Anne-Caroline Prévot-Julliard

Observations of Everyday Biodiversity: a New Perspective for Conservation?

Public involvement is one of the keys to achieving biodiversity conservation goals. Increasing public involvement in conservation activities requires investigation into what makes people more aware of nature, especially in an ordinary and local context, in their everyday lives. Among the initiatives developed to increase the public’s awareness of conservation issues and individual environmental practices, citizen-science programs are based on an invitation to observe and survey nature. In our study, we examined the consequences of participation in a participative citizen-science program that takes place in an everyday-life context on individuals’ knowledge and beliefs about biodiversity. This program, the French Garden Butterflies Watch, is addressed to the non-scientifically literate public and is run by the French National Museum of Natural History (MNHN). We examined the ways increased knowledge or strengthened beliefs or ideas about biodiversity can foster proconservation attitudes and behavior. We explored how repeated interactions with nature influence the development of knowledge in this area, and how these repeated observations of biodiversity become integrated into complex cognitive processes over time and space. We showed that repeated observations of nature can increase individual knowledge and beliefs. Our results brought out three important conclusions: (1) conservation issues must be integrated into a wider network of social relationships; (2) observing everyday nature often makes people consider its functional and evolutionary characteristics; and (3) scientific knowledge seems necessary to help people to develop their own position on ecosystems.

The need for flexibility in conservation practices: exotic species as an example.

To garner support for biodiversity from the World’s human population, conservation biologists need an open-minded, integrated conservation strategy. We suggest that this strategy should include efforts to (1) preserve existing high quality, diverse ecosystems, (2) remediate impaired systems, (3) balance the needs of people and ecological resources, and (4) engender appreciation of nature and its services. We refer to these four key tenets as reservation, restoration, reconciliation, and reconnection. We illustrate these concepts by presenting the debate surrounding the management of exotic species from an unusual perspective, the benefits of exotic species. By this example we hope to encourage an integrated approach to conservation in which management strategies can be flexible, adjusting to society’s needs and the overall goals of conservation.

Urban Biodiversity, City-Dwellers and Conservation: How Does an Outdoor Activity Day Affect the Human-Nature Relationship?

Urban conservation education programs aim to increase knowledge and awareness towards biodiversity and to change attitudes and behaviour towards the environment. However, to date, few urban conservation education studies have evaluated to what extent these programs have managed to achieve their goals. In this study, we experimentally explored the influence of an urban conservation activity day on individual knowledge, awareness and actions towards biodiversity, in both the short and longer term. We organised three activity days in Paris (France), during which people were invited to participate in urban conservation efforts. Both quantitative (questionnaire) and qualitative (interviews) methods were employed to investigate the influence of this short urban nature experience on the relationships that city-dwellers develop with nearby biodiversity. We found a strong positive correlation between the levels of participation and an immediate interest towards local urban biodiversity. In the longer term, however, although participants claimed to have gained more knowledge, local awareness and interest for species in their daily environment, they did not seem to extend this interest to participating in other related activities. These results highlight the complexity of validating the effectiveness of this type of education program for achieving conservation goals. Although such a short activity may only have a limited environmental impact, it nevertheless seems to increase peoples knowledge, awareness, interest and concern. We therefore believe that when repeated locally, these short conservation education programs could enhance peoples experience with nature in cities and achieve conservation goals more fully.

A potential role for parasites in the maintenance of color polymorphism in urban birds

Urbanization is a major challenge for biodiversity conservation, yet the evolutionary processes taking place in urbanized areas remain poorly known. Human activities in cities set new selective forces in motion which need to be investigated to predict the evolutionary responses of animal species living in urban areas. In this study, we investigated the role of urbanization and parasites in the maintenance of melanin-based color polymorphism in the feral pigeon Columba livia. Using a correlative approach, we tested whether differently colored genotypes displayed alternative phenotypic responses to urbanization, by comparing body condition, blood parasite prevalence and parasite load between colored morphs along an urbanization gradient. Body condition did not vary with urbanization, but paler individuals had a higher body condition than darker individuals. Moreover, paler morphs were less often parasitized than darker morphs in moderately urbanized habitats, but their parasite prevalence increased with urbanization. In contrast, darker morphs had similar parasite prevalence along the urbanization gradient. This suggests that paler morphs did better than darker morphs in moderately urbanized environments but were negatively affected by increasing urbanization, while darker morphs performed equally in all environments. Thus, differently colored individuals were distributed non-randomly across the urban habitat and suffered different parasite risk according to their location (a gene-by-environment interaction). This suggests that melanin-based coloration might reflect alternative strategies to cope with urbanization via different exposure or susceptibility to parasites. Spatial variability of parasite pressures linked with urbanization may, thus, play a central role in the maintenance of plumage color polymorphism in this urban species.

