Final Report for Survey of Crocodile Population in Kwale District, Kenya to Reduce Human-Crocodile Conflict

Ashley Pearcy

In cooperation with Kenya Wildlife Service- Shimoni

And Global Vision International- Kenya

January 2011

Final Report for Survey of Crocodile Population in Kwale District, Kenya to Reduce Human-Crocodile Conflict

A. Pearcy

Introduction

While crocodilians are found in various areas of the tropics and subtropics, none are so feared as the Nile crocodile Crocodylus niloticus found throughout the African continent. This fear has protected the crocodiles, until recently when expanding human populations have reduced the barrier between man and nature. Human crocodile conflict has come to the forefront of both crocodile conservation and social awareness due to increased predation on livestock and humans. Management plans have been enacted in several African countries, but some locations have not yet had the time and means to monitor their crocodile populations in order to better protect and inform their people.

The Kenya Wildlife Service of Kwlae District on the south coast of Kenya has noted an increased number of human-crocodile conflicts over the last few years. They requested assistance in seeking out solutions for reducing or preventing these conflicts to better protect the people of the district. The KWS Strategic guidelines for 2008-2010 calls first and foremost for scientific research beneficial to wildlife management. In its extended version through 2012, people become a top priority. This study was in direct line with these guidelines.

This paper discusses the work conducted, results of our limited study, and suggestions for reducing and preventing human-crocodile conflicts in the Kwale District. It includes a map from crocodile hotspots throughout the district and a manual for conducting quarterly monitoring, a necessary addition to the Kenya Wildlife Service routine if prevention of conflict is the goal.

We initially set out to estimate population size and distribution throughout the district using hot spots of conflict as field site locations. However, from our limited field time and the season in which we conducted our study (dry), we were unable to fully assess population size and/or methods of prevention. The following suggestions are based only on methods used in other areas with similar situations.

Methods

Data was collected from the Problem Animal Control (PAC) reports on human-crocodile conflict and presented below. Also, a number of hotspots were visited to assess the area. Finally, we conducted night surveys in two locations with the assistance of Global Vision International (GVI) staff and volunteers. Resources were limited and spotlighting was conducted from the banks of the river. GPS coordinates and pictures of the sites have been included to account for spelling differences.

Crocodiles of Kwale District

Given that our research time was during the dry season or short rains, the water levels were quite low. Only two locations were fresh water; all others were very saline. While Nile crocodiles can withstand some levels of salinity, they are not physiologically built for high saline waters. From this, we can assume that the majority of crocodile activity in the district occurs during and just after the wet season, when the water from upstream dilutes the river ends within the district.

Reconnaisance survey crocodile incident hotspots Kwale district

Date: 21-11-10

Observers:

• Corporal Hassan Bhanje, PAC Officer KWS

• Tim Pellissier, Terrestrial programme staff, GVI • Zeno Wijtten, Terrestrial Science Officer, GVI • Ashley Pearcy, Principal Invesitgator

Rombo Ramwana

Rombo Ramwana is Swahili for breast of the child. It is on the Ramisi river, downstream from dongo kuna and upstream from the Magical Mwazaro beach resort. According to the mzee (respected old man) the fisherman see crocodiles regularly when they go upstream and tourists from Mwazaro see crocodiles sometimes. There is a small path leading form the main Shimoni access road to the site.

According to the mzee a 12-year old child was attacked whilst swimming in 2008. The mother stayed next to the body for quite a while to protect it.

No crocodiles or tracks were recorded during a 30-minute visit. At low water, it might be possible to walk along the banks of the river.

Figure 1 Rambo Ramwana fishing village on Ramisi River

Dongo kundu

Dongo kundu is a tributary of the Ramisi River and can be reached by a two track drivable trail just off the main Shimoni access road. People fish for prawns here. According to the mzee you can see crocodiles at anytime if you go upstream.

According to the Mzee 1, an adult was attacked and injured in 2008 and one adult was killed by crocodiles.

No crocodiles or tracks were recorded during a 30-minute visit.

The bridge on the Lunga-Lunga – Ukunda road that goes over the river Ramisi is directly upstream. This site would be well surveyed by canoe. The banks are only accessible at low water.

