Elevation induced variation in the breeding traits of a nectar-feeding non-flying mammal
Factors that influence reproduction in nectar-feeding non-flying mammals are poorly described. We investigated factors that may influence the breeding traits of the eastern pygmy-possum (Cercartetus nanus), a small (25 g) nectar-feeding marsupial from eastern Australia. Females at our coastal site produced 1–3 litters (frequently of 5–6 young) over an 8-month period within the flowering period of the dominant food plant (Banksia ericifolia). The number of lactating females over time was highly correlated (R = 0.9) with the abundance of flowers on B. ericifolia, suggesting that flower availability has a substantial influence on breeding. To assess the generality of these findings and investigate whether elevation or latitude influence breeding in this species, we examined the breeding traits previously described at three other locations. Females on the tableland 70 km away produced one litter of 3–4 young over a 4-month period within the flowering period of B. ericifolia, the dominant food plant. At other coastal and tableland locations 500 km away, coastal females produced larger numbered litters more often than tableland females. A hypothesis relating to minimum temperature appears the most plausible explanation for this pattern that reflects elevation but not latitude. The mean minimum temperature drops below 5 °C for 2–5 months each year at the tableland locations but not at all at the coastal locations. Low temperatures are known to reduce nectar secretion in the dominant food plants. Thus, although the breeding traits of the eastern pygmy-possum are influenced by flowering in their dominant food plants, low temperature appears to impose a constraint on reproductive output.
KeywordsReproduction Elevation gradient Litter size variation Temperature
This research was conducted under animal ethics approvals from Southern Cross University (11/33, 12/39, 13/52, 14/44) and a New South Wales government scientific licence (SL100161). This paper has been improved by the suggestions of two anonymous referees.
- Armstrong DP, Pyke GH (1991) Seasonal patterns of reproduction in heathland honeyeaters are not responses to changing nectar availability. Auk 108:99–107Google Scholar
- Bowen M, Goldingay R (2000) Distribution and status of the eastern pygmy possum (Cercartetus nanus) in New South Wales. Aust Mamm 21:153–164Google Scholar
- Evans KM, Bunce A (2000) A comparison of the foraging behavior of the eastern pygmy possum (Cercartetus nanus) and nectarivorous birds in a Banksia integrifolia woodland. Aust Mamm 22:81–86Google Scholar
- Harris JM, Goldingay RL, Brooks LO (2014) Population ecology of the eastern pygmy-possum (Cercartetus nanus) in a montane woodland in southern New South Wales. Aust Mamm 36:212–218Google Scholar
- Huang C, Ward S, Lee AK (1987) Comparison of the diets of the feathertail glider, Acrobates pygmaeus, and the eastern pygmy-possum, Cercartetus nanus (Marsupialia: Burramyidae) in sympatry. Aust Mamm 10:47–50Google Scholar
- Tabachnick BG, Fidell LS (2013) Using multivariate statistics. Pearson Education, EssexGoogle Scholar
- Turner JM, Warnecke L, Körtner G, Geiser F (2012) Summer and winter torpor use by a free-ranging marsupial. J Comp Physiol A 162:274–280Google Scholar
- Wooller RD, Russell EM, Renfree MB (1984) Honey possums and their food plants. In: Smith AP, Hume ID (eds) Possums and gliders. Surrey Beatty, Sydney, pp 439–443Google Scholar