The incidence of dome nests in avifaunas: a comparison of Australia and southern Africa, under similar mediterranean and adjacent arid climates

INTRODUCTION

Dome nests (https://www.lls.nsw.gov.au/regions/murray/articles,-plans-and-publications/nrm-news-november-2020/birds-and-their-nests) are those combining the following characteristics:

essentially spherical, as opposed to cup- or bowl-shaped,
incorporating a roof, so that there is a restricted aperture for entrance/exit on the side of the structure,
woven out of plant fibre (and spiderweb in some cases), as opposed to being made from mud, and
located externally, as opposed to within cavities (hollows/holes in wood or the ground).

The concealment and enclosure of eggs and the incubating adult confer obvious adaptive advantages relative to predation.

Australia and southern Africa have similar climates and substrates, but differ greatly in their regimes of predation.

In general, the former landmass is relatively poor in predators, whereas the latter landmass is rich in predators. More particularly, Australia lacks counterparts for specialised predators at avian nests, such as

the snake Dasypeltis (https://www.inaturalist.org/taxa/26717-Dasypeltis-scabra), and
the raptor Polyboroides (https://www.inaturalist.org/taxa/5246-Polyboroides-typus).

AIMS

The main aim of this Post is to make an intercontinental comparison at the scale of avifaunal lists.

I base this approach on those regions with similar mediterranean-type and adjacent arid climates (https://en.wikipedia.org/wiki/Mediterranean_climate and https://link.springer.com/chapter/10.1007/978-3-642-65520-3_8#:~:text=The%20mediterranean%2Dtype%20climate%20of,the%20western%20half%20of%20Victoria. and https://www.tandfonline.com/doi/pdf/10.1080/01811789.1984.10826662).

I have excluded migratory birds that breed in the Northern Hemisphere, wintering in the Southern Hemisphere.

RESULTS

The following taxa of birds build dome nests in the relevant regions.

AUSTRALIA

Atrichornithidae:

Atrichornis clamosus https://www.inaturalist.org/taxa/7422-Atrichornis-clamosus

Estrildidae:

Stagonopleura all three spp. (https://en.wikipedia.org/wiki/Stagonopleura)

Acanthizidae:

Aphelocephala leucopsis https://www.inaturalist.org/taxa/13522-Aphelocephala-leucopsis

Calamanthus campestris https://www.inaturalist.org/taxa/979632-Calamanthus-campestris
Calamanthus fuliginosus https://www.inaturalist.org/taxa/13527-Calamanthus-fuliginosus
Calamanthus montanellus https://www.inaturalist.org/taxa/548191-Calamanthus-montanellus

Gerygone fusca https://www.inaturalist.org/taxa/13491-Gerygone-fusca
Gerygone olivacea https://www.inaturalist.org/taxa/13490-Gerygone-olivacea

Hylacola cauta https://www.inaturalist.org/taxa/72928-Hylacola-cauta
Hylacola pyrrhopygia https://www.inaturalist.org/taxa/72929-Hylacola-pyrrhopygia

Pyrrholaemus brunneus https://www.inaturalist.org/taxa/13477-Pyrrholaemus-brunneus

Sericornis maculatus https://www.inaturalist.org/taxa/1444429-Sericornis-maculatus

Smicrornis brevirostris https://www.inaturalist.org/taxa/13540-Smicrornis-brevirostris

Maluridae:

Amytornis textilis https://www.inaturalist.org/taxa/509110-Amytornis-textilis

Malurus assimilis https://www.inaturalist.org/taxa/827392-Malurus-assimilis
Malurus cyaneus https://www.inaturalist.org/taxa/12065-Malurus-cyaneus
Malurus elegans https://www.inaturalist.org/taxa/12063-Malurus-elegans
Malurus leucopterus https://www.inaturalist.org/taxa/12093-Malurus-leucopterus
Malurus pulcherrimus https://www.inaturalist.org/taxa/12072-Malurus-pulcherrimus
Malurus splendens https://www.inaturalist.org/taxa/12083-Malurus-splendens

Stipiturus malachurus https://www.inaturalist.org/taxa/12133-Stipiturus-malachurus
Stipiturus mallee https://www.inaturalist.org/taxa/12072-Malurus-pulcherrimus

Cisticolidae (https://en.wikipedia.org/wiki/Cisticolidae) :

Cisticola exilis (South Australia only) https://www.inaturalist.org/taxa/7657-Cisticola-exilis

Dicaeidae:

Dicaeum hirundinaceum https://www.inaturalist.org/taxa/13388-Dicaeum-hirundinaceum

