Royal Australasian Ornithologists Union early 20th century called themselves 'oologists', though the distinction between the notionally scientific discipline of oology and simple egg-collecting was blurred. Identification of any but the most common and distinctive species usually entailed the collection of specimens to be made into study skins. Modern field-guides did not exist and few people could afford the massive multi-volume, lavishly illustrated, handbooks of John Gould and Gregory Mathews. However, both Archibald J. Campbell and Alfred North had produced comprehensive guides to what was known about the nests and eggs of Australian birds, with illustrations of the eggs rather than of the birds themselves,
What Love Is Made Of dance music. She then got a bassline which made her "want to dance", and included it in the track. She also told the website that she wrote the song about the "feeling of love, what one person can give to you that someone else can't". What Love Is Made Of" was premiered during Irish DJ Annie Mac's eponymous program on BBC Radio 1, on 10 May 2013, though its digital download only occurred on 5 July 2013. It was serviced as an extended play, where it was bundled with three remixes, by MK (Mark Kinchen), Felix da Housecat and Brackles.