Figure 2 Dongo Kundu with informative mzee showing places of crocodile activity

Mwamose

Mwamose is a bridge over the Mwena River, limited flow-through capacity results in the bridge functioning as a dam. The water is quite saline and several saltwater fish were spotted. Downstream is what looks like an old sawmill.

No crocodiles or tracks were recorded during a 30-minute visit. It is possible to walk along the banks of the river although vegetation inhibits a good view of the stream.

According to Hassan, domestic animals were predated on here in the recent past.

Figure 3 Mwamose bridge over the Mwena River

Kiwegu

On the South side of Kiwegu, a grassland reportedly turns into a floodplain when water levels rise in the nearby Umba River during the wet season.

According to Hassan, in 2009 a 12-year-old girl was killed here by a crocodile.

Figure 4 Kiwegu floodplain, dry outside of the wet season

Umba River Bridge

Kids play and bathe in the water. None of the kids seemed to know anything about crocodiles. About 200m South-West of this site, a group of women was washing clothes in another tributary of Umba River.

Figure 5 Umba River from bridge, small from lack of rain

Diego

On the South side of Diego village a part of the Umba River forms a pond where animals drink. This is all fresh water and the area between Diego and Kiwegu reportedly turns into a floodplain at high water levels.

No attacks were reported here.

Figure 6 Animal crossing at Diego on the Umba River

Vanga

This is where Umba River meets the sea. No crocodiles were reported here, possibly because of the large human population size and activity in the harbour. Furthermore currents are big and salinity is very high due to direct connection with the sea.

Figure 7 Vanga delta

Nayeni (Lunga-Lunga)

Just before the Nayeni border control post the Lunga-Lunga-Unkunda road crosses the Umba River. With rain this is quite a fast-flowing river. KWS has an outpost in the nearby Lunga-Lunga village.

Figure 8 Nayeni bridge near the Tanzanian border at Lunga-Lunga

Mwena bridge near Mgobezi

According to present locals several goats have been attacked here and there is a crocodile breeding area a bit upstream. It is freshwater, and therefore a likely location for year-round crocodile presence.

Figure 9 Mwena River bridge showing bend where crocodile breeding has been reported by villagers

Upstream bridge over River Ramisi

The Ramisi River is quite wide at this point, about 50m. This seems like preferred habitat for crocodiles, with accessible banks, although water depth could not be estimated.

Figure 10 Upstream of Ramisi River

Kibuyuni Dam

Kibuyuni Dam is also known as the Kibuyuni-Mangawani water project. A dam of 1.5km long was built with financial aid form the EU, quite some time ago, estimated 20 years. The dam causes a permanent lake to form (estimated over 1km2). Water is being fetched by local people from this lake, this caused problems as people were attacked while doing this. A pump now brings water from the lake to nearby villages partially solving the problem.

Figure 11 Kibuyuni Dam

We have included a list of GPS locations for these sites in Appendix 1.

Night surveys

Rombo Ramwana- November 30, 2010

From 17.30 we assessed the area. Water was not to it highest flooding. We went upstream through the mangroves to look for tracks, nests, or any other indication of crocodile use. No signs of crocodiles were present.

We stayed at the opening for canoe landing (around 30m). From 19.04-19.34, we spotlighted for crocodiles along the banks of both sides. A single eye shine was noted (19.11) but not confirmed by other observers. No other eye shine was seen.

Problems

The area is in constant use by prawn fisherman who work the banks by canoe looking for prawns. Three fishermen went into the water just before we started our survey and two more when we were starting to spotlight. Their constant presence may have caused any crocodiles present to submerge or swim away. There was also a net placed 60m up from the clearing, crossing the width of the river. This could also exclude crocodiles. Salinity is quite high, especially given the season. The short rains would reduce the salinity, but not likely enough to make this a suitable/preferred habitat at any other time than during and just following the long rains.

Prawn fisherman work during low tide and not in the wet season this could be a reason for very few attacks on fisherman.

We can also only spotlight a small portion of the river from this location. The time of day was a bit too early, and while one can see eye shine with the amount of light, perhaps a later investigation would give more information.

The stories told by villagers about the crocodile attacks put the attacks high on the bank- indicative of flood season levels.

