How does elephants move

Knowledge on how animals move in their environment can give critical insight on animal's behavior that may be used in the effective management and conservation of species under study.

Water is a scarce resource in semi-arid savanna, where over half of the African elephant Loxodonta africana populations occur, and may therefore influence the movement strategies used by elephants.

Elephants are water dependent and they usually have to drink water every two to three days Stokke and Du Toit, ; Redfern et al. To survive in dry savannas, it is therefore critical for elephants to be able to efficiently find the sparsely distributed water sources, especially during the dry season. Based on the elephant's water requirements and the scarcity of water during the dry season, we expect that the movement pattern of the elephant will reflect these seasonal contrasts in water distribution.

Here, we analyse the movement paths of four male and four female elephants to address the hypothesis that elephant movement patterns show a stronger directional orientation toward water sources in the dry season compared to the wet season.

We predict that the movement path for male and female elephants are less tortuous, have longer step lengths, longer net displacements and smaller turning angles and will show stronger directionality toward water sources in the dry season than in the wet season. Past reports indicate that elephants remember and re-visit previously visited sites De Beer and Van Aarde, ; Prins and Van Langevelde, ; de Knegt et al.

Thus, longer step lengths and higher directionality of elephant movement paths toward water sources in the dry season is an indication that elephants use information to travel to these water sources.

The area is characterized by a bi-modal rainfall with long rains in mid-March to May, short rains in November to December Tyrrell and Coe, and a mean annual rainfall of — mm Tyrrell and Coe, ; Prins and Loth, The two rainfall seasons are separated by a 5 months long dry season typically ranging from June through October Tyrrell and Coe, ; Leuthold and Leuthold, ; Omondi et al.

There are two permanent rivers in Tsavo Galana river and Tsavo river and several seasonal rivers, with Voi and Tiva rivers flowing for a short time in the rainy season Ayeni, Other sources of water are the numerous natural waterholes which fill up with water during the rainy season.

Some of these waterholes can hold water throughout the short dry season January-March but all the natural waterholes dry up around July-August during the long dry season June to October Ayeni, ; Mukeka, In addition, there are three wind-pumped boreholes and a few water reservoirs located around tourist facilities and community owned ranches with constant water supply for animals in the peak of the dry months.

We used radio-telemetry data from GPS-collared elephants in the Tsavo Conservation Area to investigate the differences in elephants movement patterns between the wet and dry season. During the wet season, there is abundant water for wildlife in the Tsavo ecosystem Omondi et al. However, this area has sparsely distributed permanent water sources in the dry season when the only available water sources for wildlife are reduced to two perennial rivers, three boreholes, and a few water pools constantly refilled by the hoteliers and neighboring community ranchers Ayeni, For instance, in drier environments, elephants take an average interval of 3 days to drink water and the duration of re-visiting water points differ between sexes Stokke and Du Toit, , with bull elephants drinking every 3—5 days while breeding herds every 2—4 days Viljoen, ; Leggett, Furthermore, the breeding herds have been reported to forage close to water sources in the dry season compared to the male elephants Harris et al.

The individuals that were collared were randomly selected from five sectors in the Tsavo Conservation Area to represent elephant movement patterns across the entire park. The procedure for fitting GPS collars are described in Ngene et al. The GPS collars transmitted hourly fixes and the data were automatically transmitted to a web-linked database at the Tsavo East Research Station in Kenya. In our analysis we considered only the successive time steps with GPS fixes. Figure 1. Study areas and the hourly GPS fixes black dots for a male elephants in the dry 1 and the wet season 2 ; and for a female elephants in the dry 3 and the wet season 4.

In both sexes the individuals' movement paths seem to be tightly anchored on a river in the dry season. We analyzed elephant movement patterns for the males and the females in two seasons: the long dry season June to October and the long wet season March to May These two seasons are distinctly different in the amount of rainfall and would therefore show the relationship between the change in movement pattern related to water availability.

We calculated the distance covered by each elephant per hour based on the hourly GPS-fixes. We recorded the distance between successive hours to represent a single movement path i.

