Maternity colony

{{short description|Temporary association of reproductive female bats}}

A maternity colony refers to a temporary association of reproductive female bats for giving birth to, nursing, and weaning their pups. The colonies are initiated by pregnant bats. After giving birth, the colony consists of the lactating females and their offspring. After weaning, juveniles will leave the maternity colony, and the colony itself will break apart. The size of a maternity colony is highly variable by species, with some species forming colonies consisting of ten or fewer individuals, while the largest maternity colony in the world in Bracken Cave is estimated to have over 15 million bats.

Benefits of a maternity colony

Maternity colonies are especially prevalent in temperate regions due to the thermal benefits of roosting with other individuals.Dietz, M., & Kalko, E. K. (2006). Seasonal changes in daily torpor patterns of free-ranging female and male Daubenton’s bats (Myotis daubentonii). Journal of Comparative Physiology B, 176(3), 223-231.

Outside of the winter months, non-reproductive females and male bats enter torpor for short periods to conserve energy when temperatures are below an optimum threshold. However, torpor is detrimental to reproductive females because it delays the development of the fetus and slows milk production.

Therefore, female bats are highly incentivized to maintain a constant body temperature.

Roosting in a large group allows females to share body heat, lowering the energetic costs for individuals.

Risks of a maternity colony

Roosting in large groups brings risks to the members of a maternity colony. Predators such as hawks and owls can learn to anticipate the emergence of bats from a specific roost at sunset.Fenton, M. B., Rautenbach, I. L., Smith, S. E., Swanepoel, C. M., Grosell, J., & Van Jaarsveld, J. (1994). Raptors and bats: threats and opportunities. Animal Behaviour, 48(1), 9-18.

Smaller colonies are thought to be less risky than larger colonies, because the nightly emergence of bats would attract less attention.Wilkinson, G. S., & South, J. M. (2002). Life history, ecology and longevity in bats. Aging cell, 1(2), 124-131.

