Advanced

Intraspecific variation in migratory pattern of a partial migrant, the Blue Tit (Parus caeruleus) : An evaluation of different hypotheses

Smith, Henrik G. LU and Nilsson, Jan Åke LU (1987) In The Auk 104(1). p.109-115
Abstract

To evaluate hypotheses explaining intraspecific variation in migratory behavior in partial migrants, a local population of Blue Tits (Parus caeruleus) was studied in southern Sweden. Birds born in the study area and recaptured there in winter were compared with birds recaptured at a nearby bird station where a large number of migrant Blue Tits were passing. By comparing sex ratios among migrants and residents, we concluded that, among juveniles, more than 40% of the females and a significant proportion of the males migrated, while considerably fewer adult females and virtually no adult males did so. Migrant and resident Blue Tits did not differ in size as nestlings, but more late- than early-hatched males migrated. No differences in... (More)

To evaluate hypotheses explaining intraspecific variation in migratory behavior in partial migrants, a local population of Blue Tits (Parus caeruleus) was studied in southern Sweden. Birds born in the study area and recaptured there in winter were compared with birds recaptured at a nearby bird station where a large number of migrant Blue Tits were passing. By comparing sex ratios among migrants and residents, we concluded that, among juveniles, more than 40% of the females and a significant proportion of the males migrated, while considerably fewer adult females and virtually no adult males did so. Migrant and resident Blue Tits did not differ in size as nestlings, but more late- than early-hatched males migrated. No differences in hatching date were determined for females, presumably because most of them migrated. Our findings are consistent with the "dominance hypothesis" as an explanation of partial migration, i.e. that the individuals lowest in rank migrate. The fitness gain that leads dominants to stay as residents may be lower winter mortality or a higher probability of establishing a territory in spring. In either case, keener competition for breeding territories among males than among females as a cause tor higher residency cannot be excluded.

(Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Auk
volume
104
issue
1
pages
7 pages
publisher
BioOne
external identifiers
  • Scopus:0000892185
ISSN
0004-8038
DOI
10.2307/4087239
language
English
LU publication?
yes
id
844215c9-e511-4a80-a250-b5b363ddf104
date added to LUP
2016-07-06 20:11:01
date last changed
2016-08-10 15:53:20
@misc{844215c9-e511-4a80-a250-b5b363ddf104,
  abstract     = {<p>To evaluate hypotheses explaining intraspecific variation in migratory behavior in partial migrants, a local population of Blue Tits (Parus caeruleus) was studied in southern Sweden. Birds born in the study area and recaptured there in winter were compared with birds recaptured at a nearby bird station where a large number of migrant Blue Tits were passing. By comparing sex ratios among migrants and residents, we concluded that, among juveniles, more than 40% of the females and a significant proportion of the males migrated, while considerably fewer adult females and virtually no adult males did so. Migrant and resident Blue Tits did not differ in size as nestlings, but more late- than early-hatched males migrated. No differences in hatching date were determined for females, presumably because most of them migrated. Our findings are consistent with the "dominance hypothesis" as an explanation of partial migration, i.e. that the individuals lowest in rank migrate. The fitness gain that leads dominants to stay as residents may be lower winter mortality or a higher probability of establishing a territory in spring. In either case, keener competition for breeding territories among males than among females as a cause tor higher residency cannot be excluded.</p>},
  author       = {Smith, Henrik G. and Nilsson, Jan Åke},
  issn         = {0004-8038},
  language     = {eng},
  number       = {1},
  pages        = {109--115},
  publisher    = {ARRAY(0x8e46f70)},
  series       = {The Auk},
  title        = {Intraspecific variation in migratory pattern of a partial migrant, the Blue Tit (Parus caeruleus) : An evaluation of different hypotheses},
  url          = {http://dx.doi.org/10.2307/4087239},
  volume       = {104},
  year         = {1987},
}