# Farming Behavior by the Large Hawk‐Cuckoo Toward the Silver‐Eared Mesia and Black‐Streaked Scimitar Babbler

## TL;DR

The Large Hawk-cuckoo was observed destroying nests of host and potential host birds, possibly to encourage them to re-nest, creating new chances for parasitism.

## Contribution

First documentation of farming behavior by the Large Hawk-cuckoo toward two bird species.

## Key findings

- Large Hawk-cuckoo removed a chick from the Black-streaked Scimitar Babbler nest.
- Large Hawk-cuckoo ejected three chicks from the Silver-eared Mesia nest.
- This behavior aligns with the farming hypothesis in brood parasites.

## Abstract

Brood parasites improve their reproductive success by offloading the costs of incubation and chick‐rearing onto host species. This interaction often triggers an evolutionary arms race between increasingly deceptive brood parasites and increasingly defensive hosts. According to the farming hypothesis, when suitable host nests are limited, some parasitic birds may destroy unsuitable host nests through “Farming behavior” to induce re‐nesting, thereby creating new opportunities for parasitism. Despite its potential significance, this behavior has been documented in only a few brood‐parasitic species. In 2024, in Jindong County, Pu'er City, Yunnan Province, southwestern China, we successfully captured video evidence of Farming behavior by the Large Hawk‐cuckoo (Hierococcyx sparverioides) on its host, the Black‐streaked Scimitar Babbler (
Pomatorhinus erythrocnemis
), and potential host, the Silver‐eared Mesia (
Leiothrix argentauris
). On April 22, 2024, a Large Hawk‐cuckoo was recorded removing a 7‐day‐old Black‐streaked Scimitar Babbler chick from its nest, but the chick subsequently crawled back inside. On May 27, 2024, a Large Hawk‐cuckoo was observed ejecting three 10‐day‐old Silver‐eared Mesia chicks from their nest. This is the first recorded instance of the Large Hawk‐cuckoo removing chicks from the nests of both the host and potential host species. The observed actions are consistent with the Farming hypothesis, suggesting that such behavior may be a more widespread yet underrecognized strategy among brood‐parasitic birds.

Some parasitic birds may destroy unsuitable host nests through “Farming behavior” to induce re‐nesting, thereby creating new opportunities for parasitism. Despite its potential significance, this behavior has been documented in only a few brood‐parasitic species. This is the first recorded instance of the Large Hawk‐cuckoo removing chicks from the nests of both the host (Black‐streaked Scimitar Babbler
Pomatorhinus erythrocnemis
) and potential host (Silver‐eared Mesia
Leiothrix

argentauris).