Tarsipes rostratushoney possum

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Geographic Range

Tarsipes rostratus is native to the south western tip of Western Australia, throughout the coastal-sand plain heathlands, which contains a diverse array plant communities. (Cooper and Cruz-Neto, 2009; Nagy, et al., 1995; Richardson, et al., 1986)

Habitat

Preferred habitat of Tarsipes rostratus is banksia woodlands, which are rich in floral diversity. The overstory of banksia woodland habitat along the south western coast of Western Australia is dominated by Banksia attenuata (slender Banksia) and B. menziesii (firewood Banksia). Eucalyptus todtiana (coastal blackbutt), E. gomphocephala (Tuart), E. marginata (Jarrah), Allocasuarina fraseriana (Fraser’s sheoak), Nuytsia floribunda (christmas tree) and other Banksia species also occur, but far less frequently. Interspersed throughout the understory are various species in the families Proteaceae, Myrtaceae, Papilionaceae, and Epacridaceae (Maher et al., 2008). ("Restoration of banksia woodlands after the removal of pines Gnangara: evaluation of seeding trials.", 2008; Bradshaw and Bradshaw, 2002)

Physical Description

Tarsipes rostratus has grey fur that is brown on the dorsal side with a dark stripe starting from the nape of the neck extending down towards the base of the tail. It has white and yellow ventral pelage on its underbelly that becomes orange on its sides. The head is dorsoventrally flattened with an elongated snout that is approximately two and a half times longer than its maximum width. Tarsipes rostratus has a brush-tipped protrusible tongue that is equal in length to the head. With the exception of the incisors, which are enlarged, the dentition of T. rostratus is greatly reduced. Its hands and feet have rough pads, opposable and elongated digits, with nails that do not project beyond the toe-pads. It has a prehensile tail that is hairless on the ventral surface near the tip. Tarsipes rostratus is sexually dimorphic, with females being approximately a third heavier than males. Females range in mass from 10 to 18 g, have a body length ranging from 70 to 90 mm, and a tail that measures from 75 to 105 mm in length. Males range in mass from 6 to 12 g, have a body length ranging from 65 to 85 mm, and a tail that measures from 70 to 100 mm in length. Despite females being slightly larger, there is no difference in head length between the sexes. (Bradshaw and Bradshaw, 2007; Cooper and Cruz-Neto, 2009; Nagy, et al., 1995; Richardson, et al., 1986; Withers, et al., 1990)

Tarsipes rostratus has a higher basal metabolic rate (BMR) and field metabolic rate (FMR) than most other marsupials. It has an average body temperature of 36.6 C, which is much higher than the typical marsupial, and a BMR of 2.9 cm^3 oxygen/hour. When in torpor, if its body temperature falls below 5 degrees C it is incapable of exiting torpor. Daily energy expenditures range from 25 to 30 kJ/day, which classifies them as hypermetabolic. In order to meet their high energy demands, its diet consists primarily of pollen and nectar. (Bradshaw and Bradshaw, 2007; Cooper and Cruz-Neto, 2009; Nagy, et al., 1995; Richardson, et al., 1986; Withers, et al., 1990)

  • Sexual Dimorphism
  • female larger
  • Range mass
    6 to 18 g
    0.21 to 0.63 oz
  • Range length
    65 to 90 mm
    2.56 to 3.54 in
  • Average basal metabolic rate
    2.9 cm3.O2/g/hr
  • Average basal metabolic rate
    0.162 W
    AnAge

Reproduction

Tarsipes rostratus mates several times a year in a non-seasonal pattern. Females are polyandrous and have small litters, usually between 2 and 3 offspring but potentially up to 4, with multiple paternities. Female polyandry results in sperm competition between males. The testes of male T. rostratus are very large relative to their body size, weighing more than 4% of their total body mass. Their testes contain sperm that is larger than any other mammal. Males compete for estrous females and courtship is limited with no ongoing association after copulation. (Bradshaw and Bradshaw, 2002; Oates, et al., 2007; Rose, et al., 1997; Wooller, et al., 2000; Wooller, et al., 1999)

There is a strong association between reproductive success and diet in Tarsipes rostratus. Reproduction occurs during peak flowering periods when resources are abundant. In addition, breeding periods are affected by photoperiod and evidence suggests that the southern summer solstice triggers the first reproduction of the year. In general, breeding occurs from May to June, when day length begins to decrease and from September to October, when day length begins to increase. (Bradshaw and Bradshaw, 2002; Oates, et al., 2007; Wooller, et al., 2000; Wooller, et al., 1999)

  • Breeding interval
    Honey possums breed whenever conditions are favourable.
  • Breeding season
    Honey possums breed year round.
  • Range number of offspring
    2 to 4
  • Average number of offspring
    3
    AnAge
  • Average gestation period
    24 days
    AnAge
  • Range weaning age
    60 (high) days
  • Range time to independence
    60 (high) days
  • Range age at sexual or reproductive maturity (female)
    90 (high) days
  • Range age at sexual or reproductive maturity (male)
    90 (high) days

