Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the p... more Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the presence of many individuals. We studied king penguins (Aptenodytes patagonicus) that live in dense colonies and are constantly faced with such problems. Our aims were to describe adult penguin homing paths on land and to test whether visual cues are important for their orientation in the colony. We also tested the hypothesis that older penguins should be better able to cope with limited visual cues due to their greater experience. We collected and examined GPS paths of homing penguins. In addition, we analyzed 8 months of penguin arrivals to and departures from the colony using data from an automatic identification system. We found that birds rearing chicks did not minimize their traveling time on land and did not proceed to their young (located in creches) along straight paths. Moreover, breeding birds' arrivals and departures were affected by the time of day and luminosity levels. Our data suggest that king penguins prefer to move in and out of the colony when visual cues are available. Still, they are capable of navigating even in complete darkness, and this ability seems to develop over the years, with older breeding birds more likely to move through the colony at nighttime luminosity levels. This study is the first step in unveiling the mysteries of king penguin orientation on land.
Amphibians are a highly endangered taxonomic group, and invasion of alien species in wetland syst... more Amphibians are a highly endangered taxonomic group, and invasion of alien species in wetland systems has been involved in this decline. The Pinail Nature Reserve, Vienne, France, contains more than 5,000 ponds, many of which are occupied by introduced Pumpkinseed Sunfish (Lepomis gibbosus). We sampled ponds with and without sunfish for amphibian species presence multiple times over 2 y. The number of amphibian species was significantly greater in ponds without sunfish (3.3 ± 0.2 [SD] species in 2004; 3.5 ± 0.2 in 2005) than in ponds with sunfish (1.6 ± 0.4 in 2004; 0.9 ± 0.2 in 2005). Sunfish presence was negatively related to the frequency of occurrence in ponds for Triturus marmoratus (Marbled Newt), Hyla arborea (European Tree Frog), Lissotriton helveticus (Palmate Newt), and Pelophylax spp. (Green Frog complex). The effect was especially pronounced for Hyla arborea and Triturus marmoratus, with occupancy nearly 50% and 100%, respectively, in ponds without sunfish, but 0% and 20%, respectively, in ponds with sunfish. Our study did not reveal a significant effect of sunfish presence on three other infrequently encountered amphibian species: Bufo spinosus (Spiny Toad), Rana dalmatina (Agile Frog), and Triturus cristatus (Great Crested Newt). Stomach content analyses confirmed predation on larval amphibians by sunfish. This study showed that Pumpkinseek Sunfish can negatively affect amphibians with species-specific impacts.
Summary King penguins (Aptenodytes patagonicus) live in large and densely populated colonies, whe... more Summary King penguins (Aptenodytes patagonicus) live in large and densely populated colonies, where navigation can be challenging due to the presence of many conspecifics that could obstruct locally available cues. Our previous experiments demonstrated that visual cues were important but not essential for king penguin chicks' homing. The main objective of this study was to investigate the importance of non-visual cues, such as magnetic and acoustic cues, for chicks' orientation and short-range navigation. In a series of experiments, the chicks were individually displaced from the colony to an experimental arena where they were released under different conditions. In the magnetic experiments, a strong magnet was attached to the chicks' heads. Trials were conducted in daylight and at night to test the relative importance of visual and magnetic cues. Our results showed that when the geomagnetic field around chicks was modified, their orientation in the arena and the overall...
The Nile tilapia (Oreochromis niloticus) was introduced in Southeast Asia, such as in Thailand, i... more The Nile tilapia (Oreochromis niloticus) was introduced in Southeast Asia, such as in Thailand, in the mid-1960s for aquaculture purposes (Pullin et al., 1997; De Silva et al., 2004). The species was later promoted for aquaculture development in the early 1990s in Lao PDR (Garaway et al., 2000). In Lao People’s Democratic Republic (PDR), like in other countries, this exotic species is well established due to its self-reproduction (De Silva et al., 2004; CABI, 2018) facilitated by its particular life history traits and plasticity (Ishikawa et al., 2013). The species was then suspected to be introduced in the seventies in Laos and subsequently in the Nam Theun watershed where the NT2 Reservoir was impounded in 2008. Population parameters of this alien fish were investigated using the FiSAT II software with the most popular methods of bioparameters assessment to check their interchangeability within a same stock and the same year 2016. The length-at-age data analysis (using otoliths an...