Pomatostomidae:

Pomatostomus superciliosus https://www.inaturalist.org/taxa/14491-Pomatostomus-superciliosus

SOUTHERN AFRICA

Ploceidae:

Euplectes capensis https://www.inaturalist.org/taxa/13964-Euplectes-capensis
Euplectes orix https://www.inaturalist.org/taxa/13962-Euplectes-orix

Ploceus capensis https://www.inaturalist.org/taxa/13801-Ploceus-capensis
Ploceus velatus https://www.inaturalist.org/taxa/13804-Ploceus-velatus

Quelea quelea https://www.inaturalist.org/taxa/14005-Quelea-quelea

Estrildidae:

Coccopygia melanotis https://www.inaturalist.org/taxa/979663-Coccopygia-melanotis

Estrilda astrild https://www.inaturalist.org/taxa/13770-Estrilda-astrild

Ortygospiza atricollis https://www.inaturalist.org/taxa/204557-Ortygospiza-atricollis

Nectariniidae:

Anthobaphes violacea https://www.inaturalist.org/taxa/145130-Anthobaphes-violacea

Chalcomitra amethystina https://www.inaturalist.org/taxa/145142-Chalcomitra-amethystina

Cinnyris afer https://www.inaturalist.org/taxa/145163-Cinnyris-afer
Cinnyris chalybeus https://www.inaturalist.org/taxa/145157-Cinnyris-chalybeus
Cinnyris fuscus https://www.inaturalist.org/taxa/145189-Cinnyris-fuscus

Nectarinia famosa https://www.inaturalist.org/taxa/13300-Nectarinia-famosa

Cisticolidae:

Apalis thoracica https://www.inaturalist.org/taxa/7742-Apalis-thoracica

Cisticola fulvicapilla https://www.inaturalist.org/taxa/72731-Cisticola-fulvicapilla
Cisticola juncidis https://www.inaturalist.org/taxa/7697-Cisticola-juncidis
Cisticola subruficapilla https://www.inaturalist.org/taxa/72733-Cisticola-subruficapilla
Cisticola textrix https://www.inaturalist.org/taxa/7700-Cisticola-textrix
Cisticola tinniens https://www.inaturalist.org/taxa/7660-Cisticola-tinniens

Eremomela icteropygialis https://www.inaturalist.org/taxa/204508-Eremomela-icteropygialis
Eremomela gregalis https://www.inaturalist.org/taxa/15460-Eremomela-gregalis

Euryptila subcinnamomea https://www.inaturalist.org/taxa/7782-Euryptila-subcinnamomea

Malcorus pectoralis https://www.inaturalist.org/taxa/7703-Malcorus-pectoralis

Phragmacia substriata https://www.inaturalist.org/taxa/73280-Phragmacia-substriata

Prinia maculosa https://www.inaturalist.org/taxa/7730-Prinia-maculosa

Macrosphenidae:

Sylvietta rufescens https://www.inaturalist.org/taxa/15254-Sylvietta-rufescens

Paridae:

Melaniparus afer https://www.inaturalist.org/taxa/144845-Melaniparus-afer

Remizidae:

Anthoscopus minutus https://www.inaturalist.org/taxa/13671-Anthoscopus-minutus

DISCUSSION

On both continents, there is a major incidence of birds that build dome nests.

Most of the families differ, indicating that there has been evolutionary convergence in this aspect, in a broad sense.

However, several avifaunal elements are shared, viz.

the families Estrildidae and Cisticolidae, and
the genus Cisticola.

Meliphagidae does not feature in these lists, despite

the extreme adaptive radiation of this family on the island continent, and
the similarity of Acanthorhynchus, Lichmera, and Sugomel to certain nectariniids (https://www.inaturalist.org/journal/milewski/98889-failure-of-evolutionary-convergence-in-nectarivorous-birds-between-australia-meliphagidae-and-southern-africa-nectariniidae-part-1#).

I have no simple explanation for the broad equivalence of the two landmasses in the incidence of dome nests.

A next step would be a detailed comparison of the faunas of relevant predators in Australia and southern Africa.

However, the following intercontinental differences are noteworthy:

Among those small birds that have long beaks, adapted for nectarivory and the pollination of tubular flowers, dome nests occur in southern Africa (Nectariniidae) but not Australia.

By contrast, among wren-like birds that skulk in dense herbage/shrubbery, dome nests occur more in Australia (e.g. Maluridae and Atrichornithidae) than in southern Africa, e.g.