Specific ornamentation of orbicular walls and pollen grains,as exemplified by Acanthaceae

For the first time in Acanthaceae a comparative study of orbicules forming stable, coherent orbicular walls and the respective pollen ornamentation was undertaken. A peculiar acetolysis resistant, often species specific orbicular wall is typical for many genera. In some cases the orbicular wall ornamentation resembles closely the pollen ornamentation, in others it differs to a variable degree. The presumed function of orbicular walls is discussed.     

Functional morphology of the feeding apparatus and evolution of proboscis length in metalmark butterflies (Lepidoptera: Riodinidae)

An assessment of the anatomical costs of extremely long proboscid mouthparts can contribute to the understanding of the evolution of form and function in the context of insect feeding behaviour. An integrative analysis of expenses relating to an exceptionally long proboscis in butterflies includes all organs involved in fluid feeding, such as the proboscis plus its musculature, sensilla, and food canal, as well as organs for proboscis movements and the suction pump for fluid uptake. In the present study, we report a morphometric comparison of derived long‐tongued (proboscis approximately twice as long as the body) and short‐tongued Riodinidae (proboscis half as long as the body), which reveals the non‐linear scaling relationships of an extremely long proboscis. We found no elongation of the tip region, low numbers of proboscis sensilla, short sensilla styloconica, and no increase of galeal musculature in relation to galeal volume, but a larger food canal, as well as larger head musculature in relation to the head capsule. The results indicate the relatively low extra expense on the proboscis musculature and sensilla equipment but significant anatomical costs, such as reinforced haemolymph and suction pump musculature, as well as thick cuticular proboscis walls, which are functionally related to feeding performance in species possessing an extremely long proboscis. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 291–304.     

Horizontal orientation of zygomorphic flowers: significance for rain protection and pollen transfer

• Floral traits are recognized to have evolved under selection for abiotic and biotic factors. Complex zygomorphic flowers usually face horizontally. It has been proved that a horizontal orientation facilitates pollinator recognition and pollination efficiency, but its significance in adaptation to abiotic factors remains unknown.
• The floral orientation of Abelia × grandiflora naturally varies around horizontal (with an angle of ?30 to +33° between the floral main axis and the horizontal). We examined whether three different floral orientations affected flower thermal conditions, response to rain and pollination.
• Results showed that floral orientation had no effect on diurnal variations in flower temperature. The anthers of all three flower orientations were wetted by rainfall, but the inclined upward‐facing flowers contained significantly more rainwater. The horizontal flowers received significantly higher visitation by hawkmoths and had a higher stigmatic pollen load. In contrast, the upward flower orientation reduced pollination precision, while downward‐facing flowers had decreased pollinator attraction.
• This study indicates that horizontal flowers may have evolved as a trade‐off between rain protection and pollination. Zygomorphic flowers that deviate from a horizontal orientation may have lower fitness because of flower flooding by rainwater and decreased pollen transfer.

     

The topological differences between visitation and pollen transport networks: a comparison in species rich communities of the Himalaya–Hengduan Mountains

Pollination networks are usually constructed and assessed by direct field observations which commonly assume that all flower visitors are true pollinators. However, this assumption is often invalid and the use of data based on mere visitors to flowers may lead to a misunderstanding of intrinsic pollination networks. Here, using a large dataset by both sampling floral visitors and analyzing their pollen loads, we constructed 32 networks pairs (visitation versus pollen transport) across one flowering season at four elevation sites in the Himalaya–Hengduan Mountains region. Pollen analysis was conducted to determine which flower visitors acted as potential pollinators (pollen vectors) or as cheaters (those not carrying pollen of the visited plants). We tested whether there were topological differences between visitation and pollen transport networks and whether different taxonomic groups of insect visitors differed in their ability to carry pollen of the visited plants. Our results indicated that there was a significantly higher degree of specialization at both the network and species levels in the pollen transport networks in contrast to the visitation networks. Modularity was lower but nestedness was higher in the visitation networks compared to the pollen transport networks. All the cheaters were identified as peripheral species and most of them contributed positively to the nested structure. This may explain in part the differences in modularity and nestedness between the two network types. Bees carried the highest proportion of pollen of the visited plants. This was followed by Coleoptera, other Hymenoptera and Diptera. Lepidoptera carried the lowest proportion of pollen of the visited plants. Our study shows that the construction of pollen transport networks could provide a more in‐depth understanding of plant–pollinator interactions. Moreover, it suggests that detecting and removing cheater interactions when studying the topology of other mutualistic networks might be also important.     

