David J. Schmidly

Studies of a Contact Zone among Three Chromosomal Races of Geomys bursarius in East Texas

A zone of contact among three chromosomal races of Geomys bursarius , designated E (2N = 74, FN = 72), F (2N = 70, FN = 74), and G (2N = 70, FN = 72), was located in Burleson Co., Texas. Interactions between race E and races F and G were assessed. Differences in diploid and fundamental numbers between these two groups were sufficient to detect many potential backcross and F2 hybrid individuals. Of 42 gophers collected in the contact zone, 31% had an apparent F1 karyotype (some of these may be unrecognized backcross and F2 individuals). No karyotypically detectable backcross or F2 individuals were found except in the fetal state. Race E and races F and G could not be separated morphologically, although two general groups were evident. The F1 hybrids were not morphologically intermediate between race E and races F or G, but were more similar to the latter pair of races than to the former race. No ecological differences with regard to soil preferences were found among the three races and hybrids. The limited size of the contact zone and the apparent lack of backcrossing suggest that race E and races F and G interact as biological species where they contact. The absence of any detectable premating isolating mechanisms may be correlated with the recency of the contact zone. It is suggested that races F and G have invaded the existing range of race E, possibly as a consequence of the effects of man-made disturbances such as agriculture and the building of road rights-of-way.

Morphometric Differentiation and Taxonomy of Three Chromosomally Characterized Groups of Peromyscus boylii from East-Central Mexico

Morphometric characters are congruent with cytogenetic and genic evidence in dividing Peromyscus boylii into three groups in east-central Mexico. These include a monomorphic, low-FN group (FN = 52); a polymorphic, low-FN group (FN = 52–54); and a polymorphic, high-FN group (FN = 58–60). Univariate and multivariate analyses of morphometric features discriminate the three groups, with the overall pattern more evident in the multivariate than the univariate approach. Some of the qualitative characters show the monomorphic low-FN specimens to be distinct from the karyotypically polymorphic groups, but none of them is diagnostic. Morphometric comparisons of the three karyotypic groups with topotypic and reference samples of the recognized taxa of P. boylii in Mexico support the following taxonomic assignments for these forms: monomorphic, low-FN group, P. boylii rowleyi ; polymorphic, low-FN group, P. beatae ; and the polymorphic, high-FN group, P. levipes . The three chromosomal groups appear to represent a good example of cryptic species.

Karyotypic Variation in Peromyscus boylii from Mexico

Results are presented from an extensive survey of karyotypic variation among and within Mexican populations currently assigned to Peromyscus boylii. Considering these and previously published data, the range of autosomal polymorphism within P. boylii (FN = 48–68) would be greater than that known for any other species of Peromyscus and includes karyotypes (FN = 48–51) which are not known to occur in any other species in the genus. Based on karyotypic and distributional factors, we recognize five karyotypic groups which do not directly reflect the current intraspecific taxonomy of P. boylii. The karyotypic differences and the geographic distribution of the various karyotypic groups indicate that more than one species is represented in what is now regarded as P. boylii. The distributions of the forms beatae (FN = 48–54), levipes (FN = 58–60), and rowleyi (FN = 52) are reevaluated in terms of the karyotypic data and it is suggested that each of these represents a distinct species. Due to a paucity of data of boylii -like forms from western Mexico, the taxonomic status and systematic associations of several karyotypic forms from this region remain unresolved.

The glans penes and bacula in Latin American taxa of the Peromyscus boylii group

The glans penis and bacular morphology is described for 15 taxa of the Peromyscus boylii species group from Latin America on the basis of 17 qualitative and quantitative characters. These characters were analyzed phenetically using cluster, principal components, and minimum spanning tree analyses. A phylogenetic analysis was performed using 10 characters and 34 character states, with Osgoodomys banderanus as the outgroup taxon. Results from phenetic and phylogenetic analyses indicate that two distinct types of phalli exist among taxa in the P. boylii species group and these correspond to the dichotomous arrangement of taxa into a boylii and an aztecus assemblage as suggested by Carleton (1977). The taxa comprising each assemblage appear to be more closely related to each other than they are to any taxon in the other assemblage. In addition, evidence is presented supporting the distinction of P. b. rowleyi from the other subspecies of P. boylii .

Variation in the Glans Penes and Bacula among Latin American Populations of the Peromyscus boylii Species Complex

Geographic and nongeographic variation was examined in the glans penesand bacula of 34 samples representing five nominate taxa of Peromyscus boylii -like forms ( P. boylii rowleyi, P. b. sacarensis, P. beatae, P. levipes levipes , and P. l. ambiguus ). Sixteen qualitative and quantitative characters were analyzed by use of cluster and principal-component analyses. Five types of phalli are found among the five taxa examined. One of these types is unique in that epidermal spines are absent from the surface of the glans penis. The other four are described in terms of their differences in size, spine development, furrowing, and length of cartilaginous tip. The pattern of phallic variation among samples of P. boylii is not entirely concordant with the pattern depicted by craniometric, biochemical, and chromosomal data. Populations bearing the first, second, and perhaps third phallic types described herein apparently represent undescribed taxa in the Peromyscus boylii species complex.