Tarsipes rostratus has the smallest young of any mammal, which are reared in the pouch for about 60 days. By 60 days old young are highly mobile, fully-furred, and have eyes that are completely open. Young become sexually mature around 90 days and females often breed before their young disperse. Due to a period of embryonic diapause, gestation in T. rostratus lasts from 60 to 80 days longer than in other marsupials. Unlike other mammals, embyonic diapause in T. rostratus is not controlled by lactation. (Bradshaw and Bradshaw, 2002; Oates, et al., 2007; Wooller, et al., 2000; Wooller, et al., 1999)

  • Parental Investment
  • female parental care
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Honey possums are relatively short lived, with a lifespan of 1 to 2 years. Lifespan of captive individuals has not been documented. (Wooller, et al., 1999)

Behavior

Honey possums are nocturnal or crepuscular and are relatively nonsocial. In captivity, however, they huddle in large groups when they sleep but no such behavior has been observed in natural populations. There is little evidence of territoriality, however, females are dominant to males. (Bradshaw and Bradshaw, 2002; Rose, et al., 1997; Wooller, et al., 1999)

Home Range

Females and males have individual home ranges but there is overlap between the home ranges of the different sexes. Male home ranges are much greater than those of females, primarily because they take refuge in a various locations throughout the day to avoid dominant females. Male honey possums can travel up to 114 m during the night to reach their feeding grounds. (Bradshaw and Bradshaw, 2002; Rose, et al., 1997)

Communication and Perception

Little is known of communication and perception in Tarsipes rostratus. In other possum species, it has been suggested that secretions from the holocrine gland are used to mark habitats and signal alarm. There is no evidence indicating that possums use scent marking to attract potential mates. (Woolhouse, et al., 1994)

Food Habits

Tarsipes rostratus consumes pollen and nectar from a variety of flowering plants. It is the only flightless animal that feeds exclusively on pollen and nectar. Large amounts of pollen and nectar are consumed from plants belonging to the families Proteaceae, Epacridaceae, and Myrtacae. Tarsipes rostratus prefers to forage on Banksia spp., which are large plants with widely separated and exposed inflorescences from the family Proteaceae. The Mediterranean climate of south-west Western Australia is prone to recurrent fires, which has a significant effect on the population density of T. rostratus. Areas that remain unburnt for longer periods of time have larger plants, which bear more inflorescences. Plants with more inflorescences are correlated with increased abundance of T. rostratus. Its feet and prehensile tail are used for climbing, while their forepaws with elongated digits are used to manipulate flowers during feeding. In order to acquire the necessary nutrients from nectar, a substantial quantity of fluid must be consumed. As a result of the high water content in their diet in conjunction with their inability to concentrate urine, T. rostratus frequently excretes high volumes of dilute urine. (Bradshaw and Bradshaw, 2002; Everaardt, 2008; Richardson, et al., 1986; Slaven and Richardson, 1988; Sumner, et al., 2005; Wooller, et al., 1999)

  • Plant Foods
  • nectar
  • pollen

Predation

Aerial predators of honey possums, include barn owls (Tyto alba) and black-shouldered kites (Elanus caesuleus), and common terrestrial predators include red foxes (Vulpes vulpes) and feral cats (Felis domesticus). In certain parts of their range, Fitzgerald River National Park, other potential predators include tiger snakes (Notechis scutatus), southern monitors (Varanus rosenbergi), square-tailed kites (Lophoictinia isura), Australian kestrels (Falco cenchroides), brown falcons (Falco berigora), and boobook owls (Ninox novaeseelandiae). Honey possums are arboreal and are most commonly found in the lower canopy. As a result, the upper canopy likely provides shelter from aerial predators and being elevated off the forest floor likely decreases predation pressure from terrestrial predators. (Bradshaw and Bradshaw, 2002; Everaardt, 2003; Everaardt, 2008)

Ecosystem Roles

Honey possums are important pollinators for a number of different plants and are the principle pollinators of nodding banksia (Banksia nutans), which is common on the southern coast of Western Australia. (Wooller and Wooller, 2003)

  • Ecosystem Impact
  • pollinates

Economic Importance for Humans: Positive

There are no known positive effects of Tarsipes rostratus on humans.

Economic Importance for Humans: Negative

There are no known adverse effects of Tarsipes rostratus on humans.

