Are there additional animal studies about superstitions?
For instance, the same behavior was also shown in orang-utan and dog. Already two years after the study by Skinner (1947) mentioned in the news article, Kellogg (1949) gave a review of some of the experimental results, but advocates a less anthropomorphic interpretation:


  Kellogg, W. N. (1949) 'Superstitious' behavior in animals. Psychological Review, Vol 56(3), 172-175. doi: 10.1037/h0055221 
  
  Abstract
  
  The orang-utan and dog as well as the pigeon have shown "superstitious" behavior. It has appeared in conditioning and multiple-choice experiments. Interpreting such behavior as superstitious is mentalistic and anthropomorphic. "An alternate and less complicated interpretation would be that these activities—whether relevant or irrelevant to the solution of the problem—are ordinary instances of the association of a sequence of movements with a reinforcing stimulus."


Interestingly, superstitious behavior is still a topic of interest for research done with humans. See for example the results of a PubMed search with this search term: http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&amp;cmd=DetailsSearch&amp;term=%22superstitious+behavior%22&amp;save_search=true

References
Kellogg, W. N. (1949) 'Superstitious' behavior in animals. Psychological Review 56(3), 172-175.
Skinner, B. F. (1947) 'Superstition' in the Pigeon, Journal of Experimental Psychology 38, 168-172.