Phylogenetic Origins and Age-Based Proportions of Malacho (Elops smithi) Relative to Ladyfish (Elops saurus): Species on the Move in the Western Gulf of Mexico

Two species of ladyfish occur in the Gulf of Mexico (GOM), Elops saurus and Elops smithi, that are morphologically indistinguishable except for vertebral counts but can also be identified by mitochondrial DNA haplotypes. Here we expand on previous work, most of which has occurred in Florida, and examine the demography, phylogenetics, geographic distribution, and age—structure of ladyfishes in Texas estuaries. Fishery—independent gill net data demonstrated that ladyfishes increase in abundance from north to south along the Texas coast. The abundance of ladyfishes also increased in Texas waters from 1982–2021, which coincides with recent trends of warmer winters. Genetic data confirmed that both E. saurus and E. smithi occur in Texas waters; however, E. smithi was far less common. Contrary to previous research, we observed higher levels of genetic diversity in E. saurus due to larger sample size and thorough sampling of the western portion of its geographic range. Phylogenetic analysis supported the existence of E. saurus as a distinct species but indicated that E. smithi may be paraphyletic with other species of Elops. Otolith analysis showed that the ages of E. saurus and E. smithi ranged from 0–3 years. The lack of individuals \u3e age—3 suggests that ladyfishes migrate to the offshore GOM at age 3 and do not return to coastal areas. This study enhances knowledge of the biology of ladyfishes in inshore waters of the northwestern GOM. Future management would benefit from expanding this research to the entire geographic range of the genus Elops

Phylogeography of Scaled Quail

Scaled quail (Callipepla squamata) are distributed over much of the Chihuahuan Desert in the United States and south into central Mexico. Four subspecies have been described based on slight variations in coloration and body size, but the distinctiveness of the subspecies is unknown. We conducted a range-wide phylogeographic analysis of scaled quail based on the mitochondrial control region (D-loop). Our objectives were to: (1) ascertain the overall genetic diversity, (2) examine the phylogeographic structure of the scaled quail, and (3) examine the genetic distinctiveness of its 4 subspecies. We obtained D-loop sequences from 190 hunter-harvested wings and 38 museum specimens. Haplotype diversity (Hd 1⁄4 0.386) and nucleotide diversity (p 1⁄4 0.002) were relatively low. We found 16 D- loop haplotypes, 5 of which were shared by 2 or more subspecies. Haplotype A (carried by 178 individuals) was most widespread and occurred in nearly every population. Analysis of molecular variance revealed that most of the genetic variation in scaled quail occurred within populations rather than among subspecies. The low levels of genetic diversity probably reflect a historically restricted distribution within the Chihuahuan Desert, and wide geographic distribution of some haplotypes implies expansion from a single refugium. Our data indicate the scaled quail subspecies probably do not represent historically independent units. Phenotypic-based subspecies should not be used as proxies for management units if preserving genetic diversity and evolutionary potential is a goal of management, unless molecular data demonstrate the subspecies represent genetically distinct entities. Our data support viewing the entire species as a single management unit

