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Breeding phenology in Rana temporaria . Local variation is due to pond temperature and population size

View Article: PubMed Central - PubMed

ABSTRACT

Frog breeding phenology in temperate zones is usually compared to progress of spring temperatures at a regional scale. However, local populations may differ substantially in phenology. To understand this, local climate and other aspects must be studied. In this study, breeding phenology of the common frog, Rana temporaria, in a set of ponds in southern Sweden is analyzed. There was within year a variation of up to 3 weeks in start of breeding among local populations. Water temperature was measured in the ponds, and breeding tended to be earlier in warmer ponds (surprise!). Breeding was also earlier in ponds with a large breeding congregation. Alternative reasons for these patterns are suggested and discussed. There was a large residual variation. The common frog has a wide range of acceptable wintering sites, and I hypothesize that the particular choice by a local population may explain part of this residual variation.

No MeSH data available.


Breeding time in relation to pond temperature and size of breeding congregation. Breeding time is given as days after March 1. Temperature index is mean daily temperature from loggers during the period of monitoring (different for different years). Population size is estimated as number of spawn clumps in the pond.
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ece32356-fig-0005: Breeding time in relation to pond temperature and size of breeding congregation. Breeding time is given as days after March 1. Temperature index is mean daily temperature from loggers during the period of monitoring (different for different years). Population size is estimated as number of spawn clumps in the pond.

Mentions: There were effects of pond temperature (average logger value for 2011–2015) and number of breeding frogs (average spawn clump number 2011–2015) on average breeding time in 2011–2015 (mult. regression; temperature: t = 4.31, P = 0.001; number: t = 3.00, P = 0.008). Stated differently, some ponds are consistently early and others late. Early ponds are relatively warm and/or attract large number of breeding frogs (Fig. 5).


Breeding phenology in Rana temporaria . Local variation is due to pond temperature and population size
Breeding time in relation to pond temperature and size of breeding congregation. Breeding time is given as days after March 1. Temperature index is mean daily temperature from loggers during the period of monitoring (different for different years). Population size is estimated as number of spawn clumps in the pond.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC5016643&req=5

ece32356-fig-0005: Breeding time in relation to pond temperature and size of breeding congregation. Breeding time is given as days after March 1. Temperature index is mean daily temperature from loggers during the period of monitoring (different for different years). Population size is estimated as number of spawn clumps in the pond.
Mentions: There were effects of pond temperature (average logger value for 2011–2015) and number of breeding frogs (average spawn clump number 2011–2015) on average breeding time in 2011–2015 (mult. regression; temperature: t = 4.31, P = 0.001; number: t = 3.00, P = 0.008). Stated differently, some ponds are consistently early and others late. Early ponds are relatively warm and/or attract large number of breeding frogs (Fig. 5).

View Article: PubMed Central - PubMed

ABSTRACT

Frog breeding phenology in temperate zones is usually compared to progress of spring temperatures at a regional scale. However, local populations may differ substantially in phenology. To understand this, local climate and other aspects must be studied. In this study, breeding phenology of the common frog, Rana temporaria, in a set of ponds in southern Sweden is analyzed. There was within year a variation of up to 3 weeks in start of breeding among local populations. Water temperature was measured in the ponds, and breeding tended to be earlier in warmer ponds (surprise!). Breeding was also earlier in ponds with a large breeding congregation. Alternative reasons for these patterns are suggested and discussed. There was a large residual variation. The common frog has a wide range of acceptable wintering sites, and I hypothesize that the particular choice by a local population may explain part of this residual variation.

No MeSH data available.