Posts Tagged 'mating'

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.

blue marsh hawk and the skimmers

Posted by on 12 Jun 2014 | Category: photography, prakriti

The blue marsh hawk belong to the dragonfly family of skimmers, and are conspicuous with their blue thorax and tail.

blue marsh hawk,  orthetrum glaucaum

Dragonflies, especially the males of some species, are also territorial in nature. Research shows that among some marsh skimmers, the males with longer hind wings have an upper hand in winning territorial conflicts.

Species: orthetrum glaucaumFamily: libellulidae

Here are a few other skimmers from our earlier articles:

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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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crimson marsh glider and its pruinescence

Posted by on 09 Dec 2013 | Category: photography, prakriti

Crimson marsh gliders are crimson, and frequent visitors to marshlands.

crimson marsh glider, trithemis aurora

Well, it is the male who is crimson, and the female (below) adorns totally different colors.
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common yellow swallowtail

Posted by on 15 Jun 2013 | Category: photography, prakriti

The swallowtail family of butterflies include the largest butterflies in the world. The common yellow swallowtail here is a widespread species, through Asia, Europe and North America. The image here is from the Island of Rhodes in Greece, but a subspecies of the same occurs in India.

common yellow swallowtail, papilio machaon

It is interesting to note that in some species of the papilionidae family of butterflies, the males glue the female genital tract after mating. Mating plugs, as they are called, assures sperm storage without any loss, and also has a role in preventing the females from remating- a function to enhance male control over females in copulation. Not sure if the yellow swallowtails have this capability.

Meanwhile, the caterpillars of the common yellow swallowtails have special tactics to detract enemies. They have an eversible (turn inside out) cervical gland called osmeterium, which produces acidic secretion effective in defense against ants.
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