{"id":552234,"date":"2026-03-29T11:51:15","date_gmt":"2026-03-29T11:51:15","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/552234\/"},"modified":"2026-03-29T11:51:15","modified_gmt":"2026-03-29T11:51:15","slug":"scientists-search-for-big-answers-about-a-little-bunny-that-relies-on-disappearing-sagebrush","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/552234\/","title":{"rendered":"Scientists search for big answers about a little bunny that relies on disappearing sagebrush"},"content":{"rendered":"<p class=\"has-text-align-center has-primary-color has-text-color has-link-color has-small-font-size wp-elements-30c22dce978952de2e48918f9c6483c9\">THANKS TO OUR COMMUNITY PARTNERS<\/p>\n<p>by\u00a0<a href=\"https:\/\/wyofile.com\/author\/mike-koshmrl\/\" rel=\"nofollow noopener\" target=\"_blank\">Mike Koshmrl<\/a>, <a href=\"http:\/\/www.wyofile.com\" rel=\"nofollow noopener\" target=\"_blank\">WyoFile<\/a><\/p>\n<p>NORTHERN RED DESERT\u2014Ilaria Bacchiocchi cracked a smile as she explained the nontechnical term her research crews use for the tiny cylinder of digested sagebrush resting in her palm.\u00a0<\/p>\n<p>\u201cFresh out the butt,\u201d Bacchiocchi said Tuesday. \u201cFTB, we call it.\u201d<\/p>\n<p>The tiny pellet\u2019s green interior and pliability suggested it had been expelled quite recently, she said.\u00a0<\/p>\n<p>A pygmy rabbit, in other words, was nearby.\u00a0<\/p>\n<p><img loading=\"lazy\" data-recalc-dims=\"1\" height=\"594\" width=\"780\" decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/Pygmy-poop-1024x780.jpg\" alt=\"\" class=\"wp-image-124454\"\/>Pygmy rabbit poop is cylindrical and significantly smaller than a cottontail rabbit pellet. (Mike Koshmrl\/WyoFile)<\/p>\n<p>That was a promising sign for the University of Idaho doctoral student, who was setting out 67 live traps in the entrances of pygmy rabbit burrows in the dark. Catching one would allow her to take a tissue sample \u2014 a tiny punch through the ear \u2014 to learn how Wyoming\u2019s pygmy rabbits are genetically adapted to their environment and climate.<\/p>\n<p>The cryptic little rabbit is being subjected to research and monitoring partly because it\u2019s a\u00a0<a href=\"https:\/\/wgfd.wyo.gov\/media\/1422\/download?inline\" rel=\"nofollow noopener\" target=\"_blank\">\u201cspecies of greatest conservation need\u201d in Wyoming, where it faces threats from disease, climate change and habitat loss.\u00a0<\/a>There\u2019s also a fresh push to\u00a0<a href=\"https:\/\/www.fws.gov\/sites\/default\/files\/federal_register_document\/2024-01454.pdf\" rel=\"nofollow noopener\" target=\"_blank\">protect<\/a>\u00a0the species via the Endangered Species Act \u2014 a decision that could limit land uses in energy-rich southwestern Wyoming.\u00a0\u00a0<\/p>\n<p>Sagebrush constitutes 99% of a pygmy rabbit\u2019s wintertime diet. The little lagomorph simply can\u2019t hack it without the right combination of mature, thick sagebrush and soil that allows for den-building.\u00a0<\/p>\n<p>Finding their burrows is relatively easy. A brisk wind buffeted the crew \u2014 working quietly two hours before sunrise, to avoid spooking any rabbits \u2014 as they searched meticulously for the holes in the ground amid a thick, sagebrush-strewn draw near Bison Basin Road in the northeastern Red Desert.\u00a0\u00a0<\/p>\n<p>Getting genetic samples is surprisingly difficult. Along with two other biologists, Bacchiocchi placed the long, rectangular metal traps at one entrance after another. They draped them with light-blocking cloth, hoping to entice rabbits into thinking the trap was an entrance into the underground tunnel system. Adjacent burrow holes got \u201cplugged\u201d \u2014 wadded up black plastic bags did the trick \u2014 to deter escapes.\u00a0<\/p>\n<p><img loading=\"lazy\" data-recalc-dims=\"1\" height=\"609\" width=\"780\" decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/Trap-under-red-headlamp-1024x800.jpg\" alt=\"\" class=\"wp-image-124451\"\/>During the midnight hours on March 24, 2026, Wyoming Game and Fish Department and University of Idaho crews set 67 cage traps in the entrances of pygmy rabbit dens. (Mike Koshmrl\/WyoFile)<\/p>\n<p>Even before finding the fresh turd, there was reason to believe this was a likely haunt for pygmy rabbits.\u00a0<\/p>\n<p>\u201cWe kind of knew they were here,\u201d said Dana Nelson, a nongame mammal biologist for the Wyoming Game and Fish Department.