How elephants in Sri Lanka use protected areas

By Annie Madsen

Elephant behavior has long endeared the public. From complex social structures to tool use, hearing stories about behavior not only teaches about fantastic ecological adaptations, it shows a window into elephant’s lives that we can understand and relate to on a personal level. Showcasing behaviors has often been used to help elephant conservation. However, behaviors are sometimes disconnected from how managers actually conserve elephant populations. In a new study, we examine elephant space use behavior in the hope that it can directly inform management practices.

Although protected areas are an important part of conservation strategies, it’s important that conservationists and wildlife managers understand how animals use actually protected areas. In this study, we used observational data that the Udawalawe Elephant Research Project had collected about Asian elephants at Udawalawe National Park over nine years. A unique aspect of this study was that we it was based on direct observations rather than the movements of particular individuals that were tracked (e.g. with collars) so it represents a much larger sample than studies of space use can typically accommodate. We also had social and behavioral data so we wanted to know how certain aspects of life history affected park use for males and females. How often were elephants using the park, and critically, how often were they not using the park? This gives us an idea of how much of the population is actually residential to Udawalawe. To answer these questions, we investigated park use for males and females separately, and with different behavioral considerations. A key variable was the amount of time (days) that elapsed between consecutive sightings. The longer this interval, the further away they could potentially go from the park.

Female Asian elephants have complex social behaviors. Day to day, females spend time in small social groups of only 2-3 individuals, but they also form much larger social communities over long time periods (months to years). We found that in Udawalawe, females with strong social associations had more similar park use to each other compared to those with weaker social associations. In the larger social communities, many females used the park on a longer-term basis. Other females in the population were only seen in a couple of years. Females that used the park on a long-term basis were considered residents, but half of the female population did not meet this criterion, and only used the park during part of their lives. One of the main take-aways from this set of results is that social groups do not necessarily all travel together in and out of the park. Based on earlier research we already knew that social relationships could shift from year to year, so this shows that the decision to move is partly related to what social companions are doing but also depends on individuals’ own choices.

The study area includes only the middle section of the park, where there is a road network. The upper map shows high spatial overlap between males who were seen only foraging (f), only in musth (m) or both states (f+m). Likewise, the lower map shows spatial overlap between female groups that were less residential (3 & 9) vs. those that were more residential (10 & 12).

Compared to females, male elephants live relatively solitary lives. This is especially true during mate searching, when males enter a “musth” state. When in this state, bulls have a one-track mind for finding mates and largely abandon foraging behavior, increasing aggression and movement. We asked how males used the park differently according to their age and their main motivations for being in the park: searching for mates, foraging, or a mix of both. We found that age and motivation both affected male park use, and these were tightly linked. Younger males used the park mainly for foraging and later dispersed, while more males in the older age classes were split between using the park for both purposes, or solely for mate searching. Males were also more likely to be seen in multiple in years if their park-use strategy included both behaviors, or if they were older and used the park for mating only. However, we also found that most of the males that were considered residents used the park only for foraging, and this was a minority of males, with most being considered non-residents. A very interesting finding was that males appear to shift strategies around the age of 40, where they appear to settle into a more regular pattern of visitation exclusively during their musth periods. We think this is because males must wander around and lead a rather nomadic life for quite some time while testing and re-testing their competitive ability against other males in male-male contests before finally establishing their reproductive dominance.

Our study showed that the majority of the population (around three quarters!) is non-resident. Since most of the Udawalawe elephants primarily spend time outside of the park, this has important implications for conservation and management of this population. The landscape outside the park has variable land use, with some areas that are also protected and others that are heavily modified by agriculture and human settlements. There are thin pieces of protected land connecting National Parks that elephants use as corridors, but these areas vary between mixed-used land and sanctuaries. As we can see from our results, protected areas certainly do not qualify as a one-size-fits-all conservation strategy. In addition to maintaining protected areas, we also need to maintain connectivity with the surrounding landscapes so elephants and other wildlife can move safely between areas as they change space use depending on their individual needs and motivations.

Reference:

Madsen, A. E., Minge, C., Pushpakumara, T. V., Weerathunga, U. S., Padmalal, U. K., Weerakoon, D. K., & de Silva, S. (2022). Strategies of protected area use by Asian elephants in relation to motivational state and social affiliations. Scientific reports, 12(1), 1-13.

Full text open access at: Strategies of protected area use by Asian elephants in relation to motivational state and social affiliations | Scientific Reports

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Annie Madsen is a PhD candidate studying animal behavior at the University of Nebraska-Lincoln.

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