Status Signaling in Dark-Eyed Juncos: Perceived Status of Other Birds Affects Dominance Interactions

Abstract

In a number of avian species, individual members of the species vary considerably in appearance. Differences in plumage coloration may be correlated with social status (Rohwer 1975, Whitfield 1987, Butcher and Rohwer 1989). The status-signaling hypothesis states that variation in plumage has evolved to signal differences in individuals' abilities to win agonistic contests (Rohwer 1975, 1977, Butcher and Rohwer 1989). The fundamental assumption is that coloration is a reliable predictor of rank, so that an individual' s color at least partially determines its acquired rank during hierarchy establishment (Rohwer 1985). According to this hypothesis, superior fighters benefit from distinctive color markings ("badges of status") because they reduce either the number or intensity of contests in which they are involved in order to maintain dominant status or priority access to resources (Rohwer 1985). In addition, plumage variability may facilitate individual recognition (

Biogenic amines influence aggressiveness in crayfish but not their force or hierarchical rank

“…When lizards were treated with serotonin or sertraline (a selective 5-HT reuptake inhibitor), mixed results were obtained (Larson & Summers 2001) and only occasional were inversions of dominance found. When dyads of the dark-eyed junco, Junco hyemalis, were subject to colour changes in their plumage, the subordinates initially won most fights, but in the end the original dominant individuals started to win again (Grasso et al 1996). A likely explanation was that the colour of plumage alone does not suffice to determine dominance, appropriate behaviour being possibly needed, as shown in Zonotrichia querula (Rohwer & Rohwer 1978), where subordinates, both dyed and injected with testosterone, became successful cheaters.…”

“…A likely explanation was that the colour of plumage alone does not suffice to determine dominance, appropriate behaviour being possibly needed, as shown in Zonotrichia querula (Rohwer & Rohwer 1978), where subordinates, both dyed and injected with testosterone, became successful cheaters. However, although an individual can fake a badge of dominance, it may be incapable of equating its fighting ability to its faked status and therefore it is disadvantaged by the disproportionate costs it encounters (Grasso et al 1996). For instance, the house sparrow, Passer domesticus, once experimentally implanted with testosterone, showed reduced survival, possibly because of its increased energy consumption due to an excessive breeding effort it was constitutionally unable to sustain (Veiga 1995).…”

Feather melanin and microstructure variation in dark‐eyed juncoJunco hyemalisacross an elevational gradient in the Selkirk Mountains

“…have distinctly coloured plumage, characterised by a dark head and mantle, grey‐brown back, and pale breast (Sibley ). Dark head feathers are a sexually selected trait in males, linked to territoriality and aggressiveness (Holberton et al , Grasso et al ). Contour feathers on the head and body are replaced between February and April (Pyle ).…”

“…Ecological ( NA selected trait in males, linked to territoriality and aggressiveness (Holberton et al 1989, Grasso et al 1996. Contour feathers on the head and body are replaced between February and April (Pyle 1997).…”

Parasite Prevalence in Dark-eyed Juncos, <em>Junco hyemalis</em>, Breeding at Different Elevations

“…2003). Yet, high elevation habitats are not occupied by less competitive age or size classes of juncos, or by later arriving individuals (Bears 2002), all of which are traits that render juncos less successful competitors for territory (Cristol et al 1990;Grasso et al 1996). Further, inter-annual return of birds to their site of capture is high, and roughly equivalent among elevations (Bears 2002).…”