scholarly journals Delayed song maturation and territorial aggression in a songbird

2012 ◽  
Vol 8 (3) ◽  
pp. 369-371 ◽  
Author(s):  
Angelika Poesel ◽  
Douglas A. Nelson

Asymmetries in competitive ability can determine the outcome of social interactions in animals and are often expressed through differences in sexual traits. Competitive ability (resource holding potential, RHP), trait expression and ultimately reproductive success may vary with an individual's age or experience. In some species, reproductively mature males delay acquisition of some adult traits and thereby signal their young age. Theory on animal contests predicts that individuals assess the RHP of an opponent relative to their own, such that escalation is more common between evenly matched opponents. Here, we test predictions from this hypothesis that males respond to a territorial intruder based on their RHP relative to the intruder's RHP. We simulated white-crowned sparrows ( Zonotrichia leucophrys ) intruding into the territory of a recruit or return. Playback of a song repertoire simulating a young male (recruit) elicited a weaker response from established territory holders (return), but a stronger response from recruits. Playback of a single song type simulating an older male elicited the opposite responses. This indicates that males distinguished between simulated young and old intruders based on song, and responded differently depending on their own experience. Our study highlights the possibility that receiver as well as sender traits should be considered when interpreting animal interactions.

Behaviour ◽  
2004 ◽  
Vol 141 (1) ◽  
pp. 15-27 ◽  
Author(s):  
Jeremy Hyman ◽  
Melissa Hughes ◽  
Stephen Nowicki ◽  
William Searcy

AbstractIn many species, the ability to defend a territory is essential for a male to obtain any reproductive success at all, and even among territorial individuals, variation in the strength of territory defense could have a significant impact on how much reproductive success is obtained. Previous studies have documented consistent individual differences in the vigor with which male song sparrows (Melospiza melodia) defend their territories, as measured by the strength of their reactions to territorial intrusions simulated through song playback. Variation in the strength of defense could reflect intrinsic differences among individuals in their resource holding potential (RHP), or variation in extrinsic factors. In this study, we examined whether variation in the strength of territory defense corresponds to differences in intrinsic factors such as the age or experience of the territory owner, the extrinsic factor of the level of aggression shown by neighbours, or both. Results indicate that males that previously held territories on the study site, regardless of whether they were holding the same territory as the previous year, show higher levels of territory defense than males that are new to the study site, and, assuming that returning males are older males, suggest that age is more important than experience on a specific territory in determining strength of territory defense. In addition, we found evidence that males with high levels of territorial aggression tend to be spatially clustered. The pattern observed suggests that a combination of intrinsic and extrinsic factors contribute to the expression of individual differences in territorial aggression.


Behaviour ◽  
1990 ◽  
Vol 112 (3-4) ◽  
pp. 149-161 ◽  
Author(s):  
Elizabeth Franke Stevens

AbstractMale horses (Equus caballus) defend harems of females (bands) year-round and throughout their lifetimes. A male's lifetime reproductive success depends upon the number of females in his harem. Although harems have previously been reported as remaining stable over many years, during the two years of this study 30 % of the adult females in an island population of feral horses changed harems during late winter. The seasonal differences in harem stability resulted from seasonal differences in the abundance and distribution of food. The spacing between band members was greater and the frequency of social interactions between them was lower in winter than in summer. In addition, the amount of time devoted to grazing increased in winter. These differences are attributed to the lower availability of suitable vegetation duirng winter. Harem stability did not depend on the age of females, the size of the harem, nor the age of the harem stallion, but did depend on the presence of subordinate stallions attached to the band. All of the females that changed bands left single-male bands; multi-male bands were stable throughout the study.


1986 ◽  
Vol 64 (9) ◽  
pp. 1926-1929 ◽  
Author(s):  
Susan E. Cosens ◽  
Spencer G. Sealy

Songs of male yellow warblers (Dendroica petechia), ranging from 1 to 6 years of age, were recorded in the spring and summer of 1984. Recorded repertoire size and number of songs shared with neighbours varied positively with age in the spring but not in summer. Neither clutch initiation date nor fledging success varied with age or number of songs shared but both measures of reproductive success varied with size of recorded song repertoire.


1993 ◽  
Vol 71 (5) ◽  
pp. 1059-1061 ◽  
Author(s):  
Andrew G. Horn ◽  
Thomas E. Dickinson ◽  
J. Bruce Falls

The relationship between song repertoire size and measures of male quality and reproductive success was examined in a Manitoba population of western meadowlarks (Sturnella neglecta). Repertoire size correlated positively with the singer's wing length but not with mass or territory size. Males with larger repertoires tended to pair earlier and males with higher pairing success had larger repertoires. Repertoire size correlated positively with fledging success independently of pairing success. As suggested for other species, repertoire size might serve as a signal to females of male quality. We suggest mechanisms by which this signalling system is maintained.


