New research reveals that the New Zealand Kākāpō supplements its hormones with compounds similar to those found in native fruits and seeds.

Sirocco the Kākāpō has made the New Zealand flightless parrot species famous, but with fewer than 200 individuals, the beloved bird is at serious risk of Extinction. The Critically Endangered Kākāpō is a ground-dwelling parrot. Because it forages and nests on the ground, it is especially vulnerable to invasive species. Threats by invasive predators have led to dramatic declines in their populations, to the point that they were thought to be Extinct in the 1970s. Now, conservationists are working to rebuild a healthy and sustainable population for the bright green parrot, but invasive species are not the only challenge the threatened bird faces.

Research has shown that Kākāpō breed only every few years and often synchronously with a mast fruiting event, when native trees produce abundant fruits and seeds. 2016 was a record-breaking breeding season since management and monitoring began 25 years ago. The nocturnal parrots had 32 fledglings which increased the population by 25%. 2016 was also a mast year for native vegetation.

Irregular breeding seasons are not completely uncommon in parrot species. New Zealand’s Endangered Kākā (Nestor meridionalis) and Kea (Nestor notabilis) also breed only every few years. Researchers are now looking into the potential combination or mast fruiting events and breeding years to see if the abundance of native fruits is tied to breeding success.

Many native plants of New Zealand, such as the Rimu Tree (Dacrycarpus cupressinum), produce fruit that Kākāpō are known to seek out and eat. These fruits are high in oestrogen-like hormones called phytoestrogens, which could support fertility. Although researchers do not fully understand the connection, they hypothesize that the phytoestrogens in native fruits supplement the Kākāpō’s natural hormones and increase the likelihood of reproductive success.

Researchers are working to fully understand the pathway that allows Kākāpō to absorb this hormone supplement. Further research hopes to clarify this process so that a compound could be synthesized and given to the birds allowing higher rates of reproduction. Gaining a greater understanding of the species gives conservationists hope for the future of the Kākāpō.

Featured Photo: A Critically Endangered Kākāpō. Credit: Allie Caulfield
Source: The Conversation