Sub-lethal Effects of Chlorpyrifos on Big Brown Bats (Eptesicus fuscus).

We determined dose-response curves for sublethal effects of the organophosphorus (OP) insecticide, chlorpyrifos, on bats. Big brown bats (Eptesicus fuscus, n = 64) were given a single dose of chlorpyrifos (nominal concentrations) of 0, 5, 10, 15, 20, 25, 30, or 60 µg/g body weight and examined at 12 or 24 h after dosing. A second experiment dosed 32 bats with 0 or 60 µg/g body weight and examined 1, 3, 7, or 14 days after dosing. Skin temperature and behavioral changes were recorded, and brain and plasma cholinesterase (ChE) activity were measured. The benchmark dose (BMD10) of chlorpyrifos that altered brain and plasma ChE activity at 24 h was 3.7 and 10.1 µg/g, respectively. The 95 % lower confidence limit for the BMD10 (i.e., BMDL10) was 1.6 and 7.7 µg/g. The best of five models (as determined by AIC) for impaired flight, impaired movement, or presence of tremors provided a BMD10 of 6.2, 12.9, and 7.8 µg/g body weight of chlorpyrifos, respectively. BMDL10 for impaired flight, impaired movement, or presence of tremors was 3.5, 6.6, and 5.3 µg/g body weight, respectively. In the wild, impaired ability to fly or crawl could be life-threatening. Brain and plasma ChE activity remained low for 3 days after dosing. Gradual recovery of enzyme activity was observed by 7 days in survivors. Brain and plasma ChE activity were still significantly lower than that of the control group at 14 days after dosing.

Physiological and behavioral adaptations in bats living at high latitudes.

Widespread animals at the extremes of the species' distribution experience ecological constraints different than individuals in the core of the distribution. For example, small endotherms at very high latitudes face short summers with cool temperatures and a lack of true darkness. In particular, insectivorous bats at high latitudes may experience constraints because of their unique life history traits, and may have different energy requirements than bats at lower latitudes. To evaluate the extent of these differences, we estimated an energy budget and refueling rates for reproductively active female little brown bats (Myotis lucifugus) roosting in buildings in eastern Alaska (~63°N). Physiological parameters (torpor use and metabolic rates) and daily energy expenditures (25.7±5.3kJd(-1)) were similar to, or slightly lower than, conspecifics at lower latitudes. Northern little brown bats foraged for less time than southerly conspecifics, but measurements of plasma ß-hydroxybutyrate concentrations suggest that northern bats refuel at a rate considerably higher than those to the south. It appears that high refueling rates (and therefore foraging intensity) involve a dietary shift to orb-weaver spiders, which are abundant and likely offer higher energetic benefit than the small, flying insects consumed by individuals in other parts of the distribution. Environmental factors may limit species' distributions, but our results provide an example of a population at the limit of their geographic range that has compensated for environmental challenges by adopting unique behavioral strategies while the underlying physiology (including daily energy expenditure) remains similar to populations at the core of the species' range.

Description of nymphal stages of Periglischrus cubanus (Acari, Spinturnicidae), parasites from Erophylla sezekorni bombifrons (Chiroptera) from Puerto Rico with observations on the nymphal stages and host-parasite relationships within the genus Periglischrus.

The adults of Periglischrus cubanus were described by Dusbábek (1968). In this study, we describe the nymphal stages of this species and make some general observations on nymphal stages in the genus Periglischrus.

The two suborders of chiropterans have the canonical heavy-chain immunoglobulin (Ig) gene repertoire of eutherian mammals.

Bats comprise 20% of all mammals, yet little is known about their immune system and virtually nothing about their immunoglobulin genes. We show that four different bat species transcribe genes encoding IgM, IgE, IgA and IgG subclasses, the latter which have diversified after speciation; the canonical pattern for eutherian mammals. IgD transcripts were only recovered from insectivorous bats and were comprised of CH1, CH3 and two hinge exons; the second hinge exon was fused to CH3. IgA in all species resembles human IgA2 with the putative cysteine forming the bridge to the light chain found at position 77. Sequence comparisons yielded no evidence for a diphyletic origin of the suborders. Bats show no close similarity to another mammalian order; the strongest association was with carnivores. Data reveal that CH diversity and VDJ and CDR3 organization are similar to other eutherian mammals, although the expressed VH3 family repertoire was unusually diverse.

