Limits...
Biparental incubation patterns in a high-Arctic breeding shorebird: how do pairs divide their duties?

Bulla M, Valcu M, Rutten AL, Kempenaers B - Behav. Ecol. (2013)

Bottom Line: The amount of incubation, measured as length of incubation bouts, was on average 51min longer per bout for females (11.5h) than for males (10.7h), at first glance suggesting that females invested more than males.Overall, the daily timing of incubation shifted over the incubation period (e.g., for female incubation from evening-night to night-morning) and over the season, but varied considerably among pairs.Our results highlight how the simultaneous consideration of different aspects of care across time allows sex-specific investment to be more accurately quantified.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioural Ecology & Evolutionary Genetics, Max Planck Institute for Ornithology , Eberhard Gwinner Str. 7, 82319 Seewiesen , Germany.

ABSTRACT
In biparental species, parents may be in conflict over how much they invest into their offspring. To understand this conflict, parental care needs to be accurately measured, something rarely done. Here, we quantitatively describe the outcome of parental conflict in terms of quality, amount, and timing of incubation throughout the 21-day incubation period in a population of semipalmated sandpipers (Calidris pusilla) breeding under continuous daylight in the high Arctic. Incubation quality, measured by egg temperature and incubation constancy, showed no marked difference between the sexes. The amount of incubation, measured as length of incubation bouts, was on average 51min longer per bout for females (11.5h) than for males (10.7h), at first glance suggesting that females invested more than males. However, this difference may have been offset by sex differences in the timing of incubation; females were more often off nest during the warmer period of the day, when foraging conditions were presumably better. Overall, the daily timing of incubation shifted over the incubation period (e.g., for female incubation from evening-night to night-morning) and over the season, but varied considerably among pairs. At one extreme, pairs shared the amount of incubation equally, but one parent always incubated during the colder part of the day; at the other extreme, pairs shifted the start of incubation bouts between days so that each parent experienced similar conditions across the incubation period. Our results highlight how the simultaneous consideration of different aspects of care across time allows sex-specific investment to be more accurately quantified.

No MeSH data available.


Related in: MedlinePlus

Decrease in (a) the probability of a detectable exchange gap (≥5 s) and (b) the length of detectable exchange gaps over the incubation period. The solid lines represent the model fit, the shading represents the 95% CI, and the horizontal dashed line in (a) represents the equal probability. Model results are presented in Tables 4 and 5, and the distribution of the raw data is depicted in Supplementary Figure S6.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3860833&req=5

Figure 5: Decrease in (a) the probability of a detectable exchange gap (≥5 s) and (b) the length of detectable exchange gaps over the incubation period. The solid lines represent the model fit, the shading represents the 95% CI, and the horizontal dashed line in (a) represents the equal probability. Model results are presented in Tables 4 and 5, and the distribution of the raw data is depicted in Supplementary Figure S6.

Mentions: There was no detectable exchange gap (<5 s) during 51% of the exchanges (N = 809 exchanges at 47 nests); the median length of all detectable exchange gaps was 35 s (range: 5 s–6.7h; N = 399 detectable gaps from 44 nests). Both the probability of a detectable exchange gap and the length of detectable exchange gaps decreased over the incubation period, irrespective of the sex of the exchanging bird (Figure 5 and Tables 4 and 5). Within-nest variance in the length of detectable exchange gaps accounted for 80% of the overall phenotypic variance (Table 5).


Biparental incubation patterns in a high-Arctic breeding shorebird: how do pairs divide their duties?

Bulla M, Valcu M, Rutten AL, Kempenaers B - Behav. Ecol. (2013)

Decrease in (a) the probability of a detectable exchange gap (≥5 s) and (b) the length of detectable exchange gaps over the incubation period. The solid lines represent the model fit, the shading represents the 95% CI, and the horizontal dashed line in (a) represents the equal probability. Model results are presented in Tables 4 and 5, and the distribution of the raw data is depicted in Supplementary Figure S6.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3860833&req=5

Figure 5: Decrease in (a) the probability of a detectable exchange gap (≥5 s) and (b) the length of detectable exchange gaps over the incubation period. The solid lines represent the model fit, the shading represents the 95% CI, and the horizontal dashed line in (a) represents the equal probability. Model results are presented in Tables 4 and 5, and the distribution of the raw data is depicted in Supplementary Figure S6.
Mentions: There was no detectable exchange gap (<5 s) during 51% of the exchanges (N = 809 exchanges at 47 nests); the median length of all detectable exchange gaps was 35 s (range: 5 s–6.7h; N = 399 detectable gaps from 44 nests). Both the probability of a detectable exchange gap and the length of detectable exchange gaps decreased over the incubation period, irrespective of the sex of the exchanging bird (Figure 5 and Tables 4 and 5). Within-nest variance in the length of detectable exchange gaps accounted for 80% of the overall phenotypic variance (Table 5).

Bottom Line: The amount of incubation, measured as length of incubation bouts, was on average 51min longer per bout for females (11.5h) than for males (10.7h), at first glance suggesting that females invested more than males.Overall, the daily timing of incubation shifted over the incubation period (e.g., for female incubation from evening-night to night-morning) and over the season, but varied considerably among pairs.Our results highlight how the simultaneous consideration of different aspects of care across time allows sex-specific investment to be more accurately quantified.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioural Ecology & Evolutionary Genetics, Max Planck Institute for Ornithology , Eberhard Gwinner Str. 7, 82319 Seewiesen , Germany.

ABSTRACT
In biparental species, parents may be in conflict over how much they invest into their offspring. To understand this conflict, parental care needs to be accurately measured, something rarely done. Here, we quantitatively describe the outcome of parental conflict in terms of quality, amount, and timing of incubation throughout the 21-day incubation period in a population of semipalmated sandpipers (Calidris pusilla) breeding under continuous daylight in the high Arctic. Incubation quality, measured by egg temperature and incubation constancy, showed no marked difference between the sexes. The amount of incubation, measured as length of incubation bouts, was on average 51min longer per bout for females (11.5h) than for males (10.7h), at first glance suggesting that females invested more than males. However, this difference may have been offset by sex differences in the timing of incubation; females were more often off nest during the warmer period of the day, when foraging conditions were presumably better. Overall, the daily timing of incubation shifted over the incubation period (e.g., for female incubation from evening-night to night-morning) and over the season, but varied considerably among pairs. At one extreme, pairs shared the amount of incubation equally, but one parent always incubated during the colder part of the day; at the other extreme, pairs shifted the start of incubation bouts between days so that each parent experienced similar conditions across the incubation period. Our results highlight how the simultaneous consideration of different aspects of care across time allows sex-specific investment to be more accurately quantified.

No MeSH data available.


Related in: MedlinePlus