Russet Sparrows spot alien chicks from their nests

About eight years ago we received an email from Bulgaria. It is not uncommon to receive such emails from former Eastern bloc or other countries, particularly from the third world. However, this was a special one. Albeit the English was rather naïve, he asked us if we were interested in collaboration on studies on the common cuckoo and its hosts in Bulgaria. This potential student had already conducted a series of impressive experiments on cuckoo hosts in Bulgaria, but wanted some help in design of new studies, writing of papers and data analyses.

After a brief discussion among us, we decided to invite the young man to our lab for a discussion. He turned out to be a silent, shy, polite young person, however, we were impressed about the work he already had conducted in his field site in Bulgaria. We discussed the possibility of doing a PhD in our lab, an offer Anton acknowledged. He turned out to have very good grades, so when he applied for a competitive grade-based PhD at our faculty, he turned out to be one of the best candidates, even with many applicants from the competitive science of physics. This was in 2006, and Anton had already published several papers (Antonov et al., 2006a, 2006b, 2006c). He started his PhD work in September 2006.

Anton learned quickly. His English improved dramatically from the naïve and unripe English two years previously. His ideas were many, but at a high scientific level. However, as an experienced fieldworker he realized the limits of fieldwork. His ideas were therefore prioritized to ensure that these that were most important and feasible, were the ones with highest priority. Each year he started with larks (Antonov et al., 2010), thereafter he continued with the corn bunting (Antonov et al., 2006b), the marsh and great reed warblers (Antonov et al., 2007a, 2012) and finally the olivaceous warbler (Antonov et al., 2007b, 2007c, 2009). In between this laborious and time consuming fieldwork he managed to ensure experiments on many other potential hosts (Antonov et al., 2011). He involved himself in the academic working environment. His contributions were always mature and significant.

In 2010, Anton defended his PhD. However, having about 20 different already published scientific papers, a discussion about the topic of his PhD was extraordinary. Anton himself came up with a suggestion – his best papers were on "why cuckoos lay strong-shelled eggs" (Antonov, 2010; Antonov et al., 2012, this issue). The PhD consisted of five published papers in high quality journals (Antonov et al., 2006a, 2006c, 2008a, 2008b, 2009).

Anton's scientific and practical skills were appreciated. He has been invited to China since 2010. There he has been conducting fieldwork at several field sites. We were always deeply impressed by his nest searching skills, and in China he managed to find ten parasitized nests of the Emerald Cuckoo (Chrysococcyx maculatus) in one season. For comparison the Chinese colleagues had found only three such parasitized nests in ten seasons, proving the excellent field talents of Anton.

Anton held special intellectual talents. However, he was also a very emotional person. His emotional cycles went up and down from high mountains to deep valleys. For him therefore, life became occasionally very difficult. During such periods he went into deep depressions hard to get out of. Last winter was such a period. Life became very difficult for Anton, therefore he decided to leave us on May 21, 2012. As a scientist he had learned by Sokrades, and chose the same method as this ancient philosopher. In Anton Antonov, science has lost a great and talented scholar. However, we will remember him as a good friend and colleague, and we are sure his papers will be red for many years to come.

Some selected papers out of 30 published scientific articles

Antonov A, Stokke BG, Fossøy F, Liang W, Moksnes A, Røskaft E, Yang C, Møller AP. 2012. Why do brood parasitic birds lay strong-shelled eggs? Chinese Birds, 3:245–258.

Antonov A, Stokke BG, Moksnes A, Kleven O, Honza M, Røskaft E. 2006a. Eggshell strength of an obligate brood parasite: a test of the puncture resistance hypothesis. Behav Ecol Sociobiol, 60:11–18.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2006b. Coevolutionary interactions between Common Cuckoos and Corn Buntings. Condor, 108:414–422.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2006c. Egg rejection in Marsh Warblers (Acrocephalus palustris) heavily parasitized by Common Cuckoos (Cuculus canorus). Auk, 123:419–430.

Antonov A, Stokke BG, Ranke PS, Fossøy F, Moksnes A, Røskaft E. 2010. Absence of egg discrimination in a suitable cuckoo Cuculus canorus host breeding away from trees. J Avian Biol, 41:501–504.

Antonov A, Stokke BG, Fossøy F, Ranke PS, Liang W, Yang C, Moksnes A, Shykoff J, Røskaft E. 2012. Are cuckoos maximizing egg mimicry by selecting host individuals with better matching egg phenotypes? PLoS ONE, 7:e31704.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2007a. Factors influencing the risk of common cuckoo Cuculus canorus parasitism on marsh warblers Acrocephalus palustris. J Avian Biol, 38:390–393.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2007b. First evidence of regular common cuckoo, Cuculus canorus, parasitism on Eastern olivaceous warblers, Hippolais pallida elaeica. Naturwissenschaften, 94:307–312.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2007c. Aspects of breeding ecology of the eastern olivaceous warbler (Hippolais pallida). J Ornithol, 148:443–451.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2009. Evidence for egg discrimination preceding failed rejection attempts in a small cuckoo host. Biol Letter, 5:169–171.

Antonov A, Avilés JM, Stokke BG, Spasova V, Vikan JR, Moksnes A, Yang C, Liang W, Røskaft E. 2011. Egg discrimination in an open nesting passerine under dim light conditions. Ethology, 117:1128–1137.

Antonov A. 2010. Why do cuckoos lay strong-shelled eggs? Tests of the puncture resistance hypothesis. PhD thesis. Norwegian University of Science and Technology, Trondheim, Norway, p 70.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2008a. Does the cuckoo benefit from laying unusually strong eggs? Anim Behav, 76:1893–1900.

Antonov A, Stokke BG, Moksnes A, Røskaft E. 2008b. Getting rid of the cuckoo Cuculus canorus egg: why do hosts delay rejection? Behav Ecol, 19:100–107.