Use of spider silk for nest building by the Regent HoneyeaterAnthochaera phrygiaand the Helmeted HoneyeaterLichenostomus melanops cassidix

Abstract

The Regent Honeyeater Anthochaera phrygia and Helmeted Honeyeater Lichenostomus melanops cassidix have both suffered a dramatic decline in number and reduction in range as a result of extensive habitat clearance. As part of recovery plans aimed toward reintroduction to the wild, both species are part of an intensive captive breeding program being conducted at a number of institutions, including Taronga Zoo, Sydney. These honeyeaters incorporate arthropod silk into their nests, as has been reported for other small passerines. However, little is known about how birds choose and use the silk that they collect during nest building. We presented breeding pairs with cribellate silk from the Black House Spider Badumna sp. and ecribellate silk from the Golden Orb-weaver Nephila plumipes or 'clean/fresh' and 'dirty/old' Badumna sp. silk and observed which were taken by the birds. Lichenostomus melanops cassidix showed a preference for the cribellate silk of Badumna sp., always selecting this silk type first. Nevertheless, the ecribellate silk of N. plumipes was also taken occasionally. Anthochaera phrygia, on the other hand, showed no clear preference for the silk of either Badumna sp. or N. plumipes, though they did display a preference for clean/fresh Badumna sp. silk, which was selected more often than dirty/old Badumna sp. silk. Dissection of an A. phrygia nest indicated that silk is used within the nest to help bind the other nest materials. These observations suggest that passerines may select silk non-randomly for use within their nests, possibly preferring clean/fresh cribellate silk.

Nest-building males trade off material collection costs with territory value

“…More widely, other species of birds also show preferences for different material properties when nest-building. For example Varied Tits (Parus varius) prefer mosses with certain biotic traits and Helmeted Honeyeaters (Lichenostomus melanops cassidix) prefer cribellate over ecribellate spider silk (Du et al 2010;Low et al 2013). In the case of Zebra Finches (Taeniopygia guttata), a learnt preference for stiffer over more flexible string appeared to be related to the material's efficacy for building (Bailey et al 2014).…”

New insights on the breeding biology of the Crow Honeyeater Gymnomyza aubryana suggest convergence with the Mao G. samoensis

“…The nest consisted solely of plant material except for silk, probably from spider web. Unlike the Regent Honeyeater Anthochaera phrygia, which does not have well-defined layers in its nest (Low et al 2013), the Crow Honeyeater has four nest layers. The outer one (1) gives structure to the nest and is bound together with sticky silk, layers 2 and 3 (made of leaves) should insulate the nest contents, and the innermost layer ( 4) is looser and allows water to drain out, keeping the chick dry.…”

The recovery programme for the Regent honeyeater Anthochaera phrygia: an example of conservation collaboration in Australia

“…Regent honeyeaters use a selection of materials in nest construction, such as fine grass, feathers, pine needles and palm fibres. Spider web is a vital binding component and the provision of fresh web is a strong stimulant for nesting behaviour (Low et al ., ). The disappearance of web from an enclosure is a good indicator that the birds have bonded and are ready for nesting.…”