Posts Tagged 'birds'

baya weavers nesting

Posted by on 04 Sep 2016 | Category: photography, prakriti

It is nesting season for the baya weavers!

Baya weaver birds are small, sparrow-size birds which resemble the sparrows during the non-breeding season. During May-June, as the breeding season approaches, their gonads (sexual glands) become active and the adult males develop yellow and black color plumage on head, breast and throat; and their bills also darken. By the time the monsoon starts, the males are in bright yellow summer colors, and ready for breeding through the monsoon season (June-September).

baya weaver nest building

Why do they breed during the summer monsoon? Obviously, the grass is green during this side of the monsoon! Baya weavers forage in flocks for seeds on wild grass like these below, which are plenty after the monsoon rains. This is also the time when insects are plenty, especially to feed their young. How many bayas can you count in the image below?!

a group of baya weaver birds feeding on grass seeds

Nesting success? Baya weaver nests are exclusively built by the males and then displayed to the females. What are the factors on which the female makes it selection? Among birds, elaborate nests and decorations built by males may help females to assess a male’s quality. One of the most popular architectural attributes of the weaver nest is the entrance tube, which can get as long as 90 cm. Female birds are also selective in choosing nests which provides safety (in terms of nest height and location). So what does the baya weaver base their selection on? Is it the architecture or the location?

baya weaver nest building at Pune, Maharashtra

Safer on thorny trees: Observation shows that the female weavers are inclined towards nests which are safely located in thorny trees, farther away from the trunk and situated high above the ground. Thornless trees have higher rates of snake predation than thorny trees. Nesting success also increases with with thickness of the supporting branch and for nests which are woven with fine fiber.  Thick branches may stabilize nests during strong monsoon winds, and may also be less likely to break.

baya weaver and a garden lizard against the blue sky

Despite these precautions, garden lizards like the one above, and tree mouse do occasionally raid these nests.

Some history: Baya weavers and their unique nesting nature were first recorded in Ain-i-Akbari, the 16th-century document recording the administration of Akbar’s empire, and which is part of the a much larger document, the Akbarnama. The Volume III translation by Colonel H. S. Jarret talks about wild/domesticated bayas: “The baya is like a wild sparrow but yellow. It is extremely intelligent, obedient and docile. It will take small coins from the hand and bring them to its master, and will come to a call from a long distance. Its nests are so ingeniously constructed as to defy the rivalry of clever artificers.”

Species: Ploceus philippinus
English: Baya weaver
Location: IITM colony, Pune, Maharashtra
Date: 3 Sep 2016

References:
1. Balasubramanian, K. S., & Saxena, R. N. (1973). Effect of pinealectomy and photoperiodism in the reproduction of Indian weaver birds, Ploceus philippinus. Journal of Experimental Zoology, 185(3), 333-340.
2. Fazl, A., & Jarrett, H. S. (1983). The Ain-i-Akbari:. Royal Asiatic Society of Bengal. (No. 61).

3. Quader, S. (2006). What makes a good nest? Benefits of nest choice to female Baya Weavers (Ploceus philippinus). The Auk, 123(2), 475-486.

Indian Grey Hornbill—the seed dispersers

Posted by on 07 Aug 2016 | Category: photography, prakriti

There are about 54 species of hornbills in the world, out of which 9 occur in India. The hornbill pictured here is the Indian Grey Hornbill, which is common across the Indian subcontinent, except the wettest (Western Ghats and northeast) and the driest (northwest) parts of the country.

Indian Grey Hornbill, Ocyceros birostris at Pune, Maharashtra

Breeding/Nesting
Hornbills have unique breeding habits, where the female confines herself into a nest cavity in a tree, with only a narrow opening through which the male shares the food throughout the nesting period. For the Indian grey hornbills, the total nesting period is about 87 days, where the female is confined to the nest cavity for an average of 76 days. Most of the grey hornbill nests are in hollows of the Mahagony tree family, located nearby riverine habitats. Deforestation, agriculture and other developmental activities have restricted the range of many species like these hornbills.

Grey hornbills as seed dispersers
Hornbills play a key role in seed dissemination, germination and regeneration of trees. This is because they are mainly frugivores (fruit consuming) and can break up/swallow large fruits, and regurgitate the seeds without damaging, making them the perfect dispersers. Since they travel long distances in search of fruits, they are capable of moving these seeds to distant locations.

Grey hornbills are effective seed dispersers for trees such as Premna tomentosa (a teak like tree), Putranjiva, Fern trees and even Sandalwood trees! Many of these are medicinally and commercially valuable trees but they generate very few seeds and propagation depends on birds like these hornbills.

Mid-air play and fight
Like many other hornbills, the grey hornbill has a long curved bill, which has a casque (helmet) on the top. The male hornbills engage in midair clashes where they jar against each other’s casques to establish their dominance and as part of their social play. This behaviour is known as aerial jousting.

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re-friend a sparrow

Posted by on 20 Mar 2014 | Category: photography, prakriti

It’s world sparrow day today, 20th March. Sparrows have been those winged companions of humans for a long time. Over the recent years there has been a sharp decline in the sparrow sightings though- probably owing to the mindless advancement of their human companions?

Here are some images from our kitchen window, and ideas on how you can re-friend a sparrow.

house sparrow, passer domesticus at bird feed
A female house sparrow feeding a juvenile.
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copyright violation and the indian treepie

Posted by on 09 Mar 2011 | Category: india, life, photography, prakriti

It was sarah who spotted the bird’s picture in the magazine first. We were at the pune railway station seeing off our mom who came to visit us, and we bought this magazine for her to read. Before she boarded the train, sarah skimmed through the pages and one of the images in it looked very much familiar! The indian treepie with its pose and the papaya tree it is perching on, rang a bell! After all, sarah had even made a painting out of this photograph. The magazine had cropped and published the photograph without credits/consent from us.

The photograph which appeared on the magazine:

copyright violation of photograph of the indian treepie bird
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babbler sisters

Posted by on 01 Mar 2011 | Category: photography, prakriti

The jungle babblers are called seven sisters as they are gregarious (social, group forming) in nature and always appear in groups of around 7 birds (6~10). They also display sentinel (guard) behaviour which usually involves one or two members from the babbler group keeping watch, up in the branches, while the rest of the group search for food in the safety of the bushes.  If there is any threat, the guard on the upper branch squeals out, which is passed down to the other members, and they all fly away.

jungle babbler turdoides striatus somervillei at lonar, maharashtra

Jungle babblers can be easily identified from a distance by the chit chat and playful squeaky noise they make. Watch out next time, they are almost everywhere in India.

Species: Turdoides striatus somervillei
English: Jungle Babbler; Hindi: Saat bhai; Malayalam: Poothankeeri, Kariyilappada
Location: Lonar, Buldhana, Maharashtra
Date: 21 Feb 2011

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