantage over other browsers, drought conditions can compromise their food resource base making them vulnerable to physiological challenges associated with food and even water shortages [
The overall objective of this research was to establish the current status of the giraffe population and its recovery after the severe 2007 and 2009 droughts in the Kenya-Tanzania borderland. The specific objectives were to:
Specifically, this study examined the following objectives:
1) Evaluate the population status and distribution of the Maasai giraffe;
2) Examine the effects of 2007 to 2009 droughts on its population and recovery;
3) Assess seasonal changes in Maasai giraffe density and distribution;
4) Elaborate implications for giraffe conservation in the Kenya-Tanzania borderland.
The Amboseli-West Kilimanjaro and Magadi-Natron cross-border landscape, as comprises of various ecologically linked areas of Kenya and Tanzania, and is characterized by a high endowment of diverse wildlife species (
Amboseli region lies in the Southern part of Kenya, along the international border with Tanzania, and occupies an area of nearly 8797 Km2 (
ter resources, with a few scattered rivers, springs and swamps whose water is supplied through underground hy- drological system associated with Mt. Kilimanjaro [
Historically, the Amboseli area was predominantly occupied by the Maasai people who depended on pastoralism to meet their livelihood needs [
Typical vegetation in the region is influenced by the ecological conditions which are arid to semi-arid [
This landscape comprises of Meto, Torosei, Mbuko, Elangata Wuas, Olkiramatian, Lorngosua and Shompole ranches, which collectively cover about 5513 Km2 (
Ewaso Ngiro is the only permanent river though there are several other seasonal rivers like the Namanga and Esokota which originate from Namanga and Meto hills. The other main seasonal river is the Ol Kejuado that originates from Ilemelepo hills to the north west of Ibisil town and drains into river Kiboko.
The diverse physical features have led to spatial-temporal variation vegetation communities, but generally, the dominant woody species include a variety of Acacia spp., Commiphora spp. and Balanites spp. Key grasses include Chloris roxburgiana, Pennisetum stramenium, Pennisetum mezianum, Digitaria sp., Cynodon dactylon and Eragrostis sp. Rainfall is low, bimodal and highly variable, ranging between 400 - 600 mm, making pastoralism by the Maasai the most common land use [
The West Kilimanjaro covers an of nearly 3014 Km2 within the Longido District of Arusha, Tanzania, and the northern extent of the area is the Tanzania-Kenya border from Namanga southeastward to Irkaswa (
The area comprises of a complex mosaic of diverse communities, extensive grazing lands, and large agricultural fields at lower elevations on Mt. Kilimanjaro. There are traditional, agro-pastoral Maasai communities that graze livestock and raise subsistence crops. The area has several Protected Areas (PAs) in its neighborhoods, mainly; Kilimanjaro N. P (755 Km2) on the eastern boundary, Arusha N. P (137 Km2) to the south, and Amboseli N. P (392 Km2) in southern Kenya, 20 km north of the Tanzania-Kenya border. Other PAs in the West Kilimanjaro include Longido Game Controlled Area (GCA) (1700 Km2), and Ngasurai Open Area (544 Km2) which provide important habitats for wildlife. Additionally, there are two private conservation areas, West Kilimanjaro Ranch (303 Km2) and Endarakwai Ranch (44 Km2).
Although the area varies in elevation (1230 to 1600 m), the predominant ecological zone is semi-arid savannah interspersed with woodlands. There are extensive agricultural fields along the lower, western flank of Mt. Kilimanjaro, and lowland forests within the boundary of Kilimanjaro NP. Rainfall is unpredictable, especially at lower elevations, and highly variable from year to year. The average annual rainfall in the semi-arid lower elevations is 341 mm/year [
This landscape covers an area of about 7047 Km2, and lies west of the West Kilimanjaro area with its northern extent defined by the Tanzania-Kenya border (
For a many years since its creation, the Kenya Wildlife Service (KWS) has been undertaking total aerial counts of large herbivores using developed methods [
To improve the quality of data collected on the elephant population, both crew and planes were calibrated to aid in estimation of distance for subsequent calculation of observable strip width. Streamers were mounted on either side of the aircraft wings to create two strip categories, the inner and outer (
For each calibration made, test flights were conducted at the set altitude for streamers (300 Ft AGL) to determine how well the streamers fitted to the desired strip width on the ground. This was achieved by creating a flight line at 500 M and 250 M from a very straight and long (5 KMs) section of a road. When the aircrafts flew on this line, the road was either 500 M or 250 M from the plane and this allowed for evaluation of the streamers. To asses inter observer variability in estimation and enhance species identification, all observers were independently subjected to count a portion of the same block with different species of known numbers in mock flights.
