6 



THE OOLOGIST. 



twelve to sixteen paojes, and in order that 

 we may realize this, it is essential that onr 

 subscription list be increased. 



Our late appearance is due to many agen- 

 cies, foremost among which was the delay 

 caused in publishing the collectors' Direct- 

 ory. We are now issuing two numbers a 

 month, which will enable us to soon be 

 again on time ; jneanwhile, it shall be our 

 aim' to improve in all departments as rap- 

 idly as possible. 



How to Rightly Estimate the E- 

 conomical Value of Birds. 



T. M. BREWER. 



HAN this we know of no more im- 

 portant and certainly no more diffi- 

 cult undertaking. More than this, 

 Avhoever undertakes to decide, oif hand, 

 with only partial, imperfect and necessarily 

 incomplete observations will be pretty sure 

 to blunder in his conclusions. In the old 

 world several attempts have been made to 

 investigate this obscure and complicated 

 subject. Of these the most remarkable and 

 by far the most complete and exhaustive, 

 was made in France, several years since, 

 under the auspices and supervision of an 

 eminent savan, M. Flovert Prevost. The 

 commission of which he was the head was 

 appointed by the Emperor Louis Napoleon, 

 in consequence of applications for relief 

 against the ravages of insects brought to 

 the notice of the French government, and 

 coming from the vine-growers of Burgundy. 

 It seems that from year to year there had 

 been noticed a great decrease in the number 

 of small birds in that section of country, 

 followed by a rapid increase of insects, and 

 a wide-spread injury to the vines, the 

 diminution of the crops and a great injury 

 to vine-yards. The evil threatened to be- 

 come a calamity. 



In this exigency the Parliament recom- 

 mended the appointment of a commission 

 to investigate the whole subject of the val- 

 ue to agriculture, in all its branches, of the 



native birds. This was done, and for nine 

 years the members of this commission at- 

 tended to their duties in the most thorough 

 and exemplary manner — as thoroughly as 

 the circumstances permitted. It was deem- 

 ed best to make a long continued, most 

 thorough and persistent examination of the 

 contents of the stomachs of all kinds of 

 birds. This required the destruction of a 

 large number of all species, and a minute 

 and careful record of their work, and final- 

 ly a well considered resume of results and 

 conclusions. Some of these were very sur- 

 prising to the gentlemen themselves. 



They began their investigations with the 

 belief that the insectivorous birds were, as 

 a matter of course the most advantageous. 

 But these opinions they were obliged very 

 greatly to modify. Many, so called insect- 

 ivorous birds were found to feed chiefly on 

 certain small insects that had no apparent 

 connection, good or bad, with agricultural 

 results. Others were found, all eminently 

 insectivorous, who fed principally upon in- 

 sects more or less beneficial to agriculture, 

 arboriculture and vegetation generally, de- 

 stroying parasitic insects and thus doing 

 harm instead of good. As a whole what 

 are generally referred to as specially and 

 peculiarly insectivorous, were not so strik- 

 ingly advantageous as at first had been taken 

 for granted. To be sure there were nota- 

 ble exceptions, as in the Swallow, who cap- 

 tures on the wing, the flies who produce the 

 pear slug, the currant worms and the gnat 

 maggots, but these were marked exceptions, 

 not the rule. 



Their next great surprise was to find 

 that those birds which were found really to 

 do the most good, inasmuch as they alone 

 destroyed the insects most noxious to vege- 

 tation were birds hitherto of the worst re- 

 pute. The destructive cockchafer, which 

 both as a beetle and as a grub is the great 

 pest of Europe, was destroyed in immense 

 numbers by the Starlings, the Crows, Jays 

 and other birds of evil reputation. But the 

 greatest of all their surprises was the con- 

 clusion that the birds which must rank the 

 highest, as the most useful because it was 