\u00a0<\/p>\n<p>Nelson, who joined Bacchiocchi, is leading Wyoming\u2019s latest survey of pygmy rabbits. Past surveys in 2013 and 2019 suggested that they burrowed and bounded in this draw, she said.\u00a0\u00a0<\/p>\n<p>The pygmy\u2019s vulnerability is tied to the habitat it depends on: The\u00a0<a href=\"https:\/\/wyofile.com\/sagebrush-is-suffering-even-in-wyoming-saving-whats-left-is-complicated\/\" rel=\"nofollow noopener\" target=\"_blank\">embattled sagebrush-steppe biome<\/a>. Along with dozens of other vertebrate species, the pygmy rabbit can survive nowhere but this ecosystem, which is disappearing and degrading at an average rate of 1.3 million acres \u2014 an area about the size of Grand Canyon National Park \u2014 every year.\u00a0<\/p>\n<p>Sagebrush bound<\/p>\n<p>While some aspects of basic pygmy rabbit biology are well understood, there are big questions about how\u00a0Brachylagus idahoensis\u00a0will fare in the long run. High on the list of threats that have emerged is RHDV2, a highly contagious and deadly hemorrhagic disease. It hasn\u2019t been confirmed yet in Wyoming pygmy rabbits, but some populations in Nevada, where the disease was confirmed, appeared to blink out, Nelson said.<\/p>\n<p>There are also questions about how pygmy rabbit populations respond to mounting disruptions to habitat. Past research suggests they like for their sagebrush to be left alone: Prescribed burns and crushing sagebrush (i.e., aerator treatment) inhibit pygmy use of an area, according to\u00a0<a href=\"https:\/\/wgfd.wyo.gov\/media\/1422\/download?inline\" rel=\"nofollow noopener\" target=\"_blank\">Wyoming\u2019s species account<\/a>, and could negatively impact this species.\u00a0<\/p>\n<p><img loading=\"lazy\" data-recalc-dims=\"1\" height=\"508\" width=\"780\" decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/Walking-into-draw-1024x667.jpg\" alt=\"\" class=\"wp-image-124385\"\/>Dana Nelson, Ilaria Bacchiocchi and Sacha Wells descend into a Red Desert draw where sagebrush grows in thick \u2014 ideal pygmy rabbit habitat. (Mike Koshmrl\/WyoFile)<\/p>\n<p>\u201cFragmentation and loss of sagebrush habitat due to energy development currently is occurring throughout the species\u2019 range in Wyoming,\u201d state wildlife officials wrote. \u201cFurthermore, exposure of Pygmy Rabbit to energy development in Wyoming is predicted to increase 105% by 2030 based on models of current species distribution and projected energy development.\u201d\u00a0<\/p>\n<p>Climate change \u2014\u00a0<a href=\"https:\/\/wyofile.com\/wyoming-just-wrapped-up-its-warmest-winter-ever-surpassing-dust-bowl-records\/\" rel=\"nofollow noopener\" target=\"_blank\">the sagebrush sea is already heating up<\/a>\u00a0with more warming expected in the decades ahead \u2014 is yet another threat.<\/p>\n<p>\u201cThey do appear to be pretty thermally sensitive,\u201d Nelson said, \u201cand they have a fairly narrow range of temperatures that they can tolerate.\u201d\u00a0\u00a0<\/p>\n<p>By analyzing differences in pygmy rabbit genetics around the species\u2019 range, Bacchiocchi\u2019s research could eventually pinpoint populations that are better suited to deal with the heat.\u00a0<\/p>\n<p>Meantime, it\u2019s difficult to say exactly how pygmy rabbits respond to the various habitat stressors.\u00a0\u00a0<\/p>\n<p><img loading=\"lazy\" data-recalc-dims=\"1\" height=\"489\" width=\"780\" decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/Ground-squirrel-caught-1024x642.jpg\" alt=\"\" class=\"wp-image-124450\"\/>Wyoming ground squirrels frequently end up in cage traps meant for pygmy rabbits, which are less numerous and more difficult to capture. (Mike Koshmrl\/WyoFile)<\/p>\n<p>Partly that\u2019s because individual animals are tough to catch \u2014 their wariness on display Tuesday. Nelson, Bacchiocchi and University of Idaho wildlife tech Sacha Wells checked the 67 traps for the first time at 9 a.m. A good chunk of them, perhaps 10, were closed.\u00a0<\/p>\n<p>A small, restless mammal awaited in each.\u00a0<\/p>\n<p>Wyoming ground squirrels. Every time.<\/p>\n<p>The ubiquitous chislers were released, and traps reset for a second round of checks later in the morning.\u00a0<\/p>\n<p>Quirky little pygmies<\/p>\n<p>Pygmies, or \u201cpigs,\u201d as affectionate biologists call them, are both the world\u2019s smallest rabbit and the only lagomorph species that digs its own burrows. They\u2019re arboreal, at least with sagebrush, and sometimes leave their itty-bitty pellets behind in the waist-high crown of plants they\u2019ve climbed.