UPSC Prelims Practice Questions — How energy efficiency drives seasonal mountain bird migration
Q1. The 2026 Science Advances study which concluded that seasonal distributions of mountain birds are driven by energy efficiency rather than by tracking a fixed thermal niche was led from which one of the following institutions?
- A. University of East Anglia
- B. Yale University
- C. Georgia Institute of Technology
- D. Academia Sinica
Q2. In the Science Advances study on the energy-efficiency basis of mountain bird distributions, how many mountain slopes worldwide were analysed?
- A. 12 slopes
- B. 34 slopes
- C. 82 slopes
- D. 171 slopes
Q3. The finding that up to 65% of high-elevation-breeding Himalayan bird species are altitudinal migrants was published in Nature Communications in which year?
- A. 2019
- B. 2022
- C. 2025
- D. 2026
Q4. With reference to altitudinal migration as compared with latitudinal migration, consider the following statements:
1. Altitudinal migration is a seasonal up-and-down movement along elevational gradients, whereas latitudinal migration is a long-distance north-south movement.
2. The Science Advances study held that altitudinal migration fulfils the same ecological function as long-distance latitudinal migration.
3. Elevational gradients represent a stretched-out, expanded version of latitudinal gradients.
Which of the statements given above is/are correct?
- Altitudinal migration is a seasonal up-and-down movement along elevational gradients, whereas latitudinal migration is a long-distance north-south movement.
- The Science Advances study held that altitudinal migration fulfils the same ecological function as long-distance latitudinal migration.
- Elevational gradients represent a stretched-out, expanded version of latitudinal gradients.
- A. 1 and 2 only
- B. 2 and 3 only
- C. 1 and 3 only
- D. 1, 2 and 3
Q5. Optimal foraging theory, which frames foraging as the maximisation of net energy gain per unit time, was first formulated by which pair of ecologists?
- A. Robert MacArthur and Eric Pianka
- B. Eric Charnov and Robert MacArthur
- C. G.E. Hutchinson and Eric Pianka
- D. Robert May and Eric Charnov
Q6. The marginal value theorem, which states that a forager should leave a resource patch once its energetic yield falls below the environment's average yield, was formulated in which year?
- A. 1966
- B. 1971
- C. 1976
- D. 1981
Q7. With reference to the methodology of the 2026 Science Advances mountain bird study, consider the following statements about how the data were obtained and analysed:
1. It used freely available eBird citizen-science occurrence records (2002-2024).
2. It analysed 2,684 bird species across 34 mountain slopes.
3. It fitted a modified Seasonally Explicit Distributions Simulator (SEDS) to the data.
4. It fitted individual birds with GPS/satellite tags to track their movements.
Which of the above is/are NOT correct?
- It used freely available eBird citizen-science occurrence records (2002-2024).
- It analysed 2,684 bird species across 34 mountain slopes.
- It fitted a modified Seasonally Explicit Distributions Simulator (SEDS) to the data.
- It fitted individual birds with GPS/satellite tags to track their movements.
- A. 4 only
- B. 1 and 3
- C. 2 and 4
- D. 3 only
Q8. Regarding the SEDS model used in the mountain bird study and its authorship, consider the following statements:
1. The SEDS model was originally built to explain birds' global seasonal distribution across latitudes before being adapted to elevational gradients.
2. After adaptation, the SEDS simulations matched the empirical data on about 82% of the mountain slopes.
3. Co-author Mao-Ning Tuanmu is affiliated with Yale University.
Which of the statements given above is/are correct?
- The SEDS model was originally built to explain birds' global seasonal distribution across latitudes before being adapted to elevational gradients.
- After adaptation, the SEDS simulations matched the empirical data on about 82% of the mountain slopes.
- Co-author Mao-Ning Tuanmu is affiliated with Yale University.
- A. 1 and 2 only
- B. 2 and 3 only
- C. 1 and 3 only
- D. 1, 2 and 3
Q9. With reference to a 2025 study on climate-driven responses of mountain birds, consider the following statements:
1. Temperate mountain birds may track temperature in time through phenological (timing) shifts rather than in space through elevational shifts.
2. Tropical montane birds shift upslope even though they do not appear physiologically specialised to specific temperatures.
3. High-elevation species benefit from an expanding area of suitable habitat as they move upslope.
Which of the statements given above is/are correct?
- Temperate mountain birds may track temperature in time through phenological (timing) shifts rather than in space through elevational shifts.
- Tropical montane birds shift upslope even though they do not appear physiologically specialised to specific temperatures.
- High-elevation species benefit from an expanding area of suitable habitat as they move upslope.
- A. 1 and 2 only
- B. 2 and 3 only
- C. 1 and 3 only
- D. 1, 2 and 3
Q10. In the context of climate-change impacts on montane birds, the term 'escalator to extinction' refers to which one of the following?
- A. High-elevation species being pushed progressively upslope until suitable habitat vanishes at the mountaintop
- B. Lowland species rapidly colonising higher elevations and out-competing residents
- C. The accelerating loss of migratory species along coastal flyways due to sea-level rise
- D. The abrupt collapse of a food chain when a keystone insect prey disappears
Q11. The Tso Kar Wetland Complex in Ladakh's Changthang region is best described as which one of the following?
- A. A high-altitude complex of freshwater and hypersaline lakes that is a key breeding ground for the Black-necked Crane
- B. The world's highest freshwater Ramsar wetland at 4,595 m
- C. A brackish coastal lagoon that hosts wintering flamingoes
- D. A glacial moraine lake designated as a tiger reserve buffer
Q12. The Central Asian Flyway conservation initiative operates primarily under which one of the following international frameworks?
- A. Convention on the Conservation of Migratory Species of Wild Animals (CMS / Bonn Convention)
- B. Convention on International Trade in Endangered Species (CITES)
- C. Ramsar Convention on Wetlands
- D. Convention on Biological Diversity (CBD)