We calculated the turn angle as a measure of the change of direction between successive steps with a zero degrees turn corresponding to locomotion on a straight line without change of direction, a negative angle representing a turn to the left and a positive angle representing a turn to the right Calenge, We then analyzed the distribution of step lengths, turning angles, and squared net displacement distances NDD for both sexes and seasons with AdehabitatLT animal movement analysis package in R Calenge, We calculated the parameters of turn angle distributions such as the mean resultant length and the mean direction using CircStats package Version 0.

We only analyzed the movement paths that were directed toward the nearest water source to focus on the effects of water on movement path. Thus, all the movement paths for the elephants that were further than 15 km from the nearest water sources and those for the individuals returning from drinking water were excluded from the analysis on the assumption that they were foraging and not seeking for water. Since the range of water re-visitation frequency for the Tsavo elephants were 1—4 days for the females and 2—5 days for the males in the dry season, we also excluded all the movement paths of the day following an elephant's visitation to the water sources in the dry season.

The rest of the movement paths were included in the analysis. In order to establish whether the directionality changed with distance from the water source, or whether proximity had no effect, we also stratified our analysis to 5, 10 and 15 km from the water source.

We analyzed the effect of the fixed variables; season, sex and distance from the nearest water source, on elephant's movement pattern using linear mixed effects models LMMs.

We used the ID of the elephant as a random effect variable to account for variation due to individual differences. We also checked for the interaction effects between sex and season in our analyses. We performed these analyses using R package lme4 Bates et al. The step lengths per hour for the elephants were significantly longer in the dry season compared to the wet season Table 1A.

The step lengths changed with distance from the nearest water point, with the step lengths further from the water 15 km being significantly shorter than those closer to water points 5 and 10 km Table 1A. Also, step lengths were longer in the 10 km group than in the 5 km group. Even though both male and female elephants have longer step lengths in the dry season as compared to the wet season, the results showed a significant interaction effect of sex and season Figure 2A.

The male elephants have shorter step lengths than the females in the wet Table 1A and a longer step length in the dry season Figure 2A. Similarly, the squared net displacement for the elephants were significantly longer in the dry season compared to the wet season Table 1B.

The squared net displacements were significantly longer further away from water 15 and 10 km as compared to distance closer to the water 5 km Table 1B. Furthermore, the squared net displacement was also significantly affected by the interaction between sex and season with squared net displacement for the males being longer than the females in the wet season Table 1B.

Both sexes had similarly longer squared net displacements in the dry season Figure 2B. However, the turn angles for both sexes were large in both the wet and the dry season and did not show any significant difference between the seasons.

Table 1. Figure 2. Step length A and squared net displacement distances B for the female and the male elephants movement paths in the wet black bars and the dry gray bars season. The mean resultant length of the turning angles for both sexes showed strong directionality in the dry season compared to the wet season Figure 3. The resultant mean length of the turning angles for females were in the same range with males in wet season but much lower than the males in the dry season, although not significantly different Figure 3.

Figure 3. Females were not recorded to be at 15 km from the nearest water point in the dry season. The study of animal movement patterns in relation to resource distribution is one of the novel ways to link behavior of individuals to the spatial distribution of resources Schick et al.

Resource distribution varies in space and time, and can occur in a spectrum ranging from over-dispersed, random, in patches to highly aggregated clusters Prins and Van Langevelde, ; de Knegt et al.

We examined the role of water distribution on the movement pattern of elephants. In this study, we showed how elephant movement patterns change as a result of seasonal variation in water distribution. The results support our predictions that the movement paths of both male and female elephants are less tortuous, resulting in longer step lengths, and have longer squared net displacements in the dry season compared to the wet season.

Furthermore, the mean length of the turning angle showed strong directionality toward water sources for both the sexes in the dry season. The movement paths that were removed were for individuals returning from the water source, those that were beyond 15 km from the nearest water source and the paths for all individuals for the day following their return from drinking water during the dry season, which would not contribute to our conclusion.

The Tsavo Conservation Area is an ecosystem undergoing pronounced scarcity of water and in the long dry season, two perennial rivers and three boreholes serve as the primary water source for wildlife. Moreover, humans are responsible for huge habit loss of African elephants. As the human population in Africa increases, more and more land is converted to agriculture. A smaller habit has meant that elephants and humans are coming into contact with one another more than they did historically, and this is causing conflict.

