Rare observation of the existence and masculine behaviour of maned lionesses in the Okavango Delta, Botswana
Introduction
We describe the observation of mane growth and masculinized behaviour in female lions (Panthera leo melanochaita) within the Okavango Delta, Botswana. African lions exhibit a relatively high degree of sexual dimorphism, with the larger males typically developing a conspicuous coat of long hair on their chest, neck and back, termed a ‘mane’ (Schaller, 1972). The length and darkness of a male lion's mane is thought to be driven by sexual selection pressures, with females preferentially associating with dark-maned males and male lions preferentially attacking light-maned males (West & Packer, 2002). Mane development in male lions has been the focus of much interest over the last century (Schaller, 1972; Kays & Patterson, 2002; West & Packer, 2002; Yamaguchi et al., 2004). Potential factors driving mane development in male lions are thought to include genetics, temperature, nutritional status, hormones and vegetation thickness (Kays & Patterson, 2002; West & Packer, 2002). To date, mane development has only been reported in males, and has never been formally documented in female lions. We report on a rare observation of mane development in five female lions and document specific masculinized behaviour in one of these.
Methods and results
Study area and population
Observations were made in the Moremi Game Reserve and the surrounding Wildlife Management Areas NG33/34 in the Okavango Delta, Botswana (ca. 1500 km2 19°31'S, 23°37'E; elevation ca. 950 m). Further details can be found in McNutt (1996). Behavioural data were recorded on 34 adult females (within seven prides). Three of these females (each from a different pride) showed the development of mane hair (developing light manes mainly beneath the neck: Fig. 1a; b; c). In addition, two females outside of this study area, but still within the Okavango Delta, have shown mane development (with ‘Mmamoriri’ developing a complete, dark mane: Fig. 1d). Detailed observational data were collected on one maned lioness (ID code: SaF05, DOB estimate 2003).
Behavioural observations
Data were primarily collected between March 2014 and March 2016 by G.Gilfillan and K.Golabek, but additional data were collected by trained research technicians working for the Botswana Predator Conservation Trust. Lions were observed from a vehicle at distances of 10–40 m while resting and 20–200 m while moving, depending on terrain, vegetation and visibility. Observation sessions typically took place within 3 h after sunrise and also within three hours before sunset.
Mating behaviour
Three of the maned lionesses were observed courting with male lions, and SaF05 was observed mating on 15 occasions with seven different male lions from five different coalitions during an 8-year period. As in other observations of typical mating behaviour in lions, these mating events lasted multiple days, and involved multiple mating bouts per day (with an average of 35.2 min (+/− 33.0 SD) between each mating bout during observation sessions). In eight years of data, SaF05 was never observed to be pregnant, and was never known to have given birth. Mmamoriri was also observed mating at least once and never showed sign of pregnancy despite being observed regularly (pers. comm. Simon Dures). Additionally, SaF05 was observed displaying sexual mounting behaviour with three females within her own pride on seven occasions. None of the maneless females were observed to initiate such behaviour, and all homosexual mating attempts were either ignored by the recipient or were met with aggression.
Scent-marking behaviour
Scent marking is the main form of communication for most mammals (Brown & Macdonald, 1985) and also appears to be important for lions (G.Gilfillan, unpublished data). Detailed scent-marking behaviour (urine, faeces, face rubbing and paw marking: see Schaller, 1972 for detailed description) by SaF05 was observed. When depositing urine, marking postures of lions included standing, lying, squatting, spraying and scraping (see Schaller, 1972 for more detail). For analyses, we further grouped spray and scrape postures (overt postures) and stand, lie, squat postures (nonovert postures). An overt marking posture was defined as those postures involving complex motor patterns that often result in an elevated placement of urine and increased investigation by conspecifics (Jordan et al., 2013; Clapham et al., 2014).
SaF05 was significantly more likely to deposit face rubs, and less likely to deposit scat compared to the maneless adult females in the study population (Table 1). When urinating, SaF05 was significantly more likely to use an overt marking posture than the maneless adult females in the study population (Table 1). Male lions are more commonly observed scent marking by rubbing their head onto vegetation and depositing their urine with overt marking postures (Schaller, 1972; Lehmann et al., 2008).
| SaF05 | Maneless females | Χ2 | P | |
|---|---|---|---|---|
| Mark Type | ||||
| Paw | 9.9% | 9.5% | <0.001 | 1.0 |
| Rub | 11.7% | 3.2% | 13.98 | < 0.001† |
| Scat | 11.7% | 23.7% | 7.25 | 0.007† |
| Urine | 66.7% | 66.5% | <0.001 | 1.0 |
| Total observed marks | 111 | 624 | – | – |
| Urine Posture | ||||
| Overt | 53.4% | 33.4% | 9.88 | 0.002* |
| Nonovert | 46.6% | 67.1% | – | – |
| Total observed urinations | 73 | 413 | ||
- For all analyses, degrees of freedom = 1. The symbol ‘†’ indicates significance (with Bonferroni correction) at 0.013, whereas. ‘*’ indicates significance at 0.05.
Vocal behaviour
Acoustic communication is the main form of communication for African lions (Ramsauer, 2005). Roaring (see Schaller, 1972 for definition) is known to function for mate attraction and territory defence, and is more frequently performed by male lions, although females also roar (Schaller, 1972). SaF05 was observed to roar at a higher rate than the maneless adult females in the population (Table 2) and as such appears to exhibit a more masculinized vocal behaviour compared to the maneless females. Similarly high levels of vocal activity have been observed for Mmamoriri (pers. comm. Simon Dures).
| SaF05 | Maneless females | |
|---|---|---|
| Number of observation minutes | 15835 | 8441.6 (average) |
| Number of times observed roaring | 70 | 9.2 (average) |
| Number of roars per observation minute | 0.0044 | 0.0020 (average, S.D = 0.0035) |
Discussion
We provide the first quantified data on mane development and associated behaviour in female lions. We observed in total five females with mane development in the Okavango Delta with one developing a complete, dark mane. We suggest that mane development here (at least for SaF05) may co-occur with infertility, although heterosexual mating occurred, as well as masculine behaviours such as mounting other females, frequent roaring and male-type scent-marking behaviour. SaF05 did, however, maintain her place socially within the pride, regularly associating with the other females when resting, hunting and patrolling the territory.
Acknowledgements
We thank the Botswana government and Sankuyo Community Trust for allowing this research to take place. The Leverhulme Trust financially supported the research. The support from the Botswana Predator Conservation Trust (and their donors) was invaluable. We thank Bruce Patterson and Simon Dures for advice.
