WEBVTT Kind: captions Language: en 00:00:00.729 --> 00:00:03.845 USGS Logo Intro. 00:00:04.946 --> 00:00:09.871 Hi folks, Patrick Kleeman here,  biologist with the US Geological Survey.    00:00:09.871 --> 00:00:15.000 This Amphibian Week, I want to tell you a little bit  about the Western Spadefoot, Spea hammondii 00:00:15.000 --> 00:00:16.496 and  how we survey for them. 00:00:17.481 --> 00:00:21.117 Western Spadefoots are really cool little species of toad. 00:00:21.117 --> 00:00:29.057 They're only about 2 and a half inches long as an adult and  they're found primarily in areas with grasslands   00:00:29.057 --> 00:00:33.181 and a fair amount of sand in the soil so they can burrow. 00:00:33.181 --> 00:00:39.927 As you can see in this range map, the toads live in the Central Valley of California and in the Salinas Valley 00:00:39.927 --> 00:00:46.610 and also along the coast  down into Southern California and even into Baja California.  00:00:46.610 --> 00:00:54.686 There's two clades or groups of Western Spadefoot toads with a northern clade and a southern clade. 00:00:54.686 --> 00:01:00.106 These two clades are separated by the Transverse Mountain Range that cuts between them. 00:01:00.106 --> 00:01:06.659 Western Spadefoots have a few things that  tell them apart from other toads that live nearby such as the Western Toad. 00:01:06.659 --> 00:01:12.241 Spadefoot toads have a  vertical pupil unlike a Western Toad that has a horizontal pupil. 00:01:12.241 --> 00:01:19.830 Vertical pupils help spadefoots  gather light at night and they're mostly nocturnal and that's when they're out hunting 00:01:19.830 --> 00:01:24.631 and it also helps them in acuity in judging distance to their  prey. 00:01:24.631 --> 00:01:30.547 They eat lots of things including crickets, beetles, flies, ants, earthworms, 00:01:30.547 --> 00:01:32.681 pretty much anything they can fit in their mouth. 00:01:32.681 --> 00:01:42.256 Spadefoot toads have this black keratinized spur, or spade, on their rear feet and they use this to dig burrows. 00:01:42.256 --> 00:01:47.188 They turn their rear feet in a circular  fashion on sandy soils 00:01:47.188 --> 00:01:50.719 and they can just go  backwards and dig a burrow into the ground.  00:01:50.719 --> 00:01:57.345 I've seen this at night looking at a spadefoot toad and  all a sudden noticed that it was disappearing underground 00:01:57.345 --> 00:01:59.533 and that's what it was doing,  just digging downwards  00:01:59.533 --> 00:02:08.024 and they will spend between 100 to 200 days underground avoiding the hot temperatures of the Central Valley. 00:02:08.024 --> 00:02:14.712 Like many amphibians, Western Spadefoots can deploy chemical  defenses to ward off predators 00:02:14.712 --> 00:02:18.354 and in this case  it smells a little bit like peanut butter. 00:02:18.354 --> 00:02:25.783 You can see the black spades highlighted here on this toad  and also the vertical pupils. 00:02:25.783 --> 00:02:35.343 This is a male toad and he's calling with his inflated vocal sac and  this is what their call sounds like as recorded by Carlos Davidson. 00:02:35.422 --> 00:02:46.816 ...ribbit...ribbit...ribbit... 00:02:46.816 --> 00:02:52.137 Western Spadefoots are threatened by habitat loss, climate  change, 00:02:52.137 --> 00:02:57.109 and non-native species like bullfrogs  that are just out there eating them.   00:02:57.109 --> 00:03:02.472 We're doing surveys for Western Spadefoots so that we can find out where they still exist  00:03:02.472 --> 00:03:08.072 and to learn more about the species so that land managers can provide quality habitat for them. 00:03:08.072 --> 00:03:14.366 It's easiest for us to find the tadpoles of the toads so we do daytime surveys using dip nets 00:03:14.366 --> 00:03:20.225 where we sweep through the water and then pick through our net and see what we have in there. 00:03:20.225 --> 00:03:25.451 These shallow vernal pools where the spadefoot toads live have all kinds of stuff in them 00:03:25.451 --> 00:03:34.073 including tadpole shrimp, clam shrimp,  fairy shrimp, and other amphibians such as California Tiger Salamanders. 00:03:34.073 --> 00:03:38.140 But if we're really lucky, we get to come across Spadefoot toad tadpoles. 00:03:38.140 --> 00:03:45.920 They develop really quickly and they can go from being an egg to a little toad with all four legs in about two months time.   00:03:45.920 --> 00:03:52.929 The other way we can survey for the toads is by looking for traces of their DNA that they left behind in the environment. 00:03:52.929 --> 00:03:56.866 All animals leave traces of DNA in the environment. 00:03:56.866 --> 00:04:00.828 Just as they go throughout their day, they were continuously shedding skin cells 00:04:00.828 --> 00:04:03.933 and leaving other bits of DNA that we can detect. 00:04:03.933 --> 00:04:08.801 You can see Steve here collecting an eDNA sample as he walks around the pond 00:04:08.801 --> 00:04:16.800 with this fancy backpack on that has a pump in it that draws water through the filter that's at the end of that yellow pole. 00:04:16.800 --> 00:04:23.364 After we walk around the perimeter of the pond pumping water, we stop and we disconnect everything and remove the filter 00:04:23.364 --> 00:04:30.680 and we can send it off to the lab where they can test it and see if Western Spadefoots were in the water recently. 00:04:30.680 --> 00:04:34.517 Thanks for your interest in Western Spadefoots and amphibians in general. 00:04:34.517 --> 00:04:38.538 They're a vital part of our ecosystem and we're lucky to have them out there. 00:04:38.538 --> 00:04:39.935 Take care, bye! 00:04:39.935 --> 00:04:42.728 Credits roll 00:04:42.728 --> 00:04:53.898 ...ribbit...ribbit...ribbit... 00:04:53.898 --> 00:04:55.682 USGS Logo outro.