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2006 SOUTHEASTERN NATURALIST 5(2):361–366
Food of the Southern Short-tailed Shrew
(Blarina carolinensis) on Cumberland Island, Georgia
John O. Whitaker, Jr.1,* and Carol Ruckdeschel2
Abstract - The main foods of 73 Blarina carolinensis (southern short-tailed
shrews) taken during 2003 and 2004 on Cumberland Island, GA, were the introduced
terrestrial amphipod, Talitroides topitotum (Amphipoda, 21.8% volume),
larval beetles (Coleoptera, 12.4%), centipedes (Chilopoda, 11.8%), earthworms
(Annelida, 9.1%), moth larvae (Lepidoptera, 8.6%), and spiders (Araneae, 7.4%).
The primary foods identified in this study were similar to results from a study in
South Carolina, except that amphipods, T. topitotum, comprised 21.8% of the
Georgia food, but did not occur in the South Carolina sample, and subterranean
fungi Endogonaceae made up 16.8% of the South Carolina food, but only 3.8% in
Georgia. The importance of amphipods in the diet in coastal Georgia was probably
due to the great abundance of these amphipods in the study area. Talitroides
topitotum is a terrestrial amphipod of Indo-Pacific origin and this is apparently the
first report of this species from Georgia. There was little seasonal variation among
the primary foods, but centipedes and ants were eaten most heavily in spring,
annelids and spiders in summer, and fungi in winter.
The southern short-tailed shrew, Blarina carolinensis (Bachman), occurs
primarily in damp woods throughout the lower elevations in the southeastern
United States (Whitaker and Hamilton 1998). Little information has been
published on the food of this species. The main food items reported for this
species in the Upper Coastal Plain of South Carolina (Whitaker et al. 1994,
based on 45 individuals) were slugs and snails (Mollusca, 18% by volume),
subterranean fungi (Endogonaceae, 16%), earthworms (Annelida, 15%),
adult beetles (Coleoptera, 10%), beetle larvae (Coleoptera, 6%), and spiders
(Araneae, 5%). Little vertebrate or plant material was eaten. Two additional
studies reported food items consumed by the southern short-tailed shrew, but
both are based on much smaller sample sizes. Calhoun (1941) reported
beetles (including Scarabaeidae and Coleoptera larvae), moth larvae (Lepidoptera),
ants (Formicidae), true bugs (Hemiptera), and slugs (Limacidae)
among the food items consumed by nine southern short-tailed shrews from
Tennessee. In Florida, insect material, including the remains of a caterpillar
in one, were reported based on an assessment of three southern short-tailed
shrews (Rand and Host 1942).
The purpose of this paper is to present additional information on food
consumed by southern short-tailed shrews based on samples collected at
1Department of Ecology and Organismal Biology, Indiana State University, Terre
Haute, IN 47809. 2Cumberland Island Museum, PO Box 796, St. Marys, GA 31558.
Corresponding author – email@example.com.
362 Southeastern Naturalist Vol. 5, No. 2
Cumberland Island, a barrier island off the coast of Georgia. The southern
short-tailed shrew is the only shrew definitely occurring on Cumberland
Island. The record of a Cryptotis parva (Say) (least shrew) on Cumberland
Island by Neuhauser and Baker (1974) was from remains in an owl pellet and
it is not known if this individual originated from the island.
Materials and Methods
This study was conducted on Cumberland Island, a barrier island off the
coast of Georgia. The shrews in this study were incidentally caught during
2003–2004 in pitfall traps (sunken buckets) along drift fences during a
survey of amphibians and reptiles of the island. The traps were checked once
per day. They contained water, thus the shrews were quickly killed. A total
of 73 shrews was caught throughout the year: two in autumn (September–
November), 39 in winter (December–February), 24 in spring (March–May),
and eight in summer (June–August). Trapping was in two locations: a pineoak
scrub at the edge of a temporary pond and in a wetland at the head of a
wooded swamp. The predominant hardwoods in the trapping areas were
various scrub oaks, primarily Quercus myrtifolia Willd. (myrtle oak) and
Quercus chapmanii Sarg. (Chapman’s oak) and Acer rubrum L. (red maple)
The pines mostly were Pinus elliottii Engelm. (slash pine) and Pinus
serotina Michx. (pond pine). Persea borbonia L. Spreng. (bay) also was
common. The main understory plants were Serenoa repens (Bartram) Small
(saw palmetto), Lyonia lucida (Lamb.) K. Koch (fetterbush), and L.
ferruginea (Walter) Nutt. (rusty lyonia). Spartina bakeri Merr. (sand
cordgrass) formed the main vegetation in the temporary pond. There were
830 trap-nights in the swamp habitat that yielded 36 shrews and 3696 trapnights
in the scrub habitat that yielded 37 shrews (one of the shrews was
found dead in the scrub).
