The bat skin shows an unusual morphology that corresponds to flying adaptations but also performs multiple functions including a protective barrier against microbes and parasites. Here, we compare the microscopic structure of the skin and hairs collected from the membranes with other body parts in the Common Pipistrelle (Pipistrellus pipistrellus) in relation to parasite availability. Statistical analysis of whole‐skin thickness revealed two main groups according to body regions; the first with thin skin (wing and tail membrane) and the second with thick skin (head and dorsum, abdomen, footpad). The density of hair was evaluated by a novel method, and it revealed that the density was significantly higher in the head region than in dorsal and ventral body parts. These differences possibly play a role for bat ectoparasites when choosing the preferred region of their host. Along the axis of each hair, the scale morphology was found to be variable. Hair morphology, however, did not vary among body regions. Mast cells were numerous in the hairy areas around vessels and hair follicles of the dorsum and abdomen, which are easily accessible to ectoparasites. Increased numbers of mast cells in hair‐bearing skin are part of the host adaptation system in parasite‐preferred locations.

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We examine the impact of political risks and financial development on investments in the petroleum industry utilizing a unique dataset of investments in individual oil and gas fields around the world. We find that the expected time to investment is shorter in countries that are politically stable, have solid property rights protection and more developed financial systems. Political risks have the strongest impact on multinational companies, whereas financial development matters only for domestic national oil companies. At the company level we find that expected time to investment is shorter for companies with higher valuation and lower debt. Moreover, companies are more likely to invest in countries where they invested recently and less likely to invest in countries where their competitors invested recently.

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