The greater spear-nosed bat has a body length of around {{convert|100|-|130|mm|in|abbr=on}}, with a wing span of {{convert|455|mm|in|abbr=on}}. Despite the large size, it is very light, weighing on average {{convert|81|g|oz|abbr=on}}. Its long, thick hair is dark brown, with a slight orange tinge on the ventral side.[[6] It has a well-developed nose shaped like a spear-head, which gives it its more common name. The ears are spread far apart and are smaller than in other phyllostomids. The lower lip has a distinctive V-shaped groove and many warts.[6] Both sexes have a throat sac just above breast bone.[6] That of the male is enlarged,][ while the female's is much smaller and simpler.]
[ The average harem size is eighteen.[10] The dominant male may be in control of the harem for many years. The remaining 80% of males and young females form their own large bachelor group to complete the colony.[12] Studies by McCracken and Bradbury (1977) have shown that unrelated females in the colony often form stable factions.[10] Recent studies have shown, that even though females do live in stable co-operative groups or "tribes" with non-kin, and will protect unrelated pups of their own group, they attack and even kill pups from other groups living in the same cave.[1]]McCracken and Bradbury considered many possible reasons for group formation in P. hastatus. The most plausible are thought to be co-operation in foraging for food, and protection and defence while feeding. Once food is found, a successful bat forager alerts others in the feeding group to the location. This was also found by Wilkinson (1995), who noted that P. hastatus call on the other members of the group when finding food, in the absence of territorial calls. Feeding groups may be segregated by social status. Dominant males have feeding sites close to the roost, while single males may have to fly as far as 9 km in order to find a feeding site.[12]
Reproduction
The pattern of reproduction in P. hastatus may vary over its range. Although this bat generally only reproduces once a year, lactating females have been found throughout the year, suggesting that some may reproduce more often. They give birth to only one young at a time. The reproduction rate is very low. Even with a change of the dominant male, constancy{{Citation needed|date=March 2011}} is almost always maintained.[10] McCracken and Bradbury (1977, 1981) characterized the reproduction cycle of P. hastatus as follows:[10]
February – April; pregnancy
May – mid-July; lactation
Mid-July – late October; anoestrous
Late October – February; oestrous
It has been hypothesized that it is females that eat vertebrates, to provide protein for lactation.[10]
Economic importance
The activities of P. hastatus are both beneficial and costly to humans. They feed on insects and other pests that could harm crops, and they help pollinate many crops. However, they also consume some crops, such as bananas. Although they are not endangered, there is concern over destruction of their habitat.
References
1. ^{{cite news|last1=Walker|first1=Matt|title=When two bat tribes go to war|url=http://news.bbc.co.uk/earth/hi/earth_news/newsid_8091000/8091495.stm|accessdate=September 3, 2015|agency=BBC|publisher=BBC|date=June 10, 2009}}
2. ^1 2 3 4 5 6 7 8 {{cite book | author = Altringham JD | year = 1996 | title = Bats Biology and Behaviour | publisher = Oxford University Press | location = Oxford, UK | url = https://books.google.com/books?hl=en&lr=&id=uzZ_sGLXltMC&oi=fnd&pg=PA1&ots=FQSYbqfeKN&sig=9oD585HxfgQa2BUE6KRZTxqDtX0#v=onepage&q&f=false | ISBN = 978-0-19-850322-4}}
3. ^1 2 3 {{cite book | author = Dobson GE | year = 1878 | title = Catalogue of the Chiroptera in the collection of the British Museum, London | url = https://archive.org/details/cataloguechirop00dobsgoog}}
4. ^1 {{IUCN2008|assessor=Rodriguez, B.|assessor2=Pineda, W.|last-assessor-amp=yes|year=2008|id=17218|title=Phyllostomus hastatus|downloaded=4 March 2009}}
5. ^1 2 {{MSW3 Chiroptera | id = 13801276 | page = 410}}
6. ^1 2 3 {{cite book | author = Neuweiler G | year = 2000 | title = The Biology of Bats | publisher = Oxford University Press | location = Oxford | ISBN = 978-0-19-509950-8}}