Species that form maternity colonies

class="wikitable" style="text-align: center; width: 800px; height: 100px;" \|+Incomplete list
Common name	Scientific name	Range	Maternity colony size
Family: Vespertilionidae
Little brown bat	Myotis lucifugus	U.S., Canada	107-349Frick, W. F., Reynolds, D. S., & Kunz, T. H. (2010). Influence of climate and reproductive timing on demography of little brown myotis Myotis lucifugus. Journal of animal ecology, 79(1), 128-136.
Southeastern myotis	Myotis austroriparius	Southeastern U.S.	1000+{{cite magazine \|last1=Gore \|first1=Jeffrey\|last2=Hovis\|first2=Julie \|date=Summer 1992\|title=The Southeastern Bat: Another Cave-roosting Species in Peril \|url=http://www.batcon.org/resources/media-education/bats-magazine/bat_article/529?tmpl=component \|magazine=BATS Magazine\|publisher=Bat Conservation International \|access-date=2 March 2017 }}
Fringed myotis	Myotis thysanodes	Canada, Western U.S., Mexico	40-200{{cite web \|url=https://www.blm.gov/style/medialib/blm/wy/wildlife/animal-assessmnts.Par.82314.File.dat/FringedMyotis.pdf \|title=Species Assessment for Fringed Myotis (Myotis thysanodes) in Wyoming \|last=Keinath \|first=Douglas \|date= December 2003 \|website=Bureau of Land Management \|access-date=2 March 2017}}
Indiana bat	Myotis sodalis	Midwestern U.S.	30-300{{cite web \|url=https://www.fws.gov/MIDWEST/Endangered/section7/s7process/mammals/inba/INBAEcologySummary.html \|title=Summary of Indiana Bat Ecology \|author= \|date=4 March 2008 \|website= U.S. Fish & Wildlife Service\|publisher=Department of the Interior \|access-date=2 March 2017}}Callahan, E. V., Drobney, R. D., & Clawson, R. L. (1997). Selection of summer roosting sites by Indiana bats (Myotis sodalis) in Missouri. Journal of Mammalogy, 818-825.
Northern long-eared bat	Myotis septentrionalis	Eastern U.S., Canada	11-65Menzel, M. A., Owen, S. F., Ford, W. M., Edwards, J. W., Wood, P. B., Chapman, B. R., & Miller, K. V. (2002). Roost tree selection by northern long-eared bat (Myotis septentrionalis) maternity colonies in an industrial forest of the central Appalachian mountains. Forest Ecology and Management, 155(1), 107-114.
Bechstein's bat	Myotis bechsteinii	Europe, Asia	15-40Kerth, G., Safi, K., & König, B. (2002). Mean colony relatedness is a poor predictor of colony structure and female philopatry in the communally breeding Bechstein's bat (Myotis bechsteinii). Behavioral Ecology and Sociobiology, 52(3), 203-210.
Geoffroy's bat	Myotis emarginatus	Europe	<10-985Dekker, J. J., Regelink, J. R., Jansen, E. A., Brinkmann, R., & Limpens, H. J. (2013). Habitat use by female Geoffroy’s bats (Myotis emarginatus) at its two northernmost maternity roosts and the implications for their conservation. Visions of nature, 111.
Gray bat	Myotis grisescens	Southeastern U.S.	100,000+Tuttle, M. D. (1979). Status, causes of decline, and management of endangered gray bats. The Journal of Wildlife Management, 1-17.
Hodgson's bat	Myotis formosus	Asia	82-200Shen, H. P., & Lee, L. L. (2000). Mother-young interactions in a maternity colony of Myotis formosus. Journal of Mammalogy, 81(3), 726-733.
Eastern small-footed bat	Myotis leibii	Eastern U.S., Canada	≤22O'Keefe, J. M., & LaVoie, M. (2011). Maternity colony of eastern small-footed myotis (Myotis leibii) in a historic building. Southeastern Naturalist, 10(2), 381-383.
Greater mouse-eared bat	Myotis myotis	Europe	50-800Castella, V., Ruedi, M., & Excoffier, L. (2001). Contrasted patterns of mitochondrial and nuclear structure among nursery colonies of the bat Myotis myotis. Journal of Evolutionary Biology, 14(5), 708-720.
Cave myotis	Myotis velifer	Southwest U.S., Mexico	100-3,000
Yuma myotis	Myotis yumanensis	Western U.S.	100-1,000
Arizona myotis	Myotis occultus	Southwestern U.S.	67Hayward, B. J. (1963). A maternity colony of Myotis occultus. Journal of Mammalogy, 44(2), 279-279.
