“Western Black Widow Spiders (Latrodectus Hesperus) Remember Prey Capture Location and Size, but Only Alter Behavior for Prey Caught at Particular Sites”, Clint Sergi, Audrey Schlais, Martie Marshall, Rafael L. Rodríguez2022-09-24 (, ; backlinks)⁠:

[media] The information animals store in memory is selected to contain information that supports adaptive decision-making. Understanding the information an animal stores in memory can therefore support conclusions about the ecology of animal.

Using an assay of searching behavior, we investigated whether black widow spiders form memories of captured prey, and whether these memories include information about the prey capture location and relative prey size.

Black widow spiders remember information about captured prey, but only alter searching behavior when prey are captured at particular sites within the web.

These results inform conclusions about the ecology of black widow spiders—particularly conclusions about the relative importance of terrestrial and flying prey capture events


Animals form memories and use them to guide future behaviors. The information stored in memory is selected to include only details that result in adaptive decision-making. Understanding the contents of animal memories can provide insight into an animal’s ecology and evolution.

In this paper, we use an assay of searching behavior to reveal the contents of West black widow spiders’ memory. We provided prey in two major components of black widow webs and then stole the prey to elicit searching behavior. We used search effort, in terms of likelihood of searching and the number of bouts of searching, to determine whether spiders form memories of their prey, and whether their memories include any specific features of their prey.

Black widows were statistically-significantly more likely to search after experiencing prey theft, which demonstrates the spiders form memories of their prey. Black widows were also more likely to search for relatively larger prey, but this effect depended on the site of prey capture within the web (only for prey snared at the web’s gumfooted lines).

This indicates that black widows also form memories of the relative size of their prey and its capture location. Further, their natural history helps interpret when these details are stored or used, and when not. Our results underscore the importance of behavioral observations for understanding the contents of animal memories.

[Keywords: ecology, memory, searching, spider]