Phenology and Pollination Ecology of Three Brazilian Fig Species (Moraceae)

The phenology and pollination ecology of three native fig species were studied in southeastern Brazil. Populations displayed continual syconia production, with one species showing intra-tree flowering asynchrony. Pollination of the fig flowers was necessary for the development of the syconia; lack of pollination induced abortion of syconia. All three species follow the general pattern of pollination known for figs, but the behavior of the pollinator wasps, Pegoscapus spp., differed in some aspects from those of other neotropical and paleotropical fig wasps, mainly with respect to pollen loading and unloading during pollination. The longevity of Pegoscapus wasps outside the syconium was about two days.     

捕食风险与动物行为及其决策的关系

捕食风险与动物行为及其决策的关系边疆晖樊乃昌（中国科学院西北高原生物研究所,西宁８１０００１）（浙江师范大学,金华３１００００）ＴｈｅＥｆｅｃｔｏｆＰｒｅｄａｔｉｏｎＲｉｓｋｏｎＡｎｉｍａｌｓ’ＢｅｈａｖｉｏｒａｎｄＴｈｅｉｒＤｅｃｉｓｉｏｎ．Ｂｉａ...     

Spawning behavior and reproductive isolation of two species ofPseudolabrus

The reproductive behavior of two wrasses,Pseudolabrus eoethinus (Richardson, 1846) andP. sieboldi Mabuchi & Nakabo, 1997, was studied on a rocky coast in Shikoku, Japan, where the two species occur sympatrically. In the study area, individual males of each species established mating territories within which pair spawnings occurred. Pair spawnings were observed only between conspecifics, indicating that the two coexisting species were reproductively isolated. Both species usually spawned during the afternoon in early winter and had similar reproductive behavior. Although habitat, temporal and behavioral isolation mechanisms were not apparent, reproductive isolation seemed to occur via premating isolation through visual recognition of conspecific mates because the two species differed in body size and coloration. On one occasion a maleP. sieboldi was observed to perform streaking behavior to join a spawning pair ofP. eoethinus. Thus, postmating isolation between the two species is also discussed.     

Biological Attributes of the Nematode, Thripinema nicklewoodi, a Potential Biological Control Agent of Western Flower Thrips

Western flower thrips (WFT), Frankliniella occidentalis (Thysanoptera: Thripidae), is the most important insect pest for greenhouse flower crops, but chemical control is often difficult because of the thrips' location in flowers and buds. Thripinema nicklewoodi (Tylenchida: Allantonematidae) is an entomoparasitic nematode that attacks and sterilizes WFT, but its biology and impact on WFT are poorly understood. Methods to propagate and study T. nicklewoodi with a microscope slide arena for observation and a rolled bean leaf arena for rearing were developed. On average, 21.4 nematodes were excreted per day by a parasitized female WFT. The sex ratio of the excreted nematodes was 6.0/1.0 (female/male). After dissection of adult WFT, a maximum of 11 ovoid-shaped first-generation nematodes in a female thrips and 6 in a male thrips were found. There were more second-generation nematodes in the adult female WFT (192.6) than in the adult male WFT (93.7). When 50 healthy first instar WFT were exposed to 4 parasitized female WFT in a rolled bean leaf, a 75.3% mean parasitization rate in the adult stage of the thrips was obtained. In contrast to previous reports, male WFT can be parasitized as readily as females. Parasitism reduced the longevity of both adult female and adult male WFT, and the degree of reduction was higher in adult male WFT. T. nicklewoodi, when presented with various WFT life stages (first instar, second instar, prepupa, pupa, adult female, and adult male), achieved the highest attack rate in first and second instars and prepupa. The free-living nematodes excreted by the hosts actively migrated to a trichome on leaf disks in the observation arena and moved up this structure. Then, the nematode actively waved the anterior part of its body while attaching itself to the trichome with the posterior part of its body. After a nematode contacted the leg of a thrips, the nematode immediately moved up along the leg toward the abdomen of the host. Increased understanding of the biology of T. nicklewoodi is important to better assess its potential for biological control of WFT.     

