Wildlife & Biodiversity

What locust attack? Great Indian Bustards make a meal of pests, reproduce more

However, the population could drop again after the locust invasion gets over, experts say  

 
By Ishan Kukreti
Published: Monday 15 June 2020
Locusts are very rich in protein and are being eaten by fauna in western Rajasthan since the locust invasion of May 2019. Photo: Radheshyam Pemani Bishnoi/ERDS Foundation

The locust invasion, while proving to be a disaster for farmers across Rajasthan, has become a literal movable feast for the local biodiversity, including the endangered Great Indian Bustard (GIB) in the state. 

Locusts, that are very rich in protein, are being eaten by the local fauna, helping them increase their reproduction rate.

The pests are considered such an important source of nutrition that even captive GIBs under Wildlife Institute of India’s (WII), Habitat Improvement and Conservation Breeding of Great Indian Bustard - An Integrated Approach project are being fed locusts. 

“Locust is a very important food for GIB. Due to the high nutritional status of locusts, the fecundity of the bird has become high,” YV Jhala, dean of WII and head of the GIB conservation project, said.

 “Usually, there are four-five eggs laid every year, but last year we found 15 eggs,” he added.

The locusts are fed to the GIB both for their nutritional and recreational value as the birds like to chase the insects around. 

Jhala added that last year, his team also found evidence of re-nesting after the egg was removed. “Re-nesting is directly linked to improved nutritional intake,” he said.

GIB isn’t the only species that is benefiting from the locust invasion. Locusts are also eaten by moneys, lizards, foxes, desert cats, jackals and wolves. 

“Whenever there is a pest invasion like the current locust invasion, it is associated with an increase in the population of species. This has also been seen with cricket upsurges and increases in fox populations earlier,” Jhala said. 

The increased reproduction rates last for one-two years as the animals make the most of this additional nutrition that becomes suddenly available and reproduce more. 

Protein is an important growth nutrient which the animals feed their young. 

“We have seen that even bird species that are aren’t carnivorous, feed their chicks insects, because it helps the chicks grow,” Sumit Dookia, wildlife biologist and assistant professor at New Delhi’s Guru Gobind Singh Indraprastha University, said.

Dookia is also the honorary scientific advisor at the Ecology, Rural Development & Sustainability (ERDS) Foundation, a Jaisalmer based non-profit helping local communities with in-situ conservation of GIB.  

However, Jhala said the boom in local biodiversity usually crashes after a year or two of the invasion. 

“The locusts eat everything and leave the habitat devoid of any vegetation once they leave. This leads to a drop in the reproduction rates and the population again,” he said. 

Moreover, the chemicals sprayed to control the locust can have a negative impact on the GIB and local biodiversity. 

“The spraying can be dangerous as the GIB could feed on locusts that have died from chemicals,” Sutirtha Dutta, a faculty at WII and a member of the GIB project, said.

“The forest department in the GIB areas have been cautious and last year, they removed dead locusts from these areas. So, precautions are being taken to prevent the GIB from feeding on dead locusts,” Dutta added.   

Rajasthan is witnessing the worst locust invasion since 1993. Since May last year, when the invasion started, an area of around 5,94,808 hectares (ha) has been affected by the insects. 

So far, of the 33 districts of Rajasthan, 24 have been affected, according to Suwa Lal Jat, joint director, Plant Protection division of the Rajasthan Agriculture Department.

“These are eye estimates, the actual estimation is underway by the revenue department,” he said.

The pests have mostly destroyed cotton crops in Sri Ganganagar (4,500 ha), Hanumangarh (9,000 ha), Nagaur (70 ha) and Bikaner (830 ha) districts. On an average, every hectare of land produces around 20 quintals of cotton, that is sold for around Rs 6,000-Rs 7,000 per quintal. 

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