Nests Are Parasite-Free

photograph of a brown, white and black bird perched at the opening of nest

Biological Strategy

House sparrow

AskNature Team

Image: Nrik Kiran / Wikimedia Commons / CC BY SA - Creative Commons Attribution + ShareAlike

Protect From Animals

Animals–organisms that range from microscopic to larger than a bus–embody a wide variety of harms to living systems, including other animals. They threaten through predation, herbivory, defense, and parasitism, and they compete for resources such as water, nutrients, and space. Any given living organism commonly faces threats from a variety of animals, requiring strategies that effectively defend from each. Trout and other bony fish, for example, escape predators by having scales made of very thin, flake-like pieces of bone covered with slippery mucus. They also have behavioral strategies such as camouflage, fast swimming, and twisting and turning to achieve release from a predator’s grip.

Search this Function

Birds

Class Aves (“bird”): Eagles, hawks, sparrows, parrots

Birds are evolutionary engineering marvels. They are descended from dinosaurs, but are far from our idea of heavy, scaly reptiles. Of the specific adaptions that set them apart, most notable is flight—although some mammals can fly, birds take the prize for abundance in the skies. Many birds have hollow, lightweight skeletons and specially-designed wings to help them stay aloft. They also have feathers made of keratin that help them stay warm, attract mates, and improve navigation and aerodynamics in flight. In contrast to their dinosaur ancestors, they lack true teeth and have replaced them with specialized beaks and bills.

Search this Living System

The nests of house sparrows are kept free of parasitic insects by a lining of leaves from the neem tree, containing insect-repelling compounds.

Introduction

Birds are some of the most well-known and well-loved animals in the world. They are also some of the most diverse, with over 10,000 different species. Though they come in all shapes and sizes, they have one thing in common: they all need a safe place to raise their young.

Image: Thermos / Wikimedia Commons /

Detailed image of Sparrow (Passer domesticus). Photographed in Helsinki.

Image: Dori / Wikimedia Commons /

Image: Brams / Wikimedia Commons /

Image: Photo by User:Rex / Wikimedia Commons /

The Strategy

To protect their young from parasites and disease, many birds line their nests with plants that have insect-repelling or anti-microbial properties. The neem tree, for example, contains high concentrations of insect-repelling compounds. The paradise flower tree is rich in the anti-malarial drug quinine. The use of these plants helps to keep the nests clean and the young healthy. In one study, starlings that were raised in nests lined with these plants were found to be heavier and have stronger immune systems than those that were not.

The Potential

The use of plants to keep nests clean and safe is a strategy that could be employed by humans in a variety of ways. For example, the use of insect-repelling or anti-microbial plants could help to keep homes and other buildings free of pests and diseases.

Last Updated May 1, 2020

References

“During an outbreak of malaria in Calcutta during 1998, Dr. Dushim Sengupta and fellow scientists at Calcutta’s Center for Nature Conservation and Human Survival were surprised to witness house sparrows lining their nests with (and also eating) leaves from the paradise flower tree (Caesalpina pulcherrima), a species whose leaves are rich in the anti-malarial drug quinine. Confirming that their choice of leaves was deliberate, the sparrows swiftly gathered fresh leaves of this same species when the scientists removed those already lining their nests. Moreover, before the malaria outbreak, these birds has been using leaves from the neem tree (Azadirachta indica) for nest lining. These contain high concentrations of insect-repellent compounds, which are of great benefit to birds rearing nestlings, who are vulnerable to diseases spread by insects and to nest-dwelling parasitic insects.” (Shuker 2001:216-218)

“Similarly, in 2000 Dr. Helga Gwinner and a team of researchers from the Ornithological Unit of Germany’s Max Planck Society revealed that starlings (Sturnus vulgaris) lined their nests with herbs that ward off or kill nest parasites, such as fleas, lice, and mites. Experiments in which some nestlings were reared in nests lacking these herbs (and in which parasites therefore thrived) showed that these nestlings were anemic; nestlings reared in herb-lined nests were heavier and had stronger immune systems, as confirmed by the presence of greater quantities of infection-fighting cells in their blood.” (Shuker 2001:218)

Book