<\/p>\n<p>Like any good rabbit, they\u2019re eaten by everything. Bacchiocchi has encountered lots of weasels in colonies and she\u2019s seen evidence that ravens will go after kits.\u00a0<\/p>\n<p>\u201cTheir predation rate is nuts,\u201d Nelson said. \u201cIt\u2019s the main source of mortality. Some of the old papers say that up to 80% can die each year due to predation.\u201d<\/p>\n<p>Pygmy rabbits weren\u2019t known to exist in Wyoming until 1981, when Jackson Hole biologists Susan Clark and Tom Campbell came across some south of Kemmerer.\u00a0<\/p>\n<p>Clark remembers it well 45 years later. She was out doing black-footed ferret surveys when she came across a different critter she wasn\u2019t expecting to see, she told WyoFile.\u00a0<\/p>\n<p>\u201cEvery once in a while we\u2019d come to these draws with really big dense sagebrush,\u201d Clark recalled. \u201cI noticed this little rabbit in those areas. I worked in Idaho before, so I knew about them. And I realized pretty quickly exactly what they were.\u201d\u00a0<\/p>\n<p>Today, biologists have a pretty good grip on where exactly pygmy rabbits are found within Wyoming. Generally, they dwell in the state\u2019s southwestern corner, with a range that includes the Bear, Green and Sweetwater river watersheds, plus the Red Desert.\u00a0\u00a0<\/p>\n<p>Game and Fish\u2019s 2026 surveys include 108 different locations. Nelson and her colleagues have documented pygmy rabbit sign at about half of those sites. That\u2019s \u201cencouraging,\u201d she said, because 2013 surveys found them at a similar proportion of survey sites.\u00a0<\/p>\n<p>\u201cRelative to other parts of their range,\u201d Nelson said, \u201cWyoming looks pretty good.\u201d\u00a0<\/p>\n<p>Tuesday\u2019s Red Desert capture attempts occurred near the very easternmost reach of pygmy rabbits\u2019 eight-state range, which extends west all the way to the Cascades in southern Oregon.\u00a0<\/p>\n<p><img data-recalc-dims=\"1\" decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/Pygmy-Wyo-range.jpg\" alt=\"\" class=\"wp-image-124437\"\/>This map illustrates the predicted distribution of pygmy rabbits in Wyoming. (Wyoming Game and Fish Department)<\/p>\n<p>Pygmy rabbit populations are thought to be fragile enough that they\u2019ve repeatedly been petitioned for protections under the Endangered Species Act.\u00a0<\/p>\n<p>Efforts to list the species in 2003 and 2010 failed, though did yield \u201cendangered\u201d protections for an isolated, genetically distinct population in Washington.<\/p>\n<p>A third attempt at listing the broader species has some traction. In January 2024, the\u00a0<a href=\"http:\/\/www.fws.gov\/sites\/default\/files\/federal_register_document\/2024-01454.pdf\" rel=\"nofollow noopener\" target=\"_blank\">U.S. Fish and Wildlife Service signaled it would take another look<\/a>\u00a0in response to a new\u00a0<a href=\"https:\/\/westernwatersheds.org\/wp-content\/uploads\/2023\/03\/FINAL-030623-Pygmy-Rabbit-ESA-listing-petition-WWP-v2.pdf\" rel=\"nofollow noopener\" target=\"_blank\">listing petition<\/a>\u00a0from Western Watersheds Project. The agency wrote that \u201cthe compound effects of fire,\u00a0<a href=\"https:\/\/wyofile.com\/inside-wyomings-fight-against-cheatgrass-the-most-existential-sweeping-threat-to-western-ecosystems\/?utm_source=WyoFile&amp;utm_campaign=60100454b3-EMAIL_CAMPAIGN_2025_11_26_10_20&amp;utm_medium=email&amp;utm_term=0_-60100454b3-\" rel=\"nofollow noopener\" target=\"_blank\">cheatgrass<\/a>, and climate change\u201d suggest there is a \u201csubstantial\u201d indication that listing the pygmy rabbit rangewide \u201cmay be warranted.\u201d\u00a0<\/p>\n<p>\u2018Threatened\u2019?<\/p>\n<p>Federal wildlife officials have been studying that possible listing ever since, albeit at a pace that has displeased petitioners. Western Watersheds Project\u00a0<a href=\"https:\/\/westernwatersheds.org\/2024\/08\/lawsuit-launched-to-protect-worlds-smallest-rabbit-in-eight-western-states\/\" rel=\"nofollow noopener\" target=\"_blank\">sued over the agency\u2019s failure<\/a>\u00a0to meet timelines required by the Endangered Species Act.<\/p>\n<p>Clark, the biologist who first identified Wyoming pygmy rabbits, encouraged\u00a0<a href=\"https:\/\/wyofile.com\/trump-taps-former-wyoming-game-and-fish-chief-nesvik-to-lead-u-s-fish-and-wildlife-service\/\" rel=\"nofollow noopener\" target=\"_blank\">federal officials tasked with overseeing wildlife<\/a>\u00a0to err toward listing.