scholarly journals Intraspecific variation in wing loading affects habitat use by little brown bats (Myotis lucifugus)

1995 ◽  
Vol 73 (1) ◽  
pp. 89-95 ◽  
Author(s):  
Matina C. Kalcounis ◽  
R. Mark Brigham

Morphological constraints have been linked to habitat partitioning by different species of animals. Interspecific differences have been explored, but less is known about the relationship between individuals of the same species. The purpose of this study was to determine if habitat use by little brown bats (Myotis lucifugus) varies with body mass of individuals. From aerodynamic theory, we predicted that bats with higher body mass will have higher wing loadings, should be less manoeuvrable, and thus tend to forage in areas where there are fewer obstacles to detect and avoid (clutter). Habitat was ranked into four zones based on the degree of clutter, and habitat use was assessed by measuring the time that males and non-reproductive, pregnant, lactating, postlactating, and artificially loaded females spent in each habitat zone. To test the assumption that a selective advantage accrues to bats foraging in clutter, we measured the availability of flying insects in cluttered and open habitats. Insect trap samples revealed a higher density of insect prey in more cluttered habitats. Body mass was positively correlated with wing loading. Overall, males were smaller than females with respect to mass and wing loading; however, these differences did not translate into differential habitat use. As predicted, there was a significant relationship between individual wing loading and habitat use, with heavier bats (greater wing loading) foraging in less cluttered areas.

2015 ◽  
Vol 6 (2) ◽  
pp. 360-370 ◽  
Author(s):  
Michael J. Lacki ◽  
Luke E. Dodd ◽  
Rickard S. Toomey ◽  
Steven C. Thomas ◽  
Zachary L. Couch ◽  
...  

Abstract The rapid colonization of the Pseudogymnoascus destructans fungus across cave systems in eastern North America and the associated bat mortalities (white-nose syndrome; WNS), necessitates studies of cave-hibernating bats that remain unaffected by, or in close proximity to, the leading edge of the fungal distribution to provide baseline predisturbance data from which to assess changes due to fungal effects. Studies of the physiological ecology of cave-hibernating bats during the spring staging and autumn swarming seasons are few, and an understanding of patterns in body condition of bats associated with entry into and emergence from hibernation is incomplete. We sampled bats at the entrance to a cave in Mammoth Cave National Park, Kentucky, during swarming and staging, prior to (2011 and 2012), concurrent with (2013), and following (2014) the arrival of the WNS fungus. We evaluated seasonal and annual changes in body mass and body condition of bats entering and leaving the cave. We captured 1,232 bats of eight species. Sex ratios of all species were male-biased. Capture success was substantially reduced in 2014, following the second winter after arrival of the WNS fungus. Significant temporal variation in body mass and body mass index was observed for little brown bats Myotis lucifugus, northern long-eared bats M. septentrionalis, and tri-colored bats Perimyotis subflavus, but not Indiana bats M. sodalis. Little brown bats and northern long-eared bats demonstrated significant increases in mean body mass index in 2014; this pattern likely reflected a relatively better body condition in bats that survived exposure to the WNS fungus. Most species demonstrated highest body mass and body mass index values in late swarming compared with other sampling periods, with tri-colored bats showing the greatest percent increase in body mass (42.5%) and body mass index (42.9%) prior to entering hibernation. These data indicate significant intraspecific variation in body condition of cave-hibernating bat species, both among years and between the seasons of autumn swarming and spring staging. We suggest this variation is likely to have implications for the relative vulnerability of species to WNS infection across the distribution of the Pseudogymnoascus fungus.


1996 ◽  
Vol 74 (7) ◽  
pp. 1204-1210 ◽  
Author(s):  
Rick A. Adams

This paper correlates shifts in habitat use and diet with morphological transitions occurring during postpartum growth and development (ontogenetic niche) in little brown bats, Myotis lucifugus. Juveniles were captured in mist nets as they foraged in different microhabitats that were defined and quantified using "clutter indices" ranging from 0 (least cluttered) to 5 (most cluttered). I analyzed fecal samples from captured individuals to assess diet. Chi-squared analyses showed that there was a significant difference in habitat use and diet among juveniles captured in early, mid, and late July. Juveniles with smaller wings foraged in the least cluttered habitats, whereas juveniles with larger wings foraged in habitats with a high degree of clutter. Juveniles with larger wings were captured in all microhabitats, whereas those with smaller wings were captured predominantly in open microhabitats. Juveniles with relatively higher aspect ratios and lower wing loadings used a greater diversity of habitats than those with lower aspect ratios and higher wing loadings. In addition, differences in diet were significant and correlated with wing size. My results suggest resource partitioning between juveniles as a function of wing size. These data have important implications regarding how relative size among juveniles may effect intraspecific structuring of populations.


Ecoscience ◽  
1998 ◽  
Vol 5 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Thomas H. Kunz ◽  
John A. Wrazen ◽  
Christopher D. Burnett

1970 ◽  
Vol 25 (1) ◽  
pp. 9-13
Author(s):  
S Jahan ◽  
TR Das ◽  
KB Biswas

Background and Aims: Cord blood leptin may reflect the leptinemic status of a newborn at birth more accurately than the leptin values of blood collected from other sites. The present study was undertaken to determine the relationship of cord serum leptin concentration at birth with neonatal and maternal anthropometric parameters. Materials and Methods: Blood was taken from the umbilical cord of the babies at delivery. Maternal anthropometric measurements were recorded at admission for delivery. Neonatal anthropometric measurements were recorded within 48 hours after delivery. Linear regression analysis was used to explore the relationship between cord serum leptin concentration and anthropometric parameters of the baby and the mother. Both Serum leptin and serum C-peptide levels were measured by chemiluminescence-based ELISA method. Results: The leptin concentration (ng/ml, mean±SD) in cord blood was 39.13±14.44. Cord leptin levels correlated with birth weight (r=0.673, p<0.0001), ponderal index (r=0.732, p<0.0001) but it did not correlate with maternal body mass index, gestational age (r=0.135, p=0.349) at delivery or cord serum C-peptide concentration (r=-0.049, p=0.735) or placental weight (r=0.203, p=0.157). Conclusion: There are associations between cord leptin concentration at delivery and birth weight, ponderal index (PI) of the babies but not body mass index (BMI) of the mothers. High leptin levels of the baby could represent an important feedback modulator of substrate supply and subsequently for adipose tissue status during late gestation. (J Bangladesh Coll Phys Surg 2007; 25 : 9-13)


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