Why are juvenile elephants dying in Kerala?
Shaju Philip, Indian Express
July 20, 2024
See link
https://indianexpress.com/article/explained/juvenile-elephant-deaths-kerala-explained-9462019/
for photo.
A new report released by the Kerala government has revealed a significant
decline in the population of juvenile elephants (aged ten years and below)
over the last year.
Findings of the report
The report titled ‘Elephant Population Estimation in Kerala – 2024’,
released on Tuesday (July 16), is an annual survey of Kerala’s elephant
population. It is part of a synchronised inter-state exercise across
Kerala, Karnataka and Tamil Nadu, which intends to address the problem of
rising human-elephant conflict across state borders.
Using the block-count method, the survey has estimated the state’s elephant
population to be 1,793 in 2024, a decline of roughly seven per cent over
the previous year. 845 elephants have died across the state’s forests and
elephant reserves between 2015 and 2023, with the death rate increasing
over time.
While the death rate in elephants has declined with the increase in age,
juvenile elephants (aged ten and below) are particularly susceptible to the
Elephant Endotheliotropic Herpesviruses (EEHVs), with a 40% death rate
reported.
What are EEHVs?
EEHVs are a class of novel double-stranded DNA herpesviruses which cause
acute haemorrhaging in juvenile Asian and African elephants, with severe
cases causing death within 24 hours of infection. Given the endangered
status of the Asian elephant, EEHVs pose a dire threat to conservation
efforts. The disease itself has coexisted with elephants for millions of
years, however, young elephants are particularly vulnerable on account of
the lower EEHV-specific antibody levels compared to the seniors.
Calves in large herds of elephants benefit from shared immunity through
exposure to different EEHV strains, enabling them to develop the antibodies
to fight the virus effectively. The smaller size of herds in Kerala thus
presents a crucial challenge, with the majority of elephant sightings – 56
per cent – being reported as individuals and pairs. Clans of over ten
individuals are extremely rare and constitute one per cent of all
documented elephant sightings.
Why are elephant herds smaller?
According to the report, the size of a herd depends on the quality of its
habitat, with larger herds with calves favouring locations with an adequate
mix of grassland, forests and water sources.
The decline in forest cover and sub-optimal elephant habitats are partly
responsible for the smaller herd sizes. The report cites ‘biological
invasions,’ mainly the cultivation of alien species of plants like acacia
mangium and eucalyptus in forest tracts as a major reason. The lack of
fodder could lead the herbivores to farmlands located around the forest
areas, increasing the scope of human-elephant conflict. The smaller herd
size could also lead to changes in an individual elephant’s behaviour.
Resolving the problem of shrinking habitats and restoring them to their
natural state, free of alien species, is imperative to reducing the threat
of EEHVs to Asian elephant calves, as well as avoiding further
fragmentation of elephant herds.
https://indianexpress.com/article/explained/juvenile-elephant-deaths-kerala-explained-9462019/