Daubenton's bat	Myotis daubentonii	Europe, Asia	6-144Encarnação, J. A., Kierdorf, U., Holweg, D., Jasnoch, U., & Wolters, V. (2005). Sex‐related differences in roost‐site selection by Daubenton's bats Myotis daubentonii during the nursery period. Mammal Review, 35(3‐4), 285-294.
Long-eared myotis	Myotis evotis	Canada, Western U.S.	4Rancourt, S. J., Rule, M. I., & O'Connell, M. A. (2005). Maternity roost site selection of long-eared myotis, Myotis evotis. Journal of Mammalogy, 86(1), 77-84.
Tricolored bat	Perimyotis subflavus	Eastern U.S.	9-40Hoying, K. M., & Kunz, T. H. (1998). Variation in size at birth and post‐natal growth in the insectivorous bat Pipistrellus subflavus (Chiroptera: Vespertilionidae). Journal of Zoology, 245(1), 15-27.Winchell, J. M., & Kunz, T. H. (1996). Day-roosting activity budgets of the eastern pipistrelle bat, Pipistrellus subflavus (Chiroptera: Vespertilionidae). Canadian Journal of Zoology, 74(3), 431-441.
Parti-coloured bat	Vespertilio murinus	Europe, Asia	>30Granat, M. M. (2023). Confirmation of the presence of Vespertilio murinus maternity colony in Warsaw. Przegląd Przyrodniczy, XXXIV, 3 (2023), 101-103.
Big brown bat	Eptesicus fuscus	North America, Central America, the Caribbean	20-100{{cite web \|url=http://dnr.wi.gov/files/PDF/pubs/er/ER0707.pdf \|title=Big Brown Bat (Eptesicus fuscus) Species Guidance \|author= \|date=11 Sep 2013 \|website=Wisconsin Department of Natural Resources \|access-date=2 March 2013}}
Serotine bat	Eptesicus serotinus	Europe, Asia	5-200Catto, C. M. C., Hutson, A. M., Raccey, P. A., & Stephenson, P. J. (1996). Foraging behaviour and habitat use of the serotine bat (Eptesicus serotinus) in southern England. Journal of Zoology, 238(4), 623-633.
Northern bat	Eptesicus nilsonii	Europe, Asia	10-70Rydell, J. (1989). Site fidelity in the northern bat (Eptesicus nilssoni) during pregnancy and lactation. Journal of mammalogy, 70(3), 614-617.
Silver-haired bat	Lasionycteris noctivagans	Bermuda, Canada, Mexico, U.S.	8Betts, B. J. (1998). Roosts used by maternity colonies of silver-haired bats in northeastern Oregon. Journal of Mammalogy, 79(2), 643-650.
Townsend's big-eared bat	Corynorhinus townsendii	Canada, Mexico, U.S.	40-55Mazurek, M. J. (2004). A maternity roost of Townsend's big-eared bats (Corynorhinus townsendii) in coast redwood basal hollows in northwestern California. Northwestern Naturalist, 85(2), 60-62.
Virginia big-eared bat	Corynorhinus townsendii virginianus	Appalachian U.S.	100-6335{{cite web \|url=http://www.biologicaldiversity.org/campaigns/esa_works/profile_pages/VirginiaBigearedBat.html \|title=Virginia big-eared bat \|author= \|website=Center for Biological Diversity \|access-date=2 March 2017}}
Ozark big-eared bat	Corynorhinus townsendii ingens	AR, OK, MO	55-309Clark, B. K., Clark, B. S., & Leslie Jr, D. M. (1997). Seasonal variation in use of caves by the endangered Ozark big-eared bat (Corynorhinus townsendii ingens) in Oklahoma. American Midland Naturalist, 388-392.
Rafinesque's big-eared bat	Corynorhinus rafinesquii	Southeastern U.S.	≤118Hurst, T. E., & Lacki, M. J. (1999). Roost selection, population size and habitat use by a colony of Rafinesque's big-eared bats (Corynorhinus rafinesquii). The American midland naturalist, 142(2), 363-371.
Common noctule	Nyctalus noctula	Europe, Asia, North Africa	20-50{{cite iucn \|author=Csorba, G. \|author2=Hutson, A.M. \|date=2016 \|title=Nyctalus noctula \|volume=2016 \|page=e.T14920A22015682 \|doi=10.2305/IUCN.UK.2016-2.RLTS.T14920A22015682.en \|access-date=12 November 2021}}
Common pipistrelle	Pipistrellus pipistrellus	Europe, North Africa, Asia	92-262Webb, P. I., Speakman, J. R., & Racey, P. A. (1996). Population dynamics of a maternity colony of the pipistrelle bat (Pipistrellus pipistrellus) in north‐east Scotland. Journal of Zoology, 240(4), 777-780.
Nathusius's pipistrelle	Pipistrellus nathusii	Europe	5-150Russ, J. M., O'Neill, J. K., & Montgomery, W. I. (1998). Nathusius' pipistrelle bats (Pipistrellus nathusii, Keyserling & Blasius 1839) breeding in Ireland. Journal of Zoology, 245(3), 345-349.
