Fig. 1: Schematic diagram of the model and the simulated reintroduction approaches.

In all modelling scenarios, population restoration begins with a small founder population. The breeding cycle consists of pair formation or maintenance, reproduction, and survival stages. The inbreeding coefficients (F) of a breeding pair’s offspring were calculated by tracking the pedigree (exemplified by the cartoon, see ‘Methods’ for details). Birds of different colours represent different sexes. In the main model, inbreeding was considered to only negatively impact hatching success based on the empirical situation in crested ibises. Fledging success and nest survival (marked by asterisks in the diagram) are included in the crested ibis population restoration model (corresponding results in Fig. 2) and the reintroduction model variants (corresponding results in Fig. 3), but not for the analysis that explores broader parameter ranges (corresponding results in Figs. 4 and 5). This diagram was self-designed, and the ibis silhouettes it contains are used under a Creative Commons Attribution 4.0 license (CC BY 4.0) from Creazilla (https://creazilla.com/media/silhouette/2248/ibis).