The stomach of each shrew was removed and its contents were placed in
water in a watchglass for identification under a dissecting microscope. The
percent volume of each item in each stomach was estimated visually. Data
were compiled as percent volume (sum of individual volumes/number of
individuals) and percent frequency (percentage of individuals feeding on
each item) for each type of food in the sample (Whitaker 1988).
Results and Discussion
The primary food of 73 southern short-tailed shrews from Cumberland
Island, GA (Table 1), was the terrestrial amphipod, Talitroides topitotum
(Burt). It formed 21.8% of the volume of food overall, was found in 35.6%
of the individuals, and many stomachs contained only amphipods. This
fully terrestrial amphipod is of Indo-Pacific origin, and this is apparently
its first report in Georgia. It is not known when these amphipods arrived on
Cumberland Island, but two species, Talitroides topitotum and T. alluaudi
(Chevreux), now are common in some wetlands and low areas. However,
2006 J.O. Whitaker, Jr. and C. Ruckdeschel 363
only T. topitotum was found in the actual study area and was the only one
found in stomachs of these shrews. These terrestrial amphipods emerged in
profusion at night during rain and wet weather. They were abundant on the
ground and were often observed on the vegetation up to a height of about 1
m. There were about four centimeters of them in the sunken cans overnight
after a soaking rain. Thus, it is not surprising that they were eaten by
shrews in such numbers, and throughout the year (except fall, n = 2). Two
other vertebrate species, Rana sphenocephala Cope (Southern Leopard
Frogs) and Gastrophryne carolinensis [Holbrook] (Eastern Narrow-mouth
Toads), caught at the same site also had eaten T. topitotum (C.
Ruckdeschel, unpubl. data).
Amphipods have been reported as a food item for at least one other
shrew species in eastern North America. Sorex cinereus Kerr (masked
shrew) on Bon Portage Island, NS, Canada, ate the littoral scavenging
marine amphipod, Platorchestia platensis (Kroyer) (Stewart et al. 1989).
Like the amphipod on Cumberland Island, it was very abundant, heavily
fed upon, and many stomachs contained only amphipods. However, in
Nova Scotia, amphipods and also kelp flies (Coelopidae) occurred in greatest
numbers on the beach and decreased in abundance with distance from
the beach, whereas Talitroides topitotum on Cumberland Island was abundant
only in leaf litter in wetlands away from the beach.
The second most abundant item in the diet of southern short-tailed
shrews in coastal Georgia was unidentified larval beetles, Coleoptera
Table 1. Food of 73 southern short-tailed shrews (Blarina carolinensis) from Cumberland
Island, Camden County, GA.
Overall Seasonal percent volume
Percent Percent Winter Spring Summer Fall
Food item volume frequency (n = 39) (n = 24) (n = 8) (n = 2)
Amphipoda 21.8 35.6 22.1 21.9 25.6 0.0
Coleopteran larvae 12.4 21.9 13.6 13.5 0.0 25.0
Chilopoda 11.8 31.5 9.5 17.9 8.1 0.0
Annelida 9.1 16.4 8.3 7.5 20.0 0.0
Lepidopteran larvae 8.6 16.4 7.3 8.3 10.6 30.0
Araneae 7.4 23.3 9.2 6.9 1.9 0.0
Mollusca 6.8 11.0 10.5 3.8 0.0 0.0
Endogonaceae 3.8 6.8 6.9 0.4 0.0 0.0
Dipteran larvae 3.6 11.0 2.2 2.1 4.4 45.0
Scarabaeid larvae 3.5 5.5 1.9 7.5 0.0 0.0
Formicidae 3.2 15.1 0.2 9.2 1.3 0.0
Coleopteran adult 2.8 21.9 2.7 0.8 10.0 0.0
Plecoptera? 1.4 1.4 0.0 0.0 12.5 0.0
Insect internal organs 1.2 1.4 2.3 0.0 0.0 0.0
Salientia 1.0 1.4 1.9 0.0 0.0 0.0
Unidentified insect 0.8 8.2 0.4 0.2 4.4 0.0
Dipteran adult 0.3 2.7 0.3 0.0 1.3 0.0
Vegetation 0.2 2.7 0.4 0.0 0.0 0.0
Lygaeidae 0.1 1.4 0.1 0.0 0.0 0.0
Curculionidae 0.1 1.4 0.1 0.0 0.0 0.0
364 Southeastern Naturalist Vol. 5, No. 2
(12.4% volume). The total volume of beetles was 18.7% when larval
scarabaeids, adult Coleoptera, and Curculionidae were included (Table 1).
