Simulated Natural Habitats Research Articles

Ex situ conservation of rare and threatened orchid: Diplomeris hirsuta (Lindl.)

The Diplomeris hirsuta Lindl, is a rare and endangered orchid species indigenous to India. This delicate species faces numerous threats, including landslides and road expansion, which have decreased its population and placed the species at risk of extinction. However, there is hope for this species, as the paper has reported the successful ex situ conservation of D. hirsuta plants. The researchers achieved this feat by creating a simulated natural habitat that closely mimicked the conditions of the plant’s native environment. This simulated habitat provided the ideal environmental conditions necessary to sustain the plant’s growth and development, including temperature, humidity, light, and soil composition. As a result, the live plants of D. hirsuta were successfully conserved. This study’s ex situ conservation method is essential in preserving species’ survival, especially when their natural habitats are at risk or destroyed. The success of this conservation effort provides a potential model for future conservation efforts of other threatened plant species, giving hope for the protection and preservation of rare and endangered plant species worldwide.

Using seminatural and simulated habitats for seed germination ecology of banana wild relatives.

Ecologically meaningful seed germination experiments are constrained by access to seeds and relevant environments for testing at the same time. This is particularly the case when research is carried out far from the native area of the studied species.Here, we demonstrate an alternative—the use of glasshouses in botanic gardens as simulated‐natural habitats to extend the ecological interpretation of germination studies. Our focal taxa were banana crop wild relatives (Musa acuminata subsp. burmannica, Musa acuminata subsp. siamea, and Musa balbisiana), native to tropical and subtropical South‐East Asia. Tests were carried out in Belgium, where we performed germination tests in relation to foliage‐shading/exposure to solar radiation and seed burial depth, as well as seed survival and dormancy release in the soil. We calibrated the interpretation of these studies by also conducting an experiment in a seminatural habitat in a species native range (M. balbisiana—Los Baños, the Philippines), where we tested germination responses to exposure to sun/shade. Using temperature data loggers, we determined temperature dynamics suitable for germination in both these settings.In these seminatural and simulated‐natural habitats, seeds germinated in response to exposure to direct solar radiation. Seed burial depth had a significant but marginal effect by comparison, even when seeds were buried to 7 cm in the soil. Temperatures at sun‐exposed compared with shaded environments differed by only a few degrees Celsius. Maximum temperature of the period prior to germination was the most significant contributor to germination responses and germination increased linearly above a threshold of 23℃ to the maximum temperature in the soil (in simulated‐natural habitats) of 35℃.Glasshouses can provide useful environments to aid interpretation of seed germination responses to environmental niches.

Growth Performance and Species Interaction of Festuca rupicola Heuff. and Dianthus carthusianorum L. Subjected to Temperature Increase and Nitrogen Addition

Global processes, such as warming and eutrophication, affect plant-plant interactions. The positive (facilitation) and negative (competition) interactions depend on environmental conditions and species’ characteristics and play a key role in regulating the composition, productivity, structure and dynamics of communities and ecosystems. Recently, biodiversity in former species-rich, semi-dry grasslands has decreased due to the abandonment of traditional land use, under which grass species expanded and dicots declined. The hypothesis that this phenomenon will intensify with warming and eutrophication is tested on the expanding grass Festuca rupicola (F) and the dicot Dianthus carthusianorum (D). A competition experiment were conducted with conditions simulating current average summer temperatures (20 oC during day/10 oC during night) and predicted warmer conditions (22/15 oC) in growth-chambers, both under nutrient-poor (simulated natural habitat conditions) and nutrient-rich conditions (simulated annual N deposition). The plants were placed in pots with constant densities (five individuals per pot) but under varying mixture ratio (F5, D5, D4/F1, D3/F2, D2/F3, D1/F4). The measured plant parameters (biomass, leaf number and leaf length) and the interactions varied species-dependent: under nutrient poor conditions the performance of both species was low and the interactions were weak. After nutrient addition, growth parameters of both species developed between twofold and tenfold better and the species interacted more markedly. Under both nutrient levels, D. carthusianorum was significantly promoted by warming. But, warmed conditions did not affect the biomass and leaf length of F. rupicola, whereas leaf number significantly decreased under both nutrient levels. As such, the dicot became competed against and the grass facilitated under current conditions, while under warmed conditions the competitive ability of the grass declined and that of the dicot increased, indicating that interactions between both species reverses with warming climate. This suggests, that under predicted climate conditions, the expanding grass will decline, while the dicot will be promoted, which can have positive effects on biodiversity of semi-dry grasslands.

