Birds Caught in Spider Webs: A Synthesis of Patterns

Daniel M. Brooks
2012 The Wilson Journal of Ornithology  
Results of queries through public avian list-servers and a thorough literature search formed a data base to synthesize patterns of birds trapped in spider webs. Sixty-nine cases of birds, representing 54 species in 23 families, were reported trapped in webs. Hummingbirds were the most diverse family (nine species) and had the most cases of entrapment (n 5 20). Archilochus colubris represented the species with the most cases of entrapment (n 5 6). Mean mass and wing chord length of all species
more » ... apped were 11 g and 61 mm, respectively. Eighty-seven percent of all individuals had mass #15 g and 88% had a wing chord ,90 mm. Phaethornis longuemareus and Mellisuga minima represented the smallest species (mass 5 2 g, wing chord 5 37 mm), and Streptopelia senegalensis was the largest (mass 5 80 g, wing chord 5 138 mm). Thirty cases of birds were entrapped without human intervention: 22 died and eight not wrapped in silk freed themselves. Those wrapped in silk invariably died unless freed by a human observer. One-half of all reported spider webs were of the genus Nephila, and all were orb weavers except for a single Latrodectus. Nephila clavipes entrapped nine species representing 14 cases, ranging from Mellisuga minima (mass 5 2 g, wing chord 5 37 mm) to Catharus ustulatus (mass 5 23 g, wing chord 5 93 mm). Patterns, causes, and consequences of birds entrapped in spider webs are discussed, including orb weavers as opportunistic predators of birds trapped in webs, and spider webs as a natural environmental hazard to birds.
doi:10.1676/11-148.1 fatcat:5ymytxq5ovg6no7g2bwlvpkwpm