# Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006 > [!cite] > Jukema, Joop, and Theunis Piersma. ‘Permanent Female Mimics in a Lekking Shorebird’. *Biology Letters*, vol. 2, no. 2 (2006), pp. 161–64. [https://doi.org/10.1098/rsbl.2005.0416](https://doi.org/10.1098/rsbl.2005.0416). > [!abstract] > Female mimics are known from many species, but permanent, non-conditional, alternative mating strategies are only known from an isopod, a fish, a lizard and a bird. The single bird example refers to lek-breeding ruffs Philomachus pugnax, a shorebird for which two strategies (independent and satellite) have been known for over 50 years. Ruffs also provided the single case of an animal with two, rather than three, permanent alternative mating strategies. Here, we describe a rare female-like morph of ruffs: the ‘missing’ third alternative mating strategy, which we have called ‘faeder’. Faeders are slightly larger than females and in late April have testes 2.5 time the size of testes of normal males. On leks in aviaries and in the wild they appear to combine feminine and masculine behaviours. Faeders may represent the ancestral, care-giving, male strategy, but their relatively large testes suggest that currently they behave as sneakers. --- ‘In the fierce competition for mates and space, it sometimes pays for males to disguise themselves as females (Andersson 1994; Gross 1996). Female mimics are known from various arthropods, a mollusc, and from several groups of vertebrates, especially fish (Andersson 1994; Wikelski *et al.* 1996; Shine *et al.* 2001; Sinervo 2001; Hall & Hanlon 2002; Shine 2003; Goncalves et al. 2005), but they usually represent conditional, non-genetic, strategies (Gross 1996).’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ‘Ruffs are highly sexually dimorphic lekking sandpipers of a subfamily (Calidrinae, family Scolopacidae) that is notorious for its wide variety of mating systems (Pitelka *et al.* 1974; Myers *et al.* 1982; Piersma *et al.* 1996). [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ^2c85dd ‘This dichotomy includes an ‘independent’ strategy of males that attempt to defend small mating courts against other independents on a lek and a ‘satellite’ strategy of males tolerated on leks by independents and stealing copulations with visiting hens when independents are temporarily distracted (van Rhijn 1973, 1990; Lank *et al.* 1995; Hogan-Warburg 1966; Widemo 1998).’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ^4bbe2c ‘The two alternative mating strategies: (i) are strongly correlated with the coloration of the breeding plumage, (ii) show a slight difference in body size, (iii) are maintained for life and (iv) are consistent with a single-locus, two-allele autosomal genetic polymorphism (Lank et al. 1995; Bachman & Widemo 1999).’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ^bed0b8 ‘The evolution of these alternative mating strategies and the maintenance of their relative frequencies (5–15% of male ruffs are satellites) appear to reflect female choice (van Rhijn 1983; Hugie & Lank 1997; Widemo 1998).’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ^88ee45 ‘In our catches, we encountered small numbers of female-plumaged birds (figure 1*a*) that were intermediate in size between females and males (figure 2*a*) and in spring developed a female-like feather type (figure 2*b*). These striped feathers possibly represent the original alternate plumage of sandpipers, rather than being homologous to the showy feathers of the supplemental plumage additionally developed by males ( Jukema & Piersma 2000).’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ^1a5f93 ‘Nevertheless, in all 22 cases where blood samples were collected, ‘intermediate’ birds were molecularly identified as males. In an overlapping sample of 18 such birds, sex was additionally confirmed by the presence of testes.’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ^66f3e9 ‘In the aviary study, from 14 May to 23 June 2004, we witnessed 25 copulatory attempts involving faeders, in 13 of which faeders were mounted by independent males (including the single case with clear cloacal contact). In seven cases, a faeder mounted an independent male, in four cases a satellite and once a female was mounted.’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 162)]] ^1d6626 ‘The feminine behavioural ploys of female mimics were confirmed in the field, with observations in northern Norway of an individually colour-banded faeder (molecularly sexed as male; figure 1*a,c*). This bird visited a lek from 16 to 19 June 2004, and was mounted by an independent male on 17 June and by a satellite on 19 June (figure 1*c*; J. Champion and T. Champion 2005, personal communication).’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 163)]] ^89b49e ‘That faeders were as often ‘on top’ in homosexual mountings as ‘true’ males, suggests that their identity is known by the other males; they may appear to be ‘female mimics’ to us, but not necessarily to the ruffs themselves.’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 163)]] ^843feb ‘As envisioned by van Rhijn (1985), faeders may represent the ancestral male type, but their relatively large testes suggest that currently they behave as sneakers (Taborsky 1994).’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 163)]] ^374943 ‘Interestingly, the only other documented cases of permanent alternative strategies, in an isopod (Shuster & Wade 1991), a fish (Ryan *et al*. 1992) and probably a lizard (Sinervo & Lively 1996), also include three morphs, both representing three alleles at a single locus (Gross 1996). Do faeders similarly reflect the presence of a novel third allele, maintained in the population by negative frequency dependent selection? Or do faeders represent the expected 1% of ruffs homozygous for the satellite allele (Lank *et al.* 1995), a feature undisclosed in the single captive breeding study so far?’ [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 163–164)]] ‘Faeders are slightly larger than females and in late April have testes 2.5 time the size of testes of normal males. On leks in aviaries and in the wild they appear to combine feminine and masculine behaviours. Faeders may represent the ancestral, care-giving, male strategy, but their relatively large testes suggest that currently they behave as sneakers.’. [[Jukema and Piersma, ‘Permanent Female Mimics in a Lekking Shorebird’, 2006|(Jukema and Piersma 2006, 161)]] ^09bbd8