1979 ◽  
Vol 57 (10) ◽  
pp. 2072-2078 ◽  
Author(s):  
Reid N. Harris

The relationship between territorial aggression and reproductive success was studied on a well-established, insular population of tree swallows. Four treatments of nest boxes that differed in interbox distances were created. Short interbox distances significantly reduced the occupancy of nest boxes both between and within years. Swallows in short interbox distance treatments defended more than one nest box, which was an additional resource not necessary for their successful reproduction. Excluded potential breeders attempted to colonize vacant boxes within another swallow's territory throughout the nestling period, but were usually prevented by the aggression of the resident pair. Aggressive activity had no direct effect on three measures of a swallow's reproductive output: percent young fledged, nestling growth, and fledgling weights. The concept of intraspecific aggressive neglect is questioned. However, by excluding potential breeders from nesting, for whatever reason, breeding tree swallows increased their relative genetic contribution to future generations.


2018 ◽  
Author(s):  
Syuan-Jyun Sun ◽  
Nicholas P.C. Horrocks ◽  
Rebecca M. Kilner

AbstractSocial interactions within species, and mutualisms between species are both well characterised, but their influence on each other is poorly understood. We determined how interactions among burying beetles Nicrophorus vespilloides influence the value of their interactions with the mite Poecilochirus carabi. Beetles transport these mites to carrion, upon which both species breed. We show that mites help beetles win intraspecific contests for this scarce resource: mites raise beetle body temperature, which enhances beetle competitive prowess. However, mites confer this benefit only upon smaller beetles, which are otherwise doomed by their size to lose contests for carrion. Larger beetles need no assistance to win a carcass and lose reproductive success when breeding alongside mites. We conclude that social interactions within species explain whether interactions with another species are mutualistic or parasitic.One Sentence SummarySocial interactions within species can explain whether interactions with a second species are mutualistic or parasitic.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
C Joseph Burnett ◽  
Samuel C Funderburk ◽  
Jovana Navarrete ◽  
Alexander Sabol ◽  
Jing Liang-Guallpa ◽  
...  

When presented with a choice, organisms need to assimilate internal information with external stimuli and past experiences to rapidly and flexibly optimize decisions on a moment-to-moment basis. We hypothesized that increasing hunger intensity would curb expression of social behaviors such as mating or territorial aggression; we further hypothesized social interactions, reciprocally, would influence food consumption. We assessed competition between these motivations from both perspectives of mice within a resident-intruder paradigm. We found that as hunger state escalated, resident animal social interactions with either a female or male intruder decreased. Furthermore, intense hunger states, especially those evoked via AgRP photoactivation, fundamentally altered sequences of behavioral choice; effects dependent on food availibility. Additionally, female, but not male, intrusion attenuated resident mouse feeding. Lastly, we noted environmental context-dependent gating of food intake in intruding mice, suggesting a dynamic influence of context cues on the expression of feeding behaviors.


Author(s):  
James A.R. Marshall

This chapter considers a simple and general model of natural selection: replicator dynamics. Many animal traits and behaviors are social, in that they affect the reproductive success not just of the animal performing the behavior, but also conspecifics. Mathematical theories based on classical natural selection, which acts on direct reproduction by individuals, are able to explain the evolution of traits that are for personal advantage. However, this leaves the problem of providing an evolutionary explanation of traits and social behaviors that appear to be personally costly to the bearer, in reproductive terms, while having effects on conspecifics such as increasing their direct reproduction. This chapter uses the replicator dynamics to illustrate the action of natural selection on social behavior, including nonadditive interactions. It considers the additive and nonadditive donation game, and other social interactions, along with public goods games, threshold public goods games, and interactions in structured populations.


2018 ◽  
Author(s):  
Timothy H. Parker ◽  
Marcelina Parra ◽  
Anthony Dalisio ◽  
William E. Jensen

In many songbird species, young males learn songs from neighbors and then settle nearby, thus creating neighborhoods of conformity to local vocal culture. In some species males appear to postpone song learning until after dispersal, possibly to facilitate conformity to local dialects. Despite decades of study, we still lack a consensus regarding the selective pressures driving this delayed song learning. Two common hypothetical benefits to conformity, and thus delayed song learning, are rooted in male territorial interactions; males preferentially produce local song either to avoid detection as new arrivals (deceptive mimicry) or to be more effectively recognized as conspecific territory holders. The dickcissel (Spiza americana) is an ideal species in which to study these hypotheses. Males of this species appear to delay song learning until they arrive at their first adult territory, each individual sings a single song type, and conformity to the local song culture is high. Using playback, we contradicted both of the territorial hypotheses described above; male dickcissels did not respond differentially to local vs foreign song playback treatment. We are confident in this lack of difference because dickcissels clearly responded less strongly to a third treatment, neighbor song, than to the other two treatments, demonstrating sufficient power in our experimental design (and providing the first evidence of the dear-enemy effect in dickcissels). Our results raise the question of why dickcissels respond equally aggressively to both local and foreign songs when other bird species often show reduced aggression towards foreign song. If reduced aggression to foreign song is not ubiquitous in species that achieve conformity through delayed learning then selection from among-male territorial interaction seems unlikely to be a general explanation for such delayed learning. Reduced aggression in response to foreign songs in other species may be due to reduced exposure to the stimulus of foreign song or to different cost-benefit trade-offs when responding to songs that deviate from the local average.


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