Young dwarf mongooses have a higher chance of surviving when their group competes with rival conspecifics, according to research by Andy Radford’s group at the University of Bristol. Contrary to expectations, a larger proportion of juvenile mongooses survived the three months following their initial den departure when faced with increased rivalry. Dwarf mongooses, being the smallest predators in Africa, exhibit this unexpected trend.
Normally, conflicts between groups are anticipated to have adverse effects on reproductive success, potentially due to stress-related consequences or the loss of group members through injury or death, resulting in a lack of care for offspring. A prior study indicated that the survival rate of chimpanzee fetals was lower and inter-birth intervals were longer when facing threats from other groups, as explained by the research team.
The researchers utilized data spanning a decade from the life history of a wild population of Southern dwarf mongooses (Helogale parvula), which reside in groups of 5 to 30 individuals in southern and eastern Africa. Only the dominant pair reproduces, while the entire group contributes to the care of the offspring. The primary diet of these small predators consists of insects.
The passage describes the territorial defense behavior of mongoose groups and its impact on the survival rate of young individuals. The researchers explain that each group defends its territory against conspecifics, leading to frequent conflicts with rival groups. Surprisingly, the analysis presented in the British Royal Society’s journal “Proceedings B” indicates that the survival rate of young animals increased when the cumulative threat from such conflicts was higher.
To investigate the cause, the team closely observed the behavior of mongoose groups in South Africa. They noted that when adult animals encounter rivals or signs of their recent presence, they intensify their guard behavior. This involves taking an elevated position and keeping watch while other group members continue activities such as foraging.
The heightened vigilance also proves beneficial in another aspect: the early detection of predators. Young animals are more frequently warned in time, allowing them to seek refuge in the group’s burrow, according to the researchers’ assumptions. Consequently, their chances of surviving the particularly perilous first months of life are increased.