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Natal Colony (natal + colony)
Selected AbstractsIndividual recognition in the Damaraland mole-rat, Cryptomys damarensis (Rodentia: Bathyergidae)JOURNAL OF ZOOLOGY, Issue 3 2000D. S. Jacobs Abstract Conspecific recognition was investigated in the eusocial and subterranean Damaraland mole-rat Cryptomys damarensis. This species out-breeds and is xenophobic. Differences in the frequency of agonistic behaviours between male,male pairs were used as an indication of recognition. Focal males were tested with familiar, unfamiliar, and foreign conspecifics. Males directed significantly more aggression towards unfamiliar colony mates and foreign conspecifics than towards familiar colony mates. This happened even though both focal and test animals retained contact with their natal colonies and, therefore, any group cue. Furthermore, when male,male pairs were returned to their natal colonies they continued directing aggression towards each other but not towards the rest of the colony. These results suggest that the Damaraland mole-rat uses individually distinct cues rather than kin-specific cues based on genetic relatedness. [source] Shift from independent to dependent colony foundation and evolution of ,multi-purpose' ergatoid queens in Mystrium ants (subfamily Amblyoponinae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009MATHIEU MOLET Division of labour improves fitness in animal societies. In ants, queens reproduce, whereas workers perform all other tasks. However, during independent colony founding, queens live as solitary insects and must be totipotent, especially in species where they need to forage. In many ants, solitary founding has been replaced by dependent founding, where queens are continuously helped by nestmate workers. Little is known about the details of this evolutionary transition. Mystrium rogeri from Madagascar and Mystrium camillae from Southeast Asia (subfamily Amblyoponinae) have winged queens, but three congeneric species from Madagascar reproduce with permanently wingless queens instead. We show that this ,ergatoid' caste has distinct body proportions in all three species, expressing a mixture of both queen and worker traits. Ergatoid queens have functional ovaries and spermatheca, and tiny wing rudiments. They can be as numerous as workers within a colony, but only a few mate and reproduce, whereas most behave as sterile helpers. The shape of their mandibles makes them unsuited for hunting and, together with a lack of metabolic reserves (i.e. in the form of wing muscles), this means that ergatoid queens cannot be solitary foundresses. In comparison with winged queens, ergatoid queens are less costly per capita and they experience lower mortality. They remain in their natal colonies where they can either reproduce or function as helpers, making them a ,multi-purpose' caste. Within the Amblyoponinae, ergatoid queens replace winged queens in Onychomyrmex as well. However, in this genus, ergatoid queens are ,sole-purpose', few are produced each year and they reproduce but do not work. Hence, different types of ergatoid queens evolved to replace winged queens in ants. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 198,207. [source] Sib-mating in the ant Plagiolepis pygmaea: adaptative inbreeding?JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 12 2009N. THURIN Abstract Multiple functional queens in a colony (polygyny) and multiple mating by queens (polyandry) in social insects challenge kin selection, because they dilute inclusive fitness benefits from helping. Colonies of the ant Plagiolepis pygmaea brash contain several hundreds of multiply mated queens. Yet, within-colony relatedness remains unexpectedly high. This stems from low male dispersal, extensive mating among relatives and adoption of young queens in the natal colony. We investigated whether inbreeding results from workers expelling foreign males, and/or from preferential mating between related partners. Our data show that workers actively repel unrelated males entering their colony, and that queens preferentially mate with related males. These results are consistent with inclusive fitness being a driving force for inbreeding: by preventing outbreeding, workers reduce erosion of relatedness within colonies due to polygyny and polyandry. That virgin queens mate preferentially with related males could result from a long history of inbreeding, which is expected to reduce depression in species with regular sibmating. [source] The determinants of queen size in a socially polymorphic antJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 9 2009J. MEUNIER Abstract In social animals, body size can be shaped by multiple factors, such as direct genetic effects, maternal effects, or the social environment. In ants, the body size of queens correlates with the social structure of the colony: colonies headed by a single queen (monogyne) generally produce larger queens that are able to found colonies independently, whereas colonies headed by multiple queens (polygyne) tend to produce smaller queens that stay in their natal colony or disperse with workers. We performed a cross-fostering experiment to investigate the proximate causes of queen size variation in the socially polymorphic ant Formica selysi. As expected if genetic or maternal effects influence queen size, eggs originating from monogyne colonies developed into larger queens than eggs collected from polygyne colonies, be they raised by monogyne or polygyne workers. In contrast, eggs sampled in monogyne colonies were smaller than eggs sampled in polygyne colonies. Hence, eggs from monogyne colonies are smaller but develop into larger queens than eggs from polygyne colonies, independently of the social structure of the workers caring for the brood. These results demonstrate that a genetic polymorphism or maternal effect transmitted to the eggs influences queen size, which probably affects the social structure of new colonies. [source] The initial journey of juvenile emperor penguinsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2007Gerald L. Kooyman Abstract 1.The first major journey of emperor penguins, among several in their lifetime, is the juveniles' dispersal from their natal colony on a trip that takes them beyond Antarctic waters. The route taken by fledglings from Cape Washington (74.5°,S; 165.4°,E) was studied by applying satellite transmitters to ten individuals during December 1994,1996. In January 2001 transmitters with longer transmission capacity were also applied to six hand-fed fledglings, which had been held captive for one month while attaining a body mass exceeding that of wild birds. These post-captive birds were released at the ice edge of McMurdo Sound (77.5°,S; 165.0°,E), which is in the vicinity of other emperor penguin colonies, and 320,km south of their natal colony of Cape Washington. 2.Independent of their parents, the wild birds travelled north-east for the next two months, reaching locations as low as 57°,S. The post-captive birds travelled north also, but their trek reached only to about 63°,S before they turned south, or remained near their most northerly position from March through May. 3.It was concluded that among colonies in the southern Ross Sea: (a) most healthy fledglings survive at least the first two months at sea, feeding themselves as they go; (b) the Cape Washington fledglings travelled as far north as 57°,S, and much of this journey was in ice free waters; (c) by April, the post-captive birds reached at least as far as the large-scale pack ice edge and possibly beyond the edge at 63°,S; (d) by early March the trend north ends, and by about late March the birds travel to, or remain near the northern ice edge. 4.The reason the birds travel so far north remains a mystery. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||