SHORT COMMUNICATIONS 
401 
prey items fed to nestlings during our study 
indicated Eastern Meadowlarks exhibited clear 
preferences for arachnids when feeding their 
young. Spotted Flycatchers (Muscicapa striata) 
have also been observed to feed nestlings prey 
items deviating from their usual diet (Davies I ‘>77), 
possibly due to travel time pressures during active 
brood rearing. Possible time constraints resulting 
trom nestling nutritional and brooding require¬ 
ments could also exist for meadowlarks during the 
breeding season. Spiders were also the primary 
invertebrates fed to nestling Eastern Bluebirds 
(Sialia sialis) and Great Tits (Purus major) 
iRoyama 1970. Pinkow'ski 1978); this was attributed 
to tlieir relatively soft body parts and appendages 
(Pinkowski 1978) as well as their higher caloric 
values compared to most orthopterans and annelids 
(Colley 1961. Van Hook 1971). 
CONSERVATION IMPLICATIONS 
Nesting meadowlarks in our study commonly 
foraged in soybean fields (21% ol Imaging trips; 
Linn 2004). Arachnids in our ligature samples are 
suggestive of soybean agroecosystems as likely 
food sources for nestlings (Ferguson cl al. 1984, 
Carter and Rypstra 1995). Thus, soybean fields, 
if they provide a large amount of arachnid prey 
items, benefit Eastern Meadowlarks. However, 
spiders are thought to be important for natural pest 
removal, and foraging meadowlarks may actually 
have a negative economic impact in soybeans. 
Whether or not economically significant amounts 
of these arthropods are being consumed by 
meadowlarks and other birds should be investi¬ 
gated further. 
ACKNOWLEDGMENTS 
Wolf spiders (primarily Hogna spp.) comprised 
the largest number and volume of items fed to the 
nestlings. One possible explanation for the large 
quantity of Lycosidae could be that wolf spiders 
are often relatively large and commonly occupy 
surface habitats in many different terrestrial 
ecosystems (Marshall and Rypstra 1999). making 
them more likely to be detected by ground- 
We thank N. C. Hudson. E. U. Grissom. J. B. Towey, 
p. C. Enslrom. and E. I. Greig for field assistance. We thank 
Eastern Illinois University's (EIU) Council for Faculty 
Research, the graduate school of EIU. and the Champaign 
County Audubon Society's Kendeigh Memorial Student 
Research Fund for financial support. P. V. Switzer. T. A. 
Nelson, and S. J. Meiners helped with manuscript review and we 
are grateful to R. C. Funk for help wiUi arthropod identification. 
foraging meadowlarks than other spider taxa. Size 
and ease of detection of available prey influence 
avian food selection (Bryant 1973). The majority 
of the spiders were females carrying egg sacs and, 
because female wolf spiders are invariably larger 
than males, their size and prominent egg sacs 
could also make them more conspicuous to 
foraging meadowlarks. 
The second and third largest percentage of 
prey items were orthopterans and iepidopteran 
larvae, common foods of adult meadowlarks 
(Beal 1948) and easily found in surrounding 
grasslands and soybean fields throughout the 
breeding season. Cutworms were also common 
food items fed to young Eastern Bluebirds 
'Pinkowski 1978). Few hemipierans and homop- 
lerans were fed to nestling meadowlarks during 
the breeding season. The scarceness of these taxa 
could result from these prey types being more 
difficult for nestlings to digest or could have 
greater handling times, thus decreasing their 
caloric value (Einlen 1966, Pinkowski 1978). 
The immature gut of developing birds can lead to 
less efficient means of obtaining proper nourish¬ 
ment (Karasov 1990), and the possibility of 
feeding nestlings more soft-bodied arthropods 
could potentially aid in brood survival. 
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