Why we love batty summer nights!
AS temperatures increase in late spring/early summer, insects become more abundant and bats can be seen and heard (with a bat detector) flying around, hunting for insects.
Around this time, pregnant female bats congregate in a particular location, just perfect for successfully raising a new-born baby bat. Like any nursery, this location is safe, warm and close to a food source. Once this perfect location is found (sometimes in your own roof!), females will return year after year to give birth and raise their young. It is this aspect of their biology that allows our team in UCD to study bats as they age, catching and sampling
the same individuals at a nursery roost, first as a baby and then as an adult, year after year.
Identification and protection of these nursery roosts is crucial to ensuring the survival and conservation of our nine resident Irish bat species.
Much research has been carried out in UCD to try and understand which characteristics are important for a successful nursery roost and why bats choose one location over another. Female bats usually give birth to one pink hairless baby in late June but the exact timing depends on the temperature and can vary greatly. The mothers feed their babies milk and train them to fly and hunt for about six weeks and typically both mother and baby leave the nursery roost in August.
As late summer approaches bats must eat, eat and eat, to gain enough weight to survive the long winter months as they hibernate.
Late summer and early autumn is a time when bats mate and certain species can be seen performing an unusual behaviour known as swarming. Swarming is when many bats congregate together, typically outside of a cave and perform great feats of aerial acrobatics. Swarming has been likened to an ‘old-fashioned disco’ with both males and females highlighting their expertise and aerial skills, potentially enabling them to choose their mate.
Swarming has also been associated with locating a good site for hibernating over the winter months.
Within Ireland members of UCD’s Batlab with scientists from Queen’s University Belfast were the first to identify and confirm the location of up to 20 swarming sites, which are key conservation locations for bats’ survival.
There should be more of these sites in Ireland. Therefore, if you see this bat behaviour happening in early Autumn please make sure to take note as you may have located one of the most important places for bat conservation.
This summer we urge you to look up into the night skies at dusk and check for emerging bats. They will not fly into your hair, rather if they are near you they are probably feeding on midges attempting to feed on you! We hope you marvel at their fantastic flying feats and acrobatics, using sound to orient and move in complete darkness.
If you are interested in gaining more knowledge about bats and maybe helping to count and observe them this summer, Bat Conservation Ireland, runs many workshops and is always looking for people to get involved: www. batconservationireland.org/
SUMMER is the time when all bat biologists in Ireland do the majority of their field-work, because bats are active and easily observable only during the summer months.
Those of us in UCD’s Batlab are packing our bags and setting sail to France, for our annual month-long adventure in search of the secret of everlasting youth! Among mammals, bats are exceptionally long lived for their size and metabolic rate and it is deep within their DNA that we hope to uncover the secret to their seemingly everlasting youth.
To do this, we follow a population of long-lived bats as they age, taking tiny amounts of wing tissue and blood every year to track the genetic changes that occur with ageing in real time. By doing this we hope to work out what bats do to age so slowly and potentially use this knowledge to increase the length of our own, human ‘health-span’.