70 MR SELBY ON BIRDS OF PASSAGE. 



checked in growth, or have become sickly in constitution, the cones on 

 such occasions occupying invariably the usual situation, that is, close by, 

 or around the diverging shoots of the year, whereas, in this instance, we 

 have them occupying the greater part of the shoot, and upon a tree of 

 vigorous growth and healthy appearance. 



Table shewing the period of Arrival of several Summer Birds of PaS' 

 sa^e, in the neighbourhood of Twizell-House, for the last twenty 

 years. By P. J. Selby, Esq. of Twizell-House. 



The annexed table, shewing the period of arrival of several of our 

 summer birds of passage, in the immediate neighbourhood of Twizell, 

 for upwards of twenty years, is taken from such entries as I had made each 

 year, as the various species came under my personal observation. Im- 

 perfect as this table may probably appear to the members of the Club, 

 I may be allowed to remark, that in many cases where the entries seem 

 to be the most deficient, this has not always arisen from neglecting to re- 

 cord or watch the first appearance of a species, but from other and va- 

 rious causes. Thus, the non-appearance of a particular bird for one or 

 more seasons within the limits of my observations, prevented an entry, 

 as did also the absence of any species from the precincts of Twizell, till 

 a period considerably posterior to its known presence in other localities, 

 within a short distance, or in the same parallel of latitude. Absence 

 from home at the time of arrival also occasionally prevented the regis- 

 tration of some of the birds enumerated. As examples of birds which 

 seem to have deserted the district, or which are now but rarely met with, 

 are the Locustella avicula, grasshopper-warbler, the Hirundo urbica, 

 window-swallow or martlet, and the Saxicola rubetra^ whin-chat. The 

 first, some twenty-five years ago, used to be common, I may almost say 

 plentiful, about Twizell. This was when the plantations were young, 

 with an abundance of thick herbage and an undergrowth of whin, broom, 

 &c., a cover congenial to the retired habits of this curious little bird. 

 As this undergrowth died out and gave way to the growth of the forest 

 trees, the grass-hopper-warbler gradually forsook the locality, and it is 

 now a bird of very rare occurrence, and for the last few years has only 

 been heard occasionally at a distance on the verge of the moors to the 

 west of Twizell, where the ground still remains favourable to its habits. 

 The martlet is also now rarely seen at Twizell on its first arrival, or 

 during the breeding season, though it formerly had its clay-built tene- 



