Carnegie Museum Research Articles

Selection for increased cranial capacity in small mammals during a century of urbanization

Abstract Urbanization is a selective force that is known to drive changes in the population dynamics of wildlife. How animals adapt to changing environmental conditions is crucial to their survival in these environments. Relative brain size, or cranial capacity, is a known proxy of behavioral flexibility, and can be used to assess how well a species has adapted to a particular environment. We examined changes in cranial capacity in a time series of small mammal skulls collected from urban and rural populations in southwestern Pennsylvania. Skulls from urban populations were collected from Allegheny County, an area that experienced rapid urbanization over the past century, and skulls of rural populations from the Powdermill Nature Reserve of the Carnegie Museum, which has remained relatively unchanged forest over the same period. Our results show that Peromyscus leucopus and Microtus pennsylvanicus from urban populations had significantly greater cranial capacity than their rural counterparts, but the opposite was true for Eptesicus fuscus. We found no difference in relative cranial capacity across time in any of the small mammal species. Our results suggest that a larger cranial capacity is selected for in an urban environment and reinforces the hypothesis that behavioral flexibility is important for animals to adapt to novel environments.

Report of a Small Collection of Kohlsia mojica Tipton and Méndez, 1966 (Siphonaptera: Ceratophyllidae) from Costa Rica with a Discussion of Several Enigmatic Species of Kohlsia Traub, 1950

A collection of fleas was acquired independently from Costa Rica by two different field teams. Among these collections were a sizable series of Kohlsia mojica Tipton and Méndez which were previously reported only from the northern province of Bocas del Toro, Panama. These new records were present in two provinces of Costa Rica (Alajuela and Puntarenas). Additional specimens discovered in the Robert Traub flea collection in the Carnegie Museum of Natural History, heretofore unreported, included specimens from San Jose and Cartago provinces, Costa Rica. The primary host for K. mojica is the Mexican deer mouse, Peromyscus mexicanus Saussure. Collectively, five species of Kohlsia have been reported within the geographical boundaries of Costa Rica and Panama [K. mojica, K. azuerensis Tipton and Méndez, K. keenani Tipton and Méndez, K. graphis graphis (Rothschild), and K. traubi Tipton and Méndez]. A key is provided for these five species. Specimens of K. g. graphis are reported herein for the first time from Guatemala and Mexico, and the variegated squirrel Sciurus variegatoides Ogilby represents a new host record for K. g. graphis. Table 1 is included to illustrate the distribution of all known Kohlsia species. In addition, Kohlsia campaniger Jordan (an extralimital species) described from a single female specimen from Ecuador is discussed. Several morphological characters are provided to distinguish K. campaniger and Kohlsia felteni Smit. Jellisonia ortizi Vargas (currently valid in Kohlsia) is hypothesized to be a new synonym of Kohlsia fournieri Vargas. Kohlsia keenani is reported for the first time from Handleyomys alfaroi (J. A. Allen), Handleyomys chapmani (Thomas) and Nephelomys albigularis (Tomes).

Tactile tails: a new hypothesis for the function of the elongate tails of diplodocid sauropods

ABSTRACT Tail elongation is a trait common to many sauropod dinosaurs. In certain members of Diplodocidae, for example, the total caudal vertebrae count is as high as 70 to 80 bones, making a total estimated tail length for mature animals that is in excess of 10 metres. A number of competing hypotheses have been suggested to explain the function of this ‘hyper-elongate’ tail including use as a counterbalance, use as a defensive weapon, use as a sonic-boom-generating ‘bull-whip’ or use as a feature for sexual display. Here, a new hypothesis is presented for the function of sauropods’ hyper-elongate tails – herding co-ordination. Many sauropods are known, from multiple independent lines of evidence, to have been herding animals that moved in large groups over wide ranges; it is proposed that the elongation of the tails in many of the more massive sauropod lineages may have evolved to allow for simple and efficient communication between individuals via near continuous animal-to-animal contact during herd movement and migration. This contact, it is suggested, would have facilitated speedier, more compacted and more efficient mass movement of the animals as a group, and reduced the need for continual slowing and stopping to maintain herd formation. Institutional abbreviations: AMNH: American Museum of Natural History, New York, USA; CM: Carnegie Museum of Natural History, Pittsburgh, USA; HMN: Natural History Museum, Berlin, Germany; OMHN: Sam Noble Oklahoma Museum of Natural History, Oklahoma, USA