The target landscape was divided into blocks based on visible features from the aircraft like hills, ridges and rivers which helped the pilots to easily navigate during flight (
voice recorders, GPS units and cameras, wildlife species identification, counting, estimation of herd sizes, data processing and handling. As noted by [
Counting of large herbivores was done in each block using a light aircraft which flew along East-West and North-South flight transects of 1 - 2 Km width depending on the visibility on the ground and nature of the terrain (
In addition to elephant data, the flight observers noted and recorded human activities mainly vegetation clearing, livestock grazing, human settlements and infrastructure development. These were considered to represent key changes in the landscape which threatened its ecological integrity and elephant conservation.
Only data for the dry period of 2010 and 2013 were used so that comparisons between similar census zones and for wet and dry season could be compared. Tallies, percentages, means and standard errors for the data were calculated using standard mathematical and statistical methods [
Chi-square goodness of fit and chi-square cross-tabulations were done to establish differences and the association between ostrich numbers and ecosystem areas; periods after (2010) and post drought (2013); and seasons (wet and dry) using SPSS statistical software. Statistical tests were considered significant if type 1 error (alpha) was less than 5% (0.05) [
Since the census areas (for both wet and dry season) for 2010 and 2013 were similar, the total numbers, density and percentages (proportions) of each species of the large mammals seen were reliable measures for comparison.
The Maasai giraffe was well represented in all the landscapes and ecosystems (protected areas and dispersal areas) along the Kenya-Tanzania borderland from the end of Tsavo-Mukomazi ecosystem to that of Natron- Magadi areas during the 2010 and 2013 censuses. Amboseli and its surrounding group ranches had the highest number of Maasai giraffe (
In terms of the proportion of giraffes in each area of the borderland counted (
Generally the Maasai giraffe populations seemed to be increasing in most locations from 2010 (after the drought of 2007-2007) in the 2013. Further, the wet season numbers and densities seemed to be increasing compared to the dry season within and between the years except for 2013 dry season when numbers in Lake Natron area and West Kilimanjaro were higher in dry season than in wet season (
The positive growth in giraffe density of Magadi was then followed by a distant Lake Natron area (+37.62 ± 83.27), but with high variability in density increase. The high variation in Lake Natron area density was possibly because the area witnessed a density decline between the wet season of 2010 and 2013. The next positive increase in density occurred in Amboseli area (+38.11 ± 7.09), with density increasing in both the wet and dry seasons. West Kilimanjaro had the lowest change (but positive) in giraffe density (+3.21 ± 57.95.27) partly because it had a decline in density between the wet season of 2010 and 2013 (
Considering changes in the proportion (%) of all borderland giraffe meta-population in each of the locations of the borderland between 2010 and 2013, similar trends were observed (
Location | Year | Season | Census Area (Km2) | Giraffe Numbers | Giraffe Density (per Km2) | Proportion (%) Giraffe Numbers in the Borderland |
---|---|---|---|---|---|---|
Amboseli and Surrounding Group Ranches | 2010 | Wet | 8797.00 | 2283 | 0.26 | 54.83 |
Dry | 8797.00 | 1053 | 0.12 | 59.02 | ||
2013 | Wet | 9214.44 | 3470 | 0.38 | 66.69 | |
Dry | 9214.44 | 1444 | 0.16 | 39.82 | ||
Overall (Mean ± SE) | - | 2062.5 ± 5.34 | 0.23 ± 0.06 | 55.09 ± 5.65 | ||
Magadi/Namanga Areas | 2010 | Wet | 5513.00 | 780 | 0.14 | 18.73 |
Dry | 5513.00 | 92 | 0.02 | 5.16 | ||
2013 | Wet | 6348.32 | 991 | 0.16 | 19.05 | |
Dry | 63.48.32 | 815 | 0.13 | 22.48 | ||
Overall (Mean ± SE) | - | 669.5 ± 198.0 | 0.11 ± 0.03 | 16.35 ± 3.83 | ||
West Kilimanjaro Area | 2010 | Wet | 3014.00 | 263 | 0.09 | 6.32 |
Dry | 3014.00 | 216 | 0.07 | 12.11 | ||
2013 | Wet | 3013.18 | 119 | 0.04 | 2.29 | |
Dry | 3013.18 | 348 | 0.12 | 9.60 | ||
Overall (Mean ± SE) | - | 236.5 ± 47.8 | 0.08 ± 0.02 | 7.58 ± 2.12 | ||
Lake Natron Area | 2010 | Wet | 7047.00 | 838 | 0.12 | 20.12 |
