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How Risky Are Birds to Produce Safety?
12 Plays2 years ago
In this episode, you'll hear from Olivia Smith, a postdoctoral researcher at Michigan State University, and Phil Tocco, an MSU Extension Educator. They discuss the factors that influence the relative risk of birds to food safety.
Additional Resources
Articles Published in Scientific Journals:
- Complex landscapes stabilize farm bird communities and their expected ecosystem services
- Are we overestimating risk of enteric pathogen spillover from wild birds to humans?
- Agricultural intensification heightens food safety risks posed by wild birds
- A trait-based framework for predicting foodborne pathogen risk from wild birds
- Feedlot Association Increases Food Safety Risk Associated with Wild Birds - Photo Gallery
Press Releases:
- Bird-Friendly Agriculture: Finding the Right Balance to Benefit Birds and Farmers (and Everyone Else)
- Not-so dirty birds? Not enough evidence to link wild birds to food-borne illness
- New research reconciles wild bird conservation with farm food safety concerns
- Researchers pinpoint which bird species pose food safety risk to crops
- These bird species are most likely to contaminate our fruits and veggies
Related Podcasts:
Brief description of Kestrel Grant:
Funding for this podcast was made possible in part by the Food and Drug Administration through grant PAR-16-137. The views expressed in the posted materials do not necessarily reflect the official policies of the Department of Health and Human Services, nor does any mention of trade names, commercial practices or organization imply endorsement by the United States Government.
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Transcript
Introduction to Produce Safety
00:00:01
Speaker
Hello, and welcome to the Agri-Food Safety Produce Bites podcast, where we discuss all things produce safety and dive into the rules and regulations surrounding the Food Safety Modernization Act Produce Safety Rule.
Roles and Research Backgrounds of Olivia and Phil
00:00:14
Speaker
I'm Olivia Smith. I am a postdoctoral researcher at Michigan State University. I'm Phil Toko. I'm with Michigan State University Extension. I'm based in Jackson County, but I cover the entire state with respect to on-farm produce safety.
00:00:29
Speaker
I'm just curious a little bit about your background, Olivia, like where you're from and what you've been doing and that kind of thing. Um, I'm from Southeast Michigan, Lenaway County, and then I've been gone a while. Like I went to Ohio State for a master's and then Washington State University for a PhD and then University of Georgia for a postdoc. And then I came to MSU, um, wanting to be back in Michigan. So that, that was kind of my journey back here.
00:00:58
Speaker
And how much of your role currently is in produce safety? Is it mostly just biocontrol or do you do a lot of food safety stuff?
Bird Management and Food Safety Risks
00:01:07
Speaker
I have been working maybe 50% of my time is dedicated to trying to understand how to manage birds, thinking about food safety issues, how big of a risk they really are, and then how to reduce that risk. And then maybe the other half is a mixture of bird pest control services. And then there's another project that's totally unrelated to birds and agriculture, but
00:01:37
Speaker
Well, cool. I'm curious because I've always thought about birds being pretty monolithic. All the birds that I've ever known have had some... I mean, I always think about birds as being salmonella vectors. They've all got... In every piece of poop that comes out of a bird, it's got to have salmonella in it. I expect that if one piece of poop is one thing, lots of poop
00:01:59
Speaker
is still, it's just as bad as one piece of boot. So I'm curious, you're telling me that's not the case? You're telling me that there's some differential risk involved in that? Yeah, so maybe to start with Salmonella, we actually haven't found much Salmonella in bird feces that, you know, that's obviously a concern for farmers, but in the work that we've done,
Factors in Assessing Bird-Related Food Safety Risks
00:02:28
Speaker
It's pretty rare at about 0.5% of the birds that we tested their feces had Salmonella. So it's actually pretty uncommon. Okay. So I guess my question then is if Salmonella isn't the issue with birds, is there a food safety issue with birds? And I mean, is it like a different bug? Yeah, I guess maybe not a zero or one answer.
00:02:58
Speaker
With the birds, the most common foodborne pathogen that we find is Campylobacter, which is thought to be a wild bird commensal, meaning that it just kind of co-exists with them and doesn't cause them any problems. And E. coli also is pretty rare.
00:03:20
Speaker
stack specifically is what we're looking at was even less common than Salmonella. So Campylobacter seems to be the most common in birds and then what we were interested in also was kind of thinking beyond if the birds have the pathogen or not and then thinking about, for example, you could have
00:03:45
Speaker
a flycatcher and the flycatcher could be in your forest right next to your crops. And then if that flycatcher, maybe it has salmonella, but if it's not actually flying into the crops and it's not moving the salmonella onto the crops. So we were interested in thinking about how common it was that birds would both have the pathogen and then move into the fields and actually deposit the pathogen on the crop. Okay.
