Microclimate and Ammonia Production of an Unusual Littoral Maternity Roost for Mormoopid Bats, Pteronotus spp., in Pacific Coastal Costa Rica

This study examined behaviors associated with the formation of maternity groups by tent-making bats (Uroderma bilobatum). Both male and female bats arrived at the roost area in Guanacaste, Costa Rica, in June, coincident with the early rainy season. Although 21 tents were occupied during the 6-week study, 60% of the bats roosted in one of two tents. All females captured during the study were pregnant, and parturition occurred fairly synchronously in early July. The maternity groups lack complete sexual segregation and seem to lack strong bonds between roostmates. Grouping apparently provides thermoregulatory benefits to the bats.

Bats are highly mobile animals, moving rapidly over long distances. Detecting such movements is challenging, especially in cave areas, a commonly-used roost by bats. Brazil has a large number of caves and bat species, but details on bat mobility among caves is still poorly documented there. Such monitoring provides insights on the structuring and conservation of cave-dwelling communities, with possible legal implications for the environmental licensing in Brazil. Based on marking (2,490 bats captured; 2,142 marked) and recapture (35 events; 14 extra-site), here we present data on the mobility of mormoopid bats between two bat caves 15 km apart in northeastern Brazil. Sexual segregation between caves may explain mobility: one cave is likely a maternity roost; the other is a satellite cave used for copulae. Nomadic behavior due to seasonal distribution of resources in the semi-arid Northeastern Brazil cannot be ruled out. Based on the distance between the two caves, bats could potentially forage over an area of ~170,000 hectares, in a wider use of the landscape. Our data have implications for the conservation of bat species and their roosts, and contribute to a more evidence-based discussion of key concepts governing the environmental licensing of mining activities in Brazil.

Pteronotus is a Neotropical genus of mormoopid bats known to form large colonies in caves. Cave selection by Pteronotus is not random, and maternity roosts are characterized by the presence of a hot chamber where females give birth and raise their young. Such bat caves are unique from ecological and conservationist perspectives. Previous studies on bat caves in the drylands of Brazilian northeastern region – some holding up to 150,000 bats – have shown that P. gymnonotus presented no population structuring, with no correlation between geographical and genetic distance, and that bat caves up to 700 km apart form a very dynamic roost network used by that species. P. personatus is a smaller relative found in sympatry with P. gymnonotus. Both species frequently share the same roosts and are exposed to similar environmental conditions when foraging; therefore, they are good candidates for a comparison of their population genetic structuring. Using ddRADseq methodology, 55,836 SNPs from 72 P. personatus (21 females and 51 males) and 37,037 SNPs from 177 P. gymnonotus (93 females and 84 males) were analyzed. We observed that both species presented no strong signs of population genetic structure in the drylands of northeastern Brazil, and geographic distance is not the main factor shaping their genetic connectivity. Furthermore, our results suggest that the two Pteronotus species studied are characterized by very dynamic roost use, meaning that individuals frequently switch among caves within a landscape rather than relying on a single permanent roost. Thus, indicating that conservation initiatives should not rely solely on single-site protection but rather adopt a landscape-scale perspective.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12862-025-02465-w.

