As you can see, sparrow house-building is on at a furious pace !

I found this study from the UK : A sparrow needs to eat 82 % of its body weight in insects and centipedes daily ! but when subsisting on cereals, 36 % of its body weight will do..

The sparrow-hawk which is very similar to a Shikra has to eat 28 % of its body weight in birds. That amounts to two sparrows a day !

A Lapwing - Teetri, needs to eat 46 % of its body weight if it subsists on anthropods - insects, centipedes, milipeeds and spiders.

Here's something depressing we all need to do something about : A study published this year, is the first ever comprehensive census of the weight of living creatures. Humans account for about 36 percent of the biomass of all mammals. Domesticated livestock, mostly cows and pigs, account for 60 percent, and wild mammals for only 4 percent. The same holds true for birds. The biomass of poultry is about three times higher than that of wild birds.

Before we started doing mega destruction of other mammals, those on land were 7 times those now alive, and those in the seas were five times now alive. 

We need to actively limit our own population and even more than us, the population of the cattle whose products we consume.

Birds & Ecosystem Services

Attribution: Andrew Butko / CC-BY-SA 3.0

Everyone in the world depends completely on Earth’s ecosystems and the services they provide, such as food, water, disease management, climate regulation, spiritual fulfillment, and aesthetic enjoyment. 

Studies have sought to examine the services provided by birds in the ecosystems they inhabit.

Birds encourage more and healthier plant growth by the spread of their poop which is an excellent additive to any fertilizer. By spreading activities through different habitats, birds can move nutrients from one place to another, which is particularly relevant in places where plant growth is limited by nutrient availability. A study on the islands in the Gulf of California showed that when birds roosted on them, the guano deposits they left behind provided nutrients to plants on the island. As a result, islands with seabirds had plants that grew taller and faster and were much more productive than those on islands without birds.

Utkarsh22december / CC-BY-SA 4.0

Wetlands are considered one of the most valuable habitats, providing an array of important services like shoreline stabilization and water filtration. In the southeastern United States, snails can overgraze the grasses in salt marshes and completely convert a productive marsh into mudflats. Several species of birds such as oystercatchers, curlews, and plovers are predators of these snails and control their numbers, which regulates primary productivity of salt marshes.

Waterbirds play key functional roles in many aquatic ecosystems, including as predators, herbivores and vectors of seeds, invertebrates and nutrients. Waterbirds can maintain the diversity of other organisms, control pests, be effective bio-indicators of ecological conditions, and act as sentinels of potential disease outbreaks. They also provide important provisioning (meat, feathers, eggs, etc.) and cultural services to both indigenous and westernized societies. 

Apple Blossom @ Manali, India / Sanu N / CC-BY-SA 4.0

The construction of nest boxes for great tits in apple orchards has been shown to lead to greater numbers of birds in the area, which forage on caterpillars that can cause damage to crops, resulting in significantly higher crop yields. Similarly, the use of artificial perches for raptors around agricultural fields may increase the number of raptors that prey on rodents that can cause damage to crops. If installed and maintained properly, the construction of bird nest boxes can eliminate the need for pesticides, saving farmers money and preventing potentially dangerous chemicals from being applied.

Buffalos and crane birds, Chinawal village, India / ABHIJEET / CC-BY-SA 3.0

Many birds perch on livestock like cattle and forage on insects that live on them. Cattle egrets are particularly well known for making a living this way. When infested with ticks, cows can become anemic and milk production flags. In Pakistan, birds are capable of effectively preying on these parasites, leading to healthier and more productive cows. This predation by birds is even more effective than pesticides in some cases.

Scavenging by birds is an important mechanism of waste disposal in many areas and prevents the outbreak of diseases than can occur through the accumulation of animal carcasses. In India, declines in vultures led to increases in feral dogs as there was less competition for carrion as a food source. The explosion of the dog population led to increases in rabies outbreaks and human injuries from dog attacks. The total estimated health cost of vulture declines between 1993 and 2006 is a whopping $34 billion.

KostasGiannakis / CC-BY-SA 4.0

Another way that birds can provide regulating services is through promoting forest growth. When birds pick a seed or fruit from a plant and fly off with it, they end up transporting the seed to another place where it can germinate. This behavior is a major mechanism for seed dispersal in many plants and can increase the genetic diversity of plants in a particular area by spreading seeds. By germinating the seeds of trees, birds can contribute to the reforesting of deforested lands, diminishing the costs of restoration. In oak forests in Sweden, the cost of replacing the seed dispersal services of Eurasian jays in oak regeneration is an estimated $9,400 per hectare

Finally, cultural services by birds include spiritual enrichment, companionship, music and the appreciation of nature.

Acknowledgement : The blog post above is largely an edited version of this article.

The story of the Swallows in the Himalayas..

I found more pictures of Swallows in the Himalayas that I thought I would share.. here is this remarkable nest built on my father’s rain-shade at his front door – made with mud by the swallow parents.

And here is the parent swallow.. Janaki Lenin writes in the Hindu that ‘Unlike other birds that seek natural settings far away from humans to raise their young, barn swallows seem to idealise human-made structures.’ The article is very charming and worth a read.

While these pictures were taken by my father and husband in the Himalayas, here is a clearer one from the net.

And here are the babies in the same nest we saw before.. Janaki writes : ‘Swallows sit on overhead electric lines, watching the hustle and bustle of the street below. When one spots and insect, it swoops down, weaving its way between pushcarts, vehicles, and pedestrians. The bird snaps up its insect prey in mid-flight and dives into the shop or house to cram its prize into a hungry yellow mouth.’

Here is the final picture taken at a nearby shop of the parent swallow in mid-flight. Janaki writes : ‘Many shops in market areas across the Himalayas — from Kullu in Himachal Pradesh to Kurseong in West Bengal — host the nests of barn swallows. Some have three or four nests, and the space above people’s heads is busy with air traffic as the parent birds speed in and out, provisioning their young.’