Phylogeography of Bobwhites

Bobwhites (Colinus spp.) are a widely distributed genus of New World quails. Four species are recognized with a geographic range spanning the eastern United States to northern South America. The northern bobwhite (C. virginianus) historically occurred throughout much of the eastern United States and eastern Mexico with disjunct populations in Sonora and Cuba. The Yucata ́n bobwhite (C. nigrogularis) occurs in allopatric populations in Nicaragua and Honduras, and on the Yucata ́n Peninsula. The spot-bellied and crested bobwhites (C. leucopogon and C. cristatus) constitute a species complex with the spot-bellied bobwhite distributed from Guatemala to Costa Rica, and the crested bobwhite from Panama to northern Brazil. The 4 species exhibit substantial intraspecific variation, and up to 56 subspecies are recognized among Colinus largely on the basis of geographic distribution and male plumage coloration. However, relationships within and among species have not been studied in detail. We sampled museum study skins and obtained DNA sequences from mitochondrial control region and ND2 genes. We used concatenated sequences of control region and ND2 to investigate relationships among the bobwhite species, and the control region to assess the geographic distribution of genetic variation within each species. Maximum likelihood analysis of bobwhite phylogeny revealed Colinus is composed of two deeply divergent lineages, one clade of northern and Yucata ́n bobwhites and another of spot-bellied and crested bobwhites. The Yucata ́n bobwhite was genetically distinct from the northern bobwhite. The Yucata ́n bobwhite was composed of 2 distinct subclades, one confined to the Yucata ́n Peninsula and another occurring in Nicaragua. The genetic data showed the spot-bellied bobwhite is closely related to the crested bobwhite, but did not reveal clear support for 2 distinct species. The crested bobwhite was composed of 3 distinct lineages: a western clade that occurs in Panama and west of the northern Andes in Venezuela and Colombia, an eastern clade concentrated in Venezuela (east of the Andes), and a clade restricted to northern Brazil. We found 58 control region haplotypes, of which 29 were shared among 2 northern bobwhite subspecies and 5 haplotypes were especially geographically widespread. We found 16 haplotypes in the Yucata ́n bobwhite with 4 restricted to the Yucata ́n Peninsula and shared among the 3 subspecies found there, and 3 other haplotypes restricted to the Nicaraguan subspecies. The spot-bellied bobwhite did not share haplotypes with any of the 3 crested bobwhite subclades. We found little phylogeographic structure within the spot-bellied bobwhite, and 2 of the 5 haplotypes occurred across much of the species’ range and were shared among the 6 subspecies. The crested bobwhite exhibited strong phylogeographic structure and a lack of shared haplotypes among subspecies. The 20 haplotypes of the crested bobwhite were distributed unevenly among its 3 clades: 2 haplotypes in the Brazilian clade, 6 in the eastern clade, and 12 in the western clade. The weak phylogeographic structure and geographically widespread haplotypes of the northern bobwhite suggests large effective population size and gene flow among subspecies. The deep phylogeographic breaks within the Yucata ́n bobwhite and the spot-bellied bobwhite-crested bobwhite complex may be due to changes in the availability of suitable habitat and geological events during the Pleistocene. The lack of geographically distinct groups within the northern bobwhite implies that many subspecies may not provide good management units. Our data support the continued recognition of the Yucata ́n bobwhite as a distinct species. The 2 intraspecific groups identified in the Yucata ́n and the 4 groups within the spot- bellied/crested bobwhite complex may each represent discrete management units. Further assessment of the phylogenetic relationships and the phylogeography of the bobwhite species is warranted to clarify the phylogeny of Colinus

Application of Metapopulation Theory to Northern Bobwhite Conservation

Northern bobwhite (Colinus virginianus) populations have declined throughout the majority of the species’ range, and have experienced the largest declines in fragmented habitats, suggesting landscape scale processes may be responsible for this decline. We used the results from a stochastic population dynamics model of South Texas bobwhites as conceptual justification for use of metapopulation theory in bobwhite management. Annual quasi-extinction probabilities for isolated bobwhite populations were 0.003 (95% CI: 0.001 0.006), 0.105 (95% CI: 0.083 0.126), and 0.773 (95% CI: 0.750 0.796) for simulated populations harvested at 20, 30, and 40% annually. The probability of regional persistence at 30% harvest increased to ~ 100% in scenarios where we modeled 5 occupied hypothetical 800-ha habitat patches; however, at 40% harvest rates, probability of regional metapopulation persistence did not reach 95% until 12 habitat patches were occupied. This suggests bobwhites probably require somewhere from 800 to 9,600 ha of available habitat space to maintain 95% probability of regional metapopulation persistence as harvest varies from 0 to 40% annually. Our results have strong implications for bobwhite harvest management given the high probability of quasi-extinction of isolated populations at rates of harvest 25%. Multiple patches of habitat (where individual patch size is 800 ha) must be available to ensure bobwhite metapopulation persistence

Genetic Structure and Diversity in South Texas Bobwhites: Implications for Conservation