This can lead to both humans and elephants being killed in the conflict. How much does the average elephant weigh? African elephants are the largest land animals in the world today. The average African elephant will weigh between 5, to 14, lbs. However, the largest African elephant ever recorded was found in Angola, rocking in at a massive 24, lb 11, kg. Asian elephants tend to be a smaller than their African counterparts, weighing between 4, to 11, Ibs 2, to 5, kg.

How tall is an elephant? Asian elephants are smaller and tend to reach a shoulder height of between 6. What do African elephants eat? How much does an elephant eat a day? Elephants are gigantic animals and this means that they need to find an eat an awful lot of food. African elephants can eat as much as Ibs kg of food a day.

What is elephant dung and how much does elephant poop weigh? In fact, because of this, some animals like monkeys and dung beetles actually eat elephant dung!

Our elephant friends can deposit upwards of kg of dung daily! How do elephants have sex? Female elephants are generally ready to become a mum at around years old. A male can tell when a female is ready to mate from the chemical signs she leaves in her urine and faeces. Rumour has it that elephants mate for life. How do elephants give birth? Like other mammals, female elephants give birth to fairly developed babies via her birth canal. An elephant pregnancy lasts around 22 months, meaning that new born baby elephants are not small!

A baby elephant is called a calf and can weigh between and lbs and stand about 3 feet 1 m tall. How many babies do elephants have? Typically, elephants only give birth to one calf at a time, although twins do sometimes occur. In her lifetime elephants can live for up to 70 years in the wild! Not as many as babies you might think?

How many teeth do elephants have? Elephants usually have 26 teeth at any one time. Throughout their lives, elephants have six sets of teeth that grow one set after another. By the time they reach their 50's, most elephant have started to use their final set which is needed to last for the rest of their life.

Why do elephants flap their ears? How thick is elephant skin? Despite this, elephants have very sensitive skin and use mud and dust baths to protect their skin from burning in the sun, and to get rid of skin parasites. How far do elephants walk in a day? Despite their massive size, elephants are actually pretty nimble and can walk up to km per day, although they usually only average is only 25 km on a daily basis.

How much does an elephant's brain weigh? No wonder they say that an elephant never forgets! How long is an elephant's trunk? Scientists hope that the listing will bring more attention to forest elephants, which have often been overlooked by governments and donors when grouped together with more visible savanna elephants.

African elephants are protected to varying degrees in all the countries of their geographic range. There have been recent efforts to bring re-legalize the international trade in ivory, but those so far have failed.

Conservation groups and governments have worked to set aside land for wildlife— including corridors that connect those protected lands. Still, researchers believe that up to 70 percent of elephants' range is on unprotected land. To curb poaching, stopping the illegal trade is key. Advocates have launched campaigns that address both the supply side poaching and the demand side people who buy ivory.

Since the ban went into effect, public demand for ivory seems to have fallen. On the supply side, protecting elephants from poaching also requires a local approach. In , a study showed that the suffering of elephants is tied to that of the humans living nearby: Regions with high levels of poverty and corruption are more likely to have higher poaching rates. This suggests that helping communities develop sustainable livelihoods could reduce the lure of poaching.

Elephant family members show signs of grief and may revisit the bones of the deceased for years, touching them with their trunks. All rights reserved. Animals Photo Ark. African elephant. An African elephant photographed at Indianapolis Zoo in Indiana. Common Name: African elephants. Scientific Name: Loxodonta. Type: Mammals.

Diet: Herbivore. Group Name: Herd. Size: Height at the shoulder, 8. Weight: 2. Size relative to a 6-ft man:. Elephants recognize themselves in a mirror—something few animals are known to do.

We also found that individual elephants consistently moved in different ways from each other. This told us that they have personalities. These insights can provide clues into how elephants can be better managed to conserve their populations and to reduce conflict with humans, particularly crop raiding by elephants.

Males generally had larger home ranges and were slightly more active at night than females. They also spent less time in exploratory movements, these are long, persistent movements to new locations. It might be that the rainforest habitat provided ample forage for elephants. Water was key to elephant movements. During high rainfall, elephants moved longer distances and made more directed, exploratory movements.

Elephants also altered their movement behaviour in response to human activity.