Coleopteran larvae were eaten about equally in winter and spring, but were
not observed in summer samples, which may have reflected the small
sample size (n = 8). Despite their small sample sizes, Whitaker et al.
(1994) and Calhoun (1941) also found adult and larval beetles in the foods
consumed by southern short-tailed shrews, suggesting the importance of
beetles in the diet of this species.
Centipedes were the third most important item by volume. Centipedes
were eaten most heavily in spring. Centipedes were common within our
study area and because they have been reported as a common food of the
closely related Blarina brevicauda (Say) (northern short-tailed shrew)
(Whitaker and Mumford 1972), the occurrence in the diet of southern shorttailed
shrews was not unexpected. Centipedes were also eaten by Sorex
cinereus, S. fumeus (Miller), S. hoyi Baird, and S. longirostris Bachman
(Whitaker and Cudmore 1987, Whitaker and Ferraro 1963, Whitaker and
Earthworms are an important food of shrews, especially larger shrews
(Whitaker and Cudmore 1987, Whitaker and Ferraro 1963, Whitaker and
Mumford 1972), and they were the fourth most abundant food item in this
sample, followed by Lepidopteran (moth) larvae, spiders, and molluscs,
which are all important foods of many shrews (Whitaker and Cudmore 1987,
Whitaker and Ferraro 1963, Whitaker and Mumford 1972, Whitaker et al.
1994). Spiders were eaten throughout the year. Mollusks (slugs and snails)
were more heavily eaten in spring than in summer.
Spores of Endogonaceae were eaten primarily in winter on Cumberland
Island. They often are eaten by shrews, usually in relatively low volume
(Whitaker 1962, Whitaker and Cudmore 1987, Whitaker and Ferraro 1963,
Whitaker and Mumford 1972, Whitaker et al. 1994). It is clear that shrews
and other small mammals feed specifically on this item, rather than simply
getting it incidentally with other foods, as in a few individuals the entire
stomach may be filled with this item. We suspect that they find it using
olfactory clues. Two species of Endogonaceae were seen, one with large
black spores and one with tiny yellow spores.
Dipteran larvae, which formed a small portion of the diet throughout the
year, are commonly eaten by shrews (Whitaker and Cudmore 1987,
Whitaker and Mumford 1972, Whitaker et al. 1994).
Ants formed 3.2% of the total food, eaten least frequently in winter and
most often in spring. Frog remains were found in only one shrew, and this
was the only vertebrate in the sample. Various vertebrates are taken occasionally,
but are not important shrew foods.
There were many similarities, but some differences in the results between
our study from coastal Georgia (n = 73) and the results of Whitaker
et al. (1994) from South Carolina (n = 45). The diversity of the diet of the
2006 J.O. Whitaker, Jr. and C. Ruckdeschel 365
southern short-tailed shrew was nearly similar in these two studies with 23
food items identified from South Carolina and 20 from coastal Georgia.
The major foods reported from these two studies were amphipods, coleopteran
larvae, centipedes, earthworms, lepidopteran larvae, spiders,
slugs and snails, Endogonaceae, and adult beetles. These comprised 88.1%
of the food in our coastal Georgia sample and 79.4% in the South Carolina
sample. The biggest difference between the Cumberland and South Carolina
samples was that amphipods made up 21.8% of the Cumberland food,
but did not occur in the South Carolina sample. This was because of the
great prevalence of these amphipods in the study area on Cumberland
Island. Most primary food items were eaten by shrews in both samples.
This would suggest that they ate similar foods and that many of the differences
were related to availability. Some of the larger differences were of
the centipedes (11.8% on Cumberland, 0.5% in South Carolina) and
Endogonaceae (3.8% on Cumberland, 16.3% in South Carolina).
The winter and spring samples were large enough to be useful, but the
summer sample was small, and the fall sample was too small to draw any
meaningful conclusions from. It is of interest that in the winter–summer
samples, the amphipods formed the largest volume. However, the second
highest was different in each of the three, coleopteran larvae in winter,
centipedes in spring and annelids in summer. Beetle larvae formed about the
same volume in winter and spring, but were absent in summer. Centipedes
were most heavily eaten in spring, and formed about twice the volume that
they did in winter or summer. Earthworms and spiders were highest in
summer; mollusks were highest in winter, absent in summer; and
Endogonaceae were highest in winter.
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