Re-basing Scientific Authority: Anthropocene Narratives in the Carnegie Natural History Museum

ABSTRACT Natural history museums legitimate and motivate social and political actions through their representations of science-society relations. The Carnegie Natural History Museum has brought narratives of the Anthropocene into its museum spaces, offering novel representations and understandings of human-nature and science-society relations. As a contested concept, the Anthropocene entails at least two tensions in how it might be represented, encouraging different kinds of social and political projects: the Anthropocene may encourage new political formations and opportunities as well as new, better relations between science and society. Motivated to engage with the Anthropocene out of commitments to affirm a strong and pronounced social role of the scientific community, museum actors defend scientific authority through appeals to reflexive scientific processes and science's necessary relations with other modes of thought. Reflexive scientific processes allow scientists and scientific institutions to manage their social and political values, while science's relations with artistic and ethical thinking legitimizes the use of science in responses to explicitly political and social problems. The Carnegie Museum enacts these bases for authority through its Anthropocene narratives, re-drawing the boundaries of scientific authority to include political questions while simultaneously making the boundaries between legitimate, scientific knowledge and other modes of thought less salient.

Anatomy of the Petrosal and Middle Ear of the Brown Rat, Rattus norvegicus (Berkenhout, 1769) (Rodentia, Muridae)

The anatomy of the petrosal and associated middle ear structures are described and illustrated for the brown rat, Rattus norvegicus (Berkenhout, 1769). Although the middle ear in this iconic mammal has been treated by prior authors, there has not been a comprehensive, well-illustrated contribution using current anatomical terminology. Descriptions are based on specimens from the osteological collections of the Section of Mammals, Carnegie Museum of Natural History, and a CT scanned osteological specimen from the Texas Memorial Museum. The petrosal, ectotympanic, malleus, incus, stapes, and inner ear were segmented from the CT scans.The petrosal of the brown rat is only loosely attached to the cranium, primarily along its posterior border; it is separated from the basisphenoid, alisphenoid, and squamosal by a large piriform fenestra that transmits various neurovascular structures including the postglenoid vein. The extent of the piriform fenestra broadly exposes the tegmen tympani of the petrosal in lateral view. The floor of the middle ear is formed by the expanded ectotympanic bulla, which is tightly held to the petrosal with five points of contact. The surfaces of the petrosal affording contact with the ectotympanic bulla are the rostral tympanic process, the epitympanic wing, the tegmen tympani, two of the three parts of the caudal tympanic process, and the tympanohyal, with the ectotympanic fused to the last. The ectotympanic in turn is fused to the elongate rostral process of the malleus, which is only discoverable through the study of juvenile specimens. In addition to osteology, the major nerves, arteries, and veins of the petrosal are described and illustrated based on the literature and osteological correlates.The petrosal of the brown rat is compared with those of several Eocene rodents to put the extant form in the context of early members of the rodent lineage. Comparisons benefitted from CT scans of the middle Eocene ischromyoid Paramys delicatusLeidy, 1871, from the western United States, affording the first description of the endocranial surface of the petrosal in an Eocene rodent. The petrosals in the Eocene fossils are more tightly held in the cranium, but the ectotympanic contacts the petrosal through the same five points, with some modifications. The most unexpected discovery in Paramys delicatus was the presence of a prominent tentorial process of the parietal in contact with the reduced crista petrosa.

