Males fighting for females may yelp and growl. Some species of salamander emit a quiet squeak or yelp if attacked. Contactive gathers information from sources including Facebook, Twitter, LinkedIn, Google and Yelp. ZooKeeper is used by companies including Yelp, Rackspace, Yahoo! These often include directories such as Yelp, Yellow Pages, Facebook, etc. Hens "yelp" to let gobblers know their location. The episode primarily parodies the popularity of Yelp restaurant reviews. The eep, a short, one-second-long yelp, is the most common sound. Thousands of negative reviews of the policy were posted to Yelp and other review sites. The Yelp iPhone app was introduced in December 2008. It also operates an online reservation service called Yelp Reservations. Yelp does not disclose how the Yelp Elite are selected. MySwim Pro, Yelp, Trailforks and iHeartRadio. A long, high yelp may function to attract other fossas. As of June 2016, 72% of Yelp searches are done from a mobile device.