From May through July 2001, and June through August 2002 we surveyed 232 bridges in 9 southern Illinois counties for the presence of roosting bats. Fifteen bridges (6.5%) had bats roosting at the time they were surveyed. We encountered big brown bats (Eptesicus fuscus) most frequently. Eastern pipestrelles (Pipestrellus subflavus), little brown bats (Myotis lucifugus), and northern long-eared bats (M. septentrionalis) also were found roosting under bridges. The number of bats per bridge ranged from 1 to >100. Bats occurred in four of the five types of bridge designs surveyed. Of the 15 bridges with bats, 11 were rechecked at a later date to determine continuity of use. Seven of the 11 (63.6%) were being used by bats when rechecked. From this, we derived an estimated usage rate of 23.6 bridges (15/0.636) during the study, or about 10% of the 232 bridges surveyed. We could not determine relationships between bat presence and habitat features around bridges.
Until recently, eastern woodrats (Neotoma floridana, Ord) at Pine Hills, Union County, were believed to be the only extant population in Illinois. During 1994, additional populations in adjacent Jackson County were discovered at Fountain Bluff, Horseshoe Bluff, and Little Grand Canyon. Genetic variation among Illinois woodrat populations was estimated based on microsatellite DNA at 6 loci. The four populations were separated by 2–14 km, yet all exhibited significant genetic differentiation. Fountain Bluff was the most geographically isolated population and had the lowest genetic heterozygosity. A sample of individuals from a more contiguous population in Missouri exhibited the highest heterozygosity. Populations were monitored by mark-recapture live- trapping for 39 months at Pine Hills and 19 months at Fountain Bluff. Although the Fountain Bluff population was smaller than the Pine Hills population, seasonal demographics and reproductive output were similar. Natural dispersal from all 4 populations was limited by fragmented ahabitat, natural barriers, and anthropogenic barriers. Reintroductions of woodrats may be necessary for the species to repopulate formerly occupied sites throughout southern Illinois.
Abstract Background Manduca sexta, Heliothis virescens , and Heliconius erato represent three widely-used insect model species for genomic and fundamental studies in Lepidoptera. Large-insert BAC libraries of these insects are critical resources for many molecular studies, including physical mapping and genome sequencing, but not available to date. Results We report the construction and characterization of six large-insert BAC libraries for the three species and sampling sequence analysis of the genomes. The six BAC libraries were constructed with two restriction enzymes, two libraries for each species, and each has an average clone insert size ranging from 152–175 kb. We estimated that the genome coverage of each library ranged from 6–9 ×, with the two combined libraries of each species being equivalent to 13.0–16.3 × haploid genomes. The genome coverage, quality and utility of the libraries were further confirmed by library screening using 6~8 putative single-copy probes. To provide a first glimpse into these genomes, we sequenced and analyzed the BAC ends of ~200 clones randomly selected from the libraries of each species. The data revealed that the genomes are AT-rich, contain relatively small fractions of repeat elements with a majority belonging to the category of low complexity repeats, and are more abundant in retro-elements than DNA transposons. Among the species, the H. erato genome is somewhat more abundant in repeat elements and simple repeats than those of M. sexta and H. virescens . The BLAST analysis of the BAC end sequences suggested that the evolution of the three genomes is widely varied, with the genome of H. virescens being the most conserved as a typical lepidopteran, whereas both genomes of H. erato and M. sexta appear to have evolved significantly, resulting in a higher level of species- or evolutionary lineage-specific sequences. Conclusion The high-quality and large-insert BAC libraries of the insects, together with the identified BACs containing genes of interest, provide valuable information, resources and tools for comprehensive understanding and studies of the insect genomes and for addressing many fundamental questions in Lepidoptera. The sample of the genomic sequences provides the first insight into the constitution and evolution of the insect genomes.