Conservation Status

According to the IUCN Red List of Threatened Species, honey possums are a species of “least concern”. Due to their relative abundance and broad distribution, there are no major threats to their existence. However, bushfires can result in significant habitat loss. In addition, water mold (Phytophthora cinnamomi), which is prevalent in many high humidity environments, can cause plant pathogens that could decrease resource abundance for honey possums. Finally, feral cats may have a negative effect on honey possum abundance. (Friend, et al., 2008)

Contributors

Yengin Loay (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, John Berini (editor), Animal Diversity Web Staff.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

embryonic diapause

At about the time a female gives birth (e.g. in most kangaroo species), she also becomes receptive and mates. Embryos produced at this mating develop only as far as a hollow ball of cells (the blastocyst) and then become quiescent, entering a state of suspended animation or embryonic diapause. The hormonal signal (prolactin) which blocks further development of the blastocyst is produced in response to the sucking stimulus from the young in the pouch. When sucking decreases as the young begins to eat other food and to leave the pouch, or if the young is lost from the pouch, the quiescent blastocyst resumes development, the embryo is born, and the cycle begins again. (Macdonald 1984)

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nectarivore

an animal that mainly eats nectar from flowers

nocturnal

active during the night

polyandrous

Referring to a mating system in which a female mates with several males during one breeding season (compare polygynous).

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

scrub forest

scrub forests develop in areas that experience dry seasons.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Gnangara Department of Environment and Conservation. Restoration of banksia woodlands after the removal of pines Gnangara: evaluation of seeding trials.. Perth, AU: Murdoch University. 2008. Accessed February 24, 2011 at http://www.water.wa.gov.au/sites/gss/Content/reports/Restoration%20Banksia%20woodlands%20-%20evaluation%20of%20seeing%20trials.pdf.

Bradshaw, S., F. Bradshaw. 2007. Isotopic measurements of field metabolic rate (FMR) in the marsupial honey possum (Tarsipes rostratus). Journal of mammalogy, 88: 401-407.

Bradshaw, S., F. Bradshaw. 2002. Short-term movements and habitat use of the marsupial honey possum (Tarsipes rostratus). Journal of Zoology, 258: 343-348.

Cooper, C., A. Cruz-Neto. 2009. Metabolic, hygric and ventilatory physiology of a hypermetabolic marsupial, the honey possum (Tarsipes rostratus). Journal of Comparative Physiology, 179: 773-781.

Everaardt, A. 2003. "The impact of fire on the honey possum Tarsipes rostratus in the Fitzgerald River National Park, Western Australia." (On-line pdf). Murdoch University Research Repository. Accessed March 04, 2011 at http://researchrepository.murdoch.edu.au/66/2/02Whole.pdf.

Everaardt, A. 2008. The impact of fire upon the size and flowering of three honey possum foodplants at the western end of the Fitzgerald River National Park, Western Australia. Western Australian Naturalist, 26: 85-98.

Friend, T., K. Morris, A. Burbidge, N. McKenzie. 2008. "Tarsipes rostratus" (On-line). IUCN Red List of Threatened Species. Accessed November 11, 2010 at http://www.iucnredlist.org/apps/redlist/details/40583/0.

Nagy, K., C. Meienberger, S. Bradshaw, R. Wooller. 1995. Field metabolic rate of a small marsupial mammal, the honey possum (Tarsipes rostratus). Journal of Mammalogy, 76: 862-866.

Oates, J., F. Bradshaw, S. Bradshaw, E. Stead-Richardson, D. Philippe. 2007. Reproduction and embryonic diapause in a marsupial: Insights from captive female honey possums, Tarspies rostratus (Tarsipedidae). General and Comparative Endocrinology, 150: 445-461.

Richardson, K., R. Wooller, B. Collins. 1986. Adaptations to a diet of nectar and pollen in the marsupial Tarsipes rostratus (Marsupialia: Tarsipedidae). Journal of Zoology, 208: 285-297.

Rose, R., C. Nevison, A. Dixson. 1997. Testes weight, body weight and mating systems in marsupials and monotremes. Journal of Zoology, 243: 523-531.

Slaven, M., K. Richardson. 1988. Aspects of the Form and Function of the Kidney of the Honey Possum, Tarsipes rostratus. Australian Journal of Zoology, 36: 465-471.

Sumner, P., C. Arrese, J. Partridge. 2005. The ecology of visual pigment tuning in an Australian marsupial: the honey possum Tarsipes rostratus. Journal of Experimental Biology, 208: 1803-1815.

Withers, P., K. Richardson, R. Wooller. 1990. Metabolic Physiology of Euthermic and Torpid Honey Possums, Tarsipes rostratus. Australian Journal of Zoology, 37: 685-93.

Woolhouse, A., R. Weston, B. Hamilton. 1994. Metabolic physiology of euthermic and torpid honey possums, Tarsipes rostratus. Australian Journal of Zoology, 37: 685-693.

Wooller, R., K. Richardson, G. Bradly. 1999. Dietary constraints upon reproduction in an obligate pollen and nectar-feeding marsupial, the honey possum (Tarsipes rostratus). Journal of Zoology, 248: 279-287.

Wooller, R., K. Richardson, C. Garavanta, V. Saffer, K. Bryant. 2000. Opportunistic breeding in the polyandrous honey possum, Tarsipes rostratus. Australian Journal of Zoology, 48: 669-680.

Wooller, R., S. Wooller. 2003. The role of non-flying animals in the pollination of Banksia nutans. Australian Journal of Botany, 51: 503-507.