Structural enrichment and enclosure use in an opportunistic carnivore: the red fox(Vulpes vulpes)

AbstractAn increasing number of zoos keep their animals in natural-looking enclosures, but it is often unclear whether or not the species’ behavioural and ecological needs are being adequately met. For species that suffer predation in the wild, structural enrichment in captivity can play a crucial role in connection with enclosure use. Firstly, we examined the effectiveness of structural enrichment in modifying enclosure use in an opportunistic carnivore, the red fox(Vulpes vulpes). In a test enclosure, we placed both long wooden and cover structures that simulated natural habitat in predetermined sectors. A group of four foxes were exposed to four treatments: (i) structural enrichment in location 1 (LOC1s); (ii) structural enrichment in location 2 (LOC2); (iii) structural enrichment removed (REM); and (iv) structural enrichment again in location 1 (LOC1e). Sectors containing long wooden structures were preferred significantly compared to the rest of the enclosure. Sector use was selectively shifted to those in which cover structures were present. Structural enrichment had no significant effect on activity. Secondly, in a new outdoor enclosure, we compared the use of sectors with cover or elongated structures with that of corresponding sectors without structures. All individuals showed a significant preference for sectors containing structures. In the course of the three-week observation period, there was a significant decline in preference for structures and a significant increase in activity (week 1 < week 2 = week 3). These results suggest that in medium-sized carnivores, structural enrichment is beneficial when natural features with a net-like distribution over the habitat are simulated.

Structural enrichment and enclosure use in an opportunistic carnivore: the red fox (Vulpes vulpes)

An increasing number of zoos keep their animals in natural-looking enclosures, but it is often unclear whether or not the species' behavioural and ecological needs are being adequately met. For species that suffer predation in the wild, structural enrichment in captivity can play a crucial role in connection with enclosure use. Firstly, we examined the effectiveness of structural enrichment in modifying enclosure use in an opportunistic carnivore, the red fox (Vulpes vulpes). In a test enclosure, we placed both long wooden and cover structures that simulated natural habitat in predetermined sectors. A group of four foxes were exposed to four treatments: (i) structural enrichment in location 1 (LOC1s); (ii) structural enrichment in location 2 (LOC2); (iii) structural enrichment removed (REM); and (iv) structural enrichment again in location 1 (LOC1e). Sectors containing long wooden structures were preferred significantly compared to the rest of the enclosure. Sector use was selectively shifted to those in which cover structures were present. Structural enrichment had no significant effect on activity. Secondly, in a new outdoor enclosure, we compared the use of sectors with cover or elongated structures with that of corresponding sectors without structures. All individuals showed a significant preference for sectors containing structures. In the course of the three-week observation period, there was a significant decline in preference for structures and a significant increase in activity (week 1 < week 2 = week 3). These results suggest that in medium-sized carnivores, structural enrichment is beneficial when natural features with a net-like distribution over the habitat are simulated.

Sustained predation effects of hatchery‐reared transgenic coho salmon Oncorhynchus kisutch in semi‐natural environments

Summary 1. The potential risks of accidental or intentional introduction of transgenic organisms to nature are unknown. We have previously shown that, after being reared in the hatchery, growth hormone transgenic coho salmon Oncorhynchus kisutch can exert a stronger predation effect on natural prey under simulated natural conditions compared with hatchery‐reared genetically wild conspecifics. However, when reared in a simulated natural environment, the difference between the two genotypes was greatly reduced. 2. Here, we tested if the difference in predation rate between the two genotypes after being reared in the hatchery diminishes with time spent in a simulated natural environment. Genetically wild coho salmon reared in the hatchery were size matched to younger satiation‐fed (fast‐growing) and same age restricted‐fed (growth rates matched to wild‐type) transgenic fish. These three types of predators were released into simulated natural habitats and their effects on prey survival and growth were monitored over a 2‐month period. 3. Restricted‐fed, but not satiation‐fed, transgenic predators consumed significantly more prey (×2·7) relative to wild predators during the first month, with an increase to 3.8 times during the second period. Prey biomass decreased more in the presence of restricted‐fed predators during the first period, but a faster growth of these prey during the second period compensated for the higher predation rate resulting in no significant difference in prey biomass among predators after 2 months. Transgenic predators grew more in length than wild type, but all three types converged in weight and condition over time. 4. Synthesis and applications. Behavioural phenotypes developed in the hatchery showed little plasticity after release. Hence, development of policy on the use of transgenic organisms must incorporate knowledge of the effect of environmental conditions, experienced by the organism prior to escape or release, on phenotype. The risk posed by culture‐reared organisms may depend on the frequency of escapes, number of individuals escaping and age of escapees. Important to note is that wild‐reared organisms may be biologically different from culture‐reared and thus require separate evaluation. Our results will be important for science policy makers and regulators to consider when deciding whether to allow commercial application of transgenic species in aquaculture.