Ectoparasitic assemblages on mormoopid bats (Chiroptera: Mormoopidae) from Puerto Rico.

We performed the first quantitative survey of ectoparasitic assemblages on three species of mormoopid bats living on the Caribbean island of Puerto Rico: Mormoops blainvillii Leach (n=40), Pteronotus quadridens Gundlach (n=40), and Pteronotus parnellii Gray (n=9). We examined bats for parasites primarily on 8-10 May and 24-27 July 2002 at Culebrones Cave, near Arecibo, Puerto Rico. Only 50% of M. blainvillii were infested with at least one parasite, compared with 85-100% for Pteronotus; infested individuals of both species of Pteronotus also harbored a greater number of parasites than did M. blainvillii. The assemblage on M. blainvillii was less diverse than in the other species and more dominated by a single group of parasites, the chiggers. Chirodiscid ear mites and spinturnicid wing mites were common on both species of Pteronotus but absent from M. blainvillii. All P. parnellii harbored streblid flies, but none typically was found on P. quadridens or M. blainvillii. Adult female M. blainvillii and P. quadridens sheltered a greater number of ectoparasites than did males. All host-parasite combinations represented new associations for Puerto Rico.

Description of Cameronieta torrei dusbabeki (Acari: Mesostigmata: Spinturnicidae), new subspecies with nymphs, parasitizing Pteronotus quadridens fuliginosus (Chiroptera: Mormoopidae) from Puerto Rico.

We describe a new subspecies, Cameronieta torrei dusbabeki, a parasite of Pteronotus quadridens fuliginosus (Gray 1843) from Puerto Rico.

Use of artificial roost structures by bats at the Indianapolis International Airport.

From 1992-1996, 3204 artificial roosts of 9 types were placed in woodlots near Indianapolis International Airport in an effort to provide habitat for the federally-endangered Indiana myotis (Myotis sodalis) and to determine the feasibility of using these structures to manage bats in a rapidly developing suburban area. We surveyed these structures at least annually during 1992-1999 and found only northern myotis (Myotis septentrionalis) regularly using the structures. Four other species were occasionally found using structures including big brown bats (Eptesicus fuscus, n=14 individuals), little brown myotis (Myotis lucifugus, n=2), Indiana myotis (Myotis sodalis, n=2), and one silver-haired bat (Lasionycteris noctivagans). Single, triple, and Missouri-style batboxes were almost always used, rather than the six other types of experimental roosts that had been in place. However, after 10 years in place, it appears that Indiana bats are acclimated to boxes, as 6 of them were being used rather regularly by Indiana myotis. Bat boxes can provide roosting habitat for some species under conditions where few suitable roosts exist, but assuring an abundance of natural habitats is usually more desirable for conservation of tree-roosting bats.

Habitat Relationships of Four Species of Mice in Vigo County, Indiana.

Information on the interrelationships of Mus musculus, Peromyscus leucopus, Peromyscus maniculatus bairid, and Microtus ochrogaster was accumulated during the study of 429 25x25 m randomly selected plots in Vigo County, Indiana. P. leucopus apparently inhibited Mus musculus when the two occurred together. This may be the factor that limits Mus to cultivated areas, since P. leucopus does not flourish there. Mus and P. m. bairdi reacted in different ways in different habitates. In grassy and weedy fields, and in winter wheat they occurred together about as often as would be expected by chance, but both species were more abundant when together than when alone. In soybeans, cultivated fields, corn, and corn stubble the two occurred together less often than would be expected by chance, and both were less abundant than when alone. Both ecological separation and competitive exclusion appeared to be acting. In wheat stubble P. m bairid occurred at higher rates and Mus at lower rates when the two were together, probably because Mus had to invade and compete with the already established P. m. bairdi. Mus and M. ochrogaster, and P. leucopus and M. ochrogaster occurred together in weedy and grassy fields about as often as expected, and the species concerned were unaffected or were more abundant when together than when alone, apparently indicating similar habitat requirements but different niches. P. m. bairdi and P. leucapus occurred together much less often than would be expected by chance, and average numbers per plot were lower than together, than when either occurred alone. Apparently both ecological and competitive exclusion were occurring. P. m. bairdi and M. ochrogaster were ecologically separated, with M. ochrogaster in better cover, and P. m. bairdi in poorer cover. When together they did not affect each other appreciably.