Not so black, not so white: differences in microorganism load of contiguous feathers from white stork chicks

Abstract

Many organisms are characterised by strikingly contrasting black and white colouration, but the function of such contrasts has been inadequately studied. In the present paper, we tested the function of black and white contrasting plumage in white stork Ciconia ciconia chicks. We found greater abundance and diversity of microorganisms on black compared to adjacent white feathers. In addition, nest size was positively correlated with the abundance and diversity of microorganisms on white feathers. Flight initiation distance (FID), defined as the distance at which adult white storks took flight when approached by a human, was negatively correlated with most measurements of microorganism abundance. Breeding success was generally positively correlated with the abundance and diversity of microorganisms on black feathers. The feather growth rate was positively correlated with some and negatively correlated with other measurements of microbial abundance and diversity. Finally, chick growth was negatively correlated with the number of microbial species on black feathers and positively with the abundance and diversity of microorganisms on white feathers. These findings are consistent not only with the role of microorganisms in the maintenance of a benign microbial environment which differs between black and white feathers, but also with the hypothesis that several taxa of microorganisms found in black and white plumage are virulent, with negative effects on the fitness of their hosts.

Plumage microorganism communities of tidal marsh sparrows

“…Much of the metabarcoding work conducted on integumentary fungal microbial communities in natural systems has focused on reptiles and amphibians impacted by fungal pathogens. 33 , 34 Previous studies of fungal communities associated with avian plumage have focused on the subset of fungal taxa that are culturable 35 , 36 , 37 , 38 or have analyzed abundance (and not taxonomy) of fungal microorganisms. 39 The most common phyla detected in our study, Ascomycota and Basidiomycota, were also abundant in studies on the integument of birds, reptiles, amphibians, and healthy humans.…”

The role of chemical properties of the material deposited in nests of white stork in shaping enzymatic activity and fungal diversity

“…The taxonomic and spatial distributions of the mycobiota in nests of wetland birds appear mainly affected by the properties of materials deposited in the nest constructions (Korniłłowicz-Kowalska et al 2018 ). Most bird nests are built from various plant materials that are typically enriched by animal residues such as hairs, feathers, and insect exoskeletons, and that favour the development of various fungal groups, including cellulolytic and keratinolytic fungi (Korniłłowicz-Kowalska et al 2010 , 2018 ; AI Rubaiee et al 2021 ). Bird nests also house potentially phytopathogenic and zoopathogenic fungi (Korniłłowicz-Kowalska and Kitowski 2013 , 2017 ; Jankowiak et al 2019 ).…”

Nest Box Bacterial Loads Are Affected by Cavity Use by Secondary Hole Nesters

“…Recent research has shown that the nest microbiota plays an important role in mediating the life histories of birds. In particular, microorganisms shape the microbiome of their hosts and play a key role in food digestion (see [ 7 ] for a review) and pathogen defence [ 8 , 9 ], as well as influencing the quality of the plumage [ 10 , 11 ]. There is also a growing body of evidence showing the importance of microbial species for traits of the avian condition and, consequently, for birds’ reproductive success [ 2 , 3 , 4 ].…”