I discovered 105 effective nests, mainly whenever you are riding slow across the land
Throughout for every single breeding 12 months we wanted nests intensively around the study site. I adopted the fresh new future of each and every nest through to the eggs hatched or even the nest hit a brick wall. Nests was basically decided to go to between 0900 and 1700 days additionally the check outs lasted 200 m from the colony, ranging from 1000 and 1700 days. Length of the focal findings ranged regarding 31 minute so you can eight h, and also the full duration of observation is actually 31.5 h. Given that our very own findings varied in length so there was times in the that male is at this new nest from day to night, in order to estimate the percentage of nest desire i pooled the brand new focal observations off nests that have been in one stage regarding incubation.
Just like the males may wasteland the latest nest when disturbed at the an initial phase of your own nesting years ( Fernandez and you may Reboreda 2000), we tracked the vast majority of nests (9 of one’s eleven circumstances totaling 34 colony-days) during middle- or later incubation
The thermistor of the temperature logger was introduced in a fresh natural orphan egg (unattended eggs laid far from active nests; Navarro et al. 1998) through a small hole in the equatorial plane and fixed to the eggshell with epoxy adhesive. The egg was attached to the center of the nest and the data logger was hidden under the nest. The data logger automatically recorded the temperature at 3.8 or 6 min intervals during four or six days, respectively. We monitored egg temperatures in those 11 nests totaling 40 nest-days. In the other two cases we started the monitoring of the nest three and five days after the laying of the first egg. None of the nests used for monitoring male activity was deserted. We used the decrease in egg temperature to determine when the male left the nest ( Hainsworth et al. 1998, Flint and Grand 1999). We previously estimated egg cooling-rate of Greater Rhea eggs by heating six fresh eggs up to 33°C and then placing them in an environment at a temperature of 25°C, similar to temperatures registered in our study area between 1100 and 1300 hours (the warmest time of the day). We estimated egg cooling-rate by dividing the initial difference in temperature between eggs and the environment by the time elapsed until eggs reached a thermal equilibrium with the environment. The estimated egg cooling-rate for a temperature gradient of 8°C was 0.063 ± 0.01°C min ?1 . We assumed that the male left the nest when the difference in egg temperature was |T(t) ? T(t?1)| > 1°C, where T(t) and T(t?1) are egg temperatures at a time interval of 15 min when data loggers were set at 3.8 min intervals or 18 min when they were set at 6 min intervals. We considered that the male was outside the nest since the time at which the difference between T(t) and T(t?1) was negative until the time it was positive (i.e. the male resumed incubation). Although the sun can heat eggs when the male is absent (particularly at midday), unattended eggs never reached temperatures >30°C (see below). Therefore, it was possible for us https://lovingwomen.org/no/blog/datingkultur-i-sor-korea/ to discriminate between an increase in temperature produced by the Sun and one produced by males when they resume incubation.
We together with mentioned variation inside the eggs heat into the around three experimental nests (nests versus men attention). I made use of nests that had been in earlier times left behind as the experimental nests. From inside the for every single nest (clutch systems of 16, 21, and you may 23 eggs) we repaired one-egg which have an effective thermistor inside, on center of your own colony in a similar way you to definitely we did for the energetic nests (see a lot more than).
