Notes

Juvenile Common Coot feeding second-brood young Graham Graham Catley 42. When Common Coots Fulica atra have a second brood, the first-brood young are either driven away or remain close to the nest-site and are occasionally, as this photograph shows (at Barton Pits, Lincolnshire, in July 2010), seen feeding the chicks of the later brood (BWP).

Probable object play among gulls in Staffordshire

One of the most likely forms of avian play Water weed was the most regularly involves a bird carrying an object into the air manipulated object but twigs and leaves were to repeatedly drop and catch it in flight. With also used. In none of the observations of some variations, drop-catch behaviour has drop-catch or drop-retrieval was any object been observed in raptors, gulls, corvids and eaten. When dropping weed, the gulls typi- possibly hirundines (Ficken 1977). cally manipulated the weed into a roughly Observations of drop-catch behaviour in spherical shape before taking off from the Black-headed Chroicocephalus ridibundus, water. Chases of birds carrying weed would Lesser Black-backed Larus fuscus and Herring usually ensue, involving up to five gulls, both Gulls L. argentatus were made from the conspecific and non-conspecific. Gulls of all public hide at Aqualate Mere, Staffordshire, three species engaged in chases of gulls of the on three out of a total of 18 visits between 1st other species. The pursuers were never October 2009 and 28th February 2010. The observed to make contact with the leading behaviour was always performed over open birds in any way, and neither did they water and the gulls used only their bills to attempt to catch the weed in flight once it manipulate, carry and catch the objects was dropped. Drop-catches tended to occur involved. when the chasing birds had ‘given up’ the There were usually many more gulls pursuit. present when fishing boats were absent from Chases with no drops were more regular the mere. On the 15 dates when boats were than chases with drops. Often birds would present, aerial chases involving Black-headed simply return to the water surface, to repeat- Gulls carrying objects were observed only edly release, submerge and retrieve the weed. occasionally and no drop-catching/retrieving Dropping objects in flight with subsequent behaviours were recorded in any species. retrieval from the water surface (drop-

94 © British Birds 104 • February 2011 • 94–99 Notes retrieving) was quite regular, while drop- was no physical contact between the gulls catches were the least common behaviour. and also, when involved in drop-catches, However, Black-headed Gulls of all ages and drops or chases, the objects were never subse- immature Lesser Black-backed and Herring quently eaten. Gulls all drop-caught objects (in one Gamble & Cristol (2002) also found that instance, by an immature Herring Gull on immature birds were most often involved, 22nd January 2010, six times in succession). although they found that drop-catching was On each of the three visits where this behav- a solitary activity that declined in the close iour was recorded, it lasted from roughly presence of conspecifics. At Aqualate, drop- 11.00 to 13.00 hrs and drop-catches were catching and associated chasing behaviour numerous. appears to be a social activity. In particular, In all three species the behaviour appeared the interspecific chasing prior to drop- to fulfil Burghardt’s (2005) five criteria of catches may not have been documented play, namely that it had a limited immediate before. function, was voluntary, differed from ‘serious’ behaviour, was repeated and was References performed in a relaxed field. The fact that the Burghardt, G. M. 2005. The Genesis of Animal Play. behaviour was performed only in the absence Cambridge, Mass. of human disturbance (boats) may suggest Ficken, M. 1977. Avian Play. The Auk 94: 573–582. Gamble, J. R., & Cristol, D. A. 2002. Drop-catch that a relaxed field is important. The behav- behaviour is play in Herring Gulls Larus argentatus. iour differed from kleptoparasitism as there Anim. Behav. 63: 339–345. Stephen Hewitt, 13 Bowen’s Manor, Lurgan, Co. Armagh BT66 7RT

Marks on the iris of the Black Woodpecker

In recent years I have spent much time variable shape, occasionally giving the observing Black Woodpeckers Dryocopus impression of a ‘double pupil’. It soon martius at nesting and roosting cavities, became clear that such marks were the norm mainly in Hungary but also elsewhere in for both males and females, typically (as far central and eastern Europe. With a telescope, as I could determine) found in both eyes. I have been able to obtain close and pro- Black Woodpecker nestlings have bluish- longed views of individual birds and was sur- black eyes, in which it is difficult to distin- prised to note that many birds seemed not to guish the pupil from the iris, but it is clear have a circular pupil, but rather a pear- that many older, fully feathered chicks shaped or teardrop-shaped one. Intrigued, already show a dark mark on the iris as it I began to focus systematically upon the eyes becomes paler. of all the Black Woodpeckers I encountered, I examined over 100 close-up photo- noting the colour and shape of the pupil and graphs of the eyes of adult male and female iris. Black Woodpeckers, taken across the Gradually, it became apparent that the Palearctic range of the species, and including irregular shape of the pupil was actually both races: nominate martius (most of range) created by dark marks on the iris, i.e. the and khamensis (southwest China, Tibet). pupil was circular but the dark marks created Approximately 85% of Black Woodpeckers in an impression that it was pear-shaped. these photographs had some form of dark Indeed, BWP (1985) mentions that adult mark on the iris while 15% did not. There Black Woodpeckers have a ‘black spot in was no evidence that such marks were con- front of the pupil’. Most of the birds I fined to a particular population, region, race observed, however, showed rather more than or gender, and there was no clear evidence of a simple spot on the iris. In many cases there an irregularly shaped pupil. was a dark, elongated slit between the edge of Marks on the iris may not be unique to the pupil and the bill base, sometimes Black Woodpeckers, but seem to occur much stretching across the iris and being of rather more frequently in this species than in most

