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Declining extra-pair paternity with laying order associated with initial incubation behavior, but independent of final clutch size in the blue tit.

Vedder O, Magrath MJ, Niehoff DL, van der Velde M, Komdeur J - Behav. Ecol. Sociobiol. (Print) (2011)

Bottom Line: Although functional explanations for female engagement in extra-pair copulation have been studied extensively in birds, little is known about how extra-pair paternity is linked to other fundamental aspects of avian reproduction.Consequently, the observed decline in extra-pair paternity with laying order was unaffected by our manipulation and larger clutches included proportionally fewer extra-pair offspring.This decline in proportion of extra-pair offspring with clutch size may be a general pattern within bird species.

View Article: PubMed Central - PubMed

ABSTRACT
Although functional explanations for female engagement in extra-pair copulation have been studied extensively in birds, little is known about how extra-pair paternity is linked to other fundamental aspects of avian reproduction. However, recent studies indicate that the occurrence of extra-pair offspring may generally decline with laying order, possibly because stimulation by eggs induces incubation, which may suppress female motivation to acquire extra-pair paternity. Here we tested whether experimental inhibition of incubation during the laying phase, induced by the temporary removal of eggs, resulted in increased extra-pair paternity, in concert with a later cessation of laying, in blue tits (Cyanistes caeruleus). As expected, experimental females showed a more gradual increase in nocturnal incubation duration over the laying phase and produced larger clutches than controls. Moreover, incubation duration on the night after the first egg was laid predicted how extra-pair paternity declined with laying order, with less incubation being associated with more extra-pair offspring among the earliest eggs in the clutch. However, incubation duration on this first night was unrelated to our experimental treatment and independent of final clutch size. Consequently, the observed decline in extra-pair paternity with laying order was unaffected by our manipulation and larger clutches included proportionally fewer extra-pair offspring. We suggest that female physiological state prior to laying, associated with incubation at the onset of laying, determines motivation to acquire extra-pair paternity independent of final clutch size. This decline in proportion of extra-pair offspring with clutch size may be a general pattern within bird species.

No MeSH data available.


Related in: MedlinePlus

Typical pattern of temperature variation in the nest-bowl of an unmanipulated female over the course of the laying phase. Laying days on the x-axis represent the start of the day (i.e., 00:00 h) on which the respective egg was laid. Shaded areas represent nighttime (i.e., the time between local sunset and sunrise). Consecutive numbers in the graph indicate the small rises in temperature around sunrise, associated with laying the respective egg. Note the increasing duration of periods, starting around sunset, when the temperature is considerably higher than the fluctuations in daily temperature, reflecting female nocturnal incubation (Haftorn and Reinertsen 1985)
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Fig1: Typical pattern of temperature variation in the nest-bowl of an unmanipulated female over the course of the laying phase. Laying days on the x-axis represent the start of the day (i.e., 00:00 h) on which the respective egg was laid. Shaded areas represent nighttime (i.e., the time between local sunset and sunrise). Consecutive numbers in the graph indicate the small rises in temperature around sunrise, associated with laying the respective egg. Note the increasing duration of periods, starting around sunset, when the temperature is considerably higher than the fluctuations in daily temperature, reflecting female nocturnal incubation (Haftorn and Reinertsen 1985)

Mentions: All occupied nestboxes were checked daily during the nest building and laying phase from the start of April. Once egg laying started, all nests were randomly assigned to either a control or experimental treatment (see ‘Experimental protocol’ section), and all new eggs were numbered in the order of laying. At all assigned nests, laying commenced between April 10–19. On the day the first egg was laid, a small temperature logger (iButton [type: DS1921G]; Maxim, Sunnyvale, CA, USA) was placed in the lining underneath the nest-bowl, that recorded temperature (with a resolution of 0.5°C) every 10 min throughout the laying phase (Fig. 1).Fig. 1


Declining extra-pair paternity with laying order associated with initial incubation behavior, but independent of final clutch size in the blue tit.

Vedder O, Magrath MJ, Niehoff DL, van der Velde M, Komdeur J - Behav. Ecol. Sociobiol. (Print) (2011)

Typical pattern of temperature variation in the nest-bowl of an unmanipulated female over the course of the laying phase. Laying days on the x-axis represent the start of the day (i.e., 00:00 h) on which the respective egg was laid. Shaded areas represent nighttime (i.e., the time between local sunset and sunrise). Consecutive numbers in the graph indicate the small rises in temperature around sunrise, associated with laying the respective egg. Note the increasing duration of periods, starting around sunset, when the temperature is considerably higher than the fluctuations in daily temperature, reflecting female nocturnal incubation (Haftorn and Reinertsen 1985)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3299961&req=5

Fig1: Typical pattern of temperature variation in the nest-bowl of an unmanipulated female over the course of the laying phase. Laying days on the x-axis represent the start of the day (i.e., 00:00 h) on which the respective egg was laid. Shaded areas represent nighttime (i.e., the time between local sunset and sunrise). Consecutive numbers in the graph indicate the small rises in temperature around sunrise, associated with laying the respective egg. Note the increasing duration of periods, starting around sunset, when the temperature is considerably higher than the fluctuations in daily temperature, reflecting female nocturnal incubation (Haftorn and Reinertsen 1985)
Mentions: All occupied nestboxes were checked daily during the nest building and laying phase from the start of April. Once egg laying started, all nests were randomly assigned to either a control or experimental treatment (see ‘Experimental protocol’ section), and all new eggs were numbered in the order of laying. At all assigned nests, laying commenced between April 10–19. On the day the first egg was laid, a small temperature logger (iButton [type: DS1921G]; Maxim, Sunnyvale, CA, USA) was placed in the lining underneath the nest-bowl, that recorded temperature (with a resolution of 0.5°C) every 10 min throughout the laying phase (Fig. 1).Fig. 1

Bottom Line: Although functional explanations for female engagement in extra-pair copulation have been studied extensively in birds, little is known about how extra-pair paternity is linked to other fundamental aspects of avian reproduction.Consequently, the observed decline in extra-pair paternity with laying order was unaffected by our manipulation and larger clutches included proportionally fewer extra-pair offspring.This decline in proportion of extra-pair offspring with clutch size may be a general pattern within bird species.

View Article: PubMed Central - PubMed

ABSTRACT
Although functional explanations for female engagement in extra-pair copulation have been studied extensively in birds, little is known about how extra-pair paternity is linked to other fundamental aspects of avian reproduction. However, recent studies indicate that the occurrence of extra-pair offspring may generally decline with laying order, possibly because stimulation by eggs induces incubation, which may suppress female motivation to acquire extra-pair paternity. Here we tested whether experimental inhibition of incubation during the laying phase, induced by the temporary removal of eggs, resulted in increased extra-pair paternity, in concert with a later cessation of laying, in blue tits (Cyanistes caeruleus). As expected, experimental females showed a more gradual increase in nocturnal incubation duration over the laying phase and produced larger clutches than controls. Moreover, incubation duration on the night after the first egg was laid predicted how extra-pair paternity declined with laying order, with less incubation being associated with more extra-pair offspring among the earliest eggs in the clutch. However, incubation duration on this first night was unrelated to our experimental treatment and independent of final clutch size. Consequently, the observed decline in extra-pair paternity with laying order was unaffected by our manipulation and larger clutches included proportionally fewer extra-pair offspring. We suggest that female physiological state prior to laying, associated with incubation at the onset of laying, determines motivation to acquire extra-pair paternity independent of final clutch size. This decline in proportion of extra-pair offspring with clutch size may be a general pattern within bird species.

No MeSH data available.


Related in: MedlinePlus