The northern bobwhite (Colinus virginianus) has experienced range-wide declines in population size and reductions in geographic range during the last century. Declines in northern bobwhite population size and geographic distribution continue to occur despite vigorous conservation and research efforts directed at sustaining and enhancing populations. Viable populations of northern bobwhite have persisted only in areas with large expanses of relatively contiguous habitat, such as southern Texas, parts of Oklahoma, Kansas, and areas in southern Georgia and northern Florida. The decline of northern bobwhite populations is often associated with changes in land- use practices, including proliferation of intensive agriculture and fire suppression, which have altered, removed, or fragmented northern bobwhite habitat. Typically, the effects of changes in land use on northern bobwhites are regional in scale, given the large geographic extent which current agricultural land-use practices, such as farming and timber production, occur. It is clear that precipitation and land use affect regional population trends, but consideration of northern bobwhite population dynamics has remained confined to the local scale. Thus, the specific manner in which land-use changes have affected populations of northern bobwhites is unknown. We investigated the genetics and population structure of northern bobwhites at the landscape scale to learn if bobwhites function as metapopulations. Dispersal and exchange in a metapopulation system are critical to the long-term maintenance of populations; if interrupted, the entire network of populations might collapse. We sampled hunter-harvested northern bobwhites during 2004 to 2007 from 24 sites in South Texas, a region containing large areas of contiguous habitat where populations of northern bobwhites have been relatively stable. We extracted DNA and used bi-parentally and maternally inherited genetic markers to compare genetic structure and diversity among populations. We genotyped 567 individuals at 7 DNA microsatellite loci and sequenced 353 bp of the mtDNA control region for 190 individuals. Genetic diversity was high for microsatellite loci and mtDNA haplotypes (HO 1⁄4 0.58; H 1⁄4 0.88, respectively), and did not differ among populations. We observed little population structure across the geographic region (microsatellite FST 1⁄4 0.01; mtDNA theta 1⁄4 0.037), and Fisher exact tests of population differentiation were not statistically significant. Spatial autocorrelation analysis of the microsatellite data set revealed a positive correlation between Moran’s I and geographic distance out to .50 km. Our genetic data are surprising for an avian species that is considered relatively sedentary and a short-distance disperser. South Texas populations of northern bobwhites had high levels of genetic variation and were genetically similar across a broad region. Population genetics theory predicts that genetic diversity and similarity among local populations in a metapopulation are influenced by the rate of dispersal (gene flow). Life history theory predicts species with high turnover rates, such as northern bobwhite, should be good dispersers. The region-wide genetic similarity among populations of northern bobwhites implies dispersal may be more important in the population dynamics of the species than previous studies have indicated. We hypothesize that disruption of dispersal by habitat fragmentation may explain the overall decline of northern bobwhite populations in some regions. This may explain why patches of suitable habitat in fragmented landscapes go unoccupied by northern bobwhites. Our results lend additional support to recent calls for regional-scale management of this declining species

Molecular genetics of the northern bobwhite, scaled quail, and Gambel's quail

The New World quails (Odontophoridae) are a family of galliforms that includes nine extant genera and 32 species. Little is known about the biogeography of the family or about the evolutionary relationships among the New World quail genera and species. This study used mitochondrial DNA to examine 1) the phylogenetic relationships among the New World quail genera, and the phylogeography of the northern (Colinus virginianus), Yucatán (Colinus nigrogularis), and crested (Colinus cristatus) bobwhites, and the scaled quail (Callipepla squamata) and Gambel’s quail (Callipepla gambelii). Phylogenetic analyses revealed that Odontophoridae was composed of three distinct lineages that diverged from one another during the Miocene: a Dendrortyx group composed of the genera Colinus, Callipepla, Oreortyx, Philortyx, and Dendrortyx; an Odontophorus group of Odontophorus, Dactylortyx, and Cyrtonyx, and the tawny–faced quail (Rhynchortyx cinctus). The northern and Yucatán bobwhites are more closely related to one another than to the crested bobwhite. The deep divergence between the two complexes indicates that the phylogenetic split occurred prior to the Pleistocene (2.5 million years ago). The northern–Yucatán bobwhite complex exhibited little phylogeographic structure and showed some evidence of range or demographic expansion during the Pleistocene, whereas the crested bobwhite was composed of four geographically and genetically distinct clades in Central and South America. The scaled quail displayed low genetic diversity and little structure across its limited range, possibly as a consequence of recent demographic growth and expansion after passing through a severe bottleneck. The Gambel’s quail is composed of two genetically distinct, but geographically overlapping clades. Both clades exhibited evidence of past demographic growth. Overall, little concordance between subspecies taxonomy and genetic data was observed in any of the species studied, except in the crested bobwhite

