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101.
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103.
Effects of pond salinization on survival rate of amphibian hosts infected with the chytrid fungus
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Michelle Pirrie Stockwell Lachlan James Storrie Carla Jean Pollard John Clulow Michael Joseph Mahony 《Conservation biology》2015,29(2):391-399
The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. Recent studies show that sodium chloride (NaCl) has fungicidal properties that reduce the mortality rates of infected hosts in captivity. We investigated whether similar results can be obtained by adding salt to water bodies in the field. We increased the salinity of 8 water bodies to 2 or 4 ppt and left an additional 4 water bodies with close to 0 ppt and monitored salinity for 18 months. Captively bred tadpoles of green and golden bell frog (Litoria aurea) were released into each water body and their development, levels of B. dendrobatidis infection, and survival were monitored at 1, 4, and 12 months. The effect of salt on the abundance of nontarget organisms was also investigated in before and after style analyses. Salinities remained constant over time with little intervention. Hosts in water bodies with 4 ppt salt had a significantly lower prevalence of chytrid infection and higher survival, following metamorphosis, than hosts in 0 ppt salt. Tadpoles in the 4 ppt group were smaller in length after 1 month in the release site than those in the 0 and 2 ppt groups, but after metamorphosis body size in all water bodies was similar . In water bodies with 4 ppt salt, the abundance of dwarf tree frogs (Litoria fallax), dragonfly larvae, and damselfly larvae was lower than in water bodies with 0 and 2 ppt salt, which could have knock‐on effects for community structure. Based on our results, salt may be an effective field‐based B. dendrobatidis mitigation tool for lentic amphibians that could contribute to the conservation of numerous susceptible species. However, as in all conservation efforts, these benefits need to be weighed against negative effects on both target and nontarget organisms. 相似文献
104.
Genetic monogamy in the common loon (Gavia immer) 总被引:4,自引:0,他引:4
Walter H. Piper David C. Evers Michael W. Meyer Keren B. Tischler Joseph D. Kaplan Robert C. Fleischer 《Behavioral ecology and sociobiology》1997,41(1):25-31
We conducted behavioral observations and genetic analysis on breeding pairs of common loons in the upper Great Lakes region
from 1993 through 1995 to look for behavioral evidence of extrapair copulations (EPCs) and to determine parentage of young.
Pairs remained close to each other (usually within 20 m) during the pre-laying period, leaving little opportunity for EPCs
to occur. Males and females both maintained physical proximity by approaching each other when they became separated. Copulations
were obvious but infrequent, occurring about once every other day during the pre-laying period. Multilocus DNA fingerprinting
was consistent with behavioral findings: 58 young from 47 different families were all genetic offspring of parents that raised
them. Perfect genetic monogamy (genetic parentage of young by parents that rear them) in loons might arise as a consequence
of the need for vigorous territorial defense to prevent territorial takeover.
Received: 8 August 1996 / Accepted after revision: 22 March 1997 相似文献
105.
106.
Summary Components of the green leaf volatile complex (Z-3-hexenyl acetate andE-2-hexenyl acetate) were shown to enhance responses of tobacco budworm,Heliothis virescens, males to the sex attractant pheromone of conspecific females in the field. The results are discussed with regard to green leaf volatiles which enhance the attractant pheromone of a cohabiting species, and serve as attractants of a parasitoid of conspecific larvae. 相似文献
107.
Assessment of patch quality by ladybirds: relative response to conspecific and heterospecific larval tracks a consequence of habitat similarity? 总被引:2,自引:0,他引:2
Alexandra Magro Joseph N. Téné Nicolas Bastin Anthony F. G. Dixon Jean-Louis Hemptinne 《Chemoecology》2007,17(1):37-45
Summary. Aphid colonies can reach high levels of abundance but last for short periods of time. The larvae of aphidophagous ladybirds
(Coleoptera: Coccinellidae) that feed on these colonies might therefore suffer from starvation, which favours the occurrence
of cannibalism and intraguild predation. Thus, the assessment of patch quality becomes crucial and it has been shown that
female ladybirds refrain from laying eggs in the presence of an oviposition deterring semiochemical deposited by their larvae.
Adalia bipunctata (L.), Adalia decempunctata (L.) and Coccinella septempunctata L. are 3 sympatric species of ladybirds, which can co-occur in aphid colonies. As a consequence, their eggs and larvae are
under threat, not only from cannibalism but also intraguild predation. Females should, therefore, also use the tracks deposited
by heterospecific larvae to assess the quality of aphid colonies as oviposition sites. The expectation is that: 1- the strength
of the reaction to each other’s larval tracks should be correlated with percentage habitat overlap and that 2- the reaction
to conspecific larval tracks should be stronger than to heterospecific tracks. In order to test these hypotheses, females’
oviposition behaviour was analysed and a chemical analysis of the tracks of their larvae undertaken.
