Gilbert and Manica (2010) list Kheper nigroaeneus as the dung beetle with the lowest median lifetime fecundity, but do not in their manuscript or supplemental materials attach a reference to the individual data points in their meta-analysis. I suspect the source for this data point is Edwards & Aschenborn (1989). In the supplemental data Eurysternus balachowskyi is also listed with lifetime fecundity of 2. My best guess at a reference here is Halffter et al (1980).
Edwards & Aschenborn (1989) report that female Kheper nigroaeneus lay one egg per year, but will lay another if the larvae is unsuccessful early on. The authors further note that that “To ensure population replacement, females must live at least into a second year. We have indirect evidence (laboratory studies; tibial wear measurements) that some adults survive into a third year.” In other words, occasionally a female will produce 3 offspring.
On the other hand, there are a fair number of dung beetles listed as endangered (at least in 1st world countries, e.g. references in Buse et al. 2015, Carpaneto et al. 2007) due to habitat loss, fragmentation and reduction or extinction of associated mammal species.
Very interesting! Is the dung beetle fecundity two per female? How can the population ever grow?
Gilbert and Manica (2010) list Kheper nigroaeneus as the dung beetle with the lowest median lifetime fecundity, but do not in their manuscript or supplemental materials attach a reference to the individual data points in their meta-analysis. I suspect the source for this data point is Edwards & Aschenborn (1989). In the supplemental data Eurysternus balachowskyi is also listed with lifetime fecundity of 2. My best guess at a reference here is Halffter et al (1980).
Edwards & Aschenborn (1989) report that female Kheper nigroaeneus lay one egg per year, but will lay another if the larvae is unsuccessful early on. The authors further note that that “To ensure population replacement, females must live at least into a second year. We have indirect evidence (laboratory studies; tibial wear measurements) that some adults survive into a third year.” In other words, occasionally a female will produce 3 offspring.
On the other hand, there are a fair number of dung beetles listed as endangered (at least in 1st world countries, e.g. references in Buse et al. 2015, Carpaneto et al. 2007) due to habitat loss, fragmentation and reduction or extinction of associated mammal species.