Kibuyuni Dam- December 9-10, 2010

The dam is located roughly a 1.5 hours to 2 hours away from Shimoni. We went to the location in the early afternoon to ask permission for working in the area from the Chief and Vice-Chief of Kibuyuni. We surveyed the site for areas at which to do spotlighting during the evening, along a path, which ran next to the banks. Spotlighting began around 20.00 when it was dark.

16.20 spotted first crocodile roughly around 2m

Surveyed from six locations for a minimum of five to a maximum of 15 minutes

20.07-20.22: no crocodiles spotted following 15 minute spotlighting from top of dam split into three groups of two for the length of the dam, proceeded down path near banks

At 21.07, we spotted two crocodiles in the water, we quit the spotlighting survey at 21.17 because a crocodile was growling less than 2m away on the bank. At this point we spotted a 4m crocodile move towards the bank where we were and submerge. For safety, the group moved up hill.

We followed with two more locations but observed no crocodiles. The distance from the banks made it nearly impossible to spotlight crocodiles

We did a dawn survey at 05.34 from the dam, spotting no crocodiles. During this time we saw 11 people enter the reeds at the same location to collect water, none were harmed. (This is continuing despite the fact that the pump was installed less than 100m away from this location. People seem not

to be afraid of crocodiles here.) It might have been a bit too cold for much crocodile activity at that point.

The vice-chief informed us that the other end of the dam had far more crocodiles but we were unable to visit this site.

Other villagers are farming directly on the bank of the water (sukuma, corn, etc.), none seemed worried about crocodile attacks. The chief and vice-chief of the village insist that crocodiles are a problem for the area. We were told that the other side of the dam has many more crocodiles. This is the only location which had signs posted warning of crocodile presence.

As this location is upstream of the Ramisi River, it is likely that these crocodiles move downstream during the wet season and upstream during the dry season (during the time of this study). This is also the most livable area given that the water is fresh (only one other location at Mwena river) had freshwater. I would assume from my discussions with locals that this area has the highest density of crocodiles within the Kwale district and perhaps even feeds other areas within the watershed during and directly following the wet season.

Map

Figure 12 Map of area covered in Kwale District for crocodile survey

While the map does not completely align with our GPS coordinates, major crocodile hotspots and the area covered in the study can be seen. Shape files and log of GPS coordinates are on the included CD.

Attacks

Reported attacks may or may not account for the total number of encounters. Given the numerous stories from villagers, often with inaccurate timelines, there were several attacks in 2008. We were unable to locate the problem animal reports for 2008.

Conflicts are classified as threat, injury or casualty according to information found in the KWS P.A.C. reports. Threats can be to human or livestock. However, threat can also mean simply that crocodiles were spotted. KWS cannot verify the actual encounter as they visit the scene post-incident, if manpower and vehicle availability allow.

Table 1 Number of reported crocodile-human conflicts. Data from the KWS problem animal control reports.

2009 2010 Threats 11 20 Injuries 0 2 Casualties 2 2

In 2009, 2.75% of threats were recorded as predation on livestock. In 2010 (from Jan-Sept), those numbers decreased to 2.22% of threats were recorded as predation. In 2009, people reported threats from buffalos 16 times including one injury. This did not include reports of crop destruction, only those where villagers were afraid for their life. This is more than those between crocodile and human.

We can only speculate about the increased conflicts for 2010, but increasing human populations are likely associated.

Suggestions

Quarterly monitoring

Monitoring of the crocodile populations is an absolute necessity for the reduction of human-crocodile conflict in the Kwale District. Currently, the only method by which KWS is aware of crocodiles in the district is through conflict reports. Crocodiles in the area need to be tracked and their distribution and movement studied. This can be done through monitoring activities (methods discussed in Appendix 2). With information on distribution, movement within the watershed and general demographics, the people of the district can be better informed of crocodile activity.

Crocodile fence Kibuyuni

As we have studied the area, becoming familiar with the landscape and the way people use the water source, clearly evident from our short time, my suggestion given the predictable water levels of the dam, would be to install a crocodile fence, especially around the areas used primarily for agriculture.

