Day-670 | Daily MCQs | UPSC Prelims | ENVIRONMENT AND ECOLOGY

Answer. B
Explanation:
The interaction between cattle egret and rhinoceros can be best understood as an example of commensalism.
Cattle egret is a gregarious species and is most commonly seen foraging with grazing stock and in wetlands. It often feeds by following large animals such as cattle, rhinoceros etc.
Cattle egrets feed on different prey ranging from insects such as ticks, grasshoppers, crickets, flies, moths, spiders, frogs and earthworms. They have also been reported to feed on crustaceans, fish, lizards, rodents and vegetable matter. If a cattle egret eats ticks off the hide of grazing mammals, the relationship becomes mutualism. Cattle egrets also serve as important ectoparasitic biological agents.
From another perspective, the relationship between cattle egret and rhino/grazing cattle can be described as facultative commensalism and not obligate commensalism. It follows and sits on the cattle/rhino to look out for insects. The egrets do not die if the relationship between egret and grazing mammal ends. It has wider sources of food and foraging habits.

Answer. C
Explanation:
Options 1, 2 and 3 are correct.
Carbon dioxide Removal (CDR) takes the forms of both natural means like afforestation or reforestation and technologies like Direct Air Capture, where machines mimic trees by absorbing CO₂ from their surroundings and storing it underground.
There are also more complex CDR technologies like ‘Enhanced Rock Weathering’ where rocks are broken down chemically; the resulting rock particles can remove CO₂ from the atmosphere.
Other technologies like bioenergy with carbon capture and storage (BECCS) capture and store CO₂ from burning biomass, like wood.
Mineralization: Ocean alkalinity enhancement (and not reduction or elimination) is a type of carbon mineralization that can be done with certain types of rocks that are reactive with carbon dioxide, such as olivine. Some companies, like Vesta, are looking into mixing this ground rock with sand and spreading it on beaches. In this way, the wave action helps speed chemical reactions that lock away carbon dioxide, while also helping replenish eroded coastlines, potentially reducing storm surges. On land, ground up basalt rock that can be applied to croplands to improve soil quality while it removes carbon.
Enhanced weathering: Sprinkling powdered basalt over natural ecosystems would remove vast amounts of carbon dioxide from the Earth’s atmosphere while also improving soils. The idea is to boost the natural process by which carbon dioxide in precipitation reacts with soils and rocks to form bicarbonate ions, which eventually find their way into oceans via rivers. Adding basalt dust to soils increases the surface area available for these reactions, speeding up this chemical weathering process and drawing down more carbon.
At the same time, amending soils with basalt makes them more productive – boosting the carbon sink – and improves drainage and reduces acidity levels.
Ocean-based CDR: Some companies plan to farm seaweed such as kelps in the open ocean and are testing methods of sinking it to the deep ocean to sequester the carbon it contains. The gigantic off-shore farms are being planned in the Atlantic where Sargassum will be grown, harvested, bound up, and ultimately sunk to the bottom of the ocean. Once the bundles are sunk to the oxygen-depleted sea floor, the carbon contained within the plants is essentially permanently sequestered.

Answer. A
Explanation:
Statement 1 is incorrect but statement 2 is correct: The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) was established in response to the Busan outcome document (June 2010) which stated that “an intergovernmental science-policy platform for biodiversity and ecosystem services should be established”.
The IPBES is an independent intergovernmental body established in Panama City on 21 April 2012 by 94 governments. It is not a UN body. However, at the request of the IPBES Plenary and with the authorisation of the UNEP Governing Council in 2013, the UNEP provides secretarial services to the IPBES.
The work of IPBES can be broadly grouped into four complementary areas:
● Assessments: On specific themes (e.g. “Pollinators, Pollination and Food Production”); methodological issues (e.g. “Scenarios and Modelling); and at both the regional and global levels (e.g. “Global Assessment of Biodiversity and Ecosystem Services”).
● Policy Support: Identifying policy-relevant tools and methodologies, facilitating their use, and catalyzing their further development.
● Building Capacity & Knowledge: Identifying and meeting the priority capacity, knowledge and data needs of our member States, experts and stakeholders.
● Communications & Outreach: Ensuring the widest reach and impact of our work.
Statement 3 is correct: All States Members of the United Nations are eligible for IPBES membership. India is a founding member of the IPBES. IPBES currently has close to 140 member states.

Answer. D
Explanation:
A publication, titled “75 Endemic Birds of India”, was recently released on the 108th foundation
day of the Zoological Survey of India. It points out that about 5% of birds found in the country are
endemic and are not reported in other parts of the world.
Western Ghats, one of the 4 biodiversity hotspots of India, has recorded the highest number of endemic species of birds in the country. The following birds are found only in the Western Ghats:
● Malabar Grey Hornbill (Ocyceros griseus)
● Malabar Parakeet (Psittacula columboides)
● Ashambu Laughing Thrush (Montecincla meridionalis)
● White-bellied Sholakili (Sholicola albiventris).
Some interesting bird species which are only found in the Andaman and Nicobar Islands are-
● Nicobar Megapode (Megapodius nicobariensis);
● Nicobar Serpent Eagle (Spilornis klossi);
● Andaman Crake (Rallina canningi); and
● Andaman Barn Owl (Tyto deroepstorffi).

Answer. C
Explanation:
The excessive diversion of water from rivers in Central Asia over several decades towards agriculture has shrunk the Aral Sea, a pre-existing lake between Kazakhstan to its north and Uzbekistan to its south. It has now become the Aralkum Desert, a significant new source of sand and dust storms.