Effect of intensive rearing on functional morphology: A case study with the rock partridge (Alectoris graeca graeca)

Abstract

© 2019 Lesotekhnicheski Universitet (University of Forestry). All rights reserved. Rock partridge (Alectoris graeca) is included in Annex I of the EU Birds Directive as Species of Conservation Concern (SPEC 1), because of the continuing decline in the area of occupancy. In this context, ex situ conservation programs and production systems of captive Rock partridges suited to the wild are necessary to ensure that insurance, reintroduction or restocking goals are met. Anyway, morphological changes occurring in captive-reared animals indicate the loss of animal’s ability to survive in natural environment. In this study, we used the offspring of wild Apennine rock partridges (Alectoris graeca graeca). The young birds were divided into two groups, the first (G1) was housed in enriched and wild-like environment, the second (G2) was subjected to intensive-rearing conditions. Starting at 14 days post-hatching (DPH) and continuing up to 98 DPH, body mass (BM), tarsus length (TL), tarsus depth (TD), tarsus width (TW), head width (HW), head length (HL), wing length (WL) and beak length (BL), were measured fortnightly. Birds in G1 showed shorter heads (F = 10.50, p = 0.000) and thinner tarsi (F = 9.80, p = 0.000) at 84 DPH. At 98 DPH also the TD measurement (F = 8.71, p = 0.001) became significantly lower in G1 then in G2. Birds in G1 showed morphological disadvantages (shorter heads and less developed limbs) as a possible result of limited physical and cognitive exercise in simple artificial environment. Our results suggest that intensive rearing does not contribute to relevant morphological disadvantages within 70 DPH. Accordingly, birds for restocking or reintroduction should be translocated within this time limit into enriched and wild-like environment where they can exercise before the release into the wild. A first figure of morphological measurements for Apennine Rock partridge is reported.