One night to count the chiropts in a Landes presbytery

MArdi June 17. Moreover, the night has not yet completely fallen to the Saint-Martin-de-Noët district, between Saint-Justin and Roquefort, in the east of the Landes, that Leticia Collado, CDC Biodiversity Project Manager (emanation of the Caisse des Dépôts et Consignations) and Sébastien Roue, volunteer of the Aquitaine Chiroptera group (GCA) are preparing for an ancient plan.

“The bat is technology. Nevertheless, ” likes to say the latter by unpacking its two cameras (thermal and infrared), essential to continue the counting in the dark, its ultrasonic detector to decode the inaudible signals sent by the chiroptères to communicate or detect obstacles, and its cable acting as a receptor portico around the main outlet of these ladies. For example, He hopes to scan in full flight one of the 34 individuals “transponded” in 2019 (females. In addition, males, adults or young people equipped with an one night count chiropts landes electronic chip allowing them to be traced).

Deferred fertilization – One night count chiropts landes

“The bat is very faithful”. Nevertheless, specifies Leticia: it comes to give birth where it was born, in the same summer colony installed in attic or attics (it is a mammal which has only one small per year and which breastfeeds). Meanwhile, “The places where they lie are not the same as those where they reproduce,” continues the naturalist. Meanwhile, Mating is done before hibernation. in winter colonies established in caves or cellars, which offer a very stable temperature and a particular humidity, ensuring the protection of the wing membrane.

At the end of this “swarming”. or grouping, ranging from the end of summer to the beginning of fall (especially in the Cros valley, in Roquefort), the females will keep the sperm in them until spring, where fertilization will be triggered. We then speak of deferred fertilization.

Back to the former presbytery of Saint-Martin-de-Noët. where Leticia Collado and Sébastien Roue one night count chiropts landes are on the lookout, counter in hand, at the foot of the two exit from the occupants.

Demanding roommates

The peculiarity of this summer colony is in the cohabitation of two species which. however, are not sharing: the large rhinolopher and the murin with outlined ears, which find here an agreement. Perhaps because the murin (about 12 grams. 20 to 25 centimeters in wingspan) more spiders and flies when its neighbor (25 grams and 30 to 35 centimeters in scope) likes larger prey, such as night butterflies or Hannetons, which he hunts on the lookout in order to save his energy (his heart beats 500 minute pulsations, against 80 at rest).

As remote neighbors. Rhinolophes and Murins will not meet on the landing, because everyone has its exit, that their neighbor is well known, which has its quarters (and its gluttony of the progeniture) in the bell tower overlooking the presbytery. This one night count chiropts landes Tuesday evening. she came to perch above the exit skylight but was for her expense: the prudent presbyterians do not come out continuously but on the patrol of one to three individuals, the mother guiding her descendants and the learner to hunt after having left some specimens to ensure the safety of maternity, in case cats or foxes want to vary their ordinary.

Finally. it should be noted that all bats of bats are protected and that their guano (excrement), unlike that of pigeons, is not corrosive.

Why in Saint-Martin-de-Noët?

During the impact studies carried out by A’Liénor. upstream of the realization of the A65, a mixed colony of chiroptera was spotted in the old stationery. Following the demolition of the factory. the colony came out of the radars and then found in the former presbytery of the Saint-Martin-de-Nét district, in Saint-Justin, which CDC Biodiversity acquired in 2012. Since then, CDC Biodiversity one night count chiropts landes has been working on behalf of A’Liénor to implement the compensatory measures of the A65. But, as Leticia Collado specifies, compensation is only the ultimate phase of the ERD process (avoid, reduce, compensate).