Human-made Habitats Research Articles

Molecular phylogenetics suggest a North American link between the anthropogenic dry rot fungus Serpula lacrymans and its wild relative S. himantioides

The dry rot fungus Serpula lacrymans causes damages in wooden buildings and constructions in temperate regions worldwide. In this study, the global phylogeography of S. lacrymans and its wild relative S. himantioides has been investigated to clarify genealogical relationships and determine the origin and spread of the building strains. Internal transcribed spacer (ITS) nrDNA and parts of the beta-tubulin (tub) and the translation elongation factor (efa) 1a genes were sequenced, and phylogenetic relationships inferred. Some analyses suggest that S. lacrymans may have originated from an ancient S. himantioides lineage, but most results support that S. lacrymans and S. himantioides are monophyletic sister species. Phylogenetic analysis of the ITS data revealed two subgroups within S. lacrymans corresponding to two earlier described varieties; one group occurring frequently in houses worldwide ('Domesticus'), and one group represented by individuals from forests in Northern California ('Shastensis'). A few collections from nature were included in the Domesticus group as well, among other specimens from two newly discovered localities in Far East Russia and Siberia. In the Domesticus group little sequence variation occurs, suggesting a recent worldwide dispersal, possibly linked to human activity. Phylogenetic analyses indicate that the Domesticus group may have originated from an ancient lineage related closely to the Shastensis group. A remarkable shift in morphology and habitat preferences has occurred during the evolution of the Domesticus lineage, linked to the transition from nature to human-made habitats.

Benthic invertebrates in adjacent created and natural wetlands in northeastern Ohio, USA

The benthic invertebrates of three adjacent wetlands in northeastern Ohio, USA were sampled with a benthic corer during May–August 2001. The three wetlands consisted of a deep created wetland that overflowed into a shallow created wetland and a pre-existing natural wetland. The created wetlands were four years old and seeded with cattails. Forty-two invertebrate taxa were collected from all wetlands combined, and 11 taxa were abundant (represented >1% of total). Taxa richness, evenness, and community similarity were comparable among the three wetlands. Seed shrimp (Ostracoda), midges (Diptera: Chironomidae), copepods (Copepoda), fingernail clams (Bivalvia: Sphaeriidae), and water fleas (Cladocera) were the five most abundant taxa (38%, 13%, 11%, 9%, and 8%, respectively). Clams were significantly more abundant in the natural wetland, whereas no significant difference in density of other invertebrates was detected among wetlands. Laboratory inundations of soil taken from the rapidly drying basins of the natural and shallow created wetlands produced 10 taxa that survived the dry periods with desiccation-resistant stages and were dominated by microcrustaceans, Aedes mosquitoes (Diptera: Culicidae), clams, and annelid worms. Our data indicate that the created wetlands developed benthic invertebrate communities that were similar to the adjacent natural wetlands in a short period of time (four years), but clams were slow to colonize the human-made habitats.

Population sizes and the conservation status of endemic and restricted-range bird species on Karakelang, Talaud Islands, Indonesia

