SHORT COMMUNICATIONS 
409 
The Wilson Journal of Ornithology 123(2):409—411, 2011 
Common Raven Predation on the Sand Crab 
Paul Hendricks 1,2 and Lisa M. Hendricks' 
ABSTRACT.—We observed three Common Ravens 
(Corvus corax) hunting for live sand crabs (Emerita 
analoga ) during low tide on Netarts Spit, Oregon in 
mid-August 2010. One raven successfully extracted four 
crabs in five attempts during a 5-min period. The ravens 
hunted on a large sandy beach near the upper margin of 
the swash zone (the area covered by active wave 
action); the focal bird extracted buried crabs using an 
initial thrust of its bill into the sand to flip sand aside, 
and then followed with two or three additional jabs 
before removing a crab from the sand. Extracted crabs 
were pinned on their backs beneath a foot, whereupon 
the raven pecked at the ventral surface of the crab's 
body but did not consume the crab. The captured crabs 
were mature females, and the egg masses they carried 
appeared to be the target of the raven's attentions. Low 
tides in late summer appear to be particularly favorable 
conditions for profitable and successful hunting of sand 
crab by ravens. This is the first description of the 
method by which ravens hunt live crabs of any species, 
and is further evidence of the ability of ravens to exploit 
seemingly novel and hidden food resources. Received 
27 August 2010. Accepted 16 December 2010. 
The variety of foods documented in the diet of 
Common Ravens (Corvus corax), and the meth¬ 
ods ravens use to obtain food, are extremely 
diverse; almost anything of nutritive value that 
can be captured, picked up, or stolen through use 
of the bill or feet is likely to draw the attention of 
ravens once it is perceived (Heinrich 1989, 1999; 
Ratcliffe 1997; Boartnan and Heinrich 1999). 
Ravens inhabiting some coastal areas are afforded 
many opportunities to capture intertidal inverte¬ 
brates; coastal ravens at limes supplement their 
vertebrate diet with a variety of invertebrates, 
including polychaele worms, echinoderms, mol- 
lusks, and crustaceans, as well as coralline algae 
and sea weeds (Beni 1946, Ewias et ah 1986, 
Marquiss and Booth 1986). Remains of crabs 
tHyas and Carcinus spp.) that occupy rocky, 
muddy, and sandy habitats in exposed or protected 
areas (such as estuaries) have been documented in 
regurgitated raven pellets recovered from British 
1 Montana Natural Heritage Program, Natural Science 
205. University of Montana, Missoula. MT 59812. USA. 
Corresponding author; e-mail:phendricks(°>mt.gov 
islands (Ewins et al. 1986. Marquiss and Booth 
1986). However, the techniques used by ravens to 
capture crabs have not been described, nor have 
crabs specialized for adult life in sandy beaches 
been reported in raven diets. 
OBSERVATIONS 
On 18 August 2010 at 1350 hrs PST, while 
walking the ocean side of Netarts Spit at Cape 
Lookout State Park, Tillamook County, Oregon 
(45 25' N. 123 58' W), we encountered a group 
of three Common Ravens on the sandy beach near 
the upper edge of the .swash zone (the area 
covered by active wave action); low tide was at 
1308 hrs PST. Al -100 m distance with 10X 
binoculars we could see the ravens, spaced —20- 
30 m apart, were hunting for objects buried in the 
sand. We focused our attention on the nearest 
raven, since all three appeared to be doing the 
same thing. During the next 5 min the raven 
walked a distance of —25 m just above the upper 
limit of wave action, and paused to extract items 
buried in the sand five times, of which four 
attempts (80%) were successful. The raven was 
hunting female sand crabs ( Emerita analoga), 
based on their shape (like a pigeon egg) and size 
(~ 3.5 cm carapace length, or twice the size of 
males; Efford 1970) in the raven's bill; we also 
photographed a gravid female (3.5 cm carapace 
length) on the beach and examined the last crab 
attacked by the raven (about the same size). The 
sand crabs we found during 6 days on Netarts-area 
beaches were mostly adult females carrying 
clusters of eggs wrapped under their telsons. 
Clusters can include 1,000 eggs or more, depend¬ 
ing on female size (Efford 1970); clusters we 
examined were an orange mass half die carapace 
length. 
Upon pausing, the raven made an initial stab 
into the sand with its bill to a depth of —3-5 cm, 
flipped the sand aside, then made 2-3 additional 
stabs into the sand pit before extracting a crab 
with its bill. The crab was placed on its back on 
the sand, held in place with a foot, and then 
pecked on the ventral surface of it's body several 
times before the raven walked away to make a 