Effect of bioregulator-treated sorghum on greenbug fecundity and feeding behavior: implications for host-plant resistance

Three commercial and six experimental plant growth bioregulators were surveyed for their effect on aphid reproduction when applied to sorghum. Only CCC and PIX had a significant effect on the greenbug, Schizaphis graminum. Application of the commercial bioregulators CCC and PIX^R caused about a 50% decrease in aphid reproduction rate when applied to greenbug susceptible sorghum but had little effect when applied to a greenbug resistant sorghum line. Electronic monitoring of aphid probing behavior on CCC treated, greenbug-susceptible sorghum showed a response pattern which was indistinguishable from that normally observed on greenbug resistant lines and was different from that associated with aphid probing behavior on untreated susceptible lines. The isolated pectin content of the CCC treated susceptible sorghum was twice that of the controls and had twice the methoxy content. These results support the argument that pectin is a barrier to aphid-stylet penetration for phloem feeding aphids which probe intercellularly and that manipulation of pectin content and/or structure can be a major factor in host-plant resistance to sap-sucking insects.     

FLIPPER RUBBING BEHAVIORS IN WILD BOTTLENOSE DOLPHINS (TURSIOPS ADUNCUS)

"Flipper rubbing" behavior was quantitatively analyzed in wild Indo-Pacific bottlenose dolphins ( Tursiops aduncus ) around Mikura Island, Tokyo, Japan. We observed two types of flipper rubbing: (1) F-B rubbing; one dolphin (Rubber) rubbed its flipper over various parts of a partner's (Rubbee) body, and (2) F-F rubbing; both dolphins rubbed each other's anterior flipper edge in alternating shifts. F-B rubbings tended to be initiated by the Rubbee and were terminated by the Rubber. The Rubbee often moved actively its body part that was in contact with the Rubber's flipper, and assumed side-up, upside-down, or other postures while the Rubber remained horizontal in most cases. These facts suggest that the Rubbee engaged in F-B rubbing more actively than the Rubber, and might receive some benefit from the frictional contact during F-B rubbing. Dolphins often switched their roles as Rubber and Rubbee between episodes of flipper rubbing bout. Adults and sub-adults exchanged F-B rubbing and F-F rubbing most often with individuals of the same sex in the same age class. F-B rubbing was frequent in mother-and-calf dyads. Our results suggest that flipper rubbing is an affiliative behavior which could be a quantitative measure of social relationships among individuals of this species in future studies.     

Activity Pattern of the Trawling Phyllostomid Bat,Macrophyllum macrophyllum,in Panamá1

We studied activity patterns of long‐legged bats, Macrophyllum macrophyllum (Phyllostomidae), in the Barro Colorado Nature Monument, Panamá, using radio‐telemetry. Activity of four males and five females equipped with radio‐transmitters were monitored for 4–7 entire nights each between April and July 2002. Bats exhibited maximum activity around dusk and high activity during the night. Males and females foraged for equal amounts of time in continuous flight (mean: 7 min, maximum 1 h) with interspersed resting phases (mean: 15 min, maximum 3 h). Activity of M. macrophyllum was sensitive to several factors. Time of emergence and return to day roost were correlated with time of sunset and sunrise, respectively. Maximum bat activity coincided with high abundance of aerial insects. Finally, heavy rain caused bats to reduce or cease flight activity. Direct observations and field video recordings support the assumption that M. macrophyllum employs two distinct foraging modes: trawling of insects from and capture of aerial insects at low heights above water. Combination of foraging modes gives M. macrophyllum high flexibility and efficiency in prey search. Activity, foraging mode, and morphology, which are similar to trawling bats from other families, distinguish M. macrophyllum from all other phyllostomid species and grant it access to open habitat above water, a habitat no other phyllostomid bat has conquered.     

