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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 2. June 2012 
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Nestling age (days) 
Observer No 
present observer 
3.0 
2.8 
26 - 
Buffer Non-buffer 
FIG. I. Mean provisioning (least-squared means ± SE) rates at Dickcissei nests with young of various ages, buffer 
locations, and with/without observers present in north-central Mississippi (USA). May to August 2008-2009. 
to both small and large items (16% small, 60% 
medium, and 23% large vs. 12, 79, and 9% 1'or 
females; F 2 . M0 = 3.89, P = 0.021; Table 2); males 
in 2009 were more likely to bring small items (27 
vs. 20% for females; F 2J02h = 7.28, P < 0.001). 
Adults were slightly more likely to bring medium 
items versus small items when observers were pre¬ 
sent in 2008 (81% medium with observers vs. 76%' 
without; F 2m o = 2.35. P = 0.096). but this effect 
was small and did not appear in 2009 (F 2 l02o = 
0.11, P = 0.898). Neither placement of nest in a 
buffer nor number of nestlings affected prey size 
delivered (F = 0.01-1.92. P = 0.148-0.994). 
Foraging Distances .—Foraging distance de¬ 
creased with increased cloud cover (F 4t87S = 3.67, 
P = 0.(X)8) and increased wind speeds (F, x = 
3.09, P = 0.031; Table I. Fig. 5). Foraging distance 
increased as nestlings became older, but this 
increase was not significant (F 3 . 68 . 4 = 1.78, 
P = 0.159). Foraging distance was not different 
between nests in buffers ;uid nests peripheral to 
buffers (F,. 34 .« = 2.52, P - 0.121), was not related 
to nestling number (F 4 , 33 . 4 = 0.32, P = 0.861), was 
not different when males helped (F|. 6 s.6 = 
P — 0.310), and did not differ between years 
(/' 1 . 51 .x = 0.56, P = 0.456). Size of prey items did 
not differ across foraging distances (F| W , 49 i = 
P = 0.500). 
Probability of Male Helping. —We observed 
male helpers at four nests (22%) in 2008. We 
filmed 46 visits by males (13%) and 309 by females 
(87%) at these nests. We observed male helpers, at 
five nests (20%) in 2009 when we filmed 83 not 
visits by males (23%) and 278 by females (77% ■ 
We filmed a single case of a male brooding ice 
92 sec in 2008. Probability of male helping was n»t 
related to nestling age (F 3 ^ 39 = 1.96. P = 0.121)or 
nestling number (F 4 239 = 0.06. P = 0.993). 
DISCUSSION 
Nestling Provisioning. —Neither provisioning 
rate nor biomass delivered per nestling significant 
ly increased with nestling age. However, patfm- 
chose larger items for older nestlings. This suggC' 1 ’ 
energetic costs of changes in prey selection wen: 
less than costs of increasing number of trip s 
