Summary
Nursing observations over two summers involving 76 lactating female evening bats, Nycticeius humeralis, and 128 pups in an attic in northern Missouri indicate that communal nursing occurs rarely until 2 weeks before weaning during which time over 18% of nursing bouts involve nondescendant offspring. The average relatedness among female pairs nursing non-descendant offspring, based on identity-by-descent estimates using allozyme data, was 0.04 (SE=0.12). Mitochondrial DNA d-loop sequence comparisons confirm that at most only 2 of 20 female pairs nursing non-descendant offspring came from the same matriline. Thus, females do not nurse matrilineal kin preferentially despite female natal philopatry. In addition, the average degree of relatedness within a colony (r=0.01, SE =0.03) is too low to provide any indirect benefits from communal nursing. Female error alone is insufficient to explain these observations because females tended to allow female nondescendant young to nurse but excluded nondescendant males, particularly when they had all-male litters. Furthermore, communal nursing bouts did not differ in duration from parental nursing bouts and involved 31 % of all banded females and 24% of all banded pups observed nursing. Communal nursing occurred most frequently when pups began hunting on their own and when lactating females attained their lowest average pre-fed body weight. Mortality during this period was higher for male than female pups, and relative weights implicate starvation as the cause. Time-lapse video records of four families of bats in captivity showed that the number of nursing bouts was proportional to daily weight change. I propose that these results are consistent with both immediate and delayed benefits accruing to females which experience variable hunting success. If a female with extra milk reduced her weight by dumping milk prior to her next foraging trip, she could obtain an immediate energetic benefit and maintain maximum milk production. By restricting such milk donations to nondescendant females she may also increase colony size and thereby enhance her future acquisition of information about foraging and roosting sites.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Axelrod R, Hamilton WD (1981) The evolution of cooperation. Science 211:1390–1396
Bailey GL, Bailey RD, Jensen CL (1953) The effect of incomplete milking on the secretion of milk. Proc 13th Int Dairy Congr 2:76–83
Bain JR, Humphrey SR (1986) Social organization and biased primary sex ratio of the evening bat, Nycticeius humeralis. Florida Sci 49:22–31
Baker WW, Marshall SG, Baker VB (1968) Autumn fat deposition in the evening bat (Nycticeius humeralis). J Mammal 49:314–317
Bertram BCR (1976) Kin selection in lions and evolution. In: Bateson PPG, Hinde RA (eds) Growing points in ethology. Cambridge University Press, Cambridge, pp 281–301
Birgersson B, Ekvall K, Temrin H (1991) Allosuckling in fallow deer, Dama dama. Anim Behav 42:326–327
Boness DJ (1990) Fostering behavior in Hawaiian monk seals: is there a reproductive cost? Behav Ecol Sociobiol 27:113–122
Bryant MJ, Rowlinson P (1984) Nursing and suckling behaviour of sows and their litters before and after grouping in multiaccomodation pens. Anim Prod 38:277–282
Clutton-Brock TH, Albon SD, Guinness FE (1989) Fitness costs of gestation and lactation in wild mammals. Nature 337:260–262
Connor RC (1986) Pseudo-reciprocity: investing in mutualism. Anim Behav 34:1562–1566
Davis RB, Herreid CFI, Short HL (1962) Mexican free-tailed bats in Texas. Ecol Monogr 32:311–346
Eales L, Bullock PJ, Slater PJB (1988) Shared nursing in captive pipistrelles (Pipistrellus pipistrellus)? J Zool 216: 584–587
Esser K-H, Schmidt U (1989) Mother-infant communication in the lesser spear-nosed bat Phyllostomus discolor (Chiroptera, Phyllostomidae): evidence for acoustic learning. Ethology 82:156–168
Fogden SCL (1971) Mother-young behaviour at grey seal breeding beaches. J Zool Lond 164:61–92