印度洋中西部和大西洋西部水域大眼金枪鱼的食性比较

根据2004年8月至2005年3月大西洋西部水域及2003年12月份至2004年5月份在印度洋中西部水域金枪鱼延绳钓渔业所获取的大眼金枪鱼数据，对两个诃查区域内的大眼金枪鱼食性进行了研究。结果表明，印度洋中西部水域大眼金枪鱼的食物组成包括沙丁鱼、鱿鱼、乌贼等13个饵料类群，其中主要摄食鱿鱼和沙丁鱼；大西洋西部水域大眼金枪鱼主要摄食沙丁鱼、鱿鱼、虾类等13种饵料类群，主要以沙丁鱼为饵，其次为鱿鱼。印度洋中西部水域大眼金枪鱼空胃率非常高，基本上维持在60％以上；大西洋西部水域大眼金枪鱼空胃率相对较低，基本上都在30％以下。印度洋中西部水域大眼金枪鱼平均饱满指数变化不大，基本上维持在0．40～0．55之间。大西洋西部水域大眼金枪鱼平均饱满指数变化也不太大。印度洋中西部水域大眼金枪鱼各月平均饱满指数高于大西洋西部水域，且各月空胃率高于后者。印度洋中西部和大西洋西部水域大眼金枪鱼Shannon-Weiner多样性指数H’基本上都1．50～2．00之间变化。相同调查月份内，印度洋中西部水域大眼金枪鱼食物Pielou均匀度指数J’均高于大西洋西部水域。     

Dormancy Breaking and Storage Behavior of Garcinia cowa Roxb. (Guttiferae) Seeds: Implications for Ecological Function and Germplasm Conservation

The dormancy breaking and storage behavior of Garcinia cowa Roxb. seeds were investigated.The seeds of G. cowa had 8-11 months dormancy in their natural habitat. Seeds were matured and dispersed at the end of the rainy season (mid-late August to late September) and were scatter-hoarded by rodents as food for winter after the seeds had fallen to the ground. Seedlings often emerged in the forest during the rainy season (May to August) the following year. Intact seeds of G. cowa failed to germinate after being sown at 30 ℃ for 120 d and the mean germination time (MGT) of seeds cultured in a shade (50% sunlight)nursery was 252 d. The most effective method of breaking dormancy was to remove the seed coat totally,which reduced the MGT to 13 d at 30 ℃. Germination was also promoted by partial removal of the seed coat (excising the hilum and exposing the radicle) and chemical scarification (immersion in 1% H2O2 for 1 d).Unscarified seeds take up water rapidly in the first 96 h, but water was absorbed by the outside seed coat,without penetrating through it. The moisture content (MC) of G. cowa seeds was high (50% in fresh weight)at shedding. The seeds could tolerate desiccation to some extent, until the MC reached approximately 40%;below that, the viability decreases rapidly and all seeds died at approximately 17% of MC. Seed viability decreased rapidly when seeds were chilled at 4 ℃; germination was 2% after storage for 1 week. Even stored at 10 ℃, seeds began to be damaged after 4 weeks. Seed storage for 1 yr revealed that in both dry (relative humidity (35 ± 5)%) and moist (wet sand) storage conditions, seed viability declined, but germination percentages for seeds stored under moist conditions are better than for seed stored under dry conditions.Because of their low tolerance to desiccation, marked chilling sensitivity and relatively short lifespan, G.cowa seeds should be classified into the tropical recalcitrant category. The ecological implications of dormant recalcitrant seeds and cues on storing recalcitrant seeds were discussed.     

ACOUSTIC ECOLOGY OF FORAGING BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS), HABITAT-SPECIFIC USE OF THREE SOUND TYPES

The function(s) of a particular sound can be explored in detail only if the context of its use is well understood. The behavior of the signaler, and the habitat in which that behavior is observed, are two of the most important components of understanding context specific use of a sound. Bottlenose dolphin foraging behavior is often inferred from relatively few behavioral cues that are visible from the surface. To investigate the use of three specific sound types: echolocation, whistles, and pops during foraging, I recorded sound use by animals engaged in a set of previously defined specific foraging behaviors using a system that allowed me to see animals throughout the water column. Lone foraging animals produced all three sounds at significantly higher rates than animals foraging in groups, and the rate of sound production per animal in multi-animal foraging groups did not vary even as the groups reached up to five individuals. Production of echolocation and pops by lone foraging animals accounted for much of the difference. Foraging dolphins also displayed habitat-specific use of particular sound types. They preferentially produced echolocation and pops in the sand habitat and, at least for lone animals, in the seagrass edge habitat.