Hatching date influences age at first reproduction in the black-headed gull

In long-lived colonial birds, age at recruitment is an important life-history character. Variation in this parameter may reflect differences in several factors, including competitive ability and breeding strategies. Further, these differences may be due to timing of hatching (for instance through differences in competitive ability). We investigated the age of first-time breeders in relation to hatching date in a black-headed gull Larus ridibundus colony situated in central France, from 1979 to 1993. Age at first breeding was estimated for four groups of individuals (total n=550) according to their hatching date, using a recent capture-recapture methodology which allowed us to estimate recruitment rate without the limiting assumptions of methods relying on simple return rates. The age at first breeding was negatively correlated with the hatching date of individuals: individuals hatched earlier in the season started breeding at a younger age than individuals born later. Proportionally more 2-year-old late-hatched individuals were seen breeding on small peripheral colonies than young early-hatched individuals. This difference disappeared after age 3xa0years. These results strongly suggest that individuals hatched late in the season start to breed on peripheral colonies before recruiting to their natal colony. A difference of few weeks in hatching date has consequences which can last for several years.

Pigeons discriminate between human feeders

Considered as plague in many cities, pigeons in urban areas live close to human activities and exploit this proximity to find food which is often directly delivered by people. In this study, we explored the capacity of feral pigeons to take advantage of this human-based food resource and discriminate between friendly and hostile people. Our study was conducted in an urban park. Pigeons were fed by two experimenters of approximately the same age and skin colour but wearing coats of different colours. During the training sessions, the two human feeders displayed different attitudes: one of the feeders was neutral and the second was hostile and chased away the pigeons. During the two test phases subsequent to the training phase, both feeders became neutral. Two experiments were conducted, one with one male and one female feeder and the second with two female feeders. In both experiments, the pigeons learned to quickly (six to nine sessions) discriminate between the feeders and maintained this discrimination during the test phases. The pigeons avoided the hostile feeder even when the two feeders exchanged their coats, suggesting that they used stable individual characteristics to differentiate between the experimenter feeders. Thus, pigeons are able to learn quickly from their interactions with human feeders and use this knowledge to maximize the profitability of the urban environment. This study provides the first experimental evidence in feral pigeons for this level of human discrimination.

Reproduction management affects breeding ecology and reproduction costs in feral urban Pigeons (Columba livia)

Reproduction management of natural popsulations can have long-term consequences that have to be examined to avoid unwanted side effects. Management policies of urban Pigeons (Columba livia Gmelin, 1789) include the set up of public Pigeon houses that aim at limiting hatching rate by egg removal. However, long-term consequences of this management method on the ecology of this species are still unknown. In this study we examined how egg removal affected egg-laying cycles of Pigeons by using a powerful method of time-series analysis, the wavelet method. We compared egg-laying cycles in Pigeon houses exposed to different management treatments and found that egg-laying cycles were shorter (4xa0weeks) in Pigeon houses with egg removal compared with control Pigeon houses without egg removal (11xa0weeks), suggesting that Pigeons respond to egg-removal pressure by multiplying reproduction attempts. Furthermore, we found that egg quality, an important index of female condition, was negatively affected by egg removal. T...

Eumelanin-based colouration reflects local survival of juvenile feral pigeons in an urban pigeon house

Urbanisation introduces deep changes in habitats, eventually creating new urban ecosystems where ecological functions are driven by human activities. Th e higher frequency of some phenotypes in urban vs rural/wild areas has led to the assumption that directional selection in urban habitats occurs, which may thereby favour some behavioural and physiological traits in urban animal populations compared to rural ones. However, empirical evidence of directional selection on phenotypic traits in urban areas remains scarce. In this study we tested whether eumelanin-based colouration could be linked to survival in two urban populations of the feral pigeon Columba livia . A number of studies in diff erent cities pointed out a higher frequency of darker individuals in more urbanised areas compared to rural ones. To investigate whether directional selection through survival on this highly heritable trait could explain such patterns, we conducted mark – recapture studies on two populations of feral pigeons in highly urbanized areas. We predicted that darker coloured individuals would exhibit higher survival and/or philopatry (integrated into ‘ local survival ’ ) than paler coloured ones. No diff erence in local survival was found between adults of diff erent colouration intensities. However, on one site, we found that darker juveniles had a higher local survival probability than light ones. Juvenile local survival on that site was also negatively correlated with the number of chicks born. Th is suggests the existence of colourand/or density-dependent selection processes acting on juvenile feral pigeons in urban environments, acting through diff erential mortality and/or dispersal.

Historical evidence for nature disconnection in a 70-year time series of Disney animated films

The assumed ongoing disconnection between humans and nature in Western societies represents a profoundly challenging conservation issue. Here, we demonstrate one manifestation of this nature disconnection, via an examination of the representation of natural settings in a 70-year time series of Disney animated films. We found that natural settings are increasingly less present as a representation of outdoor environments in these films. Moreover, these drawn natural settings tend to be more and more human controlled and are less and less complex in terms of the biodiversity they depict. These results demonstrate the increasing nature disconnection of the filmmaking teams, which we consider as a proxy of the Western relation to nature. Additionally, because nature experience of children is partly based on movies, the depleted representation of biodiversity in outdoor environments of Disney films may amplify the current disconnection from nature for children. This reduction in exposure to nature may hinder the implementation of biodiversity conservation measures.

Exotic species, Experienced, and Idealized Nature

This paper is an answer to the Caplat and Coutts forum about our previous paper “The need for flexibility in conservation practices: exotic species as an example”. We precise here why we proposed to consider exotic species as well as indigenous species in the reconnection framework in human-modified environments. One argument is that consistent and understandable arguments must be used in the communication from scientists to the public, in order not to decrease the gap between science and society.