00:04:14
Speaker
So if I'm trying to rank risk or if I'm trying to think about risk of a particular population, I've really got to think about more than just, I got lots of birds, there's a problem. I have to think about maybe what kind of birds they are. What other key things should a grower think about in terms of determining whether or not a population is really gonna cause a problem versus one that's just kind of, you know, just there?
Determining Risk Levels Based on Bird Behavior and Location
00:04:40
Speaker
Yeah, I think,
00:04:42
Speaker
The first thing that I think is important to think about, which is kind of where we started with our research, was thinking about the farm's context. So are you a farm that is right next to a feedlot or are you a farm that's in the middle of a forest? And if you're a farm that's in the middle of the forest, your birds probably aren't a huge issue. But if you're a farm and you're right next to a feedlot,
00:05:09
Speaker
the birds are probably going into the feedlot where they could be picking up the pathogen. So kind of step one would be, where am I? Is it an environment that likely has the pathogen in it or am I in a pretty natural setting that might not have the pathogen? And then the second step is the types of birds that are there. So are your birds the types of birds that are going to be
00:05:38
Speaker
foraging amongst cattle feces, which is pretty risky, as opposed to birds that are up in the tree canopy, which probably have pretty low exposure. And then kind of your third thing to think about is, are the birds actually foraging in my crop or not? And if they're not in the crop, then they're probably not going to contaminate it. Okay, cool.
00:06:01
Speaker
It's interesting. Now, is there a way we can rank each of these different things or are they all the same risk sort of profile so that if I've got one that's really high probability and really, for instance, let's say I'm close to a feed lot and maybe I don't see a lot of birds in my produce. Is it one of those things where I can, one cancels out the other or is there one that's like, this is a super huge,
00:06:29
Speaker
contributor to risk, so I need to really worry about this one first. In terms of specific bird species to be concerned about? Whether it's bird species, whether it's behavior, whether it's prevalence, any one of those things. Is one of those more important than the others, I guess what I'm asking? And if so, what would be the most important? Yeah, that's a really interesting question that I
Managing Agricultural Systems to Balance Bird Activity
00:06:59
Speaker
I'm gonna say first of all, I'm not entirely sure kind of where the inflection point is between having a lot of pathogen and being in the crop a lot. Cool. But I think what we're trying to think about is kind of the interface of those two. So kind of the joint probability of them having the pathogen and being in the crop and then where is that the highest
00:07:25
Speaker
Cool, okay. You're basically doing cutting edge research. So we're kind of at the edge of our knowledge base and we keep pushing it. So I totally understand. I don't know, is a perfectly good answer to that question. Anyway, the other thing too that I saw when I was reading some of your stuff, you use this word co-management and help me understand what that means and how your work could help me achieve it.
00:07:50
Speaker
Yeah, so we are really interested in trying to figure out how to manage birds and agricultural systems for all of the good and bad things that birds do. So birds, for example, can eat spotted wing Drosophila, which is really good for fruit growers.
00:08:10
Speaker
they also eat the fruits. So that's bad for fruit growers. And then you might also think about their falcons that deter the rodents, but then the same birds can also carry the pathogen and then we're interested in conservation.
Broader Land Use and Its Impact on Food Safety
00:08:27
Speaker
And so thinking about
00:08:29
Speaker
all of these good and bad things that birds do and trying to figure out how we can manage farms to try to promote the good and deter the bad. So we're really interested in understanding how the broader land use context, for example, what your neighbors are doing, interact with what you're doing to try to have birds that are more beneficial and less harmful.
00:08:55
Speaker
That's great. And we hear it bandied about a lot. I think what's neat is the fact that this fits in your research and what you're trying to work on really is in a broader context what's happening across a lot of different disciplines. I know with our new water rule coming in,
00:09:16
Speaker
they're talking about doing a risk analysis and really thinking about the total risk that a water system poses to the crop. So you're not just looking at hazards, but you're looking at how those hazards interact to form an overall risk profile. And it sounds like that's what you're doing, but with birds.
Traverse City Project on Bird Contamination in Orchards
00:09:34
Speaker
So it's really neat. It's refreshing. Thank you.
00:09:39
Speaker
A lot of what I do is education around produce safety, specifically to farmers. And so, you know, one of the things that we're going to try and keep doing is bringing some of the research that's in process or beginning and really pushing it forward so that the growers get a chance to see what's coming. And I think that's why when I read your paper, it was like, this is exactly what we need to be talking about.