Systematics of Spiny Pocket Mice (Genus Heteromys) of the Desmarestianus Species Group from México and Northern Central America

Nongeographic and geographic variation is assessed in the desmarestianus species group of the genus Heteromys (exclusive of H. gaumeri ). Concordant results of cranial, external, and bacular variation reveal that the desmarestianus -group is represented in northern Middle America by two species, H. desmarestianus and H. goldmani . H. longicaudatus and H. lepturus are indistinguishable from H. desmarestianus . H. temporalis is arranged as a subspecies of H. desmarestianus .

Noteworthy Records of Mammals from the State of Queretaro, Mexico

context, male bobwhites seemed to seek out whistling posts where canopy coverage of brush within 30 m averaged about 20% and where visual screening from 12 to 20 dm aboveground averaged 20 to 40%. We suspect that males also selected for overhead cover at perch sites. The mean height of whistling posts exceeded the mean height of perch sites on both areas (Table 1). Also, 79% of vocalizing males (n = 61) had overhead cover at the perch site. Lastly, there was consistency between areas in height of perch site suggesting males prefer to display about 1.5-2.5 m aboveground. The pooled mean was 2.1 m (SE = 0.24).

Educational Needs of Fisheries and Wildlife Professionals: Results of a Survey

Abstract Fisheries and wildlife employees of the Minnesota Department of Natural Resources and Texas Parks and Wildlife responded to a survey that gathered information about their educational background and perception of the importance of 65 subjects typically taught in university fisheries and wildlife curricula. Respondents believed that subjects in their university education that dealt with fisheries and wildlife and ecology/natural resources were among the most important to job performance—as might be expected—but subjects regarding interpersonal interactions were equally important. Some of these latter subjects appeared to be underemphasized in college educations of the respondents, although the more recent graduates took more courses covering interpersonal interactions. Some differences in education and perception of importance existed among certain demographic groups. A strong correlation between education and perception of subject importance suggests that universities are able to exert considerabl...

Morphometric, karyotypic, and molecular evidence for a new species of Peromyscus (Cricetidae: Neotominae) from Nayarit, Mexico

Abstract Historically, specimens representing the Peromyscus boylii species group (from montane regions of western and southwestern Mexico) have been referred to as P. boylii or P. levipes. However, previous studies indicated that specimens from eastern Nayarit possessed a karyotype and mitochondrial DNA haplotype distinct from other members of the P. boylii species group. Together, these data precluded an assignment of these specimens to any currently recognized taxon in the P. boylii species group. Availability of additional specimens from this region provided an opportunity to reevaluate the taxonomic status of this complex. Analyses of 18 morphological characters demonstrated that specimens from eastern Nayarit possessed a significantly longer length of the nasals relative to the other species. Further, phylogenetic analyses (parsimony and likelihood) of DNA sequences obtained from the mitochondrial cytochrome-b gene indicate these specimens form a monophyletic clade embedded within a strongly supported clade containing representatives of P. beatae, P. levipes, and P. schmidlyi. Together, these results indicated that specimens from the Sierra Madre Occidental region of Nayarit represent an undescribed species of Peromyscus. Resumen Históricamente, los especímenes que representan al grupo de especies de Peromyscus boylii (de regiones montanas del oeste y suroeste de México) han sido identificadas como P. boylii o P. levipes. Sin embargo, estudios previos han indicado que los especímenes del este de Nayarit poseen un cariotipo y un haplotipo del ADN mitocondrial distinto al de otros miembros del grupo de especies de P. boylii. Juntos, estos datos excluyen la asignación de dichos especímenes a cualquier taxón actualmente reconocido en el grupo de especies de P. boylii. La disponibilidad de muestras adicionales de esta región permitió reevaluar la taxonomía de este complejo. El análisis de 18 caracteres morfológicos demostró que los especímenes procedentes del este de Nayarit poseen una longitud significativamente mayor del hueso nasal en relación a otras especies de este complejo. Además, análisis filogenéticos (parsimonia y verosimilitud) de secuencias de ADN obtenidas del gen mitocondrial citocromo-b indican que estos especímenes forman un clado monofilético embebido dentro de otro clado que, con fuerte apoyo estadístico, contiene a representantes de P. beatae, P. levipes, y P. schmidlyi. En conjunto, todos estos resultados indican que los especímenes de la región de Sierra Madre Occidental de Nayarit representan una especie no descrita de Peromyscus.

The mammals of coastal Texas: A comparison between mainland and barrier island faunas

Biodiversity patterns of non-volant mammals on oceanic and land-bridge islands have been well documented, but little information is available about the biodiversity of barrier islands. We compared the mammalian fauna of the barrier islands of Texas with the adjacent mainland by using historical trapping records and recent field work. The barrier islands of Texas have a depauperate mammalian fauna when compared to that of the Texas coast. A number of factors have influenced this, including hurricane events, mainland species pool for the island to draw upon, and the degree of isolation of the island from the mainland. Differences in species richness and composition among islands can be attributed to the biotic province to which an island is adjacent and island area. Differences in species richness among island complexes can be attributed to island complex length. Regression analysis demonstrates a significant correlation between species richness and island area, and a highly correlated relationship between richness and island complex length. Two similarity indices indicate that the mammalian fauna of islands within each complex is more similar than the fauna between complexes. Two nested subset analyses reveal the islands contain a nested distribution of mainland species. It appears that the dearth of mammals on the islands has not resulted from a lack of colonization events, but rather the inability of mammals to survive in the harsher island environments.