8 pagesInternational audienceIn French Polynesia, only three Ardeidae are present: Cattle Egret (... more 8 pagesInternational audienceIn French Polynesia, only three Ardeidae are present: Cattle Egret (Bubulcus ibis), Tahiti Striated Heron (Butorides striata patruelis) and Eastern Reef-Heron (Egretta sacra), and the last two breed there. The Eastern Reef-Heron is widespread in the Pacific range and its conservation status is least concern. However, the status of the Tahiti Striated Heron is critically endangered on the International Union for the Conservation of Nature Red List. In 2009, only 70 birds were estimated living in Tahiti and thus the entire French Polynesia. Threats are mainly due to the restricted distribution of breeding habitat and habitat destruction. The Tahiti Striated Heron needs coastal and riverine Hibiscus forests for foraging and nesting. However, such coastal forests are being destroyed and the heron was found on only 7% of the linear coast. We discuss possible conservation plans for this critically endangered bird including translocation on another island of th...
National audienceLa conservation des forêts afrotropicales dépend non seulement de la protection ... more National audienceLa conservation des forêts afrotropicales dépend non seulement de la protection des habitats, mais également de la protection d’espèces menacées d'extinction (IUCN 2011). Les primates frugivores sont reconnus comme d’important disperseurs de graines. Dans le site de LuiKotale (forêt tropicale de la Cuvette centrale, RD Congo) le rôle de dispersion de graines par les bonobos (Pan paniscus) a été étudié. Les bonobos sont principalement frugivores (66 % des sessions d'alimentation), passant environ 3,5 heures par jour à avaler des fruits et leurs graines, qui sont transportées pendant environ 24 heures. Ces graines appartiennent à plus de 91 espèces dispersées endozoochoriquement à une distance moyenne de 1,2 kilomètre de l'arbre--‐parent. Les graines passées par le tube digestif des bonobos germent plus rapidement, à des taux plus élevés, et avec une plus grande survie post dispersion. Notre estimation porte à 40 % le taux d’espèces d’arbres dispersés par ...
Bonobos (Pan paniscus) are threatened with extinction. They are the largest primates, and the onl... more Bonobos (Pan paniscus) are threatened with extinction. They are the largest primates, and the only apes (except human), of the southern bank of the Congo Basin. Along with chimpanzees, they are our closest living relatives and are studied by anthropologists to include/understand our hominid origins; but what about their functional role in the forest? Would their disappearance have serious consequences for forest ecology? Answering this question is the aim of this new project, with several years of observations of a free-ranging habituated group of bonobos on the LuiKotale research station (DR Congo). In this tropical rainforest, the very great majority of plants need animals to reproduce and disperse their seeds. Bonobos are the largest frugivorous animals in this region, after elephants. During its life, each bonobo will ingest and disperse nine tons of seeds, from more than 91 species of lianas, grass, trees and shrubs. These seeds will travel 24 hours in the bonobo digestive trac...
Abstract. Information on resident and wintering waterbirds in Haiti is particularly scarce, limit... more Abstract. Information on resident and wintering waterbirds in Haiti is particularly scarce, limiting knowledge needed to inform waterbird conservation across the Caribbean. Here, results from a winter census of waterbirds at five major wetland sites in Haiti in 2019 are presented. Overall, 10,265 waterbirds belonging to 34 species and 12 families were counted. Richness per site varied between 8 and 26 species, and the Shannon diversity index ranged from 2.69 to 8.54. Only 17.6% of observed species were recorded at more than three sites, and there was no significant relationship between the overall number of individuals counted per species and the number of sites where the species was observed. This was reflected in the moderate degree of similarity between the five sites in terms of shared species as calculated with Horn index. Although the species observed during the survey are currently listed as Least Concern (LC) in the Global IUCN Red List, at the local level several of them are considered threatened: White-cheeked Pintail (Anas bahamensis) and American Coot (Fulica americana); or rare: Mallard (Anas platyrhynchos) and Wilson's Phalarope (Phalaropus tricolori). Results are discussed relative to previous records of waterbirds in Haiti and need to develop ornithological research based on local expertise.
