Individual female clutch identification through yolk protein electrophoresis in the communally breeding guira cuckoo (Guira guira)

Abstract

Avian communal breeding systems generate alternative behavioural strategies for females, resulting in differences in reproductive success. Identifying eggs of different females in such systems is problematic, however, due to egg destruction before incubation, difficulty of capturing adults, and/or inaccuracy of egg identification based on egg morphometry. Here, we describe a technique that uses electrophoresis of yolk proteins to determine egg ownership, which we applied to communally breeding guira cuckoos (Guira guira). Validation of the method included identical yolk protein banding patterns in all eggs of the same female, but different patterns in eggs of different females in budgerigars (Melopsittacus undulatus), and identical patterns in yolk follicles of the same females in guira cuckoos. We applied the protocol to 195 guira cuckoo eggs from 34 joint nests in 2 years. All multiple guira cuckoo eggs laid on the same day in single nests had distinct banding patterns of yolk proteins, practically eliminating the possibility of more than one female being represented by the same pattern. Some identical banding patterns were repeated in different days within a nesting bout, indicating that some females laid several eggs in shared nests. Identical patterns occasionally occurred in renestings of groups, indicating that some females lay eggs in consecutive nestings. Yolk protein electrophoresis is a useful tool to identify egg maternity in other circumstances, such as polygynous mating systems with joint nests and intraspecific parasitism. Additionally, it is an alternative method for species where electrophoresis of egg white proteins does not show sufficient polymorphism.

Non-destructive sampling of maternal DNA from the external shell of bird eggs

“…In joint-nesting species, egg swabbing could help in assigning egg ownership to the laying female and therefore provide data to better understand female competition through egg-laying, tossing, and/or burying (Quinn and Startek-foote 2000;Macedo et al 2004). This new egg-swab method represents a potential improvement over the Cariello et al (2002) method in which egg maternity was assigned using variable maternal egg yolk protein patterns, requiring destructive sampling of egg or egg puncturing that may affect egg viability. Our DNA yields compared favorably with an alternate approach that required destructive sampling (Strausberger and Ashley 2001).…”

Brood Parasitism and Nest Takeover in Common Eiders

“…Egg albumen patterns, which represent the female only, usually differ between individuals, and can be compared between as well as within gels. This protein fingerprinting technique is, therefore, particularly suitable for analysis of brood parasitism (Andersson & Åhlund 2001, also see Cariello et al. 2002).…”

Natural History and Reproductive Biology of the Communally Breeding Greater Ani (Crotophaga major) at Gatún Lake, Panama

“…Three of the four species have been subjects of long-term behavioral studies: Groove-billed Ani (Crotophaga sulcirostris) in Costa Rica (Vehrencamp 1977(Vehrencamp , 1978Vehrencamp et al 1986;Koford et al 1990); Smooth-billed Ani (C. ani) in Florida and Puerto Rico (Davis 1940, Loflin 1983, Quinn and Startek-Foote 2000, Schmaltz et al 2008; and Guira Cuckoo (Guira guira) in Brazil (Macedo 1992;Cariello et al 2002Cariello et al , 2004Macedo et al 2004). Several individuals (both males and females) in all three species cooperate to build a single nest in which all of the females lay their eggs.…”