00:10:04
Speaker
The qualitative risk analysis of everything is really something that across the board we're seeing. Yeah, you're kind of talking about the next wave of stuff. I was thinking maybe you'd be interested in what we're doing in Michigan. Absolutely. What are you up to in Michigan? Yeah, so we have a project in the Traverse City area.
00:10:28
Speaker
working in cherry orchards. And our question was, on the one hand, how likely are birds to contaminate fruit? So thinking about the probability of the cherries having feces on them, and then of those, how many of pathogens. And then we were interested in if growers could install
00:10:52
Speaker
nest boxes for American castrols that are predatory falcons. And then if they install these nest boxes, could that improve food safety?
Impact of Harvesting Methods on Contamination Risks
00:11:03
Speaker
And the thinking is that prior work at MSU by Catherine Lindahl's lab has shown that these predatory falcons can reduce bird abundances in the orchards. And so there are fewer birds, there should be fewer feces.
00:11:17
Speaker
And so we've done one year data collection and it seems from the first year that Castrols might be a good way to improve food safety. But we also, we tested 153 fecal samples for Campylobacter and only one of them was positive. So it seems like the birds up there probably aren't a huge issue.
00:11:42
Speaker
Well, I'm curious too how that would interact with the way they're harvested. Now, did you do this in tart cherries or sweet cherries? We were specifically focusing on sweet cherries. As I'm sure that you know, the blocks are typically directly adjacent, so the casseroles are moving back and forth, but we were focusing on the sweet cherries because previously, Catherine's seen more bird activity and sweet cherries.
00:12:09
Speaker
Well, the reason I ask is not so much because they're one right next to the other, but because typically they're harvested very differently. Some sweet cherry trees are hand-picked, in which case you have a really high selectivity for things where there's no poop. I mean, they're really selective. The harvesters are very selective about what they pick and they don't pick poopy produce. That's our big mantra is don't pick poopy produce.
00:12:39
Speaker
Whereas tart cherries and even some sweet cherries are shaken and then they're put in to basically a big, the cherry tanks are basically a big tank of water and they dump them in. So you can imagine if you have just one cherry that's got poop on it, all of a sudden you have an entire cherry tank with poop in
Upcoming Research on Pathogens in Bird Feces
00:12:58
Speaker
it. See what I'm saying? Yeah. The people that we worked with this summer all
00:13:04
Speaker
that use the machines to harvest. We didn't see anyone hand picking where we were. So yeah, that's an interesting, we haven't looked at our work at kind of the likelihood of post farm processing. Like once it gets to the processing plant, it could definitely have very different dynamics.
00:13:22
Speaker
Right. And I mean, to my mind, if you're dealing with a cherry shaker, and let's say you have even a very small percentage of Campylobacter-ridden fruit, that fruit is going to have food contact surfaces all along the way that it touches. So it doesn't take a ton of poop in order to cause some pretty significant downstream negative impacts.
00:13:46
Speaker
So again, we need to know how much is happening in the field first. And then once we do, we can figure out, you know, obviously whether or not that stuff actually moves or if it, if it, if it, uh, contaminates food contact surfaces and whatnot. So. Yeah, that's pretty interesting future work. And then kind of thinking along the lines of maybe how long these bacteria will survive, we have a new grant with
00:14:15
Speaker
the collaborators at UC Davis, where we're going to be inoculating bird feces with E. coli and then seeing how long it's viable on lettuce. So we have some projects in place kind of looking at these next steps beyond what, you know, right now we're kind of looking at the first part of the pathogen contamination equation of
00:14:40
Speaker
How many birds have it? How likely is it to be on the produce? And then now we're starting to move more into this survival aspect.
00:14:50
Speaker
Sweet.
Conclusion and Accessing More Information
00:14:51
Speaker
Yeah. And that's interesting because to my mind, the next step, when you talk about that, when it's in a matrix, like when it's in the matrix of feces, sometimes it could potentially be protected against some of the things that we think deactivate those bacteria or kill those bacteria. And in some cases, it may actually be in competition with stuff that's in the poop. So I guess you never know until you test it.
00:15:19
Speaker
Yeah, we've been wanting to do a project for a while looking at how the microbial diversity in the species influences survival, but we haven't gotten to it. So maybe if any researchers listen to this, that would be really interesting to do. Okay. Sounds like you have literally a careers where the research ahead of you that's like, okay, I can do this now. Yeah. Well, thank you so much for talking with me today.
00:15:49
Speaker
Yeah, thanks for having me. Links to anything referenced in this episode are provided in our show notes, which can be accessed on the website at c-a-n-r dot m-s-u dot e-d-u slash agri-food underscore safety. Thank you to everyone for listening. And don't forget to tune in next month for another episode of our Produce Bites podcast.