Where does the wildlife go?: Tracing the paths from Kaziranga
Scientists from Conservation Initiatives walk 200km across 152 sites in 50 days to track wildlife movement during dry and flood season
By ROOPAK GOSWAMI
Guwahati, Dec. 17: Where does the wildlife move during the dry and flood season from Kaziranga National Park in Assam ?
Scientists from Conservation Initiatives, Dr Varun R. Goswami and Dr Divya Vasudev, walked a distance of 200km across 152 sites, investing an effort of 1,200 hours (50 days) across two seasons to find out these movement patterns.
The study, Coupled effects of climatic forcing and the human footprint on wildlife movement and space use in a dynamic floodplain landscape,
which reveals this, all has been published this week in Science of the Total Environment journal.
The Kaziranga study
The scientists surveyed the intervening human-dominated space on either side of National Highway 37 to assess large herbivore movement and space use between Kaziranga and Karbi Anglong.
The study area was the 204-square km strip of land lying between Kaziranga and Karbi Anglong, comprising designated wildlife corridors, tea estates and croplands, primarily under paddy cultivation and often associated with human habitation, all along the major highway.
The survey covered all tea estates and forested areas between Kaziranga and Karbi Anglong.
Three surveys were conducted in two seasons: the first in the pre-flood dry season (January–March 2015), followed by a survey during and immediately after the major floods of 2016 (flood season; July–October).
Findings of the study
The study reported findings for six large herbivore species, Asian elephant, greater one-horned rhinoceros, Asiatic water buffalo, sambar, hog deer and muntjac (barking deer).
Other species like large (tiger and leopard) and small carnivores (leopard cat, jungle cat, fishing cat), civets and porcupines, primates and other wild herbivores such as wild pigs and Indian hare were found too.
“We use three layers of information to better understand these movement decisions. The first pertains to species traits, as we look at animals ranging in body mass from the 3,000kg elephant to the 20kg barking deer, or muntjac. The second describes characteristics of the risky human-dominated space that these animals need to traverse. And finally, the extent of the flood itself,” said Dr Divya Vasudev, connectivity expert.
Walking the trails
“We walked large parts of the landscape, noting exactly where animals had moved, and where they hadn’t. We did this twice—once during the dry season and once during the monsoon season, so we could really hone in on what happens during the floods,” she said.
“We know that animals use corridors, and lands outside corridors for movement, but we don’t know this works—where do they move, what areas do they avoid, and does this change when animals are faced with floods? Importantly, are there certain actions we can take to ensure connectivity into the future? These are some of the questions we seek answers for,” she added.
Which animal moved where during the flood and dry season?
During the dry seasons, elephants avoided human habitation areas and preferred to use areas with high land-use diversity. During floods, they preferred to use forests, and areas with woodlands and bamboo cover on private lands (primarily tea estates), and they preferred to use areas where the northern surroundings were dry compared to being waterlogged.
During the dry seasons they preferred areas with more surface water closer to the Kaziranga National Park boundary and avoided areas with high bamboo cover.
During the floods season, they preferred to use forests, and areas with woodlands on private lands (primarily tea estates), closer to Kaziranga National Park boundary, but like the dry season, preferred to not use areas with high bamboo cover.
Preferred to use tea estates the most, followed by woodlands, while avoiding crop lands under paddy cultivation; they also preferred areas with high land-use diversity during the dry season.
In flood season they strongly avoided waterlogged areas and they moved up in elevation to avoid the floodwaters.
There were sufficient observations only in the dry season, when they preferred areas with high land-use diversity and surface water.
Rhinoceros and water buffalo:
Sufficient observations only in the flood season as they likely remained within Kaziranga National Park during the dry season. In the flood season, they were pushed southwards by floodwaters and they preferred to use areas with high land-use diversity as well as forests and areas with woodlands and bamboo cover on private lands (primarily tea estates).
Variation in movement across species
“As you can expect, there is a lot of variation across species. But what we found was, in general, wildlife moved through low-disturbance and heterogeneous areas during the dry season—that is, populated areas, and monoculture plantations with no woodlands in between, were strongly avoided. During the floods, there was less choice as large parts of land were under water and there was flood-driven pressure to move. In this stressful time, small woodlands or stands of trees and bamboo on people’s lands or on plantations were extremely beneficial in helping animals move in response to the floods, and as a result, survive. This really highlights the importance of participatory conservation strategies that involve and engage local communities, landowners and other stakeholders in the landscape,” said Dr Varun Goswami, senior scientist.
“There is an additional dimension, which is that climate change is expected to impact flood dynamics,” said Goswami, “making this work all the more important.”
With climate change, extreme weather events, such as floods, are expected to become all the more intense and frequent.
This study links climate change-induced stress, and risks animals face in increasingly human-dominated landscapes.
“These two stressors are likely to act in tandem,” said Goswami, emphasizing the need for adaptive connectivity planning that accounts for an entire gamut of endangered species, changing seasons and climate, and human-induced risk.
Vasudev added, “Climate change and the increasing importance of connectivity conservation underscores the need to secure animal corridors, and nurture and preserve woodlands on private lands.”