Crocodile fences are both beneficial in giving a safe area to bathe and collect water. However, it should be noted that Nile crocodiles learn habits and the use of a single place in the river could encourage conflict. Although, it is better than nothing. I will also note that the people of the area have easy access to a pump but still choose to use the banks of the water in order to not walk the 100m to the pump. No help can be given to the people if they choose not to use the facilities. The place which would be most effective for crocodile fences is along the agricultural plots, where people harvest crops directly on the banks of the river. Harvesting this closely to the banks should be discouraged in community outreach programs because it makes people vulnerable to crocodile attacks. I have included photos of fences erected in Zambia and in Sri Lanka (Fig. 12) as examples.

a)

b)

Figure 13a) Crocodile fence in Zambia (Wallace 2010) b) crocodile fence in Sri Lanka (de Silva 2008).

Other areas

Because the majority of the district has trouble with crocodiles during and just following the wet season, crocodile fences are less effective in downstream locations, especially when in areas such as Rambo Rwamwana, the attacks occur at the area where canoes enter the river. These are places which will benefit from community awareness campaigns where villagers can be informed about the time of year to expect crocodile presence in the area. Also, much of this area is floodplain and the depth of the water is dependent on the amount of rainfall. Because of this it is impossible to predict the influx of water without a study on rainfall to water level. This would be a long-term study, which would include water depth preference for crocodiles so that villagers would have an idea of when to expect crocodiles moving into the floodplains within their village. Appendix 3 discusses methods by which to do this study.

Water pumps are a feasible fix for reducing human-crocodile conflict. These offer other options than the riverbank for collecting water and bathing. The more options given to villagers that move them away from crocodile habitat, the better it would be for preventing attacks.

Community outreach

Given the unknown locality of the crocodiles from this pilot study, it is best to inform the community on crocodile ecology. Information should expand as it is gathered (i.e. distribution, seasonality, population size). Furthermore, outreach could include suggestions for sharing habitat with crocodiles. Some are as follows:

• Notice boards at local businesses of crocodile activity and times to be most aware • Crocodile hotline: number for people to call when they have conflicts or for tracking

crocodiles • Pamphlets: What does a crocodile nest look like? (must know nesting season and sites from

monitoring); what to do when you see a crocodile? (contact KWS, walk away, if child contact adult); How to protect yourself from crocodile attacks?; etc.

• Visiting schools and community meetings to teach children and adults about crocodiles in the districts, especially prior to the wet season to heighten awareness prior to the movement of crocodiles downstream.

Involving the community in the research or monitoring helps to raise awareness and enthuse participation from other villagers and villages. This support would be invaluable to KWS given the limited manpower and resources.

Problem crocodile

Ultimately, it is acceptable to kill problem crocodiles. This can act as a deterrent for other crocodiles. However, this is not an act that can be depended on for prevention of human-crocodile conflict because crocodiles are territorial and opportunistic predators. Crocodiles sustain moderate harvests with 10% of the population being adult males; this is usually more than enough to moderate conflict problems (Ross pers. comm.). The preference when killing crocodiles is to make certain that the problem crocodile is identified and killed. KWS, in the past, has handed out hooks to bait and trap crocodiles. This method will only capture small crocodiles (<2m), which are not likely those attacking humans or predating on their livestock. Only the biggest and boldest males should be removed when problems occur.

Ecotourism

Ecotourism has been suggested several times for the Ramisi River area, including the creation of a crocodile farm. Before any of this can take place, crocodile density and distribution must be assessed. We can assume that crocodiles only use the lower Ramisi River when there is enough fresh water to dilute the seawater. Some tributaries may be used, but there are certain times of year when crocodiles are not present, or present only in small numbers, on the coastal edge of the district where tourism is most attractive.

Also, without full understanding of population size and demographics, it would be impossible to determine how many animals could be used to seed a farming or tourism industry.

Training and affiliations

I suggest heightening the relationship between KWS and local communities with crocodile farmers throughout the south coast. In this way, KWS and local communities can gain proper crocodile handling skills from local investors. This training can involve harvesting techniques (both eggs and adults) so long as population sizes are equivalent to IUCN/CITES population quotas for sustainable harvesting. With these relationships, removal of problematic crocodiles may not result in the

immediate killing of the crocodiles but give them an alternative life as a breeding stock in farm. This is a sustainable way to use problematic crocodiles. Another aspect, which farmers can perhaps invest in the future, is local eco-tourism groups for crocodile viewing. The Kwale district already has large number of tourist each year for the marine park, and a strategically placed eco-tourism outlet would benefit both crocodile and human communities once crocodile populations (density, distribution, and demographics) are understood.