The results show that oviposition behaviour is not related to habitat overlap. Both species of Adalia react to tracks of their own larvae and those of C. septempunctata, but A. decempunctata reacted more strongly than A. bipunctata. C. septempunctata reacted very slightly to its own tracks but not to those of either species of Adalia.
The larval tracks are mainly composed of alkanes. Those of the two species of Adalia are qualitatively 100% similar and 60% so when the quantitative results are compared. They are, however, only 24–29% similar
to those of Coccinella septempunctata. 相似文献
108.
Joseph M. Wunderle Jr. María Santa Castro N. Fetcher 《Behavioral ecology and sociobiology》1987,21(4):249-255
Summary Adult bananaquits on negative energy budgets were presented with a patch containing two flower types with identical mean rewards, but different variances. The flower patch contained a random array of 85 yellow and 85 red artificial flowers. Flowers of one color were filled with the same quantity of nectar (constant flowers); flowers of the other color were filled with variable quantities of nectar (variable flowers). In the first series of experiments the birds were given three presentations, followed by three more presentations with the flower colors reversed, to control for color preferences. Some individuals were occasionally indifferent during a presentation, but overall the birds significantly preferred the constant flowers. In the second series of experiments two birds were give five presentations of the floral patch during a day at a rate less than minimally required to meet all 24-h energy costs. In all experiments, bananaquits on negative energy budgets were either indifferent or risk-averse, but never risk-prone. The absence of risk-prone foraging might be attributed to resource dispersion pattern, reward skew, or a species characteristic. 相似文献
109.
Donald C. Dearborn Angela D. Anders Joseph B. Williams 《Behavioral ecology and sociobiology》2005,58(4):397-406
We used detailed time-budget observations, mark-resight data, and doubly labeled water estimates of energy expenditure to test whether energy spent on courtship display by male frigatebirds functions as a sexually selected handicap signal. During a 2-day period of time budget observations, males displayed on average 29.5% of the time (range 0–100% for 15 different males), and this value was correlated with an index of season-long display effort. Season-long display effort was strongly predictive of pairing success. Average field metabolic rate (FMR) during the 2-day time budget period was 676.5 kJ/day (range 464.8–1035.0), substantially lower than the mass-specific FMR predicted from studies of other seabirds during incubation or chick-rearing. Despite a low overall FMR, display effort could function as an energetic handicap, either if FMR correlates positively with the amount of courtship performed or if high-quality males display at a high rate because they pay a lower energy cost per unit of display than do low-quality males. We found no relationship between FMR and display rate, despite good power for doing so. We also did not find a significant difference in energy spent divided by courtship time for males that were or were not chosen by females (inferred to be high- and low-quality males, respectively), though the medians differed in the predicted direction (preferred males having lower relative costs than non-preferred males) and the confidence interval on the difference between groups was very wide. Thus, we found evidence that male courtship effort is predictive of pairing success, we rejected one mechanism by which energetic cost of display could function as a handicap, and our test of the alternate energetic handicap mechanism was equivocal. 相似文献
110.
There has now been an abundance of research conducted to explore genetic bases that underlie learning performance in the honey bee (Apis mellifera). This work has progressed to the point where studies now seek to relate genetic traits that underlie learning ability to learning in field-based foraging problems faced by workers. Accordingly, the focus of our research is to explore the correlation between laboratory-based performance using an established learning paradigm and field-based foraging behavior. To evaluate learning ability, selected lines were established by evaluating queens and drones in a proboscis extension reflex (PER) conditioning procedure to measure learning in a laboratory paradigm—latent inhibition (LI). Hybrid queens were then produced from our lines selected for high and low levels of LI and inseminated with semen from many drones chosen at random. The genetically diverse worker progeny were then evaluated for expression of LI and for preference of pollen and/or nectar during foraging. Foragers from several different queens, and which had resulted from fertilization by any of several different drone fathers, were collected as they returned from foraging flights and analyzed for pollen and nectar contents. They were subsequently evaluated for expression of LI. Our research revealed that pollen foragers exhibited stronger learning, both in the presence (excitatory conditioning) and absence (LI) of reinforcement. The heightened overall learning ability demonstrated by pollen foragers suggests that pollen foragers are in general more sensitive to a large number of environmental stimuli. This mechanism could contribute toward explanations of colony-level regulation of foraging patterns among workers.Communicated by R. Page 相似文献