Abstract This study presents examples of successful restoration projects for biodiversity conserv... more Abstract This study presents examples of successful restoration projects for biodiversity conservation. In West France, the Pinail National Nature Reserve is a protected wetland interspersed with more than 6000 ponds. This wetland is inhabited by 50 species of Odonata and thus is a key biodiversity area for damselflies and dragonflies conservation. In the past, when the limestone was exploited, the streams of the plateau were artificially channeled rectilinearly, running to the Vienne River. Eventually streams were blocked by biomass and sediments resulting in water flowing mainly underground. In 2011, two restoration projects dug and recreated lost habitats such as running streams and meanders by openly reconnecting bodies of standing water (two sites: Rivau (20 m) and Hutte (400 m) streams). The Odonata species diversity and abundance are annually monitored following transect inventories since 1995 and still ongoing. Diversity and abundance were compared before and after the restoration. The abundance and species diversity increased at both sites due to the addition of lotic habitats and consequently additional new species. The number of observed species almost doubled on the Rivau (from 5.4 observed species to 9.9 spp). By extrapolation the total species number on site increased from 15 to 18 spp to 29–37 spp. The abundance also greatly increased with 770 % more individuals on the Rivau. Similarly, on the 400 m Hutte stream, the extrapolated diversity increased from 31 to 38 spp to 35–43 spp; as well as the abundance with 475 % more individuals. These restoration projects created new habitats leading to local biodiversity enrichment and conservation success. More specifically, Coenagrion mercuriale (Odonata: Zygoptera), one of Europe's most threatened damselflies and listed in the European Habitats directive, successfully recolonized the Rivau stream and colonized the Hutte stream.
Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the p... more Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the presence of many individuals. We studied king penguins (Aptenodytes patagonicus) that live in dense colonies and are constantly faced with such problems. Our aims were to describe adult penguin homing paths on land and to test whether visual cues are important for their orientation in the colony. We also tested the hypothesis that older penguins should be better able to cope with limited visual cues due to their greater experience. We collected and examined GPS paths of homing penguins. In addition, we analyzed 8 months of penguin arrivals to and departures from the colony using data from an automatic identification system. We found that birds rearing chicks did not minimize their traveling time on land and did not proceed to their young (located in creches) along straight paths. Moreover, breeding birds' arrivals and departures were affected by the time of day and luminosity levels. Our data suggest that king penguins prefer to move in and out of the colony when visual cues are available. Still, they are capable of navigating even in complete darkness, and this ability seems to develop over the years, with older breeding birds more likely to move through the colony at nighttime luminosity levels. This study is the first step in unveiling the mysteries of king penguin orientation on land.
Amphibians are a highly endangered taxonomic group, and invasion of alien species in wetland syst... more Amphibians are a highly endangered taxonomic group, and invasion of alien species in wetland systems has been involved in this decline. The Pinail Nature Reserve, Vienne, France, contains more than 5,000 ponds, many of which are occupied by introduced Pumpkinseed Sunfish (Lepomis gibbosus). We sampled ponds with and without sunfish for amphibian species presence multiple times over 2 y. The number of amphibian species was significantly greater in ponds without sunfish (3.3 ± 0.2 [SD] species in 2004; 3.5 ± 0.2 in 2005) than in ponds with sunfish (1.6 ± 0.4 in 2004; 0.9 ± 0.2 in 2005). Sunfish presence was negatively related to the frequency of occurrence in ponds for Triturus marmoratus (Marbled Newt), Hyla arborea (European Tree Frog), Lissotriton helveticus (Palmate Newt), and Pelophylax spp. (Green Frog complex). The effect was especially pronounced for Hyla arborea and Triturus marmoratus, with occupancy nearly 50% and 100%, respectively, in ponds without sunfish, but 0% and 20%, respectively, in ponds with sunfish. Our study did not reveal a significant effect of sunfish presence on three other infrequently encountered amphibian species: Bufo spinosus (Spiny Toad), Rana dalmatina (Agile Frog), and Triturus cristatus (Great Crested Newt). Stomach content analyses confirmed predation on larval amphibians by sunfish. This study showed that Pumpkinseek Sunfish can negatively affect amphibians with species-specific impacts.
