This Beetle Lays its Eggs in Dead Mice Carcasses and then Covers Them With Mucus – But it’s Endangered and Important

September 5, 2018 | 1:37 pm
Photo: Wayne National Forest
Jacob Carter
Research Director

The US Fish and Wildlife Service (FWS) rushed a scientific assessment on the endangered American burying beetle (Nicrophorus americanus) in Nebraska, seemingly because the agency didn’t want to disrupt agribusiness. Two biologists that were working on the assessment, Wyatt Hoback and Douglas Leasure, told the Washington Post that the FWS pushed them to conduct their science on an extremely constrained timeline. The beetle has been a source of contention in federal government research since 2013. The species was listed as endangered after 1989 when scientific evidence showed that the beetle had disappeared from over 90% of its historic range in the US.

Scientists pushed to conduct slapdash research

Drs. Hoback and Leasure are experts on the endangered American burying beetle, specifically in Nebraska. In 2017, the two biologists published a paper with a map of the species distribution in the state. Their expertise is the reason why the FWS asked these scientists to help them with the beetle’s status assessment under the Endangered Species Act. The FWS wanted the scientists to overlay their 2017 map of the beetle’s distribution with another map projecting future farmland to identify where agriculture may pose a threat to the beetle in the future.

When the scientists received the map projecting future farmland in Nebraska, created with data from Montana, North Dakota, South Dakota , they raised major concerns. These states have very different environments and soils so Hoback and Leasure didn’t think it would be accurate to overlay the two maps. Hoback said the two maps “were never intended to be put together.” Furthermore, they told the FWS that using a map of the distribution of the beetle at finer scales in the state would be more accurate. The agency gave the scientists “literally one day” to resolve these issues with combining the two maps – an impossible task, the biologists agreed.

Due to the constrained timeline, Hoback and Leasure voluntarily left the project, asked to have their names pulled from any resulting reports or publications, and asked that their data not be used. And even after the two biologists left the project and were removed as authors on the report, Dr. Leasure later received a draft report of the assessment from a FWS scientists that he said had “copied word-for-word,” a paragraph from his and Dr. Hoback’s 2017 publication. In February, Dr. Hoback alerted the regional director for the agency’s Mountain-Prairie Region, Noreen Walsh, of the plagiarism. Walsh replied that the paragraph was only used in a “pre-decisional draft of the analysis.” I’m glad that Dr. Hoback brought this to their attention since plagiarism is clearly defined as a violation of the agency scientific integrity policy.

The American burying beetle is important

Yes, it’s true that burying beetles are not the most charismatic of creatures. It literally lays its eggs in dead mice (gross) and then covers those mice with mucus (ew…even more gross). Do they also feed their young by vomiting in their mouths? Yes – yes they do. Look, I’m not here to convince you that this beetle is a fluffy cute puppy that you should pick up, take home, pet and call your “fur baby.” But just because this bug is not the most charismatic of creatures to humans, doesn’t mean that it isn’t critically important to our lives.

Recycling dead mice is quite important to ecosystem functioning. The cycling of energy and matter in an ecosystem is heavily dependent on the process of decomposition. Animals consume approximately 10% of organic matter generated by plants, and eventually those nutrients are returned to the system either through excreta or through the decomposition of the animal’s body when it dies (referred to as carrion). Dead animals are a highly nutrient rich resource that affects everything from scavengers and predators down to the microbial community. Therefore, where an American burying beetle places its mummified mouse, how its mucus affects the decomposition of that mouse, and where in time the mouse decomposes have profound effects on nutrient cycling and, subsequently, ecosystem functioning. And you know, you won’t see as many dead rodents around your neighborhood if the beetle does its thing!

Most scientists now agree that we are on the brink of a sixth major extinction event. Such an event will impact humans because we depend heavily on the services that these species provide, many times unknowingly. But once a species is gone, we cannot bring it back. That’s why we must fight to preserve our world’s most rare plants and animals.

Good science isn’t timed

Science, good science, takes time. For example, one of my PhD projects started in 2011 and it wasn’t published in a peer-reviewed journal until 2017. From conceptualizing the question, to understanding what was already known about this question, to determining the appropriate methodology to answer the question, to collecting the data, then analyzing the data, and finally writing a paper to be submitted to a journal, which then would go through a long process of review by my peers, to the paper being finally accepted – that took six years!

And I would say that is an average time to produce a good scientific product from start to finish. The FWS just asked two biologists to resolve a major methodological issue in “literally one day.” That is simply ridiculous. I find it difficult to believe that the FWS believed this was possible. And if they knew it wasn’t possible, then it seems there may be other reasons why they rushed these biologists. Were they fishing for an answer the whole time?

Hoback and Leasure say that the combination of the two maps that FWS wanted combined would have resulted in an analysis showing that the American burying beetle population is far safer from agricultural threats than it actually is. That sounds like a manipulation of methods to produce results that fit a political agenda, which is not science. In our 2018 federal scientists survey, FWS scientists reported that the top barrier to science-based decision-making at their agency was political interference. This example certainly supports that result.