<\/p>\n<p>\u201cThe bottom line is we need to protect all the biodiversity that we have,\u201d she said. \u201cI would be for trying to protect them. The business-as-usual things that we do need to be looked at very, very carefully.\u201d\u00a0<\/p>\n<p>For now, pygmy rabbits are keeping their current designation as a state-managed species.\u00a0<\/p>\n<p>They\u2019re slated to remain a \u201cspecies of greatest conservation need\u201d in Wyoming\u2019s\u00a0<a href=\"https:\/\/wgfd.wyo.gov\/wyoming-wildlife\/wyoming-state-wildlife-action-plan\" rel=\"nofollow noopener\" target=\"_blank\">under-review State Wildlife Action Plan<\/a>, which is set to be finalized by the end of June.\u00a0<\/p>\n<p>At this juncture, there\u2019s not a lot that land and wildlife managers do deliberately aimed at helping pygmy rabbits.\u00a0<\/p>\n<p>\u201cIt\u2019s hard to prescribe conservation actions,\u201d Nelson said, \u201cwhen it\u2019s a species we\u2019re still learning more about every day.\u201d\u00a0<\/p>\n<p>So little is known about the pygmy rabbit, even a dead one is a prize.\u00a0<\/p>\n<p>Pygmy rabbit carcasses are shockingly seldom seen, the rabbit biologists bemoaned during a break between checking traps in the Red Desert. Because they live in the thickest patches of sagebrush, people rarely tread through their habitat. When they die, they\u2019re typically eaten quickly. Even their little bones are quick to decompose.\u00a0<\/p>\n<p>\u201cIt would be a gold mine,\u201d Nelson said of coming across a dead pygmy. \u201cI don\u2019t think our state vet lab has done pathology or a necropsy on one. It would just be cool.\u201d\u00a0<\/p>\n<p><img loading=\"lazy\" data-recalc-dims=\"1\" height=\"585\" width=\"780\" decoding=\"async\" src=\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/03\/Weighing-rabbit-1024x768.jpg\" alt=\"\" class=\"wp-image-124453\"\/>Wyoming Game and Fish Department nongame mammal biologist Dana Nelson weighs a pygmy rabbit caught by a University of Idaho crew on March 19, 2026 in the northern Red Desert. (Sacha Wells)<\/p>\n<p>Sometimes pygmy rabbits are found dead after being struck and killed on roads that cross the sagebrush sea, Bacchiocchi remarked. The University of Idaho researcher hasn\u2019t seen a road-killed specimen personally, but she knows they exist.\u00a0<\/p>\n<p>\u201cThere\u2019s one in Oregon waiting for my ear punch,\u201d she said.\u00a0<\/p>\n<p>During the second trap check at 11:30 a.m., it was much of the same: Wyoming ground squirrel, then another false alarm and another. No Red Desert pygmies were captured that day.\u00a0<\/p>\n<p>The crew did manage to trap a pygmy for a Bacchiocchi ear punch the Thursday prior. Chatting during downtime on the day fresh scat was the best the biologists could do, they marveled at how plump and healthy the little rabbit seemed. She tipped the scale at 1.1 pounds \u2014 a whopper of a pygmy.\u00a0<\/p>\n<p>This article was originally published by\u00a0<a href=\"http:\/\/www.wyofile.com\/\" rel=\"nofollow noopener\" target=\"_blank\">WyoFile<\/a>\u00a0and is republished here with permission.\u00a0<a href=\"http:\/\/www.wyofile.com\/\" rel=\"nofollow noopener\" target=\"_blank\">WyoFile<\/a>\u00a0is an independent nonprofit news organization focused on Wyoming people, places and policy.<\/p>\n<p>\n\tRelated<\/p>\n","protected":false},"excerpt":{"rendered":"THANKS TO OUR COMMUNITY PARTNERS by\u00a0Mike Koshmrl, WyoFile NORTHERN RED DESERT\u2014Ilaria Bacchiocchi cracked a smile as she explained&hellip;\n","protected":false},"author":2,"featured_media":552235,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[51],"tags":[79,201],"class_list":["post-552234","post","type-post","status-publish","format-standard","has-post-thumbnail","category-wildlife","tag-science","tag-wildlife"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/552234","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=552234"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/552234\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/552235"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=552234"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=552234"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=552234"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}