Revision summary

Individual entries are updated for several reasons. This summary is about revisions concerning hunderds of entries simultanously.

theme	period	motivation
puberty	2023/06-07	Caged birds of several unrelated species show to be able to breed soon after fledging. However, breeders know that they wear out their birds this way. In the field, birds typically breed for the first time one or several years later (both in the tropics and in polar regions). This points to ecological (seasons, establishment of territory), rather than physiological causes. This can best be captured with a time-parameter for time since birth at first breeding, which is done in this revision for all 1003 bird species in AmP. In absence of data on puberty, the time since birth is assumed to be three times the fledging period, based on species for which both data is available. Reserve allocated to reproduction then dissipates till some moment before first breeding to accumulate the required reserve. Upregulation of assimilation prior to nestling might play a role, but detailed data is generally lacking. Since somatic maintenance is typically high in birds, pseudo data maintenance ratio k=0.3 is used, rather than the maturity maintenance rate coefficient k_J=0.002 1/d. Any entry with a very low somatic maintenance has this too, to avoid that k becomes larger than 1, which leads to unrealistic behaviour.
males	2023/02-03	In cases of gender size dimorphy, where the amounts of reserve and structure are equal at birth, the scaled reserve density of the larger gender is less, compared to the smaller gender. This requires a dynamic evaluation of reserve density, which is done in this revision. However, the reserve density will settle soon to a constant value at constant food density, since the change in reserve density is inversely proportional to length, which is small for neonates.
energy conductance	2022/08-09	Observed incubation times can be longer than predicted due to a delay in the onset of development. Birds suffer from the extra problem that the egg temperature can be low, especially initially; they become endothermic only after birth. Predicted incubation/gestation times were sometimes much smaller than observed, due to a too high energy conductance. This revision reduced the energy conductance for entries with a high value, to increase realism, with the constraint that the predicted incubation time is not longer than the observed one. Effects on post-natal growth are largely compensated by an increased specific somatic maintenance. An decrease in energy conductance comes with an increase of specific somatic maintenance to match the same growth curve. Since it also increases the reserve capacity, this increase of somatic maintenance is hardly felt for the individual as a whole, since it needs to be paid over a smaller fraction of mass. Very high maintenance values were avoided, however.