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showed such marks. What, if any, is the function of these dark marks on the iris? In some animals, irregular pupil shapes modulate the amount of light reaching different parts of the retina that may have different sensitivi- ties or resolution – so the shape is adaptive for vision. Iris pigmentation patterns have little effect on vision but perhaps act as signals, perhaps in terms of fitness or mate recognition. In some species iris pattern indicates gender (for example, American

Lee Mott Black Oystercatchers Haematopus bach- mani, in which the iris of adult females is patterned but that of adult males is not; Guzzetti et al. 2008), but this is clearly not the case with Black Woodpeckers, nor is it likely that the marks are colobomas or other optical defects. Rather, the high pro- portion of birds showing dark iris marks (Picidpics) could suggest that it confers an advantage of some sort and has been selected for. Indeed, the presence of two forms of iris shape within the same population may be an example of a polymorphism which is heritable; and it would be interesting to

Julio Pérez Cañestro know whether this is the case. There is 43 & 44. Adult male (43, Hungary, January 2010) clearly more to find out about the function and female (44, Barcelona, Spain, March 2007) Black of these distinctive dark iris marks in the Woodpeckers Dryocopus martius. Both photographs clearly show a dark spot on the pale iris, adjacent Black Woodpecker. to the pupil and extending from the pupil towards the base of the bill. Reference Guzzetti, B. M., Talbot, S. L., Tessler, D. F., Gill, V. A., & other picids; they are much less common Murphy, E. C. 2008. Secrets in the eyes of Black in the other (six) Dryocopus species. For Oystercatchers: a new sexing technique. J. Field Orn. 79: 215–223. example, I examined many photographs of both White-bellied D. javensis and Pileated Acknowledgments Woodpeckers D. pileatus and found that I thank Martin Collinson and Richard Chandler for very few White-bellied and no Pileated commenting extensively on a first draft of this note.

Gerard Gorman, Budapest 1511, Pf: 4, Hungary; e-mail [email protected]

Female song in the Ring Ouzel

Although bird song is generally considered to species was it stipulated that females do not be a largely male phenomenon, studies have sing (Garamszegi et al. 2007). Among British revealed a considerable number of species in passerines, female song is seemingly frequent which the females sing, and that song in both in Robins Erithacus rubecula and Dippers sexes may be the ancestral condition (Riebel Cinclus cinclus. et al. 2005). Indeed, a search of the vocalisa- The Ring Ouzel Turdus torquatus is one of tions texts in BWP revealed that, of 233 the 124 species for which there is no mention passerine species covered, female song was of female song in BWP. (In terms of a com- recorded in 101 species and in just eight parison with the Ring Ouzel’s closest rela-

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tives, BWP shows that 8 song by female Black- birds T. merula has been 6 recorded, whereas it is 4 stated that female Song

frequency kHz frequency 2 Thrushes T. philomelos do not sing.) Garam- 0 12szegi et al. did, however, time (sec) note a correlation Fig. 1. Typical simple song from a male Ring Ouzel Turdus torquatus between the length of showing the familiar three-note whistle; North Lees, , the text on voice in April 2010. BWP and the incidence of female song, sug- gesting that female song was found in those 8 species that were more closely studied. 6 For the past five years BG has been 4 recording vocalisations frequency kHz frequency of Ring Ouzels inten- 2 sively. In 2008, he 0 recorded what he 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 believed to be female time (sec) Ring Ouzel song, but Fig. 2. Typical complex song from a male Ring Ouzel Turdus torquatus, the bird was not visible North Lees, Derbyshire, April 2010. during the recording, so the record could not be 10 verified. During 2010, 8 he witnessed and 6 recorded female Ring 4 Ouzel song at two dif- ferent sites, on the

frequency kHz frequency 2 0 North Lees Estate and 123at Burbage Edge, both time (sec) near in the Fig. 3. The first, second and fourth notes are simple song from the National male Ring Ouzel Turdus torquatus, with the third and fifth notes from Park, Derbyshire. the female. The female was closer to the microphone. North Lees, Ring Ouzels have Derbyshire, 28th June 2010. two main song types: the familiar fluted 10 whistle, repeated three 8 or four times, and known as ‘simple song’ 6 (fig. 1); and a more 4 complex song, con-

frequency kHz frequency sisting of dense, atonal 2 warbling (fig. 2). BG 0 recorded female Ring 12 time (sec) Ouzels giving both song Fig. 4. The two long notes are simple song given by the male Ring types. The simple song Ouzel Turdus torquatus, and are followed by complex song from the produced by male Ring female. Burbage Edge, Derbyshire, 2nd July 2010. Ouzels is sufficiently