Functional homogenization of flower visitor communities with urbanization

Land‐use intensification and resulting habitat loss are put forward as the main causes of flower visitor decline. However, the impact of urbanization, the prime driver of land‐use intensification in Europe, is poorly studied. In particular, our understanding of whether and how it affects the composition and functioning of flower visitor assemblages is scant, yet required to cope with increasing urbanization worldwide. Here, we use a nation‐wide dataset of plant‐flower visitor (Coleoptera, Diptera, Hymenoptera, Lepidoptera) interactions sampled by citizen scientists following a standardized protocol to assess macroecological changes in richness and composition of flower visitor communities with urbanization. We measured the community composition by quantifying the relative occurrence of generalist and specialist flower visitors based on their specialisation on flowering plant families. We show that urbanization is associated with reduced flower visitor richness and a shift in community composition toward generalist insects, indicating a modification of the functional composition of communities. These results suggest that urbanization affects not only the richness of flower visitor assemblages but may also cause their large‐scale functional homogenization. Future research should focus on designing measures to reconcile urban development with flower visitor conservation.     

Variation in visitor perceptions of a polar bear enclosure based on the presence of natural vs. un-natural enrichment items

A debate exists among modern zoo staff as to whether or not the addition of un-naturalistic enrichment takes away from, or even defeats, the educational messages designers are trying to incorporate in naturalistic exhibits. A visitor study was conducted at the Central Park Zoo's polar bear exhibit in order to determine whether or not the type of enrichment in an enclosure actually alters guest perceptions. Visitors were exposed to one of two enrichment treatments in the bear enclosure: Naturalistic or Un-naturalistic. The results of this study suggest that enrichment type did not alter the perceptions of visitors. However, it did identify some of the different ways adults and youths perceive animals and zoos. Additionally, the study highlighted the varying perceptions individuals have of the concept of polar bears vs. their perceptions of the captive individuals at the Central Park Zoo. Implications for enrichment usage and exhibit design are discussed. Zoo Biol 28:292–306, 2009. © 2008 Wiley-Liss, Inc.     

Canopy invertebrate community composition on rainforest trees: Different microhabitats support very different invertebrate communities

Tropical rainforest canopies are renowned for their high invertebrate diversity and abundance. The canopy comprises a range of microhabitats representing very different food resources (including photosynthetic, reproductive, and structural tissues). As these resources vary considerably in temporal and spatial availability, nutritional quality, chemical protection and other attributes, we hypothesized that microhabitats support structurally different invertebrate communities. To test this we used the Australian Canopy Crane to sample invertebrates from mature leaves, flush leaves, flowers, fruit and suspended dead wood from 23 plant species. Invertebrate faunas on different microhabitats varied in taxonomic composition and feeding guild structure in support of the microhabitat differentiation hypothesis. Herbivores were found predominantly on new leaves (Hemiptera, Lepidoptera) and especially flowers (Coleoptera, Thysanoptera), but were relatively uncommon on mature leaves. Instead, the mature foliage community was dominated by predators, especially spiders and ants, and supported high abundances of saprophages. Ripe fruit and dead wood were scarce canopy resources that were utilized by a relatively small number of invertebrates, mostly saprophages and fungivores. Flowers supported a more heterogeneous fauna than the leaves in terms of proportional abundances of taxonomic groups and feeding guilds, both within tree species (evenness) and between tree species (non‐uniformity). These results demonstrate microhabitat differentiation in a rainforest canopy and are the first to quantify differences in taxonomic composition, guild structure and abundance patterns between such diverse invertebrate assemblages within host trees. We conclude that studies based only on sampling one microhabitat, and leaves in particular, may provide a distorted picture of invertebrate community structure.     

