440 U-S. NATIONAL MUSEUM BULLETIN 23 7 ^abt i 



(MS.) recorded this observation: "I noticed that, when alighting on 

 any older limb, the siskins would examine it closely until its ex- 

 tremity was reached, and this was particularly the case when any 

 had the appearance of being dead. Then the bird would clip or 

 break off the twig's end. I examined one of the twigs that fell and, 

 in breaking it, I found deeply embedded within a fat grayish-green 

 grub, evidently the larva of a twig-boring insect. This explained the 

 siskins' actions." 



The McCabes (1929) mention the attraction that salt and clay 

 have for siskins. In an earlier article (1928) they state: "The 

 attraction has always been some mineral food, relish, or medicament, 

 natural or artificial. Ashes, deep blue clay from a cellar hole, salt, 

 and newly-set Portland cement have all had their periods of favor." 

 The habit has been noted in different seasons and at widely separated 

 points. Mierow (1946) made the general statement that a "necessary 

 item in the siskin's diet, as well as in that of other boreal finches, is 

 some kind of mineral salt." D. S. Earner (1952) reported this habit 

 in Crater Lake National Park as follows: "Although to a much lesser 

 extent, siskins display 'salt-feeding habits' similar to those of the Red 

 Crossbills. Especially during the summer of 1951 it was possible to 

 observe siskins pecking at the powdery crusts on the andesite rocks." 



In the first half of March 1941, between Saranac Lake and Tupper 

 Lake, N.Y., the road had been treated with a mixture of sand and 

 calcium chloride — the latter apparently added as a binder for the 

 former. G. M. Meade (1942) quotes an observer as follows: 



For several days great numbers of White-winged Crossbills and small numbers 

 of Red Crossbills and Pine Siskins settled on the road to eat the salt. The road- 

 bed was covered with them and it was almost impossible to scare them away 

 even by using the horn. They appeared to be too sick to rise and even though 

 motorists drove slowly they were killed in great numbers. The surface of the 

 snow-covered road was actually reddened by the blood and feathers of the birds. 

 My estimate is that there were at least a thousand birds killed. 



From Rutherglen, Ontario, it is clear from the following observa- 

 tions for the winter of 1947-48 by Louise de Kirihne Lawrence 

 (MS.) that salt in some form is a real desideratum of siskins. She 

 writes: "At this time, the birds were encountered chiefly on the 

 highway where they assembled in dense flocks, eating gravel mixed 

 with chloride. Soon after sun-up they began to appear in these 

 places with their numbers reaching a peak around midday, followed 

 by a slow decline until, just before sunset, the last flock flew away to 

 roost. Many of these birds apparently travelled considerable dis- 

 tances to these cherished feeding-places; I saw birds winging their 

 way to and from the highway from the woods at least a mile away. 

 When disturbed, the birds swung off the road as of one accord, amid 



