GENERAL NOTES

A tube for holding birds during examination of molt in the flight feathers.--Some restrainingdevice is required for holding • live bird while it is being examined. In order to investigatewing and tail molt in membersof the crowfamily (Corvidae),I have useda rigid tube with • lengthwiseslot (Fig. 1): the bird is placed both head-first and on its b•ck into the cone but with one wingprotruding through the slot,the wingbeing supported by a flangeprojecting from the cone (Fig. 2). The wing •t the side of the cone and the t•il •t the rear are now readyfor examination.The bird canbe insertedand removedquickly but solong •s the tube is inclinedwith the narrowend lowermost,the bird will remain steadfastlybut lightly held. The cone-shapedform of the tube accom- modatesindividuals and speciesof similarbut differingbody sizes. This device servesto protectthe bird during examination, to protectthe handler from pecking •nd scratching,to maintainuniformity of examinationby consistentlypresenting in successiveindividuals only that wingon a givenside of the body,and to allow calm and careful examination.

narrow end ./ cone

end fla•e

Ft•o• 1. The holding tube.

cone

w •ng of b•rd • . ' .'•"'"'"'•'--,onitsback

turnededge of overmetal flange Fz•u• 2. Transversesection of holdingtube.

For tubesfor holdingcrows I haveused sheets of galvanizedsteel (0.82 mm thick,British standard wire gauge) obtainable from the British Steel Corporation, Shotton,Flintshire, U.K. (butfor smaller bodied species polyvinylchloride sheet, 0.8 mmthick, could be used).The metal is cutto theshape indicated in Figure3. (Boththe relativeproportions and •bsolute dimensions used will dependon the

7• vol.40, No.t GeneralNotes [75

/ edge t.obe turned over

FfGum•; 3. Shapeof fiat sheetof metal. A-E: seetext and Table 1.

TAm. e 1. Someexamples of tube dimensions(in cm.) for selectedcorvids.

Dimensions of fiat sheet Width Species of metal Diameter of cone of slot

Broad Narrow A B a C a end end Corvus albus 2 Corvus braehyrhynehos2 Corvus corone • 33 37 46 11 5 2 Corvusfrugilegus • Corvus orru 2

Cissa ehinensis ø• Corvus monedula • Cyanocitta stelleri'• Cyanocoraxviolaceus" 25 34 37 8 4 1.5 Garrulus glandarius1 Pica pica•

•Tubes of the given dimensionshave been used by the author to exmnine these species. aSpecieshaving similar body sizes,as shown by an examination of skins in the British Museum (Natural History). aIn the finished tube these dimensionsbecome reduced by 2 cm by having 1 cm turned over along each of the edgesA and D shape and size of body of the speciesto be examined--see Table 1 for some examples). Edges A and D are first turned over and presseddown to protect both the bird and the handler and then edgeD is rolled over by hand and brought down towards the center of the sheet (E) to make a cone and to leave a slot betweenD and E. (Polyvinylehloridesheet would need first to be heatedin an oven to soften it. before rolling and then allowed to cool while being held in the required form.) l)epending on whether edge I) is rolled towards or away from the observer when looking at Figure 2, the tube can be made to exposeeither right or left wing respectively. Some protective paddiug along the sharp edges of the metal, e.g. strips of adhesivetape, is desirable.--D. C. S•.:u•, Institute of Terrestrial Ecology,Bangor Research,Station, Penrhos Road, Bangor, LL57 2LQ, United Kingdom. Ileceived 9 August 1974, accepted 13 November 1974.