Comparative physiological studies on four strains of Leishmania braziliensis, isolated in pure culture from cutaneous cases of human leishmaniasis, are presented. Shorter lag phases in the growth curves were obtained for strains 0-CR and 6-CR as compared with 3-CR and 2-CR. Nitrogen content of 0-CR was higher than that of the other strains and respiratory activity for 0-CR and 6-CR was also higher. Respiratory quotients and glucose consumption per cell were higher for 0-CR, which showed greater ability to utilize some carbohydrates, nitrogen compounds, and Krebs cycle intermediates. All strains were sensitive, in different degrees, to several metabolic inhibitors while iodoacetate exerted the most marked action. The physiological findings are correlated and discussed in relation to infectivity of the strains. The oldest strain (0-CR), kept in culture for several years, presented the strongest virulence for hamsters. Strains 3-CR and 2-CR, with the lowest metabolic activities, were unable to infect hamsters or showed an extremely low virulence for them. Strain 6-CR, the newest isolate, showed characteristics in between the above strains. Physiological and biochemical observations on species of Leishmania can be found in the literature of the past 40 years. The older studies concerned themselves with the production of acids from media containing sugars (Colas-Belcour and Lwoff, 1925; Kligler, 1926; Noguchi, 1926) and with the production of ammonia by old cultures (Salle and Schmidt, 1928). Other authors have made observations on the relationship between motility of the flagellates and presence of different carbohydrates (Dubois, 1936) and on the respiration of the culture or parasitic forms of the organisms under different circumstances (Adler and Ashbel, 1940; Chang, 1948; Fulton and Joyner, 1949; von Brand and Agosin, 1955; Medina et al., 1955; Chatterjee and Ghosh, 1959). Recently, von Brand (1966) has critically reviewed some of the research on the physiology and biochemistry of Leishmania. In this paper, comparative observations on the respiratory metabolism of four Costa Rican strains of L. braziliensis and its relation to infectivity are presented. A previous note on the comparison of two of the strains has been published (Zeledon and Monge, 1966). Received for publication 24 May 1967. * This work was supported by USPHS Research Grant AI-03304-05, NIAID. MATERIALS AND METHODS The Costa Rican strains 0-CR, 2-CR, 3-CR, and 6-CR, were used in the experiments. The 0-CR strain was isolated by Dr. Alfonso Trejos at the San Juan de Dios Hospital in 1957 and has been kept in culture since then. The other three strains were isolated in pure culture by the authors, from cutaneous lesions of patients in the same hospital. The 2-CR strain was isolated in November 1960, 3-CR in July 1961, and 6-CR in April 1965. The cultures have been kept since isolation in Tobie and Rees' (1948) modification of Senekjie's medium by transferring them every 3 or 4 weeks. In order to determine growth curves the organisms were cultured in Roux bottles in the modified Senekjie medium with 10% rabbit blood taken from at least three animals and incubated at 26.5 C. In all cases, one bottle in the exponential phase of growth served as inoculum and the numbers of organisms inoculated into each batch of flasks were kept within the same limits for all four strains. The organisms of two bottles were counted with a hemocytometer and data from three to seven experiments were combined. For manometric studies, flagellates were harvested at the exponential phase of growth (days 4 to 6 for strains 0-CR and 6-CR; days 8 to 10 for strain 3-CR; days 6 to 8 for strain 2-CR) and was treated as previously described (Zeledon, 1960a, b, c, d). All substrates, in a final concentration of 0.01 M, were added at the beginning of the experiment; the final pH was 7.2. In the case of the Krebs intermediates the final pH was 5.0 since preliminary studies showed strains 0-CR, 6-CR, and 3-CR used these intermediates better at this pH. The experiments were carried out at 30 C for a period of 2 hr with interval readings at 15 to 30 min. The nitrogen content per War-

We compared the resin-core and buried-bag incubation methods for estimating nitrogen (N) transformation rates using the 15N pool dilution technique in alluvial soils of an early successional forest (ESF) and an old-growth forest (OGF) at the La Selva Biological Station in Costa Rica. Soil cores (38×100-mm) from both forests were incubated in situ for 7 days. The two methods gave generally similar estimates of net N mineralization rates for the two forests. Estimates of ammonium production by the resin-core method were higher than those by the buried-bag method in ESF, but did not differ significantly in OGF (p<0.05). Estimates of nitrate production by the two methods did not differ significantly. Nitrate averaged 74% and 81% of the total inorganic N production in ESF and OGF, respectively. Net N mineralization in ESF (6.6 mmol m-2d-1) did not differ significantly from that in OGF (5.0 mmol m-2d-1). Fluxes of ammonium and nitrate were high for both forests, but the OGF tended to have higher gross mineralization and nitrification rates than ESF. Approximately 60% of the gross nitrate production and less than 30% of the ammonium were immobilized by microorganisms.