Diversifying Displays of Biological Sex and Sexual Behaviour in a Natural History Museum

Many natural history museums present species’ life histories in their galleries, which millions of visitors use to make meaning of the ‘natural world’ to which humans belong. Because curation is inherently practiced through a human’s perspective, and often the male gaze, images depicting the ‘natural world’ may be informed more by dominant understandings of sex and gender as social constructs of idealised bodies and behaviours than by scientific understanding. In this paper, we conduct a quantitative survey of displays in the Carnegie Museum of Natural History to test for biases that naturalise socially constructed gender ideals. We statistically tested for bias to display dioecious species (species where sex is partitioned into two bodies), to display male specimens, and to physically arrange taxidermy in ways that suggest females are coy and males are passionate. We find significant evidence of the invisibility of non-binary natural histories in noting that fewer than 10% of specimens on display are from monecious or non-binary species. Based on a survey of 392 mammal and bird specimens on display, there is a significant sex bias resulting in collections displaying one female specimen for every two male specimens. Moreover, the survey shows a significant bias in how a museum portrays female and male specimens, with 63% of 56 mixed-sex groups of mammals and birds physically arranged specimens in ways that suggested females are coy and males are passionate. Finally, we identify places where signage, programming, and interventions can be used as a starting point for a museum to tell more stories of non-binary biological sex, unfixed biological sex, same-sex sexual behaviour, and diverse family arrangements.

‘How Could the Dinosaurs Be So Close to the Future?’: How Natural History Museum Educators Tackle Deep Time

AbstractNatural history museums play an important role in engaging the public in critical conversations about science and society. However, understanding complex concepts such as the Anthropocene requires thinking at large spatial and temporal scales. This challenge is at the forefront of a research‐practice partnership between the Carnegie Museum of Natural History (Museum) and the University of Pittsburgh Center for Learning in Out‐of‐School Environments (UPCLOSE). Together we designed a tool to help museum educators engage visitors in conceptualizing and connecting deep time with pressing environmental concerns. We observed educators using the tool in two settings: summer camp and on the Museum floor. We then interviewed educators to understand how they frame learning goals for understanding deep time and how their strategies support learner connections to the Anthropocene. While the tool was generally well received by educators, our observations and interviews also revealed two fundamental tensions. One tension was in pedagogical approaches – either inquiry or transmission – and the other was in learning goals – either wonder or relativity. Going forward, the Museum plans to use the tool both for exploration of deep time and as a professional development tool for Museum educators to better balance their use of these different approaches.

Reassessment of a Historical Collection of Sauropod Dinosaurs from the Northern Morrison Formation of Wyoming, with Implications for Sauropod Biogeography

The Upper Jurassic Morrison Formation of the western United States preserves one of the best-known Mesozoic paleoecosystems worldwide. The formation crops out over an area from New Mexico and Oklahoma to Montana and Utah and encompasses a time span of approximately eight million years. Recent studies indicate a high diversity of gigantic, herbivorous sauropod dinosaurs, but the geographic and temporal distributions of species or even genera of these animals remain poorly understood. In particular, sauropod specimens from northern outcrops of the formation have rarely been studied in detail, and temporal relationships among sites are imprecise. Here, we reassess the taxonomic diversity of the sauropods from a historic Carnegie Museum locality in northern Wyoming. Previous referrals of material to the well-known diplodocid genera Apatosaurus and Diplodocus cannot be confidently confirmed; instead, all these specimens more likely represent elements from the recently recognized Galeamopus. Specimens previously assigned to Camarasaurus and Haplocanthosaurus could not be referred to these genera based on apomorphies, due to a lack of detailed knowledge concerning the genus- and species-level taxonomy of these sauropods. Our findings imply that many referrals of incomplete diplodocid skeletons to Apatosaurus and Diplodocus must be reassessed. These reassessments are particularly important with regard to specimens from northern localities of the Morrison Formation, as it is becoming increasingly evident that diplodocids from this area were distinct from better-known, more southerly taxa. This geographic segregation does not seem to apply to nondiplodocid sauropods; however, these taxa are also in need of systematic revision, which may reveal species-level patterns similar to those observed in Diplodocidae.

