Searching for the ancestors of lovebirds, an update
[Genus Agapornis]
Part 1
By Dirk Van den Abeele
Ornitho-Genetics VZW
Published BVA-International Magazine April 2025
It has been a while since we tackled this topic again, which makes sense, because here we always rely on research results from palaeontologists and these studies are not so evident. We must go back as far as 2011 when I published a first article on this subject in the BVA-International magazine [1], an updated version came in my 2016 book ‘Lovebirds compendium’ [2]. But then, until late 2023, things remained quiet within this area of research. At that time, another paper was published with research results from a study in Namibia, which revealed probably (so far) the oldest fossils of members of the genus Agapornis [3]. These fossils are thought to date from the early Miocene, which is about 19-20 million years ago. And more recently, in May 2024, there was also a paper on the discovery of a long-extinct species of Agapornis from the Plio-Pleistocene [4]. That is the period running from 5.3 million to 11.7 thousand years ago.
So for us, it is high time to sharpen our insights about the ancestry of lovebirds and update our 2011 article. Do realise that in evolution, we will never have a 100% correct and complete understanding. We are forced to work with small puzzle pieces to help us form a picture of the past and this puzzle is obviously far from complete. Consequently, each new research result obtained can offer new insights and thereby turn entire theories upside down. Nevertheless, in order to gain a good understanding of this matter, it is important to frame it all in the light of natural evolution.
Evolution
That birds did not just appear overnight is a fact. Like every individual on earth, birds are also the result of millions of years of evolution. A whole evolutionary path has been taken to arrive at the bird species present today. It has long been a question of where birds came from and how they fit into the history and evolution of the animal kingdom. Entire theories have been developed on this subject over the years, and it is not our intention now to review them all as we would need more than one issue of the BVA-International magazine.
It is now generally believed that we should look for the common ancestors of our contemporary birds among the giant reptiles (dinosaurs). More specifically, among the theropod dinosaurs [5]. These giant lizards walked on their hind legs, so one of those most famous species is probably Tyrannosaurus rex. But that has not always been the opinion of researchers.
The first fossils of bird-like creatures were found in Germany in 1861 [6]. They were christened Archaeopteryx, which means as much as primordial bird. Later, nine more fossils were found of the same ‘bird’. These fossils show us an animal of +/- 50 cm in size (head to tail) that lived 150 million years ago and, most importantly, clearly had feathers. Because the animal does not yet have a true bird beak, yet there are quite a few features that we also find in reptiles, Archaeopteryx was therefore argued for years as the only transitional form between dinosaurs and birds. As always, on topics related to evolution, there has been decades of debate by supporters and opponents of this theory. Understandably, as no clear link had been found with other species at the time. It seemed like ‘birds’ had suddenly arrived. But fortunately, as always, time always yields an answer.
In 2009, in China’s Liaoning province, another large number of fossils were found of, strange but true, feathered dinosaurs. This made the scientific evidence, for the link between birds and dinosaurs, increasingly convincing [7], [8], [9], [10], [11]. We can therefore assume that many bird species evolved in this way. Some species that evolved further, others that became extinct. Admittedly, not always easy to understand, yet this is one of my favourite topics, especially since evolution and genetics are inextricably linked. It is the small genetic adjustments/adaptations that have ensured that, over the span of hundreds of thousands, even millions of years, species have formed as we know them today. In other words, nature and animals have not always looked the same, for as the Buddha stated, ‘Everything changes, nothing stays the same’.
Evolution of the genus Agapornis
Researchers assume that we should look for the origin of parakeets (psittaciformes) about an 82 million years ago [12]. From then on, the various parakeet species would have evolved. We will probably have to look for the start of the genus Agapornis about 30 million years ago [3], [12]. Then, step by step, this genus would have split off from other parakeet species. Several studies of DNA material also showed that the genus Agapornis (Selby, 1836), together with the genus Loriculus (Blyth, 1849) and the genus Bolbopsittacus (Salvadori, 1891), more than likely share one common ancestor [13], [14] and consequently still share some genetic material in common. And indeed, if we study those birds more closely, we do indeed notice similarities between Agapornis canus and Loriculus (Hanging parrot / Lories ). We also see common characteristics between the guaiabero (Bolbopsittacus lunulatus) and Agapornis swindernianus. The guaiabero is a small, short-tailed parrot-like bird found only in the Philippines. This bird is about 16 cm tall and, like Agapornis swindernianus, has a distinct neck collar and a dark grey bill. It is truly amazing to see how one species slowly merges into another. Nature at its best.
Interpretations of molecular studies suggest that Agapornis spread from Australasia to Africa at the end of the Oligocene or beginning of the Miocene (33.9 to 23.03 million years ago) [15]. Whereas some years ago it was thought that Agapornis swindernianus could be considered the oldest ancestor of the genus Agapornis [16], it is now suspected that the ancestor of Agapornis had probably first colonised Madagascar and spread from there to the African continent. Recent DNA research concludes that not Agapornis swindernianus but Agapornis canus is most likely the oldest species. From there, other lovebird species are thought to have developed [17], [18]. New species have emerged and, of course, evolution also results in species disappearing. There is evidence/proof of that too.