Karakelang, largest of the Talaud Islands, Indonesia, was visited in 1999 with the aim of producing population estimates of globally threatened and Restricted-range bird species. Density estimates were calculated from primary forest and secondary habitats using the variable circular plot method. Eight of the nine restricted-range or threatened species resident on Karakelang were recorded and density estimates calculated for five of these. Two species of rail are endemic to Karakelang, Talaud Bush-hen Amaurornis magnirostris and Talaud Rail Gymnocrex talaudensis. The bush-hen was encountered in secondary habitat but occurred at higher densities in primary forest and the estimated population was 2,350–9,560 birds. The less vocal, cryptic G. talaudensis was noted just twice, in primary forest close to rivers. Both have small populations, are threatened by habitat degradation, hunting, and possibly predation by introduced rats and should be classified as threatened. Population densities of the Endangered, endemic Red-and-blue Lory Eos histrio had remained stable since the last survey in 1997. They occurred at higher densities in primary forest, but were also common in human-made habitats. The estimated population was 8,230–21,400 birds, threatened by habitat loss and trapping for the wild bird trade. Although more commonly encountered in forest, the Near Threatened Blue-naped Parrot Tanygnathus lucionensis was found at higher densities in secondary habitats, and the population was estimated at 8,130–20,700 birds. The Restricted-range Blue-tailed Imperial Pigeon D. concinna was very common on Karakelang (14,500–27,700 birds), whilst the Vulnerable Grey Imperial Pigeon D. pickeringii was recorded rarely; both species were more frequently recorded in primary forest. The endemic Talaud Kingfisher Halcyon enigma occurred at low densities (5,290–8,690 birds), in primary forest and adjacent disturbed areas. It is heavily dependent on primary forest and threatened by habitat loss, and should be classified as Vulnerable. Approximately 350 km2 of primary forest on Karakelang is protected, 250 km2 as a wildlife reserve. However, at present, management is absent and forest is threatened by agricultural encroachment, illegal logging, and fire. Given that all endemic and threatened species were encountered more frequently or occurred at higher densities in primary forests, future conservation efforts should target these protected areas. Management of reserves should involve local stakeholders from government and representatives of island communities. Wildlife trade is a major threat to Eos histrio and strict enforcement of the species' protected status should include monitoring of roost sites, patrols of harbours and markets in Talaud, Sulawesi and the Philippines, and the control of Philippine fishing boats involved in the wild bird trade. Further species-specific research and monitoring is also required.

Dung and carrion beetles in tropical rain forest fragments and agricultural habitats at Los Tuxtlas, Mexico

At Los Tuxtlas, Mexico, presence of dung and carrion beetles, were sampled using baited pitfall traps, at the following habitats: isolated forest fragments, forest edges, plantations (coffee, cacao, mixed, citrus and allspice), live fences and pastures. A total of 14,269 beetles representing 36 species were captured. Onthophagus batesi, Canthon femoralis, Canthidium centrale, Copris laeviceps, O. rhinolophus and Deltochilium pseudoparile accounted for 75% of the captures in the overall sample from 79 sites. Across forest fragments capture rates of species and individuals were associated positively to area and negatively to isolating distance. Rarefaction analysis showed that forest fragments were the most species-rich habitats followed by the mixed and cacao plantations, the forest edge, live fences and coffee, citrus and allspice plantations. Pastures were the least species-rich habitat. Horizontal and vertical diversity of the vegetation at the habitats studied influenced the species richness of dung and carrion beetles and the number of species in common between forest fragments and human-made habitats. A significant relationship existed between the number of non-flying mammals recorded at the study sites and the richness of species and individuals of dung beetles at the habitats investigated. The relevance of this information is discussed in the light of the ecological flexibility of dung and carrion beetle species and of possible conservation scenarios involving landscapes in which isolation of forest fragments is reduced by the presence in open areas of human-made vegetation such as plantations of cacao, coffee, cacao and coffee and live fences.

Spatial and temporal distribution of resting female mosquitoes (Diptera: Culicidae) in the coastal plain of North Carolina.

The spatial and temporal distribution of 28 species of female mosquitoes resting in natural (swamp, woods, and swamp-woods ecotone) and human-made (beneath bridges) habitats in blackwater stream-associated ecosystems in Duplin County, N.C., was determined by sampling with a D-Vac vacuum aspirator during 1984 and 1985. Two types of resting distributions were evident. In type one, species including Aedes atlanticus Dyar & Knab, Ae. canadensis (Theobald), Ae. triseriatus (Say), and Psorophora ferox (von Humboldt) rested predominantly on vegetation and were not collected beneath bridges. In type two, species including Anopheles punctipennis (Say), Culex erraticus (Dyar & Knab), Cx. peccator Dyar & Knab, Cx. pipiens L. and Cx. quinquefasciatus Say and their hybrids, Cx. restuans Theobald, Cx. territans Walker, and Uranotaenia sapphirina (Osten Sacken) rested on vegetation, in natural shelters in swamp habitats, and beneath bridges. Differences in the proportion of gravid mosquitoes among habitats were evident for Ae. canadensis, An. punctipennis, Cx. pipiens and Cx. quinquefasciatus and their hybrids, Cx. restuans, Cx. territans, Ps. ferox, and Ur. sapphirina, indicating that gonotrophic condition may influence resting site selection.