ML350018371
投稿者
日付
場所
- 年齢と性別
- 成鳥オス - 1
- 行動
- エサ運び; 求愛、ディスプレイ、交尾; 飛んでいる
- 音声
- 地鳴き; フライトコール
- プレイバック(音声の再生)
- プレイバック(音声誘引)不使用
視聴覚メディア・ノート
Flight calls/display calls from a male Least Tern carrying a fish and chasing a female Little Tern as it flew past the south hide at Rogerstown Estuary. First record for Ireland and second for the Western Palearctic.
観察結果の詳細
****MEGA! First Irish record and second for the Western Palearctic. Adult male Least Tern present around the estuary out from the hide with a male and female Little Tern (both male terns chasing the female in displaying flight while carrying fish). While scanning the estuary from the hide around 08:15, I noticed two Little Terns approaching from the east. As these were the first I have seen at this site I had a quick look at them in the scope while they were approaching head on and then returned to looking through the flock of roosting waders across from the hide. While I had my head buried in the scope the terns must have flown past right in front of myself and Noel and it was at this point I heard an unusual, loud and 'squeaky' call. Initially I thought it might have come from a wader so had a quick look around but then realised that it likely came from one of the 'Little' Terns that flew past. Alarm bells rang so I trained my scope on the terns which were now about 500m up the estuary to our west. At this point I realised that three birds were present (two males chasing a female) and that one of the males lacked the obvious contrast between the grey back/wings and white rump/tail that was apparent on the two Little Terns accompanying it even at that range. I quickly informed Noel to get on the bird and I whipped out my iPhone and switched on the Voice Record Pro app knowing that if my suspicions were true, then a sound recording would be key to confirming the identification. The terns soon started heading back east towards us and we kept track of the grey-rumped male bird in our scopes. Just as the three terns flew past us (at a range of c.100m) the bird in question let out a series of almost Ring-necked Parakeet like calls! These were recorded using the smartphone recording app (see attached). The loud, explosive and squeaky nature of the calls were like nothing I've ever heard from over ten years of wardening and surveying Little Terns at breeding colonies around Ireland. I knew then that these calls along with the apparent grey rump indicated that the bird was most likely a Least Tern. Happy that a recording of the call was obtained, I suggested to Noel that we now focus on details of the rump, uppertail coverts and tail. The bird was too far away to attempt any kind of effective digi-scoping but as it headed east and away from us towards the railway bridge over the estuary it began fishing and diving, allowing for good (albeit somewhat distant) views of the rump and tail as the bird stalled in the air, spread the tail and dived. The light was good, clear and flat during this time and on all occasions when the bird banked or plunge dived, the continuous, uniform nature to the grey wings, back, rump and central tail region (right out to the tip) was apparent, with the longer outer tail feathers being the only area that looked white (and contrastingly so). This feature held true during side by side comparisons with the two Little Terns which showed the obvious sharp contrast between the grey back and white rump/all tail area. The grey rump and central tail with contrasting white outer tail feathers was true and obvious in good light even at 500-600m range. The combination of the call and grey rump/central tail area meant that this bird must be a Least Tern. I sent a quick description of the bird plus the sound recording to Killian Mullarney who confirmed my suspicions. The call matched Least and the apparent similar bill shape and head pattern to Little Tern helped to rule out Saunder's Tern. As the bird was a full adult, a grey rumped immature Little Tern was not in the mix here either and the call ruled out any of the other subspecies of Little Tern which can show grey rumps. Noel also commented that the outer primaries on this bird looked solid (in a manner which was in line with that found on Least or Little and not as wide as expected on Saunder's). The Least Tern was last seen flying east towards the outer estuary around 08:25 and we later relocated it at the Portrane Little Tern colony (as expected), where it was twitched by about 50 birders there that day with thanks to the organisation and help of the wardening team. Some pics of the bird when seen at Portrane can be found on the Irish Birding website here http://www.irishbirding.com/birds/web/Display/sighting/142201/Birding_Opportunity.html It seems the bird had already been present for two weeks at Portrane and also there in 2020 according to the wardens (who have been hearing a 'squeaky' sounding tern there for a while now but identification as Least was only made by us today).
追加される種
テクニカル・インフォメーション
- レコーダー
- Voice Record Pro on iPhone 6S
- マイク
- アクセサリ
- オリジナルのファイルサイズ
- 1.38 MB