Chinese Penduline Tit Remiz consobrinus: First Korean Breeding Record?

Dr Nial Moores, Birds Korea, August 20^th 2017

On May 20^th 2017, NM and three visiting bird conservationists from Belgium (Joost Mertens, Marc Van Mierlo and Miguel Demeulemeester) were searching for migrants in an extensive area of bushy, dried-out reedy scrubland centred at approximately 37.96, 124.71, close to the town of Jincheon on Baekryeong Island in the northwest of the Republic of Korea (ROK).  We were surprised to hear the distinctive “seee-u” calls of several Chinese Penduline Tit Remiz consobrinus, a species that is known to be a regular and locally common migrant and winter visitor to parts of the ROK, with the peak of northward migration apparently falling in April and usually only small numbers present into late May, and no records in e.g. Park (2002) or the Birds Korea Archives from June to early October when southward migration starts.

Stopping to look for the calling birds, we found an adult male in frantic song displaying to an attentive adult female – behaviour we considered might be indicative of breeding.  After a brief scan from the road,  JM located a nest about 50m away hanging about 3m off the ground from what was identified as a Black Locust Robinia pseudoacacia  – a tree species introduced to Korea in the 1890s  (Lee et al. 2011). During the next 30 minutes or so, both the male and female visited the nest several times. Both worked methodically on the outside of the nest with the female also entering and exiting the nest from the top. Although views of the nest were partly obscured by foliage, the structure appeared closest to Stage D of the nest of the closely-related Eurasian Penduline Tit R. pendulinus as shown in van Djik et al. (2014), in that there was no entrance spout and much of the top of the nest – although invisible to us – seemed still to be open.

Singing adult male Chinese Penduline Tit Remiz consobrinus, Baekryeong Island, May 2017 © Nial Moores

Adult male (upper) and adult female (lower) Chinese Penduline Tit at the nest, Baekryeong Island, May 2017 © Nial Moores. Note: Although Birds Korea maintains the policy of not showing birds at the nest in order to reduce disturbance, these images are included here as part of essential documentation of this breeding record.

Breeding habitat of Chinese Penduline Tit, Baekryeong Island, May 2017 © Nial Moores

Based on van Djik et al. (2014) we consider that the male and female were already “mated”; and also assume that eggs would not have been laid yet as egg-laying takes place after the nest reaches the subsequent Stage E.  From JM’s experience with Eurasian Penduline Tit, we also understand that nest-building by itself should not be taken as confirmation of breeding as that species often builds nests which are then abandoned.

To avoid disturbing the birds, we did not approach the belt of Black Locust trees that the nest was in and instead continued along the network of roads that criss-cross the area to search for additional individuals.  Although we failed to spot any more nests, we found a total of 15-25 Chinese Penduline Tit in this wider area of similar habitat. The next day, May 21^st, we also found 10+ Chinese Penduline Tit in Yeonhwa Ri, 6 km to the west, though these were moving rapidly and restlessly through small patches of reed and open ground, suggesting that many of them were probably still on migration.

On August 17^th 2017, NM revisited the nest site with Bernhard Seliger (Hanns Seidel Foundation, Korea). We quickly re-found the nest which had in the interim been constructed further to Stage E or F (completed with a nest hole and some suggestion of a spout). However, the nest also looked a little unkempt and rather dark, as if wet.  Within 100-150m of this nest, we then heard the call and finally located a group of four Chinese Penduline Tit feeding unobtrusively in some long grass. Although very plain looking, one of the birds was – although in a plumage unknown to NM – identified as a female (either fully adult or perhaps Second Calendar-year) that had not yet commenced the post-breeding moult. This identification was based on the all dark bill; the obscure head pattern; the adult-coloured rufous mantle; and the obviously worn and ragged-looking plumage.  The very poorly defined ear coverts enabled confirmation as Chinese Penduline rather than as the unrecorded and extralimital White-crowned Penduline Tit R. coronatus (see Bot et al. 2011 for identification criteria).  The other three birds were even more uniform-looking, with much fresher-looking, pale plumage and an obviously orange-yellow bill-base.  Based on depictions of juvenile Eurasian Penduline Tit with similar plain plumage and coloured bill base (e.g. here), these were identified as juveniles.

Group of Chinese Penduline Tit, August 2017, Baekryeong Island. The belt of Black Locust Trees with the nest are visible directly behind the birds © Bernhard Seliger

Chinese Penduline Tit, Baekryeong Island, August 2017: top two images, adult female or Second Calendar-year female, and bottom two images, juveniles © Nial Moores

Approximately 300m to the west of this group, we soon after found an additional group of 4-5 Chinese Penduline Tit. This group included an adult male in rather worn plumage (again with an all dark bill tipped paler), with the narrow black mask edged above with white (again) typical of Chinese Penduline Tit. This male was accompanied closely by 1-4 juveniles, one of which briefly tried to beg food, before all the birds were flushed by a Brown Shrike Lanius cristatus.  Several minutes later, the same or a different juvenile emerged to preen. This bird had extensive orange in the bill base, an even plainer head pattern and a noticeably shorter tail than the three juveniles seen near to the nest.  Although we visited Yeonhwa Ri and many other parts of the island, we did not find any additional Chinese Penduline Tit.

Chinese Penduline Tit, Baekryeong Island, August 2017: top adult male, below juvenile © Nial Moores

According to the English-language summary in Tong et al. (1985), the Chinese Penduline Tit starts to arrive in the Xiang-hai Nature Reserve in Jilin Province, China in the middle of April and breeds from the beginning of May to the middle of July. During their study, clutch size varied from 5-9 eggs; the incubation period lasted 13 days; the period of feeding lasted 18±2 days; and the average number of surviving nestlings was 2.53 per pair of adults.

