Cogau 2021 Cuckoo's

 

Cuckoos are essentially African birds, very much birds of the tropical forests who venture north every spring to breed. Long distance migration is full of hazards and many birds do not survive either the journey north or the return home to Africa in autumn.

In 2011 the BTO started following Cuckoos on their migration, initially to discover the routes they take, and where they went for the winter. It was found that they winter in the Congo basin, and get there via a route that takes them through Italy and across the Mediterranean into Libya before crossing the Sahara. Some English birds take a more westerly route via Spain and Gibraltar. It was found that the survival rates for both routes was different with Italian birds surviving better.

In 2012 5 Cuckoos were tagged in the Tregaron are of mid Wales, with David going on to complete 4 migrations back and forth to Africa. Sadly, his transmitter failed in 2017 and despite looking for him in his summer patch near Tregaron he was not re found. I would like to think he is still there and that the equipment has fallen off.

 

This year another two Cuckoos were tagged in Wales.

 

                                                                              JAC   Photo Kelvin Jones

JAC was tagged at Worlds end near Llangollen on the morning of 1^st June.  For those that have been to Worlds end at dawn, it is a magical place with the sound of lecking Black grouse in the distance and calling Red grouse.  Kelvin Jones from BTO Cymru got there early on the morning and set up the catching equipment ready for BTO tagger Lee Barber to arrive. Immediately caught a Meadow pipit and a female Sparrowhawk. Lee turned up them and the cuckoo tape was put on, and before they had ringed the Sparrowhawk a nearby male Cuckoo responded and minutes later was in the net. JAC was named in memory of Professor Jenny Clack a world leading palaeontologist, who was widely acknowledged as the leading authority on the evolution of land vertebrates from fish. The name JAC was chosen by jenny’s husband who said “It seemed appropriate I should contribute to this important scientific study of Cuckoos in memory of a top-class scientist, whom I adored” JAC seems to have started his southwards migration at the time of writing.

 

 

The second Cuckoo 50042 was caught at the RSPB’s Lake Vyrnwy on the 5^th June, by Lee and local ringer Mike Haigh. Interestingly he has not begun his southwards journey yet but has twice left Vyrnwy and gone to the outskirts of Llanymynech, Lee was brought up here so I wonder what he whispered in the birds ear whilst tagging was ongoing.  50042 is as yet un named, so if you would like to sponsor the name please go to https://www.bto.org/our-science/projects/cuckoo-tracking-project.

                                                                          50042  Photo Lee Barber

It will be fascinating to see if these birds from a different part of Wales will follow in the footsteps of David and his 2012 Tregaron cohorts and go via Italy, or go via the English route and Spain.

For daily updates and more information on the project https://www.bto.org/our-science/projects/cuckoo-tracking-project

 

 

 

 

Aderyn Affricanaidd ydyw'r gog yn y bôn; aderyn y coedwigoedd trofannol, sy'n mentro i'r gogledd bob gwanwyn i fridio. Peth peryglus ydyw ymfudo pellteroedd maith ac nid yw llawer o'r adar yn goroesi, naill ai ar y daith i'r gogledd neu wrth ddychwelyd adref i Affrica yn yr hydref.

Yn 2011 dechreuodd y BTO ddilyn y cogau wrth iddynt ymfudo. Y bwriad cyntaf oedd i ddarganfod y llwybrau y maent yn eu cymryd, a darganfod i ble yr ânt am y gaeaf. Canfuwyd eu bod yn gaeafu ym masn y Congo, ac yn cyrraedd yno ar hyd llwybr sy'n mynd â nhw drwy'r Eidal ac ar draws Môr y Canoldir, i mewn i Libya cyn croesi'r Sahara. Ond y mae rhai adar o Loegr yn cymryd llwybr mwy gorllewinol, trwy Sbaen a Gibraltar. Canfuwyd bod y cyfraddau goroesi ar gyfer y ddau lwybr yn wahanol, gydag adar yr Eidal yn goroesi yn well.

Yn 2012 tagiwyd pum gog yn Nhregaron. Cafwyd bod y gog a alwyd yn David yn mynd ymlaen i gwblhau pedwar ymfudiad, yn ôl ac ymlaen i Affrica. Ond yn anffodus, methodd ei drosglwyddydd yn 2017 ac er chwilio amdano yn ei ardal haf ger Tregaron, ni ddaethpwyd o hyd iddo. Hoffem feddwl bod David yn dal i ddychwelyd i'r ardal ond bod yr offer wedi cwympo oddi ar ei gefn.

 

Eleni tagiwyd dau gog arall yng Nghymru.

 

                                                     JAC                         Llun Kelvin Jones

Enwyd un yn Jac a chafodd ei dagio ar Fynydd Eglwyseg, Llangollen ar fore Mehefin y cyntaf. Bydd y rhai ohonoch sydd wedi bod ar Fynydd Eglwyseg ar doriad gwawr, yn gwybod ei fod yn lle hudolus gyda sŵn y grugieir duon i'w glywed yn y pellter. Cyrhaeddodd Kelvin Jones o BTO Cymru yno yn gynnar yn y bore a sefydlodd yr offer dal yn barod ar gyfer Lee Barber (modrwywr y BTO) ac, ar un waith, fe ddaliwyd corhedydd a iâr gwalch glas. Cyrhaeddodd Lee a gosodwyd tâp o'r gog yn galw cyn iddynt fynd ati i fodrwyo y gwalch glas. Yn syth, fe ymatebodd gog gwrywaidd ac ymhen munudau yr oedd yn y rhwyd. Fe'i enwyd yn Jac er cof am yr Athro Jenny Clack, palaeontolegydd blaenllaw, a gafodd ei chydnabod fel yr awdurdod blaenllaw ar esblygiad fertebratau-tir-sych o bysgod. Dewiswyd yr enw Jac gan ŵr Jenny ac fe ddywedodd “Yr oedd yn addas iawn i mi gyfrannu at yr astudiaeth wyddonol bwysig hon o gogau er cof am wyddonydd o’r radd flaenaf yr oeddwn i yn ei haddoli.” Ymddengys bod Jac wedi dechrau ymfudo tua’r de ar yr adeg yr ysgrifennwn hyn.

Daliwyd yr ail gog (50042) ar safle RSPB Llyn Efyrnwy ar y 5^ed o Fehefin, gan Lee a’r modrwywr lleol Mike Haigh. Yn ddiddorol, nid yw y gog hwn wedi cychwyn ar ei daith tua'r de eto ond y mae wedi gadael Efyrnwy ddwywaith ac wedi mynd i gyrion Llanymynech, ble y magwyd Lee; tybed beth a sibrydodd Lee yng nghlust yr adar wrth iddo eu modrwyo? Nid yw 50042 wedi'i enwi hyd yma, felly os hoffech noddi'r enw ewch i https://www.bto.org/our-science/projects/cuckoo-tracking-project

 

                                                           50042                               Llun Lee Barber

Bydd yn hynod ddiddorol gweld a fydd yr adar hyn, o ran gwahanol o Gymru, yn dilyn ôl troed David a'i griw o Dregaron yn 2012 gan fynd drwy'r Eidal, ynteu a ydynt am ddilyn llwybr cogau Lloegr a Sbaen.

I gael diweddariadau dyddiol a mwy o wybodaeth am y prosiect ewch i wefan- https://www.bto.org/our-science/projects/cuckoo-tracking-project