Evening bat	Nycticeius humeralis	Eastern U.S.	≤492Whitaker Jr, J. O., & Clem, P. (1992). Food of the evening bat Nycticeius humeralis from Indiana. American Midland Naturalist, 211-214.
Gould's wattled bat	Chalinolobus gouldii	Australia	20-30Dixon, J. M., & Huxley, L. (1989). Observations on a maternity colony of Gould’s wattled bat Chalinolobus gouldii (Chiroptera: Vespertilionidae). Mammalia, 53(3), 395-414.
Southern forest bat	Vespadelus regulus	Australia	<25Taylor, R. J., & Savva, N. M. (1988). Use of roost sites by four species of bats in state forest in south-eastern Tasmania. Wildlife Research, 15(6), 637-645.
Lesser long-eared bat	Nyctophilus geoffroyi	Australia	3-23
Pallid bat	Antrozous pallidus	Canada, Western U.S., Mexico	10-150Davis, R., & Cockrum, E. L. (1963). Bridges utilized as day-roosts by bats. Journal of Mammalogy, 44(3), 428-430.
Barbastelle	Barbastella barbastellus	Europe	10Hillen, J., Kiefer, A., & Veith, M. (2009). Foraging site fidelity shapes the spatial organisation of a population of female western barbastelle bats. Biological Conservation, 142(4), 817-823.
Allen's big-eared bat	Plecotus phyllotis	Southwestern U.S., Mexico	18-97Cockrum, E. L., & Musgrove, B. F. (1964). Additional records of the Mexican big-eared bat, Plecotus phyllotis (Allen), from Arizona. Journal of Mammalogy, 45(3), 472-474.
Family: Rhinolophidae
Mehely's horseshoe bat	Rhinolophus mehelyi	Europe, Middle East	<60Sharifi, M. (2004). Postnatal growth and age estimation in the Mehely's horseshoe bat (Rhinolophus mehelyi). Acta Chiropterologica, 6(1), 155-161.
Lesser horseshoe bat	Rhinolophus hipposideros	Europe, North Africa, Asia	2-750Bontadina, F., Arlettaz, R., Fankhauser, T., Lutz, M., Mühlethaler, E., Theiler, A., & Zingg, P. (2000). The lesser horseshoe bat Rhinolophus hipposideros in Switzerland: present status and research recommendations. Le Rhinolophe, 14, 69-83.{{cite journal \|last1=Knight \|first1=Tessa \|last2=Jones \|first2=Gareth \|title=Importance of night roosts for bat conservation: roosting behaviour of the lesser horseshoe bat Rhinolophus hipposideros \|url=https://doi.org/10.3354/esr00194 \|journal=Endangered Species Research \|date=2009 \|volume=8 \|issue=1–2 \|page=2 \|doi=10.3354/esr00194}}
Rufous horseshoe bat	Rhinolophus rouxii	Asia, Southeast Asia	50-60Biswas, J., & Shrotriya, S. (2011). Dandak: a mammalian dominated cave ecosystem of India. Subterranean Biology, 8, 1.
Family: Molossidae
Mexican free-tailed bat	Tadarida brasiliensis	U.S., Central America, South America	≤15 million{{cite web \|url=http://www.batcon.org/our-work/regions/usa-canada/protect-mega-populations/bracken-cave \|title=Protecting a Jewel in Texas \|author= \|website=Bat Conservation International\|access-date=2 March 2017 }}
Big free-tailed bat	Nyctinomops macrotis	North America, Central America, South America	≤2,000Sparks, D. W., & Valdez, E. W. (2003). Food habits of Nyctinomops macrotis at a maternity roost in New Mexico, as indicated by analysis of guano. The Southwestern Naturalist, 48(1), 132-135.
Family: Phyllostomatidae
Geoffroy's tailless bat	Anoura geoffroyi	Central America, South America	<150Galindo-Galindo, C., Castro-Campillo, A., Salame-Méndez, A., & Ramírez-Pulido, J. (2000). Reproductive events and social organization in a colony of Anoura geoffroyi (Chiroptera: Phyllostomidae) from a temperate Mexican cave. Acta Zoológica Mexicana, (80), 51-68.
Family:Miniopteridae
Common bent-wing bat	Miniopterus schreibersii	Europe, Asia, Australia	2,500-5,000Vincent, S., Nemoz, M., & Aulagnier, S. (2010). Activity and foraging habitats of Miniopterus schreibersii (Chiroptera: Miniopteridae) in southern France: implications for its conservation. Hystrix: The Italian Journal of Mammalogy, 22(1).
Family: Pteripodidae
Bornean large flying fox	Pteropus vampyrus	Borneo	<15,000Gumal, M. T. (2004). Diurnal home range and roosting trees of a maternity colony of Pteropus vampyrus natunae (Chiroptera: Pteropodidae) in Sedilu, Sarawak. Journal of Tropical Ecology, 20(03), 247-258.

References

Category:Bats