We receive 105 productive nests, mainly when you are operating slowly along the land
Throughout the for every reproduction season we sought out nests intensively all-over the research site. I then followed brand new fate of each and every nest up until the egg hatched or perhaps the nest unsuccessful. Nests was basically went along to between 0900 and 1700 times additionally the visits lasted 2 hundred m away from the colony, ranging from 1000 and you will 1700 occasions. Length of the latest focal findings varied out of 30 min so you’re able to 7 h, in addition to total duration of observation was 30.5 h. As the our very own findings varied in length there was in fact circumstances for the that men was at the fresh new nest throughout the day, so you’re able to imagine brand new portion of nest attention i pooled the newest focal findings out of nests which were in one stage out of incubation.
Once the men are more likely to wilderness this new nest when interrupted at the an early stage of your own nesting duration ( Fernandez and you may Reboreda 2000), i monitored a lot of the nests (nine of your own eleven instances totaling 34 nest-days) during the mid- otherwise late 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 to discriminate between an increase in temperature produced by the Sun and one produced by males when they resume incubation.
I as well as mentioned adaptation from inside the egg heat from inside the three fresh nests (nests in place of men focus). We put nests that were in earlier times discontinued https://lovingwomen.org/tr/badoo-inceleme/ as experimental nests. Within the per nest (clutch products away from 16, 21, and 23 eggs) we repaired one-egg having a good thermistor to the, with the cardiovascular system of the nest similarly one to we did toward effective nests (discover a lot more than).