Dry | 7047.00 | 423 | 0.06 | 23.71 | ||
2013 | Wet | 7047.26 | 623 | 0.09 | 11.97 | |
Dry | 7047.26 | 1019 | 0.14 | 28.10 | ||
Overall (Mean ± SE) | - | 725.8 ± 129.4 | 0.10 ± 0.02 | 20.98 ± 3.42 |
Location | Season | Giraffe Density (per Km2) (mean ± SE) | Giraffe % Numbers in Location (mean ± SE) | Change (%) in Giraffe Density over 3 Years | Change (%) in Giraffe Proportion over the 3 Years |
---|---|---|---|---|---|
Amboseli and Surrounding Group Ranches | Wet | 0.32 ± 0.06 | 60.76 ± 5.93 | +45.11 | +51.99 |
Dry | 0.14 ± 0.02 | 49.42 ± 9.60 | +30.92 | +37.13 | |
Overall | 0.23 ± 0.06 | 55.09 ± 5.65 | +38.11 ± 7.09 | +44.56 ± 7.43 | |
Magadi and Namanga Areas | Wet | 0.15 ± 0.01 | 18.89 ± 0.16 | +10.33 | +27.05 |
Dry | 0.07 ± 0.06 | 13.82 ± 8.66 | +669.31 | +785.87 | |
Overall | 0.11 ± 0.03 | 16.35 ± 3.83 | +339.82 ± 329.49 | +406.46 ± 379.41 | |
West Kilimanjaro Area | Wet | 0.06 ± 0.02 | 4.30 ± 2.01 | −54.74 | −54.75 |
Dry | 0.09 ± 0.02 | 10.85 ± 1.26 | +61.15 | +61.11 | |
Overall | 0.08 ± 0.02 | 7.58 ± 2.12 | +3.21 ± 57.95 | +3.18 ± 57.93 | |
Lake Natron Area | Wet | 0.10 ± 0.02 | 16.05 ± 4.08 | −25.66 | −25.66 |
Dry | 0.10 ± 0.04 | 25.91 ± 2.20 | +140.89 | +140.90 | |
Overall | 0.10 ± 0.02 | 20.98 ± 3.42 | +57.62 ± 83.27 | 57.62 ± 83.28 |
giraffes in the borderland (+3.18 ± 57.93) since there was a decline in this proportion in the wet season between 2010 and 2013 (
In terms of wet season and dry season comparison for every year, all the locations in the borderland had significantly different giraffe numbers between wet and dry season for every year; and between pairs of dry seasons and wet seasons of subsequent years (
Census Location | Year | Season Census Done | Chi-Square Goodness of Fit Value | Conclusion | |
---|---|---|---|---|---|
Wet Season | Dry Season | ||||
Amboseli | 2010 | 2283 | 1053 | Χ2 = 453.51, df = 1, p < 0.001 | For 2010, wet season numbers were higher than dry season number. |
2013 | 3470 | 1444 | Χ2 = 835.30, df = 1, p < 0.001 | For 2013, wet season numbers were higher than dry season number. | |
Chi-Square Value | Χ2 = 244.91, df = 1, p < 0.001 | Χ2 = 61.23, df = 1, p < 0.001 | For each set of wet season, and dry season, the giraffe numbers were significantly higher for 2013 than 2010. | ||
Magadi | 2010 | 780 | 192 | Χ2 = 355.70, df = 1, p < 0.001 | For 2010, wet season numbers were higher than dry season number. |
2013 | 991 | 815 | Χ2 = 17.15, df = 1, p < 0.001 | For 2013, wet season numbers were higher than dry season numbers. | |
Chi-Square Value | Χ2 = 25.14, df = 1, p < 0.001 | Χ2 = 385.43, df = 1, p < 0.001 | For each set of wet season, and dry season, the giraffe numbers were significantly higher for 2013 than 2010. | ||
West Kilimanjaro | 2010 | 263 | 216 | Χ2 = 4.61. df = 1, p = 0.032 | For 2010, wet season numbers was higher than dry season number. |
2013 | 119 | 348 | Χ2 = 112.29, df = 1, p < 0.001 | For 2013, dry season numbers were higher than wet season number. | |
Chi-Square Value | Χ2 = 54.28, df = 1, p < 0.001 | Χ2 = 30.89, df = 1, p < 0.001 | For each set of wet and dry season, the giraffe numbers were different. They were higher in the wet season of 2010, but higher in the dry season of 2013. | ||
Natron | 2010 | 838 | 423 | Χ2 = 136.58, df = 1, p < 0.001 | For 2010, wet season numbers were higher than dry season number. |
2013 | 623 | 1019 | Χ2 = 95.50, df = 1, p < 0.001 | For 2013, dry season numbers were higher than wet season numbers. | |
Chi-Square Value | Χ2 =31.64, df = 1, p < 0.001 | Χ2 = 246.34 df = 1, p < 0.001 | For each set of wet and dry season, the giraffe numbers were different. They were higher in the wet season of 2010, but higher in the dry season of 2013. |
in all cases) for 2013 than 2010 for Magadi/Namanga area (
In Kilimanjaro area for 2010 (
In terms relationships between giraffe numbers in different locations (closer or further away from protected areas), influence of seasons on giraffe numbers varied among the locations in the borderland (
The Maasai giraffe was found to widely using the Kenyan-Tanzanian borderland than most herbivores, but looking at their distribution they are increasingly being confined to certain areas and not present in some. The distribution showed that Amboseli (and the group ranches) were the core area of giraffe locations, with over half of the giraffe population in the borderland being located in Amboseli area. Therefore, like other species such as
