Novel Observation: Northern Cardinal (Cardinalis cardinalis) Perches on an Invasive Jorō Spider (Trichonephila clavata) Web and Steals Food

Abstract

An invasive spider (Trichonephila clavata [L. Koch 1878], or jorō spider) is rapidly expanding throughout the southeast of the United States, engendering many questions about how native fauna will be affected. Here, we describe an observation of a northern cardinal (Cardinalis cardinalis, L.) consuming prey items from a jorō web, which serves as an example of a native species deriving a (small) benefit from this new invader. Moreover, the manner of the kleptoparasitism is also noteworthy; the cardinal perched directly on the web, which supported its weight (which is 42–48 g in this species). This appears to be the first documented case of a spider web supporting a perching bird. We also include measurements of other jorō webs, where web strength had been assessed using a force gauge, which revealed that typical webs can support masses up to 70 g before collapsing. Collectively, this information adds to the small but growing body of knowledge about the biology of this non-native spider.

DNA metabarcoding analysis of three material types to reveal Joro spider (Trichonephila clavata) trophic interactions and web capture

“…Trimmed reads were assembled using PEAR (Zhang et al, 2014). Subsequent analyses were performed using VSEARCH v2.8.2 (Rognes et al, 2016). We filtered sequences by quality (fastq_maxee = 1) and dereplicated.…”

Spider Ecology and Behaviour—Spiders as Model Organisms

“…The Special Issue also features two brief reports on spiders and invasive species. In the first [32], Arty Schronce and Andrew Davies studied an interesting interaction in the US between the invasive Joro spider, Trichonephila clavate, and the native northern cardinal, where the bird perches on top of the very strong orb web and steals prey items directly from the web. In the second [33], El Ellsworth and colleagues looked at how invasive plants and other management strategies impact spider communities (predominantly webbuilding spiders) in five parks in the greater Memphis area in the US.…”

Startle Responses of Jorō Spiders (Trichonephila clavata) to Artificial Disturbance

“…Since our lab is located in northeast Georgia, we have been endeavoring to understand the biology of jor ō spiders in this introduced range, including by evaluating how their physiology allows them to live in a more temperate climate than their golden silk spider cousin [7]. We have also recently reported how the physical strength of jor ō spider webs is far beyond that of native species' webs [12]. Here, we describe results from a simple laboratory experiment which was designed to test if jor ō spiders differ, in terms of disturbance reactions, from other spiders that are native to (or that have ranges in) North America.…”