Augmented Reality Brings the Real World into Natural History Dioramas with Data Visualizations and Bioacoustics at the Carnegie Museum of Natural History

AbstractThis paper introduces the AR Perpetual Garden App and highlights reasons why it is unique and important in its use of immersive, augmented reality for informal learning. The design and construction of the application created a virtual diorama based on facts, using realistic 3D models and accurate perspective. Design affordances permit annotations with interactive and multimodal facts and stories, delivering interactive knowledge artifacts. The app combines real and virtual into one holistic and comprehensive learning experience, transferring scientific knowledge to the novice in an instant. The use of immersive augmented reality produced from accurate information, data visualizations, and bioacoustics creates context‐sensitivity experiences inside the gallery and outside in the gardens. Distribution through the Apple and Google app stores to schools and homes can extend the broader impact of the educational mission of the Carnegie Museum of Natural History and its biological research center, the Powdermill Nature Reserve.

History and geology of the Cope’s Nipple Quarries in Garden Park, Colorado—type locality of giant sauropods in the Upper Jurassic Morrison Formation

The discovery in 1877 of what proved to be an extensive multi-taxa bonebed from the Upper Jurassic Morrison Formation helped kick-start the first Jurassic “Dinosaur Rush.” Located north of Cañon City, Colorado, the site, known today as Cope’s Nipple within the Garden Park National Natural Landmark, was worked by Oramel and Ira Lucas from 1877 to 1884, again by the Carnegie Museum in 1901, and sporadically by the Denver Museum of Natural History from 1991 to 1996. The history of this work is presented in depth for the first time using extensive archival records. The quarries occur in a single horizon around the base of Cope’s Nipple and represents a widespread bonebed in distal overbank silty mudstone that was subsequently modified by pedogenesis. Limited taphonomic data indicate the bonebed was a mix of allochthonous and autochthonous bone.

History and geology of the Cope’s Nipple Quarries in Garden Park, Colorado—type locality of giant sauropods in the Upper Jurassic Morrison Formation

The discovery in 1877 of what proved to be an extensive multi-taxa bonebed from the Upper Jurassic Morrison Formation helped kick-start the first Jurassic “Dinosaur Rush.” Located north of Cañon City, Colorado, the site, known today as Cope’s Nipple within the Garden Park National Natural Landmark, was worked by Oramel and Ira Lucas from 1877 to 1884, again by the Carnegie Museum in 1901, and sporadically by the Denver Museum of Natural History from 1991 to 1996. The history of this work is presented in depth for the first time using extensive archival records. The quarries occur in a single horizon around the base of Cope’s Nipple and represents a widespread bonebed in distal overbank silty mudstone that was subsequently modified by pedogenesis. Limited taphonomic data indicate the bonebed was a mix of allochthonous and autochthonous bone.

The Mammalian Parasphenoid: Its Occurrence in Marsupials

In non-mammalian amniotes, the parasphenoid is a midline dermal element with a narrow rostral portion, the cultriform process, linked to the interorbital septum and an expanded distal portion, the alae or wings, forming part of the ventral skull base. In mammals, the parasphenoid has not been found in extant monotremes and only a handful of reports of a reduced parasphenoid (a remnant of the cultriform process) have been made for extant marsupials and placentals. Most reports are in serially-sectioned perinatal specimens where the contrast between the intramembranous origin of the parasphenoid and the overlying endochondral basisphenoid facilitates delimiting the different elements forming the skull base. The only report of a parasphenoid remnant in adult marsupials is in the white-eared opossum, Didelphis albiventris, and it was published more than 100 years ago. Here, we report the results of a survey of 576 specimens of Didelphidae and 115 other Marsupialia in the extant collections of the Section of Mammals, Carnegie Museum of Natural History. We observed what we interpret as a parasphenoid remnant in some juveniles and adults from ten of the 27 didelphid species studied: Didelphis albiventris, Didelphis marsupialis, Didelphis virginiana, Marmosa murina, Monodelphis arlindoi, Monodelphis domestica, Philander opossum, Thylamys elegans, Thylamys pusilla, and Thylamys venustus. This element was variable in its presence within the collection, as well as in its size, form, and position. In our largest specific sample, the Virginia opossum, Didelphis virginiana, a parasphenoid was present in 55% of 238 specimens. It is uncertain if the variable occurrence reflects a true absence of the parasphenoid or its loss during specimen preparation. Outside of Didelphidae, we noted a substantial parasphenoid in the microbiothere Dromiciops gliroides, contributing to a midline septum that partially divides the nasopharynx into two channels, and a probable small one in the macropodid Thylogale sp.In extinct mammals and non-mammalian cynodonts, a midline mesocranial ridge interpreted by prior authors as composed of or including a parasphenoid has a wide distribution, supporting the presence of this structure as primitive for Mammalia. It is suggested here that the Miocene platypus Obdurodon has a well-developed parasphenoid further supporting the presence of a parasphenoid as a plesiomorphic feature for Mammalia that is independently lost in some therians and apparently in extant monotremes.