Bringing in partner affiliations such as GVI would benefit both the monitoring and community outreach programs, especially considering the limited manpower on the Shimoni base. Recruiting hotels that are on or near the watershed, such as Paradise Lost or Magical Mwazaro, to do spotlighting or day surveys throughout the year would also be of benefit. These places are aware of and use crocodile populations to increase their tourism and therefore would not likely be opposed to doing counts for KWS (methods are explained in the manual but it is imperative that counts be done throughout the year to gain knowledge on how the crocodiles move throughout the watershed during different seasons.) A text message with number of crocodiles seen that day would go a long way to increase the data collected by KWS and the understanding of crocodiles in the district.

Summary

In order for human-crocodile conflict to be reduced or prevented in the Kwale District, three major priorities need to be set within the KWS PAC regime.

First and foremost, crocodile monitoring program, at least quarterly, and within different sites in the district. This information is integral to the success of human-crocodile conflict reduction

Community outreach programs for raising awareness and education about crocodiles need to be instigated. This would include information on when the crocodiles are where, how to avoid conflict, and to gain a general respect of crocodiles

Follow through with the goals of KWS and pursue scientific endeavors to further understand the crocodiles of the district and initiate innovative ways for human-crocodile conflict prevention (some of which are suggested in this report)

Strengthen affiliations both with partners such as GVI and extend to others such as crocodile farms for training, information and assistance, and the tourism businesses which, at least partially, use crocodiles to attract clientele.

Kenya Wildlife Service has the capacity to reduce human-crocodile conflict within the district if these actions are taken to further understand one of the main predators in the district. For further advice, guidance or explanation, please contact:

Ashley Pearcy Herpetologist ashley.pearcy@gmail.com Zeno Wijtten Terrestrial Biodiversity Officer- GVI Shimoni, Kenya shimoni@gviworld.com Andrew Hayes Base Manager- GVI Shimoni, Kenya mkwiro@gviworld.com This report and shape files for the GPS coordinates have been copied onto a CD accompanying this report for safekeeping and continued use.

Acknowledgements- Global Vision International, specifically Zeno Wijtten for his trusted expertise spotting crocodiles and for arranging for volunteers to assist with the project. Tim Pellesier for accompanying on all trips. Kenya Wildlife Service for their assistance and support and for allowing me to help on this project. I would specifically like to thank Corporal Bhanje for his input, advice, and support in the field. Warden Richard Lamarkat did not hesitate to provide support and arrange fieldtrips where possible.

References de Silva, Anslam (2008) The status of the Saltwater crocodile (Crocodylus porosus) inhabiting the Nilwala River, Matara District and its impact on the community. Project Report. Sri Lanka

Ross, Perran (personal communication) Department of Wildlife Ecology and Conservation, IFAS, University of Florida. 29 November 2010 Wallace, Kevin (2010) Human crocodile conflict in the Chiawa Game Management Area, Zambia. Update Report for the IUCN/CSG Student Research Assistance Scheme Grant.

Appendix 1: GPS Locations of Hotspots

Location GPS coordinates

Water body

Notes

Rombo Ramwana

04.34.427 039.23.387

Ramisi River

Part of Kiwambale

Dongo Jundo

04.33.576 039.23.054

Ramisi River

Inc. Kidumu village

Ramisi Bridge

04.32.027 039.23.409

Ramisi River

Momasa 04.34.146 039.14.168

Mwena River

Near Majoreni, mainly used for domestic use

Kiwegu 04.38.043 039.12.189

floodplain Currently dry (Nov 2010)

Umba River Bridge

04.38.650 039.11.523

river Not ideal habitat, used mostly during floods

Jego 04.39.016 039.11.663

Small river

Wild crossing and freshwater-only freshwater found

Vanga near mouth of Umba

04.39.596 039.13.139

Delta

Umba River at border

04.33.481 039.07.584

River

Mwena River

04.29.908 039.07.963

river Lies between Mwena village and Mymkimbezi?, slightly salty, said to be a breeding area by locals

Kibiyuni Dam

04.24.089 039.19.324

Dam/lake

Appendix 2: Manual: Quarterly Monitoring

Both day and night surveys can and should be conducted in each site throughout the district, beginning with locations of confirmed crocodile presence, but adding others as more information is obtained. It is preferable to spend at least three nights in a location, but a minimum of one night. A few hours during the day to look for sign of crocodiles such as nests and tracks should be allotted.

