Sampling Blood from Big Brown Bats (Eptesicus fuscus) in the Field with and without Anesthesia: Impacts on Survival

Abstract

ABSTRACT:Blood was collected from wild big brown bats (Eptesicus fuscus) with and without anesthesia in Fort Collins, Colorado in 2004 to assess the impacts of these procedures on shortterm survival and 1-yr return rates. Short-term survival and 1-yr return rates after release were passively monitored using PIT tag detection hoops placed at selected buildings. Comparison of 14-day maximum likelihood survival estimates from bats not bled (142 adult females, 62 volant juveniles), and bats sampled for blood with anesthesia (96 adult females, 23 volant juveniles) and without anesthesia (112 adult females, 22 volant juveniles) indicated no adverse effects of either treatment (juveniles: x 2 553.38, df541, P50.09; adults: x 2 539.09, df544, P50.68). Return rates of bats one year after sampling were similar among adult female controls (75.4%, n5142, 95% CI567.4-82.2%), females sampled for blood with anesthesia (83.0%, n5112, 95% CI574.8-89.5%), and females sampled without anesthesia (87.5%, n596, 95% CI579.2-93.4%). Lack of an effect was also noted in 1-yr return rates of juvenile females. These data suggest that the use of anesthesia during sampling of blood has no advantages in terms of enhancement of survival in big brown bats.

Variability in Seroprevalence of Rabies Virus Neutralizing Antibodies and Associated Factors in a Colorado Population of Big Brown Bats (Eptesicus fuscus)

“…Blood was obtained through interfemoral vessels as described by Wimsatt et al [44], except that anesthesia was discontinued because there was no difference in survival between anesthetized, unanaesthetized, and unbled bats [49]. Oropharyngeal secretions of bats were sampled at the laboratory using cotton-tipped swabs inserted into 0.5 ml of BA-1 medium (Minimal Essential Medium with Hanks’ balanced salt solution containing 0.05 M Tris buffer at pH 7.6, 1% Bovine Serum Albumin, 0.35 g/L of Sodium bicarbonate, 50 mg/L Gentamicin, and 2.5 mg/L Amphotericin B).…”

“…We based the survival estimates on encounters of tagged bats with PIT tag readers in fixed positions at entrances of five roosts monitored from 2001–2005 [46]. Survival was calculated using Program Mark with differences between the seropositive and negative groups determined by χ 2 goodness-of-fit tests in Program Release Test 1 [49], [65]. A more detailed multi-model analysis of factors influencing adult survival that does not include serological status was previously published [27].…”

Prevalence of Neutralizing Antibodies to Rabies Virus in Serum of Seven Species of Insectivorous Bats From Colorado and New Mexico, United States

“…Sampling and handling techniques for bats were described in detail by Wimsatt et al (2005) and Ellison et al (2006). Bats captured at roosts were selected for sampling at random, whereas bats captured over water were sampled ad libitum.…”

Minimally invasive collection of adipose tissue facilitates the study of eco‐physiology in small‐bodied mammals

“…The method of inserting a needle into the subcutaneous space is similar with both techniques with the biggest difference being that PIT tag needles are generally much larger (12 gauge). Research conducted on the effects of using needles on small mammals have found no long-term injuries or decreases in survival rate associated with the insertion of PIT tags (Neubaum et al 2005;Ellison et al 2006).…”