Season of the Year | Year | Location of Census Area | Chi-Square cross Tabulation Value | Conclusion | |
---|---|---|---|---|---|
In or around Protected Areas | Away from Protected Areas | ||||
Wet Season | 2010 (After Drought) | 2546 | 1618 | Χ2 = 62.85, df = 1, p < 0.001 | In the wet season, giraffes numbers in location was dependent on year, with the number increasing over time near protected areas than further away. |
2013 (Post Drought) | 3589 | 1614 | |||
Dry Season | 2010 (After Drought) | 1269 | 615 | Χ2 = 161.53 df = 1, p < 0.001 | In the dry season, giraffes in location was dependent on year, with giraffe numbers increasing with time both near protected areas but more so further away from protected areas. |
2013 (Post Drought) | 1792 | 1834 | |||
Overall Wet Season | 6135 | 3232 | Χ2 = 145.29, df = 1, p < 0.001 | Generally giraffes numbers in locations were depended on season, with giraffe numbers increasing in all locations, more near than further from protected areas in the wet season. |
elephants, Amboseli area still the most important area in the borderland for giraffe conservation, and therefore conservation of the Amboseli Ecosystem must remain a priority especially for Kenya Wildlife Service. So while we must continue to strengthen our giraffe protection and maintain the landscape ranging for giraffes it is emerging that habitat destruction (especially the trees and shrubs on which these specialized browsers feed) could be the main threat. Giraffe numbers have also become a concern in the borderland ecosystems because they have become popular and easy targets for bush meat trade. Poachers use crude weapons like machetes to cut off giraffe meat and pack them in sacks and transport them on donkeys across borders to market places and other demand areas for sale.
Despite Amboseli supporting more than half of the Maasai giraffe in the borderland, the fastest growth in density and numbers of giraffes was in Magadi and Lake Natron. This area (especially if natural connectivity can be maintained) represent a much more promising area for giraffe population growth and source for other sink areas in the ecosystem. The fact that the growth in these two locations is faster than in Amboseli and West Kilimanjaro seem to suggest that there is still great potential for giraffe population to continue to grow in these areas and possibly further from carrying capacity (for which possibly the Amboseli-West Kilimanjaro continuum has been attained). It is therefore important to also focus on this cross-border area with a view of securing not only natural giraffe habitats of continuous trees and shrublands, but also security from poachers. Since giraffes are not very vulnerable to predation by large herbivores (except may be a group of lions) due to both their size and ability to kick with both their front and hind legs, poaching by humans (bush meat), human encroachment and habitat destruction (habitat clearing for agriculture, cutting of tree and shrub resources for various uses, increasing commercial charcoal and firewood kilns to expanding markets and urban areas) represents the common threat to giraffes in the borderland.
It is likely that these giraffe populations may be connected as a Meta-population which is stabilized by each other in the borderland area. It is therefore very important that key corridors and connectivity pathways are maintained across the border between Magadi and Lake Natron on one hand, between Lake Natron and West Kilimanjaro through the expansive Longido rangelands, and between West Kilimanjaro and Amboseli. Natural vegetation with good tree and shrub cover and minimal degradation by human impacts and overgrazing will al- low for this critical connectivity between these ecosystems so as to continue to maintain the larger borderland giraffe Meta-Population. There seems to be little hindrances to ostrich movement across various ecosystems on the Kenyan side of the borderland, including ease crossing of the busy Nairobi-Namanga highway. This means that connectivity in the greater ostrich Meta population in the borderland is available and just controlling poaching, habitat and human encroachment will allow ostrich populations to continue to thrive over time. General habitat destruction such as increasing charcoal kilns in the borderland rangeland lends support to concerns about habitat destruction.
