Preen gland removal increases plumage bacterial load but not that of feather-degrading bacteria

  title={Preen gland removal increases plumage bacterial load but not that of feather-degrading bacteria},
  author={G{\'a}bor {\'A}rp{\'a}d Czirj{\'a}k and P{\'e}ter L{\'a}szl{\'o} Pap and Csongor I. V{\'a}g{\'a}si and Mathieu Giraudeau and Cosmin Mureșan and Pascal Mirleau and Philipp Heeb},
The preen gland is a holocrine sebaceous gland of the avian integument which produces an oily secretion that is spread on the plumage during preening. It has been suggested that birds may defend themselves against feather-degrading bacteria (FDB) and other potential pathogens using preen gland secretions. However, besides some in vitro studies, the in vivo bacterial inhibitory effects of the preen oil on the abundance of feather-associated bacterial species has not yet been studied in… 
Experimental study of the effect of preen oil against feather bacteria in passerine birds
This is the first study providing experimental evidence that preen oil represents an important antimicrobial mechanism against those plumage bacteria that are attached to feathers.
Feather bacterial load affects plumage condition, iridescent color, and investment in preening in pigeons
It is found that birds of both sexes had a plumage in higher condition and invested less in preen secretion quantity and preening behavior when feather bacterial load was lower, suggesting that preening is an inducible antibacterial defense.
Preen oil and bird fitness: a critical review of the evidence
  • G. Moreno-Rueda
  • Biology
    Biological reviews of the Cambridge Philosophical Society
  • 2017
The uropygial gland appears to have several non‐mutually exclusive functions in birds, and thus is likely to be subject to several selective pressures, and future studies should consider how the inevitable trade‐offs among different functions drive the evolution of uropyGial gland secretions.
The effect of uropygial gland secretions of Spectacled Thrushes (Turdus nudigenis) on feather degradation and bacterial growth in vitro
The results support that uropygial secretion of Spectacled Thrushes retarded feather degradation not through a chemical effect, but possibly by alternative mechanisms such as the formation of a physical barrier that isolated feather-degrading bacteria from feathers.
Uropygial gland size and composition varies according to experimentally modified microbiome in Great tits
This study provides the first experimental evidence for modifications of investment in the defensive trait that is the uropygial gland in response to environmental microorganisms in a wild bird.
Plumage micro-organisms and preen gland size in an urbanizing context.
Author response for "Innate and adaptive immune proteins in the preen gland secretions of male house sparrows"
Lysozyme functions as an antimicrobial agent, and both lysozyme and IgY likely act in local immune defence of the preen gland, and may also play a role in regulating the local microbiome, with potentially important consequences for chemical communication and signalling.
Feather-Degrading Bacteria: Their Biochemical and Genetic Characteristics
The present review characterizes in detail a wide range of keratinases isolated from feather-degrading bacteria with potential application in feather waste processing.
Sources of variation in uropygial gland size in European birds
The results show that the role of the uropygial gland dynamically varies during the annual cycle, potentially in response to seasonal variation in parasitic infection risk, and aquatic environments may promote the production of gland oil.
Manipulation of parental effort affects plumage bacterial load in a wild passerine
It has been suggested that plumage microorganisms play an important role in shaping the life histories of wild birds. Some bacteria may act as pathogens or cause damage to feathers, and thereby


Effect of preen oil on plumage bacteria: An experimental test with the mallard
A test on whether a feather-degrading bacterium can degrade feathers of live birds housed outdoors under seminatural conditions found no evidence that B. licheniformis degraded wing feathers of Northern Cardinals when applied twice during the winter, despite the fact that it degraded Northern Cardinal feathers when incubated in the authors' laboratory.
Feather micro‐organisms and uropygial antimicrobial defences in a colonial passerine bird
It is suggested that the uropygial gland plays a specific role in regulating the abundance of feather-degrading bacteria that furthermore depends on the social environment of the host.
Seasonally Changing Preen-Wax Composition: Red Knots' (Calidris Canutus) Flexible Defense Against Feather-Degrading Bacteria
It is suggested that preen waxes protect feathers by forming a physical barrier to microbes rather than through chemical properties of the waxes.
The results are the first rigorous demonstration that preen oil is important for plumage condition in nonwaterfowl and that it has insecticidal properties and that reduction in plumages condition on birds without glands is due to an increase in ectoparasites.
Effects of access to preen gland secretions on mallard plumage
It is shown that preen oil acts to maintain plumage condition and suggests that feather microstructure is essential to maintain feathers waterproofness, and shows that plumage waterproofness is mostly due to the spatial micro-structure of feathers.
Chemical warfare? Effects of uropygial oil on feather‐degrading bacteria
Results suggest that birds may defend themselves against some feather-degrading bacteria using uropygial oil, which appears to enhance the growth of one weakly feather- Degrading isolate.
The evolution of size of the uropygial gland: mutualistic feather mites and uropygial secretion reduce bacterial loads of eggshells and hatching failures of European birds
The size of the uropygial gland was positively related to eggshell bacterial loads, and bird species with higher diversity and abundance of feather mites harboured lower bacterial density on their eggshells (Enterococcus and Staphylococcus), in accordance with the hypothesis.
Symbiotic association between hoopoes and antibiotic- producing bacteria that live in their uropygial gland
A tight symbiotic interaction between bacteria that produce antibiotic substances and the hoopoes is suggested, as well as the association with the presence of bacteria living inside their uropygial gland.
Influence of fowl uropygial gland and its secretory lipid components on the growth of skin surface fungi of fowl.
Addition of total lipids and the wax diester component of free-flowing uropygial secretion as 0.2% suspension in Sabouraud's agar medium of individual fungal isolates caused marked suppression of the population growth of A. tamarii, Absidia corymbifera and to some extent of S. brevicaulis.