Summary King penguins (Aptenodytes patagonicus) live in large and densely populated colonies, whe... more Summary King penguins (Aptenodytes patagonicus) live in large and densely populated colonies, where navigation can be challenging due to the presence of many conspecifics that could obstruct locally available cues. Our previous experiments demonstrated that visual cues were important but not essential for king penguin chicks' homing. The main objective of this study was to investigate the importance of non-visual cues, such as magnetic and acoustic cues, for chicks' orientation and short-range navigation. In a series of experiments, the chicks were individually displaced from the colony to an experimental arena where they were released under different conditions. In the magnetic experiments, a strong magnet was attached to the chicks' heads. Trials were conducted in daylight and at night to test the relative importance of visual and magnetic cues. Our results showed that when the geomagnetic field around chicks was modified, their orientation in the arena and the overall...
The Nile tilapia (Oreochromis niloticus) was introduced in Southeast Asia, such as in Thailand, i... more The Nile tilapia (Oreochromis niloticus) was introduced in Southeast Asia, such as in Thailand, in the mid-1960s for aquaculture purposes (Pullin et al., 1997; De Silva et al., 2004). The species was later promoted for aquaculture development in the early 1990s in Lao PDR (Garaway et al., 2000). In Lao People’s Democratic Republic (PDR), like in other countries, this exotic species is well established due to its self-reproduction (De Silva et al., 2004; CABI, 2018) facilitated by its particular life history traits and plasticity (Ishikawa et al., 2013). The species was then suspected to be introduced in the seventies in Laos and subsequently in the Nam Theun watershed where the NT2 Reservoir was impounded in 2008. Population parameters of this alien fish were investigated using the FiSAT II software with the most popular methods of bioparameters assessment to check their interchangeability within a same stock and the same year 2016. The length-at-age data analysis (using otoliths an...
8 pagesInternational audienceIn French Polynesia, only three Ardeidae are present: Cattle Egret (... more 8 pagesInternational audienceIn French Polynesia, only three Ardeidae are present: Cattle Egret (Bubulcus ibis), Tahiti Striated Heron (Butorides striata patruelis) and Eastern Reef-Heron (Egretta sacra), and the last two breed there. The Eastern Reef-Heron is widespread in the Pacific range and its conservation status is least concern. However, the status of the Tahiti Striated Heron is critically endangered on the International Union for the Conservation of Nature Red List. In 2009, only 70 birds were estimated living in Tahiti and thus the entire French Polynesia. Threats are mainly due to the restricted distribution of breeding habitat and habitat destruction. The Tahiti Striated Heron needs coastal and riverine Hibiscus forests for foraging and nesting. However, such coastal forests are being destroyed and the heron was found on only 7% of the linear coast. We discuss possible conservation plans for this critically endangered bird including translocation on another island of th...
National audienceLa conservation des forêts afrotropicales dépend non seulement de la protection ... more National audienceLa conservation des forêts afrotropicales dépend non seulement de la protection des habitats, mais également de la protection d’espèces menacées d'extinction (IUCN 2011). Les primates frugivores sont reconnus comme d’important disperseurs de graines. Dans le site de LuiKotale (forêt tropicale de la Cuvette centrale, RD Congo) le rôle de dispersion de graines par les bonobos (Pan paniscus) a été étudié. Les bonobos sont principalement frugivores (66 % des sessions d'alimentation), passant environ 3,5 heures par jour à avaler des fruits et leurs graines, qui sont transportées pendant environ 24 heures. Ces graines appartiennent à plus de 91 espèces dispersées endozoochoriquement à une distance moyenne de 1,2 kilomètre de l'arbre--‐parent. Les graines passées par le tube digestif des bonobos germent plus rapidement, à des taux plus élevés, et avec une plus grande survie post dispersion. Notre estimation porte à 40 % le taux d’espèces d’arbres dispersés par ...