Food for Thought: Assessing Visitor Comfort and Attitudes toward Carcass Feeding at the ABQ BioPark Zoo

Enrichment is a key to keeping animals in zoos healthy and stimulated. For carnivores, the practice of feeding vertebrate animal carcasses, like those of goats or deer, or whole body prey animals like chickens or rabbits, can be an effective form of enrichment. While it is beneficial for animal care, carcass feeding may also be off-putting to some visitors. This research aimed to address this concern by describing the attitudes and comfort levels of visitors who viewed carcass feeding in three exhibits at the ABQ BioPark Zoo in Albuquerque, New Mexico: spotted hyena (Crocuta crocuta), Tasmanian devil (Sarcophilus harrisii), and African painted dog (Lycaon pictus). Results showed that visitors stayed at exhibits longer when a carcass was introduced and reported feeling generally comfortable and at ease while viewing carcass feeding. Findings also showed that visitors felt carcass feeding was beneficial to animal care and welfare.     

Community‐wide impacts of early season herbivory on flower visitors on tall goldenrod

1. The flower visitor community consists not only of pollinators but also of non‐pollinators, such as florivores, thieves and predators that attack flower visitors. Although there is increasing evidence that early‐season foliar herbivory influences pollinator visitation through changes in floral traits, few studies have explored indirect effects of foliar herbivory on community structure of the flower visitors. We examined how early‐season foliar herbivory influences the flower visitor community established in late season. 2. We conducted an inoculation experiment using a lacebug (Corythucha marmorata), which is a predominantly herbivorous insect attacking leaves of tall goldenrod (Solidago altissima) in Japan. 3. Flower abundance significantly decreased when damaged by the lacebug. The numbers of pollinators, florivores and thieves were positively correlated with flower abundance, whereas predators were not. In response to flower abundance, florivores decreased on damaged plants. On the other hand, thieves increased on damaged plants, and pollinators and predators did not differ between damaged and undamaged plants. 4. When effects of flower abundance were excluded, foliar herbivory still influenced florivores negatively and thieves positively. This implies that factors besides flower abundance may have affected the numbers of florivores and thieves. 5. Community composition of flower visitors on damaged plants significantly differed from undamaged plants, although overall abundance, taxonomic richness and taxonomic evenness were unaffected by foliar herbivory in the early season. It is important to recognise that only evaluating species diversity and overall abundance may fail to detect the significant consequence of early‐season herbivory on the flower visitor community.     

Crab spiders (Thomisidae) attract insect flower‐visitors without UV signalling

1. Crab spiders (Thomisidae) indirectly affect insect flower‐visitor and flowering plant interactions by consuming and altering the behaviour of insects. 2. Although one expects insect flower‐visitors to avoid crab spiders actively, some crab spider species are known to attract flower‐visitors. Crab spiders may use UV signalling to lure potential prey to the flowers they occupy. 3. In the present study, a field experiment was conducted to examine the effects of crab spiders occupying three prairie plant species for the insect flower‐visitor community. Pollinating insects were significantly attracted to inflorescences with crab spiders compared to inflorescences without crab spiders for two plant species, and herbivorous insects were attracted to inflorescences with crab spiders for one of these plant species. The two flowering plant species with increased pollinator visitation showed increased seed weights for plants with crab spiders, indicating crab spider presence indirectly increased pollination. 4. To test the UV signalling hypothesis, inflorescences with crab spiders of one plant species were observed under both a UV‐blocking plastic and a clear plastic control. Contrary to our prediction, flower‐visitors were not more likely to land on inflorescences under the clear plastic; the UV signalling hypothesis was not supported. Other unknown explanations underlie prey attraction to inflorescences with crab spiders.     

