92 
WOODPECKERS TX RELATION TO TREES. 
Joseph Grinnell records the following observation upon the same 
Species Of woodpecker: 
At Seven Oaks, June 24, 1!»<><;. we had been watching a Sierra sapsucker (Sphyrapicus 
r. daggetti) industriously running a line of bark pits around the branch of an alder, 
when a California woodpecker . . . (lew down and drove off the sapsucker . . . then 
went the rounds of the borings himself , "dipping" from each. 1 
This observation suggests thai the other records of species of wood- 
peckers besides sapsuckers tapping trees should refer only to their 
purloining sap from punctures made by the latter. Be that as it 
may, the assertion lias frequently been made that some of our wood- 
peckers, uotably the downy and the hairy, mark trees in a fashion 
almost indistinguishable from that of the sapsucker. Some of the 
European woodpeck- 
v 
i -' 
I 
( r 1 ' 
, , I i { M C 1 
i r ir rri 
ers very closely re- 
lated to our species of 
the genus Dryobates 
do a great deal of 
similar work, even 
producing large swol- 
len girdles on trees, 2 
and it would be sur- 
prising if our species 
were found to be en- 
tirely innocent of 
such practices. Mr. 
Henry Bryant , of 
Boston, published 
the following testi- 
mony in 1866: 
It has long been known 
thai some of our smaller 
woodpeckers pick out por- 
tions of the sound bark of 
trees, particularly of apple 
trees, where there are no 
. . . They [the pecks] are 
Fig, 38.— Yellow-bellied sapsucker. Note the black spot on breast. 
larva- and apparently no inducement for them to do so. 
generally seen in circles round the limbs or trunks of small irregularly rounded holes. 
and in this vicinity are made almost exclusively by the downy woodpecker, 
/'. pubescent, aided occasionally by the hairy woodpecker. P. villosus.* 
Dr. J. A. Allen corroborates these statements as follows: 
The perforations made in the bark of trees by woodpeckers, forming transverse rings, 
and sometimes so numerous as to do serious injury to the trees, have of late been very 
commonly attributed almost solely to this species [yellow-bellied woodpecker]. 
especially at the West, where it is BO numerous. Thai it is. from this habit, often 
greatly injurious to fruit trees is not to he denied ; but that this species — now commonly 
styled the 'true Bapeucker," to whose depredations it is said should be assigned the 
' t nh. calif. Pub. /.col . v. 66 66, 1008. 
i ucii-. Gilbert Dbei daa EUngeln der Bpechte undihrVerhaltengegen dlekleinereo Forstsch&d- 
fosttachr. f. Landu. Poretwtrtschaft, [11,317 Ml, 1905. 
• Pro K, 91 2 1866. 