Bonobos (Pan paniscus) are threatened with extinction. They are the largest primates, and the onl... more Bonobos (Pan paniscus) are threatened with extinction. They are the largest primates, and the only apes (except human), of the southern bank of the Congo Basin. Along with chimpanzees, they are our closest living relatives and are studied by anthropologists to include/understand our hominid origins; but what about their functional role in the forest? Would their disappearance have serious consequences for forest ecology? Answering this question is the aim of this new project, with several years of observations of a free-ranging habituated group of bonobos on the LuiKotale research station (DR Congo). In this tropical rainforest, the very great majority of plants need animals to reproduce and disperse their seeds. Bonobos are the largest frugivorous animals in this region, after elephants. During its life, each bonobo will ingest and disperse nine tons of seeds, from more than 91 species of lianas, grass, trees and shrubs. These seeds will travel 24 hours in the bonobo digestive trac...
Abstract. Information on resident and wintering waterbirds in Haiti is particularly scarce, limit... more Abstract. Information on resident and wintering waterbirds in Haiti is particularly scarce, limiting knowledge needed to inform waterbird conservation across the Caribbean. Here, results from a winter census of waterbirds at five major wetland sites in Haiti in 2019 are presented. Overall, 10,265 waterbirds belonging to 34 species and 12 families were counted. Richness per site varied between 8 and 26 species, and the Shannon diversity index ranged from 2.69 to 8.54. Only 17.6% of observed species were recorded at more than three sites, and there was no significant relationship between the overall number of individuals counted per species and the number of sites where the species was observed. This was reflected in the moderate degree of similarity between the five sites in terms of shared species as calculated with Horn index. Although the species observed during the survey are currently listed as Least Concern (LC) in the Global IUCN Red List, at the local level several of them are considered threatened: White-cheeked Pintail (Anas bahamensis) and American Coot (Fulica americana); or rare: Mallard (Anas platyrhynchos) and Wilson's Phalarope (Phalaropus tricolori). Results are discussed relative to previous records of waterbirds in Haiti and need to develop ornithological research based on local expertise.
Abstract This study presents examples of successful restoration projects for biodiversity conserv... more Abstract This study presents examples of successful restoration projects for biodiversity conservation. In West France, the Pinail National Nature Reserve is a protected wetland interspersed with more than 6000 ponds. This wetland is inhabited by 50 species of Odonata and thus is a key biodiversity area for damselflies and dragonflies conservation. In the past, when the limestone was exploited, the streams of the plateau were artificially channeled rectilinearly, running to the Vienne River. Eventually streams were blocked by biomass and sediments resulting in water flowing mainly underground. In 2011, two restoration projects dug and recreated lost habitats such as running streams and meanders by openly reconnecting bodies of standing water (two sites: Rivau (20 m) and Hutte (400 m) streams). The Odonata species diversity and abundance are annually monitored following transect inventories since 1995 and still ongoing. Diversity and abundance were compared before and after the restoration. The abundance and species diversity increased at both sites due to the addition of lotic habitats and consequently additional new species. The number of observed species almost doubled on the Rivau (from 5.4 observed species to 9.9 spp). By extrapolation the total species number on site increased from 15 to 18 spp to 29–37 spp. The abundance also greatly increased with 770 % more individuals on the Rivau. Similarly, on the 400 m Hutte stream, the extrapolated diversity increased from 31 to 38 spp to 35–43 spp; as well as the abundance with 475 % more individuals. These restoration projects created new habitats leading to local biodiversity enrichment and conservation success. More specifically, Coenagrion mercuriale (Odonata: Zygoptera), one of Europe's most threatened damselflies and listed in the European Habitats directive, successfully recolonized the Rivau stream and colonized the Hutte stream.
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