NOTEWORTHY WINTER PREY OF SHORT-EARED OWLS IN SOUTHERN TEXAS: A CASE STUDY

The winter range of North American short-eared owls (Asio flammeus) encompasses much of the United States, including southern Texas, where it is a common winter resident (Oberholser 1974, Rappole and Blacklock 1985). Winter food habits of short-eared owls are relatively weJl documented, but the majority of investigations have been conducted in eastern Canada and northeastern U.S. (Clark 1975, Holt 1993); midwestern U.S. (Colvin and Spaulding 1983); and British Columbia and Pacific northwestern U.S. (Bogiatto et al. 2001). The short-eared owl has a narrow trophic niche, generally preying on small mammals, with voles (Microtus spp.) and deer mice (Peromyscus maniculatus) usually reported as the most prevalent prey in North America (Holt and Leasure 1993). Only one study of short-eared owl food habits in Texas (Hogan et al. 1996) can be considered representative. Our objectives were to identify and enumerate mammalian prey in the winter diet of the short-eared owl in an area in southern Texas, and report two previously undocumented prey items in the diet of the short-eared owl

Molecular Ecology of New World Quails: Messages for Managers

Recent genetic studies of New World quails (Odontophoridae) have yielded important, and sometimes, counter-intuitive insights regarding their evolutionary relationships, genetic diversity, population structure, and biogeographic history. Many of these new insights have important implications for managers. New World quails are a distinct family within galliforms, most closely related to guineafowl (Numididae) and pheasants (Phasianidae) rather than guans and chachalacas (Cracidae). The African stone partridges (Ptilopachus spp.) are the closest living relatives of the New World quails. The combination of phylogeographic studies with ecological niche modeling has revealed the biogeographic history of several species of New World quails, including Pleistocene refugia and post-Pleistocene range expansions, contractions, or stasis. Divergence times within and among genera often date to climactic or geologic events 1–5 million years ago. The many subspecies of quail described over the past 100 years were based on minor differences in plumage and probably represent artificial sectioning of latitudinal clines rather than historically isolated and evolutionary distinct units. Subspecies are often used as proxies for management units, but conservation efforts directed at the northern bobwhite (Colinus virginianus) and scaled (Callipepla squamata), California (C. californica), and Gambel’s (C. gambelii) quails may not benefit from such an approach. Ecological regions, rather than subspecies, are probably more appropriate as a ‘‘management unit.’’ The overall lack of population structure, evidence of long-distance dispersal and historical gene flow among populations, and the cyclical population dynamics of these species suggest that there is a biological basis for conserving large blocks of interconnected habitat. Focal areas of restoration projects should be spatially extensive and interconnected to facilitate dispersal and recolonization. With a better understanding of how quail populations responded to past climactic conditions, we are better able to predict how quail may respond to future conditions and ensure the conservation of these iconic New World birds

NOTEWORTHY WINTER PREY OF SHORT-EARED OWLS IN SOUTHERN TEXAS: A CASE STUDY

The winter range of North American short-eared owls (Asio flammeus) encompasses much of the United States, including southern Texas, where it is a common winter resident (Oberholser 1974, Rappole and Blacklock 1985). Winter food habits of short-eared owls are relatively weJl documented, but the majority of investigations have been conducted in eastern Canada and northeastern U.S. (Clark 1975, Holt 1993); midwestern U.S. (Colvin and Spaulding 1983); and British Columbia and Pacific northwestern U.S. (Bogiatto et al. 2001). The short-eared owl has a narrow trophic niche, generally preying on small mammals, with voles (Microtus spp.) and deer mice (Peromyscus maniculatus) usually reported as the most prevalent prey in North America (Holt and Leasure 1993). Only one study of short-eared owl food habits in Texas (Hogan et al. 1996) can be considered representative. Our objectives were to identify and enumerate mammalian prey in the winter diet of the short-eared owl in an area in southern Texas, and report two previously undocumented prey items in the diet of the short-eared owl