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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 2. June 2012 
were orb weavers except for a single case, an 
African black widow (Latrodectus sp.) that killed 
a Red-billed Firefineh ( Lagonosticta senega la). 
One-half ot all reported cases (n = 23) that 
identified the spiders entrapping birds in webs 
were in the genus Nephila. including N. inaurata 
0), -V. maculara (2), and N. clavipes (14). Other 
f orms of orb weavers included six cases for the 
genus Argiope including 4. auruntia (I) and A 
caphinarium (3). two cases for Eriophora biapi - 
cata and Nepliilengys crueniata. and single cases 
for Aranens trifolium. Mastophora sp., and 
Neoscona hentzii. 
I he only species of spider with sufficient 
tor analysis of patterns of bird entrapment 
• clavipes. This species entrapped nine spi 
representing 14 cases (31% of all spider reco 
lapped birds ranged in si/e from Ver 
Hummingbird (,m, ss = 2 g> wing t , hord 
-7 ram) to Swain.son's Thrush (mass - r 
themselves, and wrapped birds dying in the web; 
the remaining seven were released with human 
intervention. 
DISCUSSION 
Patients of Birds Trapped in Spider Webs.— 
Most entrapped birds had a mass of ^15 g and 
wing chord <90 mm. Larger species of birds am 
especially vulnerable to entrapment when the w< 
was approached at an indirect angle with dc" 
flight speed (Cox and Nesmith 2007). Largerbinfc 
with longer, more powerful wings appear t< he 
able to break through webs easier than snul-* r 
birds, which would explain the higher rate' 
entanglement for smaller species (Fig. D- 
longer a bird is entrapped, the more likely it i> 1 
succumb due to stress and fatigue. It is po>sibl l 
that large species (>)5 g mass, s90 mm win; 
chord) were entangled more frequently, hut in** 1 
themselves before the event could be documented 
It is not surprising that hummingbirds (range 
2-5 g mass, 37-56 mm wing chord) represent not 
only the most diverse family (9 species), but aU 
the family with the most cases of being trapped 