Effect of felid activity on zoo visitor interest

The extent to which the presence of zoo visitors influences animal behavior, and the ways in which animal activity influences visitor interest and perception, are of great interest to zoological parks. Visitors have been variously characterized as being enriching for zoo animals, as being stressors, and generally as influencing behavior in measurable ways. Most studies have focused on primates, and have assumed a “visitor effect” paradigm (i.e., visitors influence animal behavior). Here we present findings from a study of a nonprimate group (felids), and examine the “visitor attraction” model, which assumes that visitors are attracted to active animals. We assessed visitor interest and number at seven cat exhibits at the Brookfield Zoo during the spring and summer of 2002. Data were collected during 1‐min scans of each exhibit at 10‐min intervals. The results indicate that visitor presence per se did not influence cat activity, and that visitor interest was generally greater when cats were active. Various species differences may be explained by visitor familiarity with the species, variations in exhibit design, and species‐specific activity budgets. We conclude that the visitor attraction model may be more appropriate for taxa, such as large cats, that tend naturally to be largely inactive and to respond little (if at all) to visitor disturbances or efforts to engage. The relationship must be viewed as bidirectional: visitors influence animal behavior, and animal behavior influences visitor interest. However, the strength and primary direction of this relationship is likely taxon‐specific. We suggest that a visitor attraction model may be more appropriate not only for felids, but for other taxa with similar behavioral patterns and responses as well. Zoo Biol 22:587–599, 2003. © 2003 Wiley‐Liss, Inc.     

Visitor behavior in zoos: A review

Abstract

Visitors are integral components of zoological parks and their importance has led to a research area devoted to understanding the people–zoo relationship. This paper reviews, and provides a point of entry into, the literature relating to visitor research in zoos. The field emerged relatively recently and is diverse and interdisciplinary (it shares common ground with sociology, education, psychology, zoology, and other academic disciplines). Several areas can be identified in the literature (audience analysis, circulation and orientation, exhibit evaluation, and interactions with animals), and these areas have revealed visitors' demographic and behavioral characteristics, people's behavioral responses to endogenous and exogenous factors, the impact of exhibit design, and visitors' movements around zoos. Limitations of existing work include independence between research areas, lack of international studies, limited generalizability of results, and the minority status of the field. Therefore, suggestions for future work include integrating different research areas, more research from outside Europe and America, and increased interaction within the visitor research community.     

Visitors or Visits? An Examination of Zoo Visitor Numbers Using the Case Study of Australia

Usually cited in reference to the potential reach of zoo education, one of the popular figures for global zoo visitation is that 600 million people visit zoos annually. However, this number needs clarification on two fronts. First, there are many zoo visitors who are not included in the calculation because they visited a zoo that was not included in the count. Second, it does not take into consideration the people visit either the same or different zoos more than once annually. Using data collected from several sources, including zoo visitors themselves, this article focuses on one country—Australia—that contributes 15.6 million to the visitation total, and contends that the correct number of unique annual zoo visitors to Australian zoos is likely to be between 8 and 10 million. However, rather than suggesting an overemphasis on the potential of zoos for educating visitors, having regular repeat visitors represents a distinct advantage for zoos, allowing for progressive education opportunities. Zoo Biol. 32:37‐44, 2013. © 2012 Wiley Periodicals, Inc.     