20/20: The Studio Museum of Harlem and the Carnegie Museum of Art

Exhibition schedule: Carnegie Museum of Art, July 22–December 31, 2017

Rediscovery of Cylindera (Cylindera) uudata (W. Horn, 1915) (Coleoptera: Carabidae: Cicindelini) from Durango, Mexico: Systematics, Neotype Designation, and Recognition

We document the rediscovery of Cylindera (Cylindera) nudata (W. Horn, 1915), a rarely collected tiger beetle species, from Durango, Mexico, nearly a century after its description in 1879. This rediscovery is based on a single female collected in 1972, and is only the second known specimen. Images of this specimen are provided, together with an English translation of the original German description and a review of its nomenclature. The unique female specimen is here designated as neotype for this species because it is the only extant specimen known. The holotype, the sole male and sole specimen in the original description, was destroyed during World War II. The neotype is deposited at the Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA. The information presented here will assist tiger beetle taxonomists in recognizing this species should it ever be collected in the future in Durango, or from adjoining Mexican states.

A new genus Thubdora Park, gen. nov. and seven new species of the subfamily Torodorinae (Lepidoptera, Lecithoceridae) from Cameroon and Rep. of Congo, Africa

Abstract Based on the material collected from Cameroon in 1913–1918 and Congo in 1993 which are preserved in the Carnegie Museum of Natural History, Pittsburgh, USA, a new genus Thubdora Park, gen. nov. and seven new species of the subfamily Torodorinae (Lecithoceridae) are described. They are Torodora efulenensis sp. nov., Dragmatucha hispidula sp. nov.; and five species of Thubdora: T. acutalis sp. nov., T. bilobella sp. nov., T. aciphalla sp. nov., T. ambliodes sp. nov., and T. cameroona sp. nov. In addition, six species of Lecithocera Herrich-Shaffer described by Viette, 1955 , Viette, 1986 and Meyrick, 1931 , Meyrick, 1933 are newly transferred to Torodora and its related genera, due to the male genital characters: Idiopteryx adella ( Viette, 1955 ), comb. nov.; Thubdora decavella ( Viette, 1955 ), comb. nov.; Thubdora mocquerysella ( Viette, 1955 ), comb. nov.; Torodora kambanella ( Viette, 1986 ), comb. nov.; Torodora masoalella ( Viette, 1955 ), comb. nov.; Torodora monobyrsa ( Meyrick, 1931 ), comb. nov.; and T. ochrometra ( Meyrick, 1933 ), comb. nov. For the new species, images of adults with their labels and genitalia are provided.

A Royal Pain, But Worth It: New Storage for Old Collections

Three years ago, the Section of Anthropology, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA, received a grant from the National Endowment for the Humanities to rehouse its 1.5-million-specimen archaeological collection. The entire Anthropology collection was affected by the movement of the archaeology material, and required additional attention. With a staff of two people, a conservator, and a host of wonderful volunteers and interns, the security and accessibility of the collections were greatly enhanced through the creation of custom housing for a variety of objects, including pottery, textiles, spears, bows and arrows, saddles, etc. This poster shows a sampling of the storage upgrades that resulted from this intense project.

