EnvironmentFlora and FaunaWildlife

STUDIES ON BAR HEADED GEESE REVEAL REASONS FOR DISPERSAL

Manjunath S Nayak:

Scientific studies on the migration patterns, count and dispersal of Bar Headed Geese have been going on in both Mongolia and India for many years now. However, for the past decade, researchers, birders, and foresters have been studying the arrival of these birds in India.

The bar-headed geese breed in Central Asia in colonies of thousands near mountain lakes but winters in South Asia and they fly as far south as peninsular India. They fly at high altitudes from Mongolia and Tibet to India to roost and find shelter at many wetlands during Nov-March. In this background, studies and recordings are being done at various levels in many of the wetlands but Magadikere Bird Conservation Reserve, Gadag district in Karnataka state is our focus.

In this regard, the year wise migration of Bar Headed Geese has been observed and recorded by me, Sidramappa L Vibhooti, Deputy RFO, Lakshmeshwar section, Shirhatti range, Prakash Ganiger, Beat Forester, Shirhatti Range and Somappa S Pashupatihal, Forest Watcher at the Magadikere Bird Conservation Reserve, Karnataka Forest Department, Gadag. As per our observations and recordings, the following data has been arrived at which we have tabulated.

Bar Headed Geese Year Wise Migratory Count

YearNumber of Birds arrivedDispersal nearby wetlandsBird Count  
Jan-20236500-7000Water level increased    –
2022-237500-8500Shettikere1500-2000
2021-226000-7500Shettikere1000-1200
2020-215500-6000Shettikere800-1000
2019-205000-5500Shettikere700-900
2018-194500-5000  
2017-18__Desilting of Tank
2016-173900-4300   
2015-163800-4000   
2014-153500-4000   
2013-143000-3500   
2012-133300-3500   

As per recent scientific studies being done in countries that witness the migration of these birds, the Bar Headed Geese’s yearly migration is trigged by environmental signals.

In fact, this allows them to overcome the monsoon months and the worst winter storms they face back in their homelands of Central Asia.

REASONS FOR DECLINE

The reasons for declining numbers of Bar Headed Geese at Magadikere are varied and diverse. They are the following:

  • Due to climatic changes, temperature variations change in pressure belts and the resulting wind belts.
  • This year (2022-23) Southern India saw periods of depression and cyclones and heavy rains.
  • Rainy moods in clouds also deterred them
  • Resulting wind belts changed the bird’s migratory path.
  • Changed water levels due to heavy rains received in Gadag district for 4 years (non-seasonal rains)
  • Bar headed geese like shallow water bodies, but due to increased rains, water level has risen.
  • Crop change and damaged crops that bar headed geese depended on like Bengal gram, Ground nut, Safflower, Paddy, Wheat which resulted in food scarcity.
  •  Decline in numbers is climate change caused by global warming. As temperature rises, birds are thrown from their migration cycle and when birds reach their destinations, they rely on certain foods to survive through the seasons.

DISPERSAL OF GEESE

For the past few years, birders and foresters have been sighting these birds in new places and they have been observed in districts like Davangere, Mysuru, Bagalkot, etc in Karnataka state.

Now where do these Geese disperse and how do they find new wintering sites? To mention a few wetlands, the Bar Headed Geese have dispersed to  Bankapur lake, Hadinaru Lake near Nanjangud and Kunduvada Lake, Davangere. 

In view of this species behavior, a few birders and wildlife lovers like Sangamesh S Kadagad from Jakkali , Sharanu K Goudar, and Harish N, from Kanakpur have started observing, recording and documenting these birds. They have diligently used the Block Counting Method (Block of Flocks) to count the Bar Headed Geese which have a slightly larger wing area to aid their yearly, long migration of thousands of kilometres.

RECORDINGS AT BAGALKOT WETLANDS

Apart from this, Praveen Baddi, Range Forest Officer (RFO), Research Range, Badami has been regularly recording and studying the winter arrival and summer departure of Bar Headed Geese in a few wetlands of Bagalkot district.

Since 2018, Praveen Baddi has been observing these high-flying birds which flies altitudes of 7000-8000 meters when they cross Himalayas on their journey from Mongolia to India. The RFO has been focusing on the following wetlands: Herakal, Anawadi, Mallapur, and Bennur to study these beautiful grey and white birds with two horse-shoe shaped brownish-black bars on the back of its white head.

YearNumber of Birds arrivedDispersal nearby wetlandsBird Count  Tagged Bird
2023802   
20222959   
20212005   
20202036   
20193037   
20184728   

With declining numbers of Bar Headed Geese recorded in the last few years, researchers, bird experts and birders call for more studies to alleviate their situation in the coming years.

(The author is a Biodiversity Researcher, Gadag, Karnataka)