Chris Gomersall / 2020VISION / Atlantic mackerel (Scomber scombrus) in fish separator on board Shetland pelagic trawler 'Charisma', with crew member David Anderson taking a sample for measurement. Shetland Isles, Scotland, UK, Octo...

Roland Seitre / Hoffman's Two Toed Sloth (Choloepus hoffmanni) being weighed and recorded. Aviarios del Caribe Sloth Refuge, Costa Rica, 2008.

Juergen Freund / Split level of solar powered gauge measuring sea temperature, West New Britain, Papua New Guinea, May 2010

Mark Carwardine / Black rhinoceros (Diceros bicornis) - darted and being prepared for translocation by rangers from the Kenya Wildlife Service, being measured Nairobi National Park, Kenya, Endangered / threatened spec...

Chris Gomersall / 2020VISION / Atlantic mackerel (Scomber scombrus) catch in fish separator on board Shetland pelagic trawler 'Charisma', with crew member David Anderson taking a sample for measurement. Shetland Isles, Scotland, UK...

Bertie Gregory / 2020VISION / Peregrine falcon (Falco peregrinus) chick, aged three weeks, being measured during a ringing session, Bristol, England, UK, May.

Benoit Stichelbaut / Marine carpenter working on the hull of a boat in Ateliers de l'Enfer workshop in Douarnenez, Brittany, France 1994.

Rick Tomlinson / Sailing north from South Georgia to Rio de Janeiro onboard SY "Adele", Mark Thirkettle practices with the sextant off the Brazilian Coast, February 2007.

Ernie Janes / Water level marker at dried-up woodland pond in Norfolk Nature Reserve, UK

Bryan and Cherry Alexander / Thermometer on tree reading -36 degrees celsius during winter in Yakutia. Eastern Siberia, Russia, 2001.

Bryan and Cherry Alexander / Thermometer showing reading of -52 degrees celsius at Verkhoyansk. Yakutia, Siberia, Russia, 1999.

Michael D. Kern / Research worker monitors eggs in nest of Snowy Plover (Charadrius occidentalis) as part of San Francisco Bay Bird Observatory Survey, California, USA, July 2008

Tim Laman / African Goshawk (Accipiter tachiro) captured for measurement and then released, Bioko Island, Equatorial Guinea, January

Barry Bland / A man navigating by Sextant, a measuring instrument generally used to measure the angle of elevation of a celestial object above the horizon. Model Released. ^^^Making this measurement is known as sig...

Barry Bland / A man navigating by Sextant, a measuring instrument generally used to measure the angle of elevation of a ^^^celestial object above the horizon. Making this measurement is known as sighting the object...

Toby Roxburgh / Scientists from the Welsh Marine Environmental Monitoring team measure the carcass of a Sowerby's Beaked Whale (Mesoplodon bidens), washed up on the coast near Porthcawl, South Wales, Model released.