Launching a Risk Assessment Project

In 2017 Carnegie Museum of Natural History (CM) received funding from the Institute for Museum and Library Services (IMLS) to conduct a risk assessment for collections. CM had already conducted two general conservation surveys (1989 and 2010) and an environmental survey (2011), all funded by IMLS. The next logical step was to do a risk assessment. The initial planning was done through the development of a funding proposal. Both the concept and the process had to be supported by administration and staff, which was ensured up front through the development of the grant application. At the time, we were fortunate enough to have a new administration that supported this project as a logical step toward developing a long-term collection care strategy. In the application we identified the most experienced subject matter expert as a consultant (R. R. Waller, Project Heritage Inc.). Waller has a longstanding relationship with CM, having been part of the core team in the general conservation surveys. Waller worked closely with the grant application team to develop the project schedule and internal team. Additionally, the grant application proposed the use of Waller's Cultural Property Risk Analasys Model (CPRAM) to assess our risks. One key element in developing the proposal was the acknowledgment of limited staff time. This was solved by including money to hire a Collections Associate dedicated to the project, full time for the two-year duration of the project. There is a steep learning curve for the process. Having this "gatekeeper" to manage the data being gathered maintains consistencey and focuses adequate staff time to keep the project moving forward. The overall goal of the project is to identify risks to the collections in a quantifiable manner. Using these data we will prioritize those risks and subsequently develop reasonable strategies to reduce the risks. This project will inform the overall strategic plan currently being developed for CM. By strategically including a few non-collection staff in the project, the risk assessment work will also promote better understanding and communication of collection concerns across the museum and our parent organization. This poster examines the initial phase of the two-year project. It demonstrates how we, at CM, are approaching the organization of the CPRAM, training staff, and beginning this complex project.

Three new genera and ten new species of the subfamily Lecithocerinae (Lepidoptera, Lecithoceridae) from Cameroon, Africa, based on material collected in 1913-18.

Based on material collected in Cameroon, Africa in 1913-18 and deposited in the Carnegie Museum of Natural History, Pittsburgh, USA, three new genera and 10 new species of Lecithocerinae (Lecithoderidae) are described and illustrated. The new genera are Paniculata gen. nov., Furcalis gen. nov., and Notioseus gen. nov. The new species are Homaloxestis rawlinsi sp. nov., Lecithocera afrotella sp. nov., L. dysmica sp. nov., L. cyclisca sp. nov., Paniculata weberi sp. nov., Notioseus cupripennis sp. nov., N. acidodes sp. nov., Furcalis efulenica sp. nov., F. triodonta sp. nov., and Lacuniola noda sp. nov. Adults and their labels, and the genitalia of all the species treated herein are illustrated.

Dodo by Jeffrey Carpenter et al.

