THE BIRD DEPARTMENT 



39 



Every leaf suppurted a dozen worms and when we 

 jarred a l)ranch, hundreds of them dropped toward 

 the grouiiil on silken threads by which they could 

 climb back up to their work of destruction as soon as 

 danger was past. So many of them were there that, in 

 spite of the flocks of birds, including even house spar- 

 rows, which came to feed upon them, countless numbers 

 reached maturity transformed into fluttering yellow 

 moths, again escajied the birds and mated with the wing- 

 less females which were crawling around the trunks of 

 the trees. Now that winter is here, all the moths have 

 died, but on the bark are countless little clusters of eggs 

 awaiting the spring sunshine to transform them into 



A GREAT WEED SEED DESTROYER 



A tree sparrow. The tree sparrow has been estimated 1o destroy over 

 800 tons of weed seed each winter in tile State of Iowa. 



ravenous worms. P.ut such is not to be the case. Flocks 

 of nuthatches and brown creepers are finding the store 

 and will search every crevice in the bark until few eggs 

 are left to hatch. 



In the spring when the apples were just beginning to 

 form, small brownish codling moths appeared and laid 

 eggs updu the newl\- formed fruit. The eggs hatched, 

 the larvae bored to the center of the fruit and before long 

 the ground was covered with wormy apples ; no crop was 

 harvested. Unwittingly the apples were left upon the 

 ground. The worms crawled out and climbing up the 

 trunks of the trees, hid beneath loose flakes of bark, thus 

 to pass the winter. The worms in the center of the apples 

 were inaccessible, but now is the birds' opportunitv. 

 Downy and hairy woodpeckers flock to the orchard. Up 

 and down the trunks they go tapping every loose piece of 

 bark, stopping only long enough to drill small holes and 

 extricate the larvae. The best way to control the codling 

 moth, we are told in books on fruit insects, is to fasten 

 pieces of beef suet to the branches to attract the wood- 

 peckers. They will come to depend upon the suet to carry 

 them through times of stress, but most of their day will 

 be spent gleaning the larvae from under the bark. 



It is during the winter that many of our insect pests 

 are most easily controlled by birds, so whatever we do 

 toward attracting and feeding them through these cheer- 

 less months is far more than repaid. 



But all iiur winter birds are not insect eaters. What 

 do we owe to these that spend their time gleaning the 

 seeds of weeds? According to Professor Beal, of the Bio- 

 logical Survey, at Washington, a single species, the tree 

 sparrow, consumes over SOO tons of weed seed every year 

 in the State of Iowa alone. Single meals of such birds 

 as the bolj-white and mourning dove, as shown by the 

 contents of their crops, have consisted of over 5,000 

 seeds of obnoxious weeds. 



If we stop for a moment to consider the reproductive 

 capacity of weeds we can appreciate the need of such 

 efficient engines of destruction as the birds. A single 

 plant of henbane, for example, bears annually 10,000 

 seeds. If all the seed should germinate and reach 

 maturity, in less than five years there would be a henbane 

 plant for every square foot of land on the globe. (3ther 

 weeds are even more prolific. The many species of spar- 

 rows, in this case, the juncos, the redijolls and the snow 

 buntings that twitter about our weed-grown fields and 

 gardens are yielding us a service almost as valuable as are 

 the chidadees and woodpeckers in the orchard and woods. 



There is also a third group of birds, the'hawks and 

 owls, much malinged by the ignorant, some of which 

 remain with us all winter. Most of the owls and some 



EVIDEN'CES OF I.NDUSTRV 



Flalves of apple tree bark showing the work of woodpeckers in destroy- 

 ing codling moth larvc-e and pupa?. The lower row shows the holes 

 made by the woodpeckers, the upper the empty cocoons. 