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young in the nest and then joined in the 8 simple song, immedi- ately after the second 6 note of the male. The combined effect of this 4 duet produced a some- 2 what syncopated frequency kHz frequency rhythm, which can be 0 seen in the resulting 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 sonogram (fig. 3). BG time (sec) made this recording Fig. 5. The rattling flight call of a male Ring Ouzel Turdus torquatus with while watching the male 13 component notes. North Lees, Derbyshire July 2010. and female singing distinctive to identify individual males using together. Fig. 3 shows the characteristic sonograms. At the first nest-site, at North downturned tip of the male’s notes, with the Lees on 28th June 2010, the male sang simple female’s notes being similarly pitched. To our song on territory immediately after feeding ears, the female’s notes sounded ‘thinner’ and 12-day-old (second-brood) chicks in the more ‘tinny’ than the male’s. At the time of nest. Soon afterwards, the female also fed the this recording there were no other adult Ring Ouzels nearby, the nearest nest being more than 1 km away. At the second nest-site, on Burbage Edge, 3 km to the south of the North Lees ter- ritory, a female Ring Ouzel was recorded singing under similar cir- cumstances just after both parents Mike Breedon Mike had fed second- brood young in the nest, on 2nd July 2010. The female (plate 45) was recorded giving the complex song over the male’s simple song (fig. 4). Again, the male (plate 46) was observed singing while the recording was made, the sono- gram confirmed Mike Breedon Mike 45 & 46. Female (45) and male (46) Ring Ouzels Turdus torquatus, the characteristics Burbage Edge, Derbyshire, July 2010 (these are the birds featured in of the resident the sound recordings in figs. 4 & 5). male and there

98 British Birds 104 • February 2011 • 94–99 Notes were no other adult Ring Ouzels in the made no mention of female song in this vicinity (the nearest territory was more than species. We also contacted the members of 1 km to the north). the Ring Ouzel Study Group to see whether BG’s recordings have also demonstrated anyone had heard, or suspected, female song, that both males and females give a rattling but no-one had. As far as we can determine, call not dissimilar to that of the Mistle therefore, this is the first reported incidence Thrush T. viscivorus. This has been heard on of female song in the Ring Ouzel. numerous occasions, but was recorded twice as birds took flight, lasting c. 0.2 seconds and References comprising 13 and 17 component notes (see Appleyard, I. 1994. Ring Ouzels of the Yorkshire Dales. Maney & Son, Leeds. fig. 5). A high, thin, ‘seep’ note, similar to that Clement, P., & Hathway, R. 2000. Thrushes. Christopher of Blackbird or Robin, has also been recorded Helm, London. from the adults of both sexes when they were Garamszegi, L. Z., Pavlova, D. Z., Eens, M., & Møller, A. P. close to nests with chicks. 2007. The evolution of song in female birds in Europe. Behav. Ecol. 18: 86–96. Appleyard (1994) concluded that female Riebel, K., Hall, N. E., & Langmore, M. L. 2005. Female Ring Ouzels in the Yorkshire Dales do not songbirds still struggling to be heard. Trends in sing, while Clement & Hathway (2000) also Ecology and Evolution 20: 419–420. Tim Melling, RSPB North Region, Westleigh Mews, Wakefield Road, Denby Dale, West Yorkshire HD8 8QD Bill Gordon, North Lees Estate, Birley Lane, Hathersage, Derbyshire S32 1BR

Corn Bunting taking Praying Mantis

On 18th July 2010, I was watching and pho- were obvious. My attention was drawn to one tographing broods of fledged Corn Buntings bird, which had caught a Praying Mantis Emberiza calandra in Lanquedoc-Roussillon, Mantis religiosa. I cannot find reference in France. The weather was extremely hot the literature to this species being recorded as (34°C) and sunny and many flying insects prey for the Corn Bunting. Derek Moore, Rowan Howe, Gors Road, Salem, Llandeilo SA19 7LY Derek Derek Moore 47. Corn Bunting Emberiza calandra with Praying Mantis Mantis religiosa, Lanquedoc-Roussillon, France, July 2010.

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