Important Daily Facts of the Day

Study sheds light on prey-predator relationship in Himachal

Why in news?

Recent the Zoological Survey of India (ZSI) released a study titled ‘Landscape use and co-occurrence pattern of snow leopard (Panthera uncia) and its prey species in the fragile ecosystem of Spiti Valley, Himachal Pradesh’

Details:

·         The study under National Mission on Himalayan Studies revealed a strong link between habitat use by Snow Leopard and its prey species Siberian ibex and blue sheep.

·         Scientists used camera traps and sign surveys to evaluate the co-occurrence patterns of snow leopards and its prey species (Siberian ibex and blue sheep) in Spiti valley of Himachal Pradesh.

Habitat of snow leopard:

·         The snow leopards use rugged mountainous areas or non-forested areas covering an altitude between 3200m-5200m.

·         Snow leopards have a vast but fragmented distribution across the mountainous landscape of central Asia, which covers different parts of the Himalayas such as Ladakh, Himachal Pradesh, Uttarakhand, and Sikkim.

·         The study suggested that habitat covariates, such as barren area, grassland, aspect, slope and distance to water were important drivers of habitat use for the snow leopard as well as its prey species.

·         The Spiti Valley possessed a good habitat in and outside the protected areas which could support a viable population of both threatened snow leopard and its prey species.  

Threats:

·         This charismatic species is largely threatened because of the loss of natural prey species, retaliatory killing due to conflict with humans and illegal trade of its fur and bones. 

·         Classified as ‘Vulnerable’ by the International Union for Conservation of Nature (IUCN) Red list and listed in Schedule-I species of the Indian Wildlife (Protection) Act, 1972, snow leopards are elusive mountain cats whose survival depends on depends primarily on wild ungulates.

Key findings:

·         The study aimed at examining how the predator used habitat in presence or absence of its prey species and vice-versa.

·         They also tested how the environmental variables are influencing the distribution of the species in presence or absence of the other species.

·         Higher up in the mountains, predators such as snow leopards regulated the populations of herbivores such as the blue sheep and Siberian ibex, thereby safeguarding the health of grasslands and a long-term absence of snow leopards could cause trophic cascades as ungulate populations would likely increase, leading to depletion of vegetation cover. 

·         It said that protecting snow leopards may result in a cascade of benefits to the ecosystem as a whole. 

Way Forward:

·         The knowledge about the relationships among the species will be useful for developing better conservation and management strategies for the long-term viability of snow leopard and its prey species in the landscape of Spiti Valley. 

·         Maintenance of areas having potential habitat for top predators in and outside the protected areas can serve as a useful tool for conservation and management planning.

Bioluminescence in Chennai beaches: NCCR study

(GS Paper 3, Science and Tech)

Why in news?

·         Recently, the National Centre for Coastal Research (NCCR) released a study focused on the occurrence of bloom along a 16-km stretch following a spell of heavy rain in August 2019.

Key Findings:

·         Adequate nutrients brought by substantial rain and a high abundance of the plankton, called diatom Thalassiosira sp. triggered the (bioluminescent) bloom of Noctiluca scintillans. 

·         The plankton is available in the ocean and due to nutrition available, it will multiply and becomes the bloom.

·         Low wind speed, lowering of atmospheric temperature, high rain and low sea surface temperature are cited as probable environmental cues.

·         Local hydrodynamics and the diverging currents governed the presence and dispersion of the sudden outbreak of the bioluminescent dinoflagellate Noctiluca scintillans bloom in the region. 

After decline in bloom:

·         The paper explained that once the bloom reduces, there is an increase in bacterial population associated with the phyto-plankton bloom. The lowest count was recorded on the Panaiyurkuppam beach and the maximum on Elliot’s Beach. Total coliform too was recorded in the waves.

·         Bioluminescence was observed owing to turbulence and intense wave breaking in the surf zone, stimulating bioluminescence in Noctiluca scintillans cells.

·         Within two days after the appearance of bioluminescence, the blooming cells slowly degenerated and moved away by the current, and finally declined.

Heat waves in the United States

(GS Paper 1, Geography)

Why in news?

·         Virtually all the contiguous United States experienced above normal temperatures recently, with more dangerously hot weather forecast

·         The US heat wave followed record heat that killed hundreds if not thousands of people and sparked wildfires in Europe.

What is a heat wave?

·         A heat wave has no single scientific definition. Depending on the climate of a region, it can be determined by a certain number of days above a specific temperature or percentile of the norm.

Arctic warming and jet stream migration:

·         The Arctic is warming three to four times faster than the globe as a whole, meaning there is ever less difference between northern temperatures and those closer to the equator.

·         That is resulting in swings in the North Atlantic jet stream, which in turn leads to extreme weather events like heat waves and floods.

Heat domes:

·         Warmer oceans contribute to heat domes, which trap heat over large geographical areas.

·         Scientists have found the main cause of heat domes is a strong change in ocean temperatures from west to east in the tropical Pacific Ocean during the preceding winter

·         As prevailing winds move the hot air east, the northern shifts of the jet stream trap the air and move it toward land, where it sinks, resulting in heat waves.

El Nino & La Nina:

·         Every few years, the climate patterns known as El Niño and, less frequently, La Niña occur.

·         El Niño brings warm water from the equatorial Pacific Ocean up to the western coast of North America, and La Niña brings colder water

·         At present, La Niña is in effect. Because summer temperatures trend lower during La Niña, climate scientists are concerned about what a serious heat wave would look like during the next El Niño, when even hotter summer weather could be expected.

Human-influenced climate change:

·         Climate change caused by the burning of fossil fuels is a global phenomenon that is certainly playing a role in what the United States is experiencing.

·         Climate change is making extreme and unprecedented heat events both more intense and more common, pretty much universally throughout the world.