Individual variation in the strength of territory defense in male song sparrows: Correlates of age, territory tenure, and neighbor aggressiveness

Jeremy Hyman, Melissa Hughes, William Searcy, Stephen Nowicki

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

In 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 melodid) 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.

Original languageEnglish
Pages (from-to)15-27
Number of pages13
JournalBehaviour
Volume141
Issue number1
DOIs
StatePublished - Jan 1 2004

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Sparrows
Passeriformes
Music
animal communication
aggression
Aggression
Individuality
Intrinsic Factor
Aptitude
vigor

Keywords

  • Aggression
  • Melospiza melodia
  • Song sparrow
  • Territoriality

ASJC Scopus subject areas

  • Animal Science and Zoology
  • Behavioral Neuroscience

Cite this

Individual variation in the strength of territory defense in male song sparrows : Correlates of age, territory tenure, and neighbor aggressiveness. / Hyman, Jeremy; Hughes, Melissa; Searcy, William; Nowicki, Stephen.

In: Behaviour, Vol. 141, No. 1, 01.01.2004, p. 15-27.

Research output: Contribution to journalArticle

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