The Penguin Parade exhibit at the Jurong BirdPark Singapore

An indoor temperature-controlled house exhibiting penguins and puffins was opened at Jurong BirdPark in 1990. The two exhibits are viewed through glass panels from a darkened public area and a ramp leads the visitor past an underwater view to the main viewing gallery. Southern hemisphere penguins and terns, and northern alcids and ducks are contrasted in simulated natural habitats. Of particular importance in a tropical-climate zoo is the control of the environment within the exhibits and in the public area.

The Foraging Ecology of the Gray Rat Snake (Elaphe obsoleta spiloides)—Visual Stimuli Facilitate Location of Arboreal Prey

We examined the responsiveness of adult gray rat snakes to avian prey in enclosures that simulated natural habitat conditions. Subjects searched for arboreal nest contents in the presence or absence of a bird model flown so as to simulate avian provisioning behavior. In the absence of the model, gray rat snake latency to capture prey was over 92 % greater than when searching for nest contents with the model. Snakes responded to model flight by turning their heads in the direction of its movement. We conclude that gray rat snakes perceive relatively distant visual cues from prey, and that nest provisioning (activity localized around a nest) may facilitate snakes correctly choosing to ascend trees that contain active nests and ignoring those that do not.

A DNA module encoding bph genes for the degradation of polychlorinated biphenyls (PCBs).

In this report we describe the development and construction of a DNA module which encodes bph genes for the metabolism of PCBs and which is capable of stable integration into the chromosome of Gram negative bacteria. Introduction of the bph-module into Pseudomonas putida KT2442, Pseudomonas sp. strain B13 and its genetically engineered derivative B13FR1 expanded the biodegradative ability of these strains to include biphenyl and 4-chlorobiphenyl. The bph operon was stably inherited under laboratory conditions. Behavior of the genetically engineered strains was evaluated under simulated natural habitat conditions in lake sediment microcosms with respect to survival and removal of 4-chlorobiphenyl. The genetically engineered strains persisted under these conditions and were effective in degrading 4-chlorobiphenyl over a five day incubation period.

Mating Systems and Reproductive Strategies in Three Australian Gryllid Crickets: Bobilla victoriae Otte, Balamara gidya Otte and Teleogryllus commodus (Walker) (Orthoptera: Gryllidae: Nemobiinae; Trigonidiinae; Gryllinae)

AbstractThe behaviour of B. victoriae and B. gidya in simulated natural habitats is described. Regular predictable sequences of behaviour are represented by ethograms.The mating systems of B. victoriae and B. gidya are compared with that of T. commodus which shows a sedentary call‐and‐reside strategy. B. victoriae shows an elaborated male call‐search strategy while in B. gidya the male strategy is one purely of searching rather than advertising for mates. Males of B. victoriae and B. gidya were less territorial and less aggressive than males of T. commodus.Males of B. victoriae attracted females and monopolized them for repeated matings by providing what might be a nutritional resource in the form of multiple spermatophores which females were allowed to eat soon after copulation. Males of B. gidya produced fewer but much larger spermatophores than males of B. victoriae or T. commodus and females of B. gidya became unreceptive after mating.The reproductive strategies of the three species are analyzed in terms of environmental variables.

A Study of the Behaviour of the Australian Field Cricket Teleogryllus commodus (Walker) (Orthoptera: Gryllidae) in the Field and in Habitat Simulations

Abstract and SummaryThe behaviour of T. commodus (Walker) in the field and in simulated natural habitats is described. Regular predictable sequences of behaviour are represented by an ethogram.Most behaviour was centred around burrows or sheltered sites. Burrows appeared to be a limiting resource and there may be behavioural dimorphism in ♂ ♂ (burrower and non‐burrower strategies).Individuals were found to form gregarious clusters and appeared to be attracted to areas already occupied by crickets. Territorial spacing and other social interactions occurred within these clusters.♂ ♂ and ♀ ♀ were found to be mobile, and moved continually between sites. The movement of ♂ ♂ and ♀ ♀ between burrows (calling sites) was measured. Adult ♂ ♂ never remained at a burrow for longer than two days. In simulated natural habitats ♂ ♂ moved in response to two factors: first, and most common, as a result of eviction by other ♂ ♂ second, as a response to the absence of ♀ ♀. When cricket density was increased in habitat simulations crickets clustered at calling sites.The adaptive significance of T. commodus behaviour is discussed.

