ADVERTISEMENT

How The White Stork Protects Sparrows

More than 10% of bird species breed colonially, in assemblages. This strategy has several advantages. Birds in colonies can detect predators more efficiently, defend communally or perform communal feeding trips.

One particular form of communal breeding is the nesting of small-bodied species, such as passerines within nests of larger birds, like raptors. Passerines that inhabit nests of other, non-passerine birds may have an advantage over others that breed in a less safe location in terms of predation. Usually, they choose nests of more aggressive species, which may help to increase breeding success.

ADVERTISEMENT

An example of this phenomenon is the nesting of passerines in white stork nests. In Europe, house and tree sparrows and starling are the most common residents of a white stork nest. Storks build large, thick nests, that are reused and rebuilt for several breeding seasons, providing good shelter from harsh weather conditions, like low temperatures and strong wind or rain, and they are available year-round.

Although this phenomenon is well-known thanks to many papers, the particular factors driving the occurrence of passerines within stork nests have not been widely studied.

It was worthwhile to address this issue especially because populations of sparrows are currently declining in many European countries, including Poland. Availability of nesting niches has become lower because many settlements have been restored and covered by thermal insolation. This is the most important factor, besides food availability, causing the decline of sparrows. In this context, stork nests may be a key element in farmland to provide favorable breeding sites for passerines.

In our study, we aimed to find out which factors determine the presence or absence, the number, and their abundance of species within stork nests. We conducted our research in an extensively used, traditional farmland in northeast Poland. There, the white stork breeds in the highest densities. We surveyed over 200 stork nests to record the presence of breeding passerines, and which species, in what number breed there. More than a half (57%) of stork nests were inhabited by passerines. These were as follows: house sparrows, 68%; tree sparrows, 65%; and starlings, 30%.

ADVERTISEMENT

During the survey, we also recorded factors such as stork nest thickness, whether the nest was currently occupied by the white stork, the type of nest, location, and several environmental variables like the surface of arable fields, meadows, and distance to human settlements. We checked which factors drove the number of passerine inhabitants of the nest of the stork.

We also checked if the number of residents was increased by the interaction between different species. Sparrows usually forage in open areas like crop fields, meadows, or set-asides. We predicted a possible inter-species competition between them when sharing the same foraging and nesting niches. Research from urban populations led us to assume so. We found more breeding passerines in thicker stork nests and in those currently occupied by a pair of white storks. The probability of breeding passerines was higher in stork nests located on electricity poles and in those which were closer to buildings. We found more passerines in stork nests with a higher number of crop fields in the surrounding areas.

White Stork nests are favorable nesting sites for passerines because they are well-insulated and probably safer from predators (mammal and avian). They may offer specially protected sites for small passerine birds. By protecting stork nest sites, we can also protect several other declining birds.

These findings are described in the article entitled Factors determining presence of passerines breeding within White Stork Ciconia ciconia nests, recently published in the journal The Science of Nature. This work was conducted by Adam Zbyryt from The Polish Society for Birds Protection, Dariusz Jakubas from the University of Gdańsk, and Marcin Tobółka from Poznań University of Life Sciences.

ADVERTISEMENT

Comments

READ THIS NEXT

Types Of Connective Tissue With Examples

The types of connective tissue include cartilage, bone, collagen fibers, reticular fibers, elastic fibers, blood, hemopoietic/lymphatic, adipose tissue, bone marrow, […]

Cellular Stress And Ampk Activators Including Metformin And The Anesthetic Drug Propofol Promote Restoration Of Human Consciousness

The neural mechanisms that give rise to human consciousness have been described as one of the greatest and most profound […]

Icing Conditions Forecasting: Using WRF Model And MSG To Predict Dangerous Flight Conditions

As the natural environment for an aircraft is the atmosphere, meteorology is a major variable in aviation safety management. The […]

Trump Administration Kills NASA Program For Monitoring Greenhouse Gases

The Trump Administration has recently rescinded funding for a program which measures atmospheric levels of greenhouse gases. NASA’s Carbon Monitoring […]

How Many Amino Acids Are In The Body: Essential And Non-Essential

Amino acids are compounds which contain the functional groups amine and carboxyl, and are composed of the elements hydrogen, oxygen, […]

Using Siglec-8 Endocytic Mechanisms To Target Human Eosinophils And Malignant Mast Cells

Pharmacological selectivity remains a critical goal in medicine. Most drugs act on a number of molecular targets and are also […]

What Continent Is India In?

India is in the Asian continent, however, some people consider India as being in the Indian subcontinent since it is […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?