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Abundance of owls and bramblings Fringilla montifringilla in relation to mast seeding in south-eastern Sweden.

Lithner, S and Jönsson, Ingemar LU (2002) In Ornis Svecica 12(1-2). p.35-45
Abstract
We investigated the relationship between mast seeding in beech Fagus sylvaticus and oak Quercus spp., and the occurrence of the rodent-dependent predators Tengmalm's Owl Aegolius funereus, Long-eared Owl Asio otus and Tawny Owl Strix alaco in south-eastern Sweden (Blekinge) 1992-2000. We also compared available data on seed production with data on winter flocks of Brambling Fringilla montifringilla, mainly depending on beech seeds as winter food. Years of good beech mast production were followed by years of high frequency of Tengmalm's Owl and Long-eared Owl, indicating a rapid numerical response to improved food conditions. The Tawny Owl did not respond in the same way, but tended to reach high densities two years after mast seeding.... (More)
We investigated the relationship between mast seeding in beech Fagus sylvaticus and oak Quercus spp., and the occurrence of the rodent-dependent predators Tengmalm's Owl Aegolius funereus, Long-eared Owl Asio otus and Tawny Owl Strix alaco in south-eastern Sweden (Blekinge) 1992-2000. We also compared available data on seed production with data on winter flocks of Brambling Fringilla montifringilla, mainly depending on beech seeds as winter food. Years of good beech mast production were followed by years of high frequency of Tengmalm's Owl and Long-eared Owl, indicating a rapid numerical response to improved food conditions. The Tawny Owl did not respond in the same way, but tended to reach high densities two years after mast seeding. These results suggest that mast seed production may influence the populations of rodent- feeding predators, and that the numerical response may be very rapid in potentially nomadic specialist predators. This was indicated particularly for the Tengmalm's Owls arriving in Blekinge rather late in spring of 1999. Winters following good beech mast production normally held large numbers of Bramblings. However Bramblings were absent in Blekinge during the winter of 1992/93 despite the very good year for beechnut production in 1992. Thus, low number of Bramblings was no reliable indication for low numbers of owls the following spring. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Ornis Svecica
volume
12
issue
1-2
pages
35 - 45
publisher
Sveriges Ornitologiska Förening
external identifiers
  • scopus:0036067093
ISSN
1102-6812
language
English
LU publication?
yes
id
9bef8145-b988-4f6c-95fa-9391b0d64846 (old id 149285)
date added to LUP
2007-07-03 13:41:02
date last changed
2017-01-01 07:22:12
@article{9bef8145-b988-4f6c-95fa-9391b0d64846,
  abstract     = {We investigated the relationship between mast seeding in beech Fagus sylvaticus and oak Quercus spp., and the occurrence of the rodent-dependent predators Tengmalm's Owl Aegolius funereus, Long-eared Owl Asio otus and Tawny Owl Strix alaco in south-eastern Sweden (Blekinge) 1992-2000. We also compared available data on seed production with data on winter flocks of Brambling Fringilla montifringilla, mainly depending on beech seeds as winter food. Years of good beech mast production were followed by years of high frequency of Tengmalm's Owl and Long-eared Owl, indicating a rapid numerical response to improved food conditions. The Tawny Owl did not respond in the same way, but tended to reach high densities two years after mast seeding. These results suggest that mast seed production may influence the populations of rodent- feeding predators, and that the numerical response may be very rapid in potentially nomadic specialist predators. This was indicated particularly for the Tengmalm's Owls arriving in Blekinge rather late in spring of 1999. Winters following good beech mast production normally held large numbers of Bramblings. However Bramblings were absent in Blekinge during the winter of 1992/93 despite the very good year for beechnut production in 1992. Thus, low number of Bramblings was no reliable indication for low numbers of owls the following spring.},
  author       = {Lithner, S and Jönsson, Ingemar},
  issn         = {1102-6812},
  language     = {eng},
  number       = {1-2},
  pages        = {35--45},
  publisher    = {Sveriges Ornitologiska Förening},
  series       = {Ornis Svecica},
  title        = {Abundance of owls and bramblings Fringilla montifringilla in relation to mast seeding in south-eastern Sweden.},
  volume       = {12},
  year         = {2002},
}