Tong et al. (1985) and our observations suggest that one nest on Baekryeong Island likely produced three or more young (if from the nest we observed, perhaps with egg-laying before the end of May; incubation and feeding through much of June; and fledging in early July); and a second nest, not found by us, that produced three or four fledglings which, based on the food-begging we observed and the more extensive orange to the bill base, had likely hatched rather later than the first, perhaps as recently as late July or even the very beginning of August.  However, it is unclear how many adult birds were involved. Although not referred to in the summary in Tong et al. (1985), Czyz et al. (2012) clarify that breeding Eurasian Penduline Tit in Poland are: multi-brooded; one of the parent birds deserts the nest to leave the other to incubate the eggs and to feed the young; both sexes undergo dispersal within the breeding period; and both males and females can pair up with multiple partners when breeding. These behaviours documented in Eurasian Penduline Tit might or might not be shared with Chinese Penduline Tit, but seem to be in accord  with the presence of two different females close to the nest, with the much better-marked bird seen nest-building in May, and the poorer-marked female associating with young in August.

Unless new information comes to light (i.e. earlier records of Korean breeding), we consider that our observations provide the first confirmation of breeding by Chinese Penduline Tit in the ROK and on the Korean Peninsula.  The record therefore indicates a southward extension of the breeding range by several hundred km. However, Korean breeding was not unexpected.  The species is increasingly recorded in Korea as a migrant and in winter (e.g. Duckworth 2006) and has been known to breed close to the Korean Peninsula for several decades at least, e.g. in Jilin Province, China (Tong et al. 1985).  Moreover, since the early 1990s, the species has also started to colonise parts of  the Primorsky Krai Region of Far East Russia, with many pairs now present there at multiple sites (Gluschenko et al. 2014); and in recent years breeding has also been found at several new sites in China, including in southern Liaoning Province (P. Holt public comment in 2013 on the Species Alive page of the Handbook of Birds of the World).

With Chinese Penduline Tit now known to breed along the Russian border with the DPRK, Gluschenko et al. (2014) already assumed breeding within the northeast of the DPRK itself.  However, there are no such records in Tomek (2002), who considered the species to be a rare migrant, tracing only one historical record from the northeast of the DPRK.  Although her assessment requires revision following several recent records of birds in western DPRK during the migration periods, including of flocks (e.g. Duckworth 2006; Moores 2016a; Adrian Riegen  in lit. August 2017) the Birds Korea-Hanns Seidel Foundation surveys in Rason in far northeastern DPRK found no Chinese Penduline Tit in several days spent in suitable habitat in July 2016; and found only one there in April 2017 (Moores 2016b; Moores 2017).

We welcome your comments, corrections and any new information that can help to improve the accuracy and usefulness of this draft-paper.

 

References

• Bot, S., Brinkhuizen, D., Pogany, A., Szekely, T. & van Dijk, R. 2011. Penduline tits in Eurasian:         distribution, identification and systematics . Dutch Birding 22: 177-187, 2011.
• Czyz, B., Borowiec, M., Wasinska, A., Pawliszko, R. & Mazur, K. 2012. Breeding-season dispersal   of  male and female Penduline Tits (Remiz pendulinus) in south-western Poland. Ornis Fennica 89: 216-221.
• Duckworth, J.W. 2006. Records of some bird species hitherto rarely found in DPR Korea. Bull. British Ornithologists’ Club. 2006 126 (4) 253-290.
• Gluschenko, Y.N., Burkovskiy, O.A. & Tiunov, I.M. 2014. The History of the Settling of the Chinese Penduline Tit Remiz consobrinus (Remizidae, Passeriformes, Aves) in the Primorsky Krai Territory.Achievements in the Life Sciences 8: Issue 2, October 2014, pp. 133-136. Hosting by Elsevier B.V. on  behalf of Far Eastern Federal University.
• Lee Y-C., Nam J-M. & Kim J-G. 2011. The influence of black locust (Robinia pseudoacacia) flower and  leaf fall on soil phosphate. Plant and Soil. April 2011, Volume 341, Issue 1–2, pp 269–277.
• Moores, N. 2016a. Bird Species Recorded During a Visit to the DPRK, May 16th-20th 2016. Internal Report to the Hanns Seidel Foundation, Korea.
• Moores, N. 2016b. Breeding Bird Survey Rason, July 1^st-6^th, 2016. Internal Report to the Hanns Seidel Foundation, Korea. Summary accessed in August 2017 at: https://www.birdskoreablog.org/?p=18303
• Moores, N. 2017. Rason, April 20-24 2017: Internal Report for the Hanns Seidel Foundation (HSF). Summary accessed in August 2017 at: https://www.birdskoreablog.org/?p=19352
• Park, J-Y. 2002. Current status and distribution of birds in Korea. Department of Biology, Kyung Hee University, Seoul (unpublished thesis, in Korean).
• Tomek, T. -2002. The birds of North Korea. Acta Zoologica Cracoviensia. Volume 2 Passeriformes. 45:  1-235 (in English).
• Tong J-C., Zhou W-W., Yang X-M. & Jiang M-L. 1985. Studies on the Breeding Ecology of the Penduline Tit. Acta Zoologica Sinica. 31 (2) 154-161. (In Chinese with English Summary). Accessed in August 2017 at: http://en.cnki.com.cn/Article_en/CJFDTOTAL-BEAR198502009.htm
• Van Djik, R.E., Szentirmai, J. & Szekely, T. 2014. Practical Field Guide for Investigating Breeding   Ecology of Penduline Tits Remiz pendulinus. Verson 1.5, August 2014. University of Bath, UK.