Gates WH (1941) A few notes on the evening bat, Nycticeius humeralis (Rafinesque). J Mammal 22:53–56
Gittleman JL, Thompson SD (1988) Energy allocation in mammalian reproduction. Am Zool 28:863–875
Hamilton WD (1964) The genetical evolution of social behavior. J Theor Biol 7:1–51
Harris H, Hopkinson DA (1976) Handbook of enzyme electrophoresis in human genetics. American Elsevier, New York
Hoogland JL, Tamarin RH, Levy CK (1989) Communal nursing in prairie dogs. Behav Ecol Sociobiol 24:91–95
Humphrey SR, Cope JB (1970) Population samples of the evening bat, Nycticeius humeralis. J Mammal 51:399–401
Jones C (1967) Growth, development, and wing loading in the evening bat, Nycticeius humeralis (Rafinesque). J Mammal 48:1–19
Loudon ASI, Kay RNB (1984) Lactational constraints on a seasonally breeding mammal: the red deer. Symp Zool Soc Lond 51:233–252
Loudon ASI, McNeilly AS, Milne JA (1983) Nutrition and lactational control of fertility in red deer. Nature 302:145–147
MacDonald DW (1981) Dwindling resources and the social behaviour of capybaras, (Hydrochoerus hydrochoerus) (Mammalia). J Zool Lond 194:371–391
Mattingly DK, McClure PA (1985) Energy allocation during lactation in cotton rats (Sigmodon hispidus) on a restricted diet. Ecology 66:928–937
McCracken GF (1984) Communal nursing in mexican free-tailed bat maternity colonies. Science 233:1090–1091
McCracken GF, Wilkinson GS (1988) Allozyme techniques and kinship assessment in bats. In: Kunz TH (ed) Ecological and behavioral methods for the study of bats. Smithsonian Institution Press, Washington DC, pp 141–156
Mepham B (1976) The secretion of milk. Edward Arnold Limited, Southampton
Millar JS (1977) Adaptive features of mammalian reproduction. Evolution 31:370–386
Muhlbock O (1959) Factors influencing the life-span of inbred mice. Gerontologia 3:177–183
Packer C, Lewis S, Pusey A (1992) A comparative analysis of non-offspring nursing. Anim Behav 43:265–282
Queller DC, Goodnight KF (1989) Estimating relatedness using genetic markers. Evolution 43:258–275
Riedman ML (1982) The evolution of alloparental care and adoption in mammals and birds. Q Rev Biol 57:405–435
Rood JP (1972) Ecological and behavioural comparisons of three genera of Argentine cavies. Anim Behav Monogr 5:1–83
Schalm OW, Mead SW (1943) The effect of incomplete milking on chronic mastitis caused by Streptococcus agalactiae. J Dairy Sci 26:823–831
Scherrer JA, Wilkinson GS (1992) Isolation calls of evening bats provide evidence for heritable signatures. Anim Behav in press
Steele SRE (1991) The energetics of reproduction in the evening bat, Nycticieus humeralis. University of Maryland, College Park, MS thesis
Trivers RL (1971) The evolution of reciprocal altruism. Q Rev Biol 46:35–57
Tulloch DG (1979) The water buffalo, Bubalus bubalis, in Australia: reproductive and parent-offspring behaviour. Austr Wild Res 6:265–287
Wade MJ (1980) Kin selection: its components. Science 210:665–667
Watkins LC (1970) Observations on the distribution and natural history of the evening bat (Nycticeius humeralis) in northwestern Missouri and adjacent Iowa. Trans Kans Acad Sci 72:330–336
Watkins LC, Shump KAJ (1981) Behavior of the evening bat Nycticeius humeralis at a nursery roost. Am Midl Nat 105:258–268
Wilkinson GS (1985) On estimating relatedness using genetic markers. Evol 39:1169–1174
Wilkinson GS (1992) Information transfer at evening bat colonies. Anim Behav 44:501–518
Wilkinson GS, Baker AEM (1988) Communal nesting among genetically similar house mice. Ethology 77:103–114
Wilkinson GS, Chapman AS (1991) Length and sequence variation in evening bat d-loop mtDNA. Genetics 128:607–617
Wilkinson L (1989) SYSTAT: The system for statistics. SYSTAT, Inc., Evanston
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wilkinson, G.S. Communal nursing in the evening bat, Nycticeius humeralis . Behav Ecol Sociobiol 31, 225–235 (1992). https://doi.org/10.1007/BF00171677
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00171677