10.5061/DRYAD.SQ651
Källander, Hans
Lund University
Hasselquist, Dennis
Lund University
Hedenström, Anders
Lund University
Nord, Andreas
Lund University
Smith, Henrik G.
Lund University
Nilsson, Jan-Åke
Lund University
Data from: Variation in laying date in relation to spring temperature in
three species of tits (Paridae) and pied flycatchers Ficedula hypoleuca in
southernmost Sweden
Dryad
dataset
2016
Egg laying
Spring temperature
2016-11-16T14:05:01Z
2016-11-16T14:05:01Z
en
https://doi.org/10.1111/jav.01287
225522 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
This study documents the advancement of laying dates in three species of
tits (Paridae) in southernmost Sweden during recent decades, and the
absence of a similar response in the pied flycatcher Ficedula hypoleuca.
It is based on several different nestbox studies; the oldest one starting
in 1969. During 1969 to 2012, mean spring temperatures in the study area
increased by between 0.06 and 0.08°C per year, depending on the period
considered. Great tits Parus major, blue tits Cyanistes caeruleus and
marsh tits Poecile palustris, which generally start egg laying between the
last week of April and the first week of May, all advanced laying date at
a similar rate during the study period (0.25 d yr–1). This indicates that
these species were similarly affected by increasing temperatures. When
accounting for mean spring temperature variation, we still found an
advancement of laying date over the study period, mostly due to such
relationships among marsh and blue tits. This result could reflect ongoing
microevolution favouring earlier laying, but could also be a result of
other factors such as increased intra- or inter-specific competition for
early breeding. Pied flycatchers, which generally lay during the third
week of May, did not significantly advance the date of egg laying despite
that the long-term trend in the increase in ambient temperature during the
30-d period preceding the start of egg laying was similar for pied
flycatchers compared to the tit species.
All laydateFile All laydate: Year = year Sp = Species 1 = Marsh tit; 2 =
Blue tit; 3 = Great tit; 4 = Pied flycatcher Reg. = Region 1 = Revinge; 2
= Linnebjer; 3 = Vomb; 4 = Dalby Norreskog; 5 = Frueräften; 6 =
Kungsmarken Temp = Mean ambient temperature for the 30 d preceding the
mean laying date for each species and year Date = Laying of the first egg
in a clutch; 1 = 1 April Anno = Year since the first year in the study; 1
= 1969