Reproductive Parameters in the Critically Endangered Blue-Throated Macaw: Limits to the Recovery of a Parrot under Intensive Management

Abstract

Rediscovered in the wild twenty years ago, the breeding biology of wild Blue-throated Macaws remains largely unexplored, yet is essential to its effective conservation and recovery. Here, we analyse reproductive parameters in an intensively managed wild population of Blue-throated Macaws, providing the first data on the breeding biology of this critically endangered species. During the six-year study period, 2007–2012, the number of active breeding pairs either remained constant or decreased, depending on the site, and no new breeding pairs were discovered despite extensive searching. We documented nesting attempts in natural cavities in dead palms or live hardwoods, and artificial nest boxes. Egg-laying was concentrated during the end of dry season and the beginning of the wet season, August through December. Hatching failure was the greatest cause of egg losses. Half of the breeding attempts of Blue-throated Macaws produced at least one fledging, on average two, after a 85 days nestling period. An average of 4.3 nestlings per year fledged from all known wild nests combined. Each pair lost roughly 65% of its initial reproductive investment at each nesting attempt. In most successful nesting attempts of individualized pairs, a new nesting attempt was not detected the following year. All monitored breeding pairs showed high nest site fidelity, reusing hardwood-tree cavities and nest boxes. Our findings will aid conservation efforts by refining current actions and prompting new approaches towards the conservation and recovery of the Blue-throated Macaw.

Long‐term monitoring of Yellow‐naped Amazons ( Amazona auropalliata ) in Costa Rica: breeding biology, duetting, and the negative impact of poaching

“…Thus, as reported for several other species of parrots, Yellow‐naped Amazons use two extremes in terms of nesting trees; relatively short, decaying tubes and tall mature trees (Brightsmith ,b, Berkunsky et al. ).…”

“…Yellow‐naped Amazons appear to be less specialized in their selection of nest trees than several other species of parrots where 50% or more of breeding populations nest in two or three different species, including Blue‐throated Macaws ( Ara glaucogularis ; Berkunsky et al. ), Scarlet Macaws (Vaughan et al. ), Tucuman Parrots ( Amazona tucumana ; Berkunsky and Reboreda ), and Lilac‐crowned Amazons (Salinas‐Melgoza et al.…”

Exotic parrots breeding in urban tree cavities: nesting requirements, geographic distribution, and potential impacts on cavity nesting birds in southeast Florida

“…Other parrot species are reported to breed in palm snags in their native ranges (Berkunsky et al 2014;Dahlin et al 2018). Amazona parrots are increasing in population and expanding their range in the southern United States, particularly Florida and California, where palm trees are common (Mori et al 2017).…”

Assessing the use of forest islands by parrot species in a neotropical savanna

“…In the case of M-palm, its presence would explain part of the use of forest islands by five parrot species: Blue-throated Macaw, Blue-and-yellow Macaw, Yellow-collared Macaw, Scaly-headed Parrot, and Dusky-headed Parakeet. M-palm is a common food and nesting resource for many neotropical parrots (Yamashita and de Barros Machado 1997, Ragusa-Netto 2006, Berkunsky et al 2014). …”