Increasing Survival of Wild Macaw Chicks Using Foster Parents and Supplemental Feeding

Gabriela Vigo-Trauco,Rony Garcia-Anleu,Donald J Brightsmith

doi:10.3390/d13030121

Abstract

The use of foster parents has great potential to help the recovery of highly endangered bird species. However, few studies have shown how to successfully use these techniques in wild populations. Scarlet Macaws (Ara macao macao) in Perú hatch 2–4 chicks per nest but about 24% of all chicks die of starvation and on average just 1.4 of them fledge per successful nest. In this study we develop and test new techniques to increase survival of wild Scarlet Macaw chicks by reducing chick starvation. We hypothesized that using foster parents would increase the survival of chicks at risk of starvation and increase overall reproductive success. Our results show that all relocated macaw chicks were successfully accepted by their foster parents (n = 28 chicks over 3 consecutive breeding seasons) and 89% of the relocated chicks fledged. Overall, we increased fledging success per available nest from 17% (2000 to 2016 average) to 25% (2017 to 2019) and decreased chick death by starvation from 19% to 4%. These findings show that the macaw foster parents technique and post relocation supplemental feeding provide a promising management tool to aid wild parrot population recovery in areas with low reproductive success.

Highlights

The use of foster parents in avian population management is a technique with great potential to aid in the recovery of highly endangered species in the wild [1]
Twenty-eight foster Scarlet Macaw chicks were placed in nests with wild macaw foster parents
Foster chicks were initially fed less than resident chicks, but feeding ratio increased progressively until feedings were similar for both chicks 10 days after relocation

Summary

Introduction

The use of foster parents in avian population management is a technique with great potential to aid in the recovery of highly endangered species in the wild [1]. The majority of species hatch their eggs asynchronously over a period of 1 to 14 days [5,8,9,10,11,12,13,14] which results in a size-based hierarchy among brood members [9,15,16] which often leads to the death of younger chicks [8,9,13,14,17] In this scenario, decreasing hatching asynchrony has been proposed as a potential management tool to increase numbers of young for harvesting for conservation purposes [7]. Despite this high level of acclimatization of the birds, we did not weigh, measure or manipulate broods until second chick hatched in each brood in order to reduce disturbance at the nest and maximize hatching success

Methods

Results

Discussion

Conclusion