Maasai giraffe population is generally increasing in all the areas of the borderland, especially in the wet sea- son after the devastating effects of 2007-2009 droughts in the borderland ecosystems. This is expected because wet season is associated with lush growth in vegetation and plenty of available surface water. Much forage and water will improve not only resources for ostrich growth, viability and reproduction fitness, but will also provide thermal cover and reduced competition with livestock and wild herbivores for plant resources and water. The buildup of insects and other food items including forbs and grass allow for increasing of ostrich ranging and numbers during the wet season. Like other borderland wild herbivores, ostrich also disperse widely during the wet season, but may be confined in the dry season because of thermal load and patchy distribution of water and food sources. Nevertheless, ostrich can also get (preformed) water from eating lush vegetation and insects as such tissues contained water which will often meet metabolic requirements of ostriches, especially in dry season and areas of water scarcity.
Generally, it was expected giraffe populations to be increasing in Amboseli and Magadi/Namanga locations from 2010 through 2013 as a recovery from droughts of 2007 and 2009, and in the wet season when forage is more plentiful. However, this was not the case for West Kilimanjaro and Lake Natron areas, as the dry season numbers in giraffe numbers were higher than the wet season. Two reasons may explain this, first that in some areas, giraffe numbers will concentrate in places where there is more water availability, partly to access free flowing water, but secondly and more importantly because such areas may be associated with lush acacia and other tree and shrub densities that will provide critical forage in the dry season. Since this may be accompanied by reduced landscape ranging and movements as giraffes settle in places where forage availability and distribution will likely support them more in the dry season, these may lead to enhanced concentration of giraffes in such places and hence have a more elevated giraffe numbers in dry season than the wet season when they disperse more and venture in other areas due to a wide availability of forage.
Results indicated that in the wet season, giraffe number increased over time near protected areas than further away from the protected areas. But in the dry season, giraffe numbers increased with time both near protected areas, but more so further away from the protected areas. This is an interesting finding because it underscores the importance of protected areas as core and safe areas of building wildlife populations. They serve as a source for dispersal for wildlife to other locations especially in the dispersal areas associated with these protected areas. The increase in protected areas and away from protected areas in different seasons of the year indicates that while the long term strategy in giraffe conservation must be increasing and at a minimum maintaining its populations over time, we can only achieve this with a holistic landscape approach where both the protected areas and their dispersal areas (other landscape ranges for giraffes away from the network of protected areas) must be considered in the national protection strategy. This calls for the increased involvement and encouragement of the landowners and communities on whose land Maasai giraffe roams outside of protected areas to support the initiative, develop conservation areas of their own and if possible be helped (in terms of capacity and technical support) to benefit from ecotourism ventures associated with giraffes and other large mammals on their land. This strategy will provide for more conservation space outside protected areas, but also encourage connectivity among key populations. The other critical consideration if the forming of partnerships and collaborative management between the communities and national government of Kenya and Tanzania to promote and enhance conservation of biodiversity across the borderland.
The status and distribution of the Maasai giraffe is still very good in the mid borderland of Kenya-Tanzania. Most of the giraffes however are found in Amboseli and Lake Natron area, but there is also a good population in Magadi/Namanga area and West Kilimanjaro in Tanzania. The population growth was positive after the droughts, indicating that the giraffe population was revering well in the borderland, with a high recovery seen in Magadi/ Namanga area and West Kilimanjaro possibly because of high birthrate and immigration from Amboseli and Lake Natron areas. The population is expected to grow only if there is concerted effort in both Kenya and Tan- zania and the borderland communities to avoid habitat destruction, giraffe poaching in bush meat, snaring and harassment of giraffes. Further, joint monitoring between Kenya (KWS) and Tanzania (TAWIRI) will enhance science-based management through population monitoring and trend. The giraffe population status and distribution is good enough to make it not a species of conservation concern unless the poaching and habitat destruction now on the increase becomes a serious threat to its population status.
We humbly appreciate the contributions made by the Kenya and Tanzania census teams, and the incredible financial and moral support offered by various organizations and institutions. In particular, funding, personnel and logistical support were provided by AWF, KWS, TAWIRI, WD, TANAPA and ATE. We are equally grateful to the Director KWS, Director ATE, Director of Wildlife in Tanzania, Director General of TANAPA and Mr. Peter Zannetti for provision of aircraft and experienced pilots and observers. The ground crew and support personnel showed a lot of commitment which ultimately went a long way in making this research successful. Finally, we honor all those people who participated in one way or another in this exercise and whose names have not been mentioned. Their input equally contributed to the good work that was accomplished in all the census sessions.