A Learning Paradigm and the Behavioral Demonstration of Audition for the Lizard Anolis grahami

Audition in Anolis grahami was investigated using classical conditioning of subjects within a simulated natural habitat. The conditioned stimulus (CS) was a tone which matched the dominant frequency of the species' agonistic type A vocalization; shoving a subject from its perch with a rod was the aversive unconditioned stimulus (UCS). Before conditioning experiments took place, baseline observations showed no observable responses by the lizards to the tone. Furthermore, during the conditioning experiments, evidence of learning (i.e., orienting and avoidance behavior during presentation of the tone) was more evident when visual cues were reduced. These results indicate that the species will respond to sounds, but that it has a greater reliance on visual rather than auditory information.

Photosynthetic adaptation of Solanum dulcamara L. to sun and shade environments : I. A Comparison of Sun and Shade Populations.

The photosynthetic response properties of individuals of Solanum dulcamara L. collected from sun and shade habitats were compared in controlled environments. Light-saturated photosynthetic rates and seven additional parameters associated with photosynthetic and growth performance were measured over a range of 12 environmental conditions that simulated natural habitat differences in light intensity, moisture availability and daily temperature amplitude. In contrast to previous studies, the results suggest there is no ecotypic differentiation with respect to the sun and shade environments from which the individuals were collected. It appears that all but one of the field-collected individuals are capable of successfully inhabiting the full range of light environments from which the species was collected.

Genetic mechanisms controlling the domestication of a wild house mouse population (Mus musculus L.).

A controlled reenactment of the domestication process provided information on the relative effects of natural selection, inbreeding, and habitat upon an originally wild house mouse population. Effects were assessed by testing offspring that were bred under either laboratory or simulated natural conditions, systematically inbred or outbred, and postnatally fostered in laboratory or simulated natural habitats. Ten generations of domestication failed to reveal any behavioral differences due to either natural selection or habitat on nine different behavioral tests. Inbreeding strongly reduced intermale aggression, partially reduced resistance to recapture by humans, but failed to affect any of the seven other behaviors.

Studies on the Behavior of Sorex Vagrans

The individual and social behavior patterns of adult and immature Sorex vagrans were studied in the laboratory. Isolated shrews were observed in simulated natural habitats in order to describe the behavior of solitary individuals. The social behavior patterns were studied by (1) establishing groups of adults and immature shrews in the same cage, and (2) staging a series of three-minute encounters be- tween two individuals in a neutral testing arena. The shrews could be kept in groups with little fighting but the adults denned separately. Immature shrews denned together until they were about 7 weeks old. In the staged encounters agonistic behavior patterns accounted for only 4-5% of all the social interactions. Moving away was the most fre- quent response comprising almost 40% of the social behavior recorded. Encounters between animals from the same group were free from agonistic behavior. On the other hand, shrews encountering as strangers showed occasional bouts of chasing and fighting behavior. The imma- ture shrews displayed little agonistic behavior when encountering a strange immature, but at three months of age the same animals showed agonistic tendencies.

Aggressive behaviour and social dominance in the six-lined racerunner (Cnemidophorus sexlineatus)

Field and experimental studies on the lizard Cnemidorphorus sexlineatus (six-lined racerunner) were made on marked populations in Oklahoma. Aggressive chases, followed often by biting, were common in both field and confined populations. As a means of testing dominance, as indicated by aggressive activity, seven groups of racerunners were confined in simulated natural habitats both indoors and outdoors. In any particular encounter between two individual lizards, the pursuer was recorded as dominant and the pursued as subordinate in social rank. Each group had one or two individuals which were more aggressive and accounted for over one half of the recorded encounters. Males were usually dominant over females, and the smallest lizards were the most subordinate. Dominant lizards were more active over longer periods of time. A peculiar submissive posture was observed occasionally in subordinates. The retreat behaviour of the female was sometimes different from that of the male. In the field, aggressive behaviour could not be directly related to possible territoriality. Courtship display was not apparent for this species and the chase and retreat behaviour may be a necessary part of sex recognition and attraction.