Seasonal changes in foraging strategies of nesting blackbirds (Turdus merula L.)

J. Török, Éva Ludvig

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Blackbirds are usually multiple-prey loaders and forage mainly on the ground. We analysed the foraging behaviour of ten males in an urban park in Budapest during the breeding season from 1984 to 1986. At the end of April and in May blackbirds fed their nestlings mainly on earthworms (load type I). In this period the average scarching time and route were shorter, and the territories of the pairs tended to be smaller, than in June, when males in addition brought a great variety of invertebrates per load (load type II) to the young. The average dry weight and energy content of the two load types did not differ significantly. However, the average energy delivery rate (energy content/intervisiting time) and rate of energy gain (energy content/searching time) were higher when males collected earthworms, because intervisiting and searching times were shorter. The frequency distribution of searching times for load type I suggests that the encounter with earthworms was random. For load type II birds seemed to employ a fixed-mass foraging strategy. In June, the drier conditions reduced the availability of earthworms, and blackbirds extended their foraging areas.

Original languageEnglish
Pages (from-to)329-333
Number of pages5
JournalBehavioral Ecology and Sociobiology
Volume22
Issue number5
DOIs
Publication statusPublished - May 1988

Fingerprint

Turdus merula
Oligochaeta
earthworms
earthworm
energy content
foraging
energy
loaders
Invertebrates
breeding season
nestling
foraging behavior
invertebrates
Birds
Breeding
forage
invertebrate
birds
bird
Weights and Measures

ASJC Scopus subject areas

  • Behavioral Neuroscience
  • Ecology
  • Animal Science and Zoology

Cite this

Seasonal changes in foraging strategies of nesting blackbirds (Turdus merula L.). / Török, J.; Ludvig, Éva.

In: Behavioral Ecology and Sociobiology, Vol. 22, No. 5, 05.1988, p. 329-333.

Research output: Contribution to journalArticle

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