Palaeontology is the field of research that uses fossils to study extinct species. We are all familiar with museums where we can admire excavated skeletons. Yet research into the ancestors of these birds is not that easy; after all, very few useful fossils of birds have survived. This, of course, has everything to do with the fact that birds are not that big and consequently their skeletons are not strong. The chances of a bird fossil emerging spontaneously are therefore quite small. Nevertheless, fortunately some discoveries have already been made that can help us further in our search for the ancestors of extinct lovebird species. This can help us reconstruct the family tree of the genus Agapornis.
In a next article, we will explain the discoveries about the genus Agapornis.
Keep up the good work!!
Dirk Van den Abeele
Ornitho-Genetics VZW
Literature:
[1] D. Van den Abeele, ‘Agapornis atlanticus en co, op zoek naar de voorouders van onze agaporniden’, Agapornis.info, nr. 2, 2011.
[2] D. Van den Abeele, Lovebirds Compendium, 1ste dr. Warffum- The Netherlands: About Pets, 2016.
[3] C. M.-C. M. Pickford, H. Mocke, en A. Nduutepo, ‘Small birds (Psittaculidae, Galliformes and Passeri) from the Early Miocene of Namibia’, 2023.
[4] M. Pavia e.a., ‘A new species of Lovebird (Aves, Psittaculidae, Agapornis) from the Plio-Pleistocene of the Cradle of Humankind (Gauteng, South Africa)’, Geobios, aug. 2024, doi: 10.1016/j.geobios.2024.05.006.
[5] S. L. Brusatte, J. K. O’Connor, en E. D. Jarvis, ‘The Origin and Diversification of Birds’, Curr. Biol., vol. 25, nr. 19, pp. R888-R898, okt. 2015, doi: 10.1016/j.cub.2015.08.003.
[6] C. Nedin, All About Archaeopteryx. 1999.
[7] C.-M. Chuong e.a., ‘Adaptation to the sky: Defining the feather with integument fossils from mesozoic China and experimental evidence from molecular laboratories’, J. Exp. Zoolog. B Mol. Dev. Evol., vol. 298B, nr. 1, pp. 42-56, 2003, doi: 10.1002/jez.b.25.
[8] X. Xu, H. You, K. Du, en F. Han, ‘An Archaeopteryx-like theropod from China and the origin of Avialae’, Nature, vol. 475, nr. 7357, pp. 465-470, jul. 2011, doi: 10.1038/nature10288.
[9] X. Xu, Z. Zhou, en X. Wang, ‘The smallest known non-avian theropod dinosaur’, Nature, vol. 408, nr. 6813, pp. 705-708, 2000.
[10] X. Xu, Z. Zhou, X. Wang, X. Kuang, F. Zhang, en X. Du, ‘Four-winged dinosaurs from China’, Nature, vol. 421, nr. 6921, pp. 335-340, jan. 2003, doi: 10.1038/nature01342.
[11] X. Xu, H. You, K. Du, en F. Han, ‘An Archaeopteryx-like theropod from China and the origin of Avialae’, Nature, vol. 475, nr. 7357, pp. 465-470, jul. 2011, doi: 10.1038/nature10288.
[12] T. F. Wright e.a., ‘A Multilocus Molecular Phylogeny of the Parrots (Psittaciformes): Support for a Gondwanan Origin during the Cretaceous’, Mol. Biol. Evol., vol. 25, nr. 10, p. 2141, 2008.
[13] R. S. de Kloet en S. R. de Kloet, ‘The evolution of the spindlin gene in birds: sequence analysis of an intron of the spindlin W and Z gene reveals four major divisions of the Psittaciformes’, Mol. Phylogenet. Evol., vol. 36, nr. 3, pp. 706-721, 2005.
[14] G. Mayr, ‘The phylogenetic affinities of the parrot taxa Agapornis, Loriculus and Melopsittacus (Aves: Psittaciformes): hypotarsal morphology supports the results of molecular analyses’, Emu, vol. 108, pp. 23-27, 2008.
[15] A. Manegold, ‘Two new parrot species (Psittaciformes) from the early Pliocene of Langebaanweg, South Africa, and their palaeoecological implications’, Ibis, vol. 155, nr. 1, pp. 127-139, 2013, doi: 10.1111/ibi.12009.
[16] A. Manegold en L. Podsiadlowski, ‘On the systematic position of the Black-collared Lovebird Agapornis swindernianus (Agapornithinae, Psittaciformes)’, J. Ornithol., pp. 1-9, 2014, doi: 10.1007/s10336-013-1039-z.
[17] S. Huynh, A. Cloutier, en S. Y. W. Sin, ‘Museomics and phylogenomics of lovebirds (Psittaciformes, Psittaculidae, Agapornis) using low-coverage whole-genome sequencing’, Mol. Phylogenet. Evol., vol. 185, p. 107822, aug. 2023, doi: 10.1016/j.ympev.2023.107822.
[18] B. T. Smith, G. Thom, en L. Joseph, ‘Revised Evolutionary and Taxonomic Synthesis for Parrots (Order: Psittaciformes) Guided by Phylogenomic Analysis’, Bull. Am. Mus. Nat. Hist., vol. 2024, nr. 468, pp. 1-87, jun. 2024, doi: 10.1206/0003-0090.468.1.1.
