Nick Upton / Catherine McNicol reading the PIT tag number of a Grey Squirrel (Sciurus carolinensis) she has re-trapped in a live capture trap while monitoring the squirrel population in the area where their predat...

Pete Oxford / Whale Shark (Rhincodon typus) with scuba diving scientist using PIT tag receptor to check shark is tagged. Cenderawasih Bay, West Papua, Indonesia.

Pete Oxford / Whale Shark (Rhincodon typus) biologist Brent Stewart from Hubbs Sea World Research Institute checking if shark has been PIT tagged as part of a study to determine geographical range, numbers and loca...

Pete Oxford / Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) biologist, Stephen Spear, reading PIT tag in adult to identify individual, Hiwassee River, Cherokee National Forest, Tennessee

Pete Oxford / Galapagos Giant Tortoise (Chelonoidis nigra) young being injected with PIT tag, Wolf Volcano, Isabella Island, Galapagos Islands, Ecuador

Pete Oxford / Galapagos Land Iguana (Conolophus subcristatus) juvenile has pit tag checked and will be released, individual came from captive breeding program, Baltra Island, Galapagos Islands, Ecuador

Pete Oxford / Reading PIT tag of Waved albatross (Phoebastria irrorata) Punta Suarez, Española / Hood Island, Galapagos Islands

Doug Perrine / Scientist uses microwave scanner to read PIT tag in Kemp's ridley turtle {Lepidochelys kempii} female laying eggs in nest on beach, Rancho Nuevo, Gulf of Mexico, Mexico 2002

Sebastian Kennerknecht / Santa Catalina Island Fox (Urocyon littoralis catalinae) biologist, Julie King, looking for PIT tag in fox during vaccination and health check up, Santa Catalina Island, Channel Islands, California

Donald M. Jones / Black-footed Ferret (Mustela nigripes) emerging from burrow at night, electronic chip reader at burrow entrance reads chip, noting which individual has passed, UL Bend National Wildlife Refuge, Montan...

Pete Oxford / Whale Shark (Rhincodon typus) biologist Brent Stewart from Hubbs Sea World Research Institute checking if shark has been PIT tagged as part of a study to determine geographical range, numbers and loca...

Pete Oxford / Eastern Hellbender (Cryptobranchus alleganiensis alleganiensis) biologist, Stephen Spear, injecting PIT tag in adult to identify individuals, Hiwassee River, Cherokee National Forest, Tennessee