Resolution:
## Figure 1.
Time-dependent dynamics of competitive fertilisation. (a) The probability that a low-mobility ejaculate wins sperm competition declines
drastically over a laying sequence, and more so when its numerical advantage is reduced.
The fertilising advantage of the low-mobility ejaculates was restricted to the first
eggs ovulated following insemination. The extent of this initial fertilising advantage
was determined by the numerical superiority of the low-mobility ejaculate over the
high mobility ejaculate. In the 4:1 treatment, the low-mobility ejaculate retained
a fertilising advantage over the eggs produced in the first five days, in the 2:1
treatment, this fertilising advantage was restricted to the eggs produced in the first
day. Data points represent paternity share averaged for all the hens of a male pair,
and across the five male pairs (vertical bars: SE). (b) The difference in sperm mobility
between competing ejaculates had a progressively stronger influence on paternity towards
the last days of a laying sequence and more so when the numerical advantage to the
low-mobility ejaculate was reduced (2:1 treatment). For each laying day (1–12), within
each insemination treatment (2:1 and 4:1), we analysed the linear regression of the
probability of paternity by the low-mobility ejaculate of a male pair over its mobility
ratio (n = 5 for each treatment/laying day combination). The graph presents the slope
(b) of these regression functions obtained over successive laying days for the 2:1 (black
data points) and the 4:1 (grey) insemination treatments. The slope of probability
of paternity over mobility ratio becomes steeper over the laying sequence, and more
so in the 2:1 treatment.
Pizzari |