Sharon has 3 children, sired by either Corey, Mike or Kenn**; but she is not that concerned because Dawn suspects that her 17 little ones might not only have been from these three young males, as there were also many visits by Jochen and many a pleasant afternoon spent with Charlie, who now lives in another area. Dawn and Sharon are neighbours, but the males move freely through and between the two areas. And their Facebook status is always stuck on “its complicated” – a stable marriage of three males and two females. Nice.
((** all names have been changed to protect identities and have been substituted with (almost) randomly chosen substitutes suitable for a family of Alpine Accentors.))
Over the next few days, the Alpine Accentors (Prunella collaris) will arrive on their high-Alpine breeding grounds – it is time to start singing, despite that the treeless Alpine landscape is still under metres of snow. At first, they seem to “stage” in the general area of their breeding territories, feeding in skiing resorts or anywhere else where the snow is a little more open and food is a little more available. Over the next month, they will spend more and more time singing in their breeding territories, and travelling to feed in other areas, up until they can find enough food within their territories:
typical Alpine Accentor (Prunella collaris) habitat at breeding time
So you have probably come across cases of Polygyny (one male, multiple females), as in the case of lions, Red-winged Blackbirds or Northern Harrier; and you may even have heard of a few cases of Polyandry (one female, multiple males), such as Red Phalarope and many Jacanas.
all Alpine Accetor photos digiscoped (c) Dale Forbes. Swarovski ATM scope & Canon A590
Now Alpine Accentors have a much more interesting strategy: 3-5 males defend a single breeding territory, containing 2-3 spatially separated female Accentors. All individuals in this Polygynandrous relationship may mate with each other, but more dominant males will typically have greater access to females.
Here are two really interesting papers on the fascinating private lives of Alpine Accentors, if you would like to read a little more:
Heer, L 1996 Cooperative breeding by Alpine Accentors Prunella collaris: Polygynandry, territoriality and multiple paternity. Journal of Ornithology 137 (1): 35-51
N. B. Davies et al. 1995 The polygynandrous mating system of the alpine accentor, Prunella collaris. I. Ecological causes and reproductive conflicts. Animal Behaviour 49 (3):769-788
Polygynandry seems to be rather rare, but some examples of other species which may potentially be partially or fully polygynandrous include:
Highland Tinamou (Nothocercus bonapartei), Slaty-breasted Tinamou (Crypturellus boucardi), Great Tinamou (Tinamus major), Chilean Tinamou (Nothocercus
perdicaria), Brushland Tinamou (Nothocercus cinerascens), Spotted Nothura (Nothura maculosa) and Red-winged Tinamou (Rhyncothus rufescens) (see Brennan 2004 and references therein).
Purple Swamphen/Pukeko (Porphyrio porphyrio melanotus) (Jamieson & Craig 1987)
Acorn Woodpecker (Melanerpes formicivorus) cooperative breeders with up to 6 co-breeding males, 3 females in the same nest, and numerous non-breeding helpers (work by Koenig, Stacey, Mumme and Pitelka and references therein)
The New Zealand honeyeater-like bird, the Stitchbird / Hihi (Notiomystis cincta) (Castro, Mino, Fordham & Birkhead 1997)
Indigo Bunting (Passerina cyanea) (Carey & Nolan 1979)
Bicknell’s Thrush (Catharus bicknelli) (McFarland, Rimmer & Goetz 2000)
Smith’s longspur (Calcarius pictus) (Meddle, Owen-Ashley, Richardson & Wingfield 2003)
Galapagos hawk (Buteo galapagoensis) (Faaborg, Parker, DeLay, De Vries, Bednarz, Paz, Naranjo & Waite 1995 – the authors refer to the system as being cooperative polyandry but numerous authors have quoted this paper as evidence of polygynandry in the Galapagos Hawk)
Tasmanian Native Hens (Gallinula mortierii) exhibit all of monogamy, polygyny, polyandry and polygynandry in the same population (Goldizen, Buchan, Putland, Goldizen & Krebs 2000)
and the “lowland” accentor: Dunnock (Prunella modularis) (Davies, Hartley, Hatchwell & Langmore 1996 and references therein). I cannot seem to find any evidence that any of the other accentors are polygynandrous; at least some of them seem not to be.
If you know or hear of other examples, please let me know and I will add them to this list.