what's being proposed along the 101 freeway in agoura hills is to build a crossing, a wildlife crossingthis is not a new concept. a lot of other countries have aladady built ththese wildlife crossings. what these are are not just bridges, but they're bridges that are vegetated, that have nice restoration that's done leading up to these crossing points and fencing that funnel these animals. heise: the cost is comparative. so, it's $50 million that we will invest in mountain lion habitat that we won't invest in something else. so, i think there needs to be democratic decision making anand extensive consultation about whether we want to do this and who will raise the monney for this, who will pay for this. what do we owe mountain lions, what do we owe to other species of plants and animals? pauly: man-made structures act as barriers for lots of species in urban areas. but some aspects of our infrastructure actually allow non-native species to thrive. the big moment for thinking about water in los angeles is 1913. once you hahave perermanent watr on the landscape, lots of non-native species