The following is my translation of an article called: Schädlichkeit der fliegenden Hund von F Lupsa, Ackerbauministerium von Siam. It appeared in a German popular science magazine, Kosmos Handweiser für Naturfreunde 1913, Heft 10, Seiten 380-382.
I'm not aware of any previous translation.
Trevor Dykes.

Damage done by Flying foxes by F Lupsa, the Agriculture Ministry of Siam
In order to be able to accurately assess the level of damage inflicted by a genus of animal on agriculture and horticulture, it is appropriate to estimate it in terms of money based upon thorough observations. I have done this for several animal genera in Siam, and produced a report on the subject over recent years for the Ministry of Agriculture. The following is a short extract on the enormous damage caused by the Flying fox (Pteropus edulis), which is also called the Flatterhund or kalong, and it assails horticulture of that land year in and year out and, therefore, forces the owners of fruit plantations to have much concern about their yields.

The otherwise fully harmless, attractive animals, which adapt well to captivity and will also eat meat, belong to the order of the bats (Chiroptera), have a body length of some 40cm and a wingspan approacching 1.5m. They have a dog-like snout, long, naked, pointed ears and an excellently developed flight membrane; they do not possess a tail. The back of the head, neck and underside are rust-red, while the rest of their colouring is brown-black. This Flying fox, which is found in great quantities in the whole of the East Indies and the Malayan archipelago, and is held to be holy by Hindus, only eats fruit in the freedom of nature, and will take any fruit be it thick and tough shelled coconut or the thin skinned, tasty fruit of the mango.

During my many inspection tours into the countryside, I repeatedly came across roosts containing thousands of individuals which, as nocturnal animals, spend the day hanging in high trees. As they hang there, the head and body is enveloped by the flight membrane, the rear feet are clamped strongly to the branch, and the head points down while they sleep. They do not willingly leave the place or the trees which have once been used by such a society. When I was in Phrakanong, an area of orchards south of Bangkok, I repeatedly went out to hunt these animals, and always found them in more or less the same spot as previously. They hung so closely packed together that, for example, a single shot could bring down 6-15 animals. I often had the opportunity to estimate their numbers during their period of rest, and came to a result of about 10,000 individuals. According to my observations, swarms are so distributed, that each area will be visited by the same group on a more or less regular basis. Smaller groups (5-20 individuals and more) are usually encountered in areas where horticulture is not very strongly developed.

Should the morning star decline to set, then it will lively among the swarm, as group after group will fly off in much the same direction to search the district in the poetic symphony of the tropical night near and far, and to gnash themselves full on the sweet fruits of various kinds.

They fly through the whole night from tree to tree and, as well as the damage caused by the fruits they have sought out, many more have been sent falling to the ground or been injured by being flown into or from wing beats. This will either reduce the market value of the fruit or make it rot, especially the ripe, thin-skinned sorts. According to my statistical analysis, a Flying fox causes damage worth 77.50 tical per year, or around 116.25 marks, and this loss is constantly to be carried by the horticulture of Siam. If the bill were calculated for all the many thousands of these animals, then the result would look like something from a fairy tale, but it is actually based on precise observations.

An index of more of my translations of old Kosmos articles can be found at:

Kosmos Translations Archive

A number of Mesozoic (and post-Mesozoic) location summaries can be found at Localities.