Pregnancy impairs bats’ sensing abilities, according to a new study

Some studies have found that pregnant women’s cognitive skills are compromised. According to a new Tel Aviv University study, bats’ capacity to forage and orient in space declines during pregnancy as well. This limitation is caused by the fact that they generate around 20% less calls, which allow them to orient yourself using echolocation, in addition to flying at a slower rate and at a lower height. To the extent that they know, this is the first proof of pregnancy impacting animals’ sensory capacities, according to the researchers.

Yes, that is correct. According to a recent study by Tel Aviv University, pregnancy can impair the sensing abilities of bats, affecting their ability to navigate and find prey through echolocation. The study found that Pregnancy impairs bats exhibit reduced sensitivity and accuracy in their echolocation calls, which can affect their overall fitness and survival. The study’s findings could have implications for understanding the impacts of reproductive trade-offs and resource allocation on sensory systems and ecological interactions in other animals.

Mor Taub, a research assistant in Prof. Yossi Yovel’s laboratory at Tel Aviv University’s Sagol School of Neuroscience and faculty of the Department of Zoology, Wise College of Life Sciences, led the study. The outcomes of the study were published in the journal BMC Biology.

“During the peak of pregnancy, bats carry around 20% more than their typical body weight,” Mor Taub continues, “and it is apparent that this additional weight reduces their flying capabilities.” In this study, we sought to see if and how pregnancy impacts bats’ echolocation abilities, or sonar. Sonar is used by bats to map their environment by sending and receiving powerful and frequent noises. Bats, like us, must transmit high-pressure air from the lungs to the voice cords, or vocal membranes, which includes numerous muscles, including the chest and diaphragm. We wanted to explore if the extra weight from pregnancy affected sound output.”

Prof. Yovel and his colleagues taught bats to seek for and land on a small landing pad in a flying chamber in Tel Aviv University’s Garden for Zoological Research’s bat laboratory. They recorded the echolocation of two groups of bats: pregnant and non-pregnant. The researchers discovered that the pregnant bats made noises at a substantially lower pace than the control group, with 20% longer intervals between each sound.

Prof. Yovel: “Bats adjust the rate at which they generate noises in response to the complexity of the task.” The typical pace is roughly ten calls per second, but when the bat lands, the rate can reach one hundred calls per second. The pregnant bats made only approximately seven noises per second and flew a little slower and lower. Presumably, this slowing down will have an impact on their hunting. When a bat produces fewer calls, it gets less information about its surroundings, increases its chances of colliding with things, and diminishes its chances of locating food – all at a time when the bat needs additional food to maintain the foetus in its womb. We employed a computer simulation in the second phase of the study to model the effect of slowed call rate on bat performance, and we found that the slowed rate makes it more difficult for the bats to identify prey.”

The bats used in the experiment were of the Kuhl’s pipistrelle variety, which are small bats weighing only six grammes (when they are not pregnant). These bats are prevalent in Israel and mostly feed on mosquitoes. Bats, despite their size, may live for decades, and their pregnancies are thus relatively protracted, lasting around four months. Prior research on other species of bats has indicated that during pregnancy, bats’ diets shift. Formerly, it was assumed that the shift in diet was related to the bats’ trouble flying, but the present study suggests that it might also be owing to their sensory problems in spotting particular types of prey.

“This is the only evidence we discovered in the professional literature that pregnancy alters the sensory capacity of animals,” adds Mor Taub. “We think that analogous situations exist in other animals as well, but this is the first time that researchers have been able to detect and objectively demonstrate the damage.” Apart from scientific reasons, it is critical to protect mammal species in the wild, particularly during pregnancy and newborn care, when animals are more vulnerable.”