Decline in the frequency and benefits of multiple brooding in great tits as a consequence of a changing environment

TY - JOUR

T1 - Decline in the frequency and benefits of multiple brooding in great tits as a consequence of a changing environment

AU - Husby, A.

AU - Kruuk, L.E.B.

AU - Visser, M.E.

N1 - Reporting year: 2009 Metis note: 4458;CTE; PVD ; AnE; file:///L:/Endnotedatabases/NIOOPUB/pdfs/PDFS2009\Husby_ea_4458.pdf

PY - 2009

Y1 - 2009

N2 - For multiple-brooded species, the number of reproductive events per year is a major determinant of an individual's fitness. Where multiple brooding is facultative, its occurrence is likely to change with environmental conditions, and, as a consequence, the current rates of environmental change could have substantial impacts on breeding patterns. Here we examine temporal population-level trends in the proportion of female great tits (Parus major) producing two clutches per year (‘double brooding’) in four long-term study populations in The Netherlands, and show that the proportion of females that double brood has declined in all populations, with the strongest decline taking place in the last 30 years of the study. For one of the populations, for which we have data on caterpillar abundance, we show that the probability that a female produces a second clutch was related to the timing of her first clutch relative to the peak in caterpillar abundance, and that the probability of double brooding declined over the study period. We further show that the number of recruits from the second clutch decreased significantly over the period 1973–2004 in all populations. Our results indicate that adjustment to changing climatic conditions may involve shifts in life-history traits other than simply the timing of breeding.

AB - For multiple-brooded species, the number of reproductive events per year is a major determinant of an individual's fitness. Where multiple brooding is facultative, its occurrence is likely to change with environmental conditions, and, as a consequence, the current rates of environmental change could have substantial impacts on breeding patterns. Here we examine temporal population-level trends in the proportion of female great tits (Parus major) producing two clutches per year (‘double brooding’) in four long-term study populations in The Netherlands, and show that the proportion of females that double brood has declined in all populations, with the strongest decline taking place in the last 30 years of the study. For one of the populations, for which we have data on caterpillar abundance, we show that the probability that a female produces a second clutch was related to the timing of her first clutch relative to the peak in caterpillar abundance, and that the probability of double brooding declined over the study period. We further show that the number of recruits from the second clutch decreased significantly over the period 1973–2004 in all populations. Our results indicate that adjustment to changing climatic conditions may involve shifts in life-history traits other than simply the timing of breeding.

U2 - 10.1098/rspb.2008.1937

DO - 10.1098/rspb.2008.1937

M3 - Article

SN - 0962-8452

VL - 276

SP - 1845

EP - 1854

JO - Proceedings of the Royal Society B-Biological Sciences

JF - Proceedings of the Royal Society B-Biological Sciences

IS - 1663

ER -