Visitor Behaviors and Perceptions of Jaguar Activities

ABSTRACT

Zoo animals serve an important function in helping educate the public about their conservation needs. Despite this important function, little is understood about how visitors perceive different zoo exhibits and the animals that reside within them. In the present study, the behaviors displayed by two jaguars located at the Woodland Park Zoo were correlated with visitor behaviors and perceptions. Overall, visitors perceived their enjoyment to be lower when a jaguar was out of sight and rated the behavioral welfare of the jaguar to be lower when it was engaged in stereotypic behaviors. In addition, visitors who described a jaguar's behavior as stereotypic were significantly more likely to give lower ratings than those who perceived the jaguar to be active. It is suggested that by understanding how visitors perceive exhibited animals, zoos can address these perceptions in order to create more positive experiences for their visitors.     

Ineffective crypsis in a crab spider: a prey community perspective

Cryptic coloration is assumed to be beneficial to predators because of an increased encounter rate with unwary prey. This hypothesis is, however, very rarely, if ever, studied in the field. The aim of this study was to quantify the encounter rate and capture success of an ambush predator, in the field, as a function of its level of colour-matching with the background. We used the crab spider Misumena vatia, which varies its body colour and can thereby match the colour of the flower it hunts upon. We carried out a manipulative field experiment using a complete factorial design resulting in six different colour combinations of crab spiders and flowers differing in their degree of colour-matching. A rich and diverse set of naturally occurring insects visited the flowers while we continuously video-recorded the spider''s foraging activity. This enabled us to test the crypsis, the spider avoidance and the flower visitor attraction hypotheses, all three supported by previous studies. Flower visitors of different groups either avoided crab spiders independent of colour-matching, such as solitary bees and syrphid flies, or ignored them, such as bumble-bees and honeybees. Moreover, colour-matched spiders did not have a higher encounter rate and capture success compared to the visually apparent ones. Thus, our results support the spider avoidance hypothesis, reject the two other hypotheses and uncovered a fourth behaviour: indifference to predators. Because flower visitors reacted differently, a community approach is mandatory in order to understand the function of background colour-matching in generalist predators. We discuss our results in relation to the size and sociality of the prey and in relation to the functional significance of colour change in this predator.     

游客密度对动物园中黇鹿行为的影响

2006年9月20日-10月10日,以江苏省扬州市茱萸湾公园半散放鲇鹿为研究对象,采用目标动物取样法和全事件记录法,研究了不同游客密度条件下黇鹿日行为时间分配.并探讨了游客密度对鲇鹿日活动的影响.结果表明:在游客高峰期与低峰期,雄性取食、观望行为,雌性观望以及幼鹿取食、观望和修饰行为之间均存在显著差异(P＜0.05).在游客低峰期,雄性与雌性取食、反刍、卧息行为,雄性与幼鹿观望、其它行为,雌性与幼鹿取食、卧息、观望均存在极显著差异(P＜0.01);在游客高峰期,雄性与雌性取食、卧息,雌性与幼鹿取食、卧息、观望及移动行为均差异极显著(P＜0.01),雄性和幼鹿观望行为差异显著(P＜0.05).不同游客密度条件下游客活动对鲇鹿的取食、观望具有显著影响,当游客密度达到6人·min-1以上时,雄性观望行为显著增加,当达到16人·min-1以上时,雄性取食行为差异极显著(P＜0.01),此时雌性和幼鹿观望行为差异亦达到极显著水平(P＜0·01).因此,在旅游管理中,应将游客密度限制在16人·min-1以下,以减少对鲇鹿日活动影响.     

Clubiona spider (Araneae: Clubionidae) visiting flowers of nectariferous orchid Neottianthe cucullata

Spiders are usually thought to obtain their energy for growth, maintenance and reproduction from captured prey. However, not all spiders should be assumed to receive all of their energy from prey. Accumulated studies have documented nectarivory in a wide variety of hunting spiders. We report a Clubiona spider visiting flowers of the nectariferous orchid Neottianthe cucullata as an example of spider nectarivory. In addition, during the visitations by Clubiona spider, pollinia removal was observed. The impact of the Clubiona spider on the N. cucullata reproductive success is also discussed.