EasternScreechOwl_BountiesandPoisons_Weber_MaryAnne_HoustonTX_2July2020_Reel4026.mp3
Mary Anne Weber [00:00:00] I do give a little history lesson (I love history) to the kids about the Migratory Bird Treaty Act that was passed in 1918, you know, this wonderful law that's been around for over 100 years.
Mary Anne Weber [00:00:15] In those early years, it did not protect raptors. Raptors were the bad, the bad bird. And up until the mid early '70s, in over half of the states in our country - so the 1970s really weren't that long ago - you were you were paid by your local game warden five dollars for any dead owl that you brought to the to their office.
Mary Anne Weber [00:00:41] So this whole idea of understanding raptors in their role is almost a new thing.
Mary Anne Weber [00:00:48] And even when the protection went into place and DDT was outlawed for use in our country, we were still the number one manufacturer of DDT and we just shipped it south of the border. And again, that whole idea that our birds are migratory. Number one, we're sending DDT down to the countries that are making food that they ship back to us. That's a problem right there. But that our birds are traveling. And so the battle was, and probably is, far from over.
Mary Anne Weber [00:01:22] And then the whole rodenticide situation on top of that, you know, warfarin, of course, was the anti-coagulant that was the first generation. But humans don't like to have to pick up their messes. You know, they'd rather just kind of sweep it under the rug and not deal with it. And certainly to create a poison where they wouldn't have to deal with the mouse or the rat problem anymore - you know. "see no evil, hear no evil" kind of thing.
Mary Anne Weber [00:02:01] These great new second-generation poisons that were created where the mouse would eat it. They didn't have to come back multiple times. They would go off and die somewhere else. Seem like, you know, too many to perfect, the perfect scenario. They didn't have to get their hands messy, deal with a dead body, deal with a dead mouse or a rat. And those second-generation anticoagulants, you know, were welcomed and embraced. But what people didn't realize was their impact on wildlife and not just raptors, but lots of different lots of different wildlife.
Mary Anne Weber [00:02:39] And that is still a huge problem out there today, even though in 2015, some of the worst of the worst were taken off the shelves for regular consumer use. They're still fully used in agriculture and commercial use, and by commercial companies. So I don't think we've really done much to eliminate them from the environment. All it takes is a commercial license to use these second-generation rodenticides.
Mary Anne Weber [00:03:20] And again, it's black box. Nobody really knows what's in there. Nobody understands its impact.
Mary Anne Weber [00:03:29] You know, a raptor is an opportunistic hunter and if they see a mouse, you know, hobbling along. They're gonna go for it. It's much easier to catch a sickly mouse than a healthy one that's racing all over the place.
Mary Anne Weber [00:03:46] And because birds fly and can leave an area, and it's not an instantaneous death, that's one of the problems in tracking how these poisons are are getting out into the food chain.
Mary Anne Weber [00:04:03] Just like it took Rachel Carson and her Silent Spring book. And a lot of hard work, you know, a decade of hard work after that was published before people finally agreed that DDT, you know, was bioaccumulating in the environment in these organisms.
Mary Anne Weber [00:04:22] There's plenty of research being done to show these rodenticides can bioaccumulate in tissues and have long-lasting impacts.
Mary Anne Weber [00:04:33] But it's tricky because with birds, you know, they will consume a mouse or a rat that's been poisoned. And it might not kill them, but it could, but it could sicken them. And birds, with their incredibly high metabolic rate, they can't go very long without eating or drinking. These rodenticides make them extremely thirsty, which could potentially put them in danger from other predators, which again, keep things going up the food chain. And if they're not feeling well enough to hunt, they're not going to last very long in the environment. But they've flown away from wherever it was that they caught that mouse or that rat.
Mary Anne Weber [00:05:21] So to be able to pinpoint what caused their deaths is extremely hard. ... It's a big problem.