Spotlighting should begin after dark. Torches with bright lights should be used to scan the water’s surface and banks for eyeshine. Crocodile eyes reflect red when shone upon.

Daytime surveys include checking the banks for crocodiles basking, sightings in the water as well as tacks or nests.

While all numbers from population surveys should be recorded. The largest confirmed number of crocodiles from one survey should be the number to represent the population in that area at that time.

It is preferable to use a boat to conduct both day and night surveys. At night the engine noise should be kept to a minimum and a general speed maintained throughout the survey area. The length of survey is of course dependant on the resources available but a 5 to 10km span of river (or longer) offers more information that a single location from the bank.

If boats are not available than spotlighting can be done from the banks but becomes far less reliable as bushes can hinder line of sight. In this study we had to do patch surveys along a trail near the bank, where safe, and therefore only could locate a very small number of crocodiles. Crocodiles also may use the banks more freely at night, also increasing dangers. Daytime bank surveys are suggested, primarily for locating nesting sites.

The visible parts of a crocodile in water can very from the entire body to just the nostrils or eyes. It is important to be ale to gauge the size of the animal from the visible head parts when the crocodile is in water. Roughly, the estimate is 1 to 7, so multiply the length of the head by 7 for an estimate on body size.

Figure 1 Picture of what can be seen of crocodile surfacing to distinguish between head and dorsal armor

Alternative methods: crocodile hotline- have people send a text of their location when they see a crocodile

Appendix 3: Water level monitoring for estimating arrival of crocodiles

Most of the Kwale district is susceptible to crocodiles only during or directly following the long wet season when saltwater, which has moved in from the coast, becomes diluted from water upstream. Because of this, a number of locations become inundated with water that, during other parts of the year, dry and used for grazing animals or even as football fields. The dynamic of areas such as these often has the consequence of more human crocodile conflict. I suggest a method here for the prediction of when crocodiles will enter floodplains, tributaries or even move down stream. This is not a quick solution. It will take at least one wet season to initiate the study and several others to confirm the findings, but at least an idea can be given of what to expect in the following season.

The main issue of the Kwale District is that large portions become floodplains during the wet season or the riverbanks swell, allowing crocodile movement into areas that, during other parts of the year, are dry and safe. I propose a long-term study to gain knowledge on two major aspects with regard to watershed flooding.

1) Identify the amount of rainfall to water level rise

2) Identify at which water level the crocodiles start to move into the floodplain

By these objectives, the villagers can gain an understanding of when crocodiles begin to use the area following rainfall. This can help them in following wet seasons to be more aware of crocodile presence by being aware of the rainfall.

This is not a guaranteed method. Crocodiles may choose not to be in an area during a certain year or season or they may adapt to preference based on other environmental factors such as availability of food. However, they do have minimum requirements of a location in which they stay as opposed to just move through. Hopefully these minimums could be assessed, further identifying areas more prone to crocodile attacks.

Methods

Place a rain meter (millimeter marked cup) near a measuring stick (Fig. 1) near the source of water for floodplains and along the bank on rivers. These can be placed in multiple locations along the river or the floodplain dependent on resources (Fig. 2). Check the amount of rainfall and water level following each rain or daily. Spotlight for crocodiles nightly (or more feasibly for KWS, have the villagers send a text when they first see a crocodile in that location) or conduct day reconnaissance surveys.

An extension of this study, especially for floodplains, is to measure how far in the water comes into the floodplain from its source or how much the bank swells with rainfall. Linking this number with influx of crocodiles would also be beneficial. By placing the measuring sticks with rain meter 10m distances from each other along a transect within the floodplain, this can be measured. Other adaptations would include tying a rope to the stick at source, pulling the rope to the edge of the new swollen bank or spread of water in a floodplain. The rope could then be measured. This growth should be checked following each rain when possible.

Fig 1 Rainmeter showing measuring stick and marked water collection tube

Fig 2. Visual of location of rainmeters (x) in a floodpain and along a river