Reviewed by: Dodo by Jeffrey Carpenter et al. Shelby Brewster DODO. Co-created by Jeffrey Carpenter, Gab Cody, Tami Dixon, and Sam Turich. Bricolage Production Company, Carnegie Museum of Art and Carnegie Museum of Natural History, Pittsburgh. October 20 and November 4, 2017. In the late 1890s, famed US industrialist Andrew Carnegie founded the Carnegie Museums of Art and Natural History. Bricolage Production Company’s immersive work DODO, co-created by Jeffrey Carpenter (director), Gab Cody (lead writer), Tami Dixon (director), and Sam Turich (director), gave audiences a dreamlike journey through the public and private spaces of both museums. Through a series of encounters with performers, museum staff, and collections, DODO explored the social and cultural meanings of collecting in light of climate change. Upon arriving at the museums, I joined the small group who would journey through the performance with me. A representative (Fred Frances) of the “National Self-Preservation Society” welcomed us to our “donation process”—what we were donating remained mysterious at this point. He interviewed each of us and based on our answers gave us an object that would determine our path. The first time I attended, I was given a sprig of eucalyptus; the second time, a small bone. We took a service elevator into the art museum, where the Docent (Emilie Sullivan) guided us through the darkened galleries. After asking to see our objects, she directed each of us to contemplate a particular piece of art until she came to retrieve us. While enjoyably meditative, the connection between this first encounter with museum collections and the performance’s framing was unclear. Standing before John McCracken’s sculpture Untitled (Blue Leaning Plank), I wondered exactly how I should respond. Being in the gallery after hours created a delicious sensation of breaking the rules, but the lack of framing left me feeling lost. We crossed into the natural history museum’s polar exhibit: dioramas of Canadian Inuit seal hunting and taxidermied polar bears. The gregarious Explorer (Michael McBurney), a high-society type with a penchant for hunting, regaled us with tales of his exploits. He lamented the loss of his sport as he and his fellows were hunting their prey to extinction. Our engagement with the Explorer brought out questions of the provenance of the museums’ acquisitions: How do the legacies of colonialism continue to play out in contemporary cultural institutions? Across the hall in the Egyptian exhibit, two of my counterparts and I were met by a pensive Yasmine (Watipaso Kumwenda). She described her home in a future where it was difficult to breathe unless you could afford your own climate. Surrounded by funerary boats, she asked us what would be left of humans? (The answer: plastics.) Yasmine sent my companions off, asking me to crawl through a small tunnel behind a sarcophagus. Suddenly, a flashlight interrupted us. A guard scolded me for being in a restricted area, then led me away. On a catwalk above the museum, I entered the nest of an avian couple: Maeve (Kelsey Robinson) and Marvin (Tyler Ray Kendrick). Maeve treated me and another participant to a song on her ukulele. The jovial mood was broken when Marvin announced that they could keep only one of us. He asked me: What makes me keepable? As I dumbly blurted out that I make a good chicken pot pie, he shouted my answers to Maeve. They decided that I was not worth keeping and sent me away. With two other participants, I met a museum scientist preserving the body of a small bird. As we entered her work-room she asked one of us to open a chest freezer and remove a plastic bag containing a specimen. I expected to hand it to her, but instead she asked me to hold the frozen bird in my hands, thawing it. For the next several minutes, as she showed us other specimens and tools of her trade, I held the cold, plastic-wrapped bird between my palms. These encounters drew attention to the ways in which life is circumscribed as worth conserving within the confines of the museum, and the ways that life is deemed valuable (or not) outside of it. Click for larger...

Comparative studies need to rely both on sound natural history data and on excellent statistical analysis.

We certainly agree with Schradin [1] that comparative studies need to use the best information available—as well as clear definitions, up-to-date statistical techniques and common sense. We have divided our response into two sections: the first dealing with Schradin's critique of our 2017 paper and the classification of the social organization of shrews; the second dealing with three general issues that his commentary raises. The paper that Schradin is commenting on [2] asks whether cooperative breeders (which we define as species where non-breeding helpers assist breeders to raise their young) in mammals are more commonly found in arid environments than monogamous species (defined as species where breeding pairs of males and females remain together for more than one season) from which cooperative breeders appear to be derived [3]. It shows that, as in birds, cooperative breeders tend to live in relatively arid habitats compared to monogamous species. As we describe below, these conclusions are unaffected by differences between our classification of the social organization of shrews and the classification suggested by Schradin. Schradin's first criticism is that the categorizations of shrews that we have used in this analysis were based on one paper on a single species. This is incorrect, for our categorization of shrews was based on more than 70 separate sources (see electronic supplementary material, appendix S1). When we published our dataset [4], we were required to reduce the associated reference list by the editors of the journal and, to comply, we removed around 75% of our 2000+ sources, often listing a single reference per species or group of species, and frequently using generic reviews for particular groups where these were available: for example, for many rodent species, we simply listed Wolff and Sherman's Rodent Societies [5], and …