Sophie Rouys

Factors determining the distribution of introduced mammals in nature reserves of the southern province, New Caledonia

We studied the distribution of introduced mammals in six nature reserves of New Caledonias southern province. Polynesian rats (Rattus exulans) were common in both rainforest and shrubland but their abundance decreased with increasing altitude. Ship rats (Rattus rattus) were abundant in rainforest but less numerous in shrubland and their abundance did not increase with altitude. We found no Norway rats (Rattus norvegicus) or house mice (Mus musculus domesticus) in reserves. Feral pigs (Sus scrofa) used mainly rainforest but also shrubland and preferred foraging in valleys with alluvial soils. Rusa deer (Cervus timorensis) selected shrubland over rainforest. Feral cats (Felis catus) were widely distributed in the reserves, whereas dogs (Canis familiaris) strayed into reserves but did not form feral populations.

Cooperative breeding, mate guarding, and nest sharing in two parrot species of New Caledonia

We provide evidence for cooperative breeding in two endemic parrot species of New Caledonia, the New Caledonian Parakeet (Cyanoramphus saisseti) and the Horned Parakeet (Eunymphicus cornutus). We intensively monitored 11 breeding attempts in two nests of New Caledonian Parakeets over 5 years, and noticed that two males of different size fed the female and the chicks in each nest. During one breeding attempt, the larger male guarded the female and the smaller male tried to copulate with her inside the nest. Genetic analyses showed that males shared paternity. During 17 breeding attempts in 11 Horned Parakeet nests, we observed two pairs sharing a nest on one occasion but we never saw feeding helpers.

Do Orthoptera need human land use in Central Europe? The role of habitat patch size and linear corridors in the Białowieża Forest, Poland

We studied Orthoptera, Dermaptera, and Blattodea of the Bial.owieza Forest (Poland) in order to assess (1) the minimum patch size of open habitat necessary for each species, (2) the role of linear corridors as habitat, and (3) the impact of herbivores on diversity by comparing the fauna at periods of different ungulate densities. Many species occurred in the farthest clearings from the forest edge to arable land. Two third of species occurred in clearings smaller than 10,000 m2. Dry linear corridors of 10–40 m width and wet linear corridors of 100–200 m width had a species richness that corresponded to that of clearings of about 10,000 m2. Four species disappeared from the Bialowieza Forest when ungulate density decreased from 20 individuals/km2 (3000 kg/km2 biomass) at the beginning of the 20th century to 10 individuals/km2 (1000 kg/km2) at the end of the 20th century. We conclude that most Orthoptera, Dermaptera, and Blattodea species could survive in Central Europe if human land use was replaced by intensive grazing and browsing by wild herbivores.

Group Territoriality as a form of Cooperative Breeding in the Flightless Kagu (Rhynochetos jubatus) of New Caledonia

ABSTRACT. Birds that live in family groups and cooperatively defend the familys territory are currently recognized as cooperative breeders only if helpers assist with chick rearing. We observed breeding Kagus (Rhynochetos jubatus) and video-monitored nests to determine whether help with feeding or family size affected their reproductive success. During >5,500 h of nest monitoring, helpers never provided parents or chicks with food. The reproductive success of families increased with group size nonetheless. Family size affected breeding success more than habitat-related parameters. Nonbreeding Kagus reacted to playback calls as often as breeding birds did. Observations of territorial fights gave additional evidence that nonbreeding group members help defend the familys territory and can, therefore, improve reproductive success. Our results suggest that cooperative territory-defense was the most important factor that increased the breeding success of Kagus. We propose that group territoriality should be considered a form of cooperative breeding.

Detectability and Disappearance of Ungulate and Hare Faeces in a European Temperate Forest

We counted droppings of ungulates and hare on transects in order to assess (1) seasonal changes in detectability and disappearance of pellet groups, (2) whether the detectability varies according to the forest type, and (3) the degree of misidentification between pellets of roe deer (Capreolus capreolus) and red deer (Cervus elaphus). The summer decrease in detectability of pellet groups was the most important factor for all species but European bison (Bison bonasus). Detectability did not significantly depend on forest type. In summer, decay reduced significantly the dropping density of red deer, roe deer, wild boar (Sus scrofa) and European hare (Lepus europaeus) but not those of bison and moose (Alces alces). Misidentification of roe and red deer droppings did not influence much density estimates of red deer but resulted in an important overestimation of roe deer in areas were roe deer were much less common than red deer.

How does parental role influence the activity and movements of breeding wolves

We studied the activity and movements of a male and a female wolf during breeding in the Bieszczady Mountains, Poland. The female was less active and mobile and on average closer to the den than the male. The male was less active and mobile when the pack size was seven compared to a year when the pack consisted only of the breeding pair. We conclude that the roles played by breeding males and females rearing pups influence their activity, and that breeding males in larger packs move less during the nursing period because of help by other pack members.

Accuracy of radio-tracking to estimate activity and distances walked by European bison in the Bialowieza Forest, Poland

To determine the accuracy of radio-tracking estimates of activity and distances walked by European bisonBison bonasus (Linnaeus, 1758), we observed bison while simultaneously conducting radio-tracking in the Bialowieża Forest (Poland). Single radio-tracking estimates often did not represent the actual activity of the bison, but the mean time spent active calculated from radio-tracking and direct observations did not differ significantly. Radio-tracking provided overestimates of the distances walked by bison when the animals walked between 0 and 25 m and underestimated the distances walked by bison if they walked further than 25 m in a radio-tracking interval. Activity was best estimated when radio-trackers were between 200 and 300 m from the bison. The mean activity calculated with a sampling interval of 15 min needed about 8 days of radio-tracking and the mean of distances walked about 35 tracking days to stabilise. We concluded that collars without activity sensors can measure the mean activity of bison but cannot represent the length of their activity bouts or the type of their activity and that our radio-tracking estimates of distances walked by bison needed to be corrected before further analyses.

TEMPORAl VARIATION IN FlOCk SIzE AND hAbITAT USE OF PARROTS IN NEw CAlEDONIA

Abstract. We examined daily activity patterns, flock-size variations, use of vertical space, and small-scale habitat selection of the New Caledonian Parakeet (Cyanoramphus saisseti), Horned Parakeet (Eunymphicus cornutus), and New Caledonian Rainbow Lorikeet (Trichoglossus haematodus deplanchii) on mainland New Caledonia. All three species had bimodal patterns of activity, with most encounters occurring in the morning and a second smaller peak of encounters in the late afternoon. The parakeets were usually seen singly or in twos, and most flocks contained fewer than four individuals. Parakeet flocks remained relatively consistent in size through the day and through the year. Most Rainbow Lorikeet flocks contained only a few individuals, though some reached up to 40 birds. Rainbow Lorikeets were encountered mainly in small flocks during the breeding season from September to January, and their average flock size was higher and more variable for the rest of the year. Rainbow Lorikeets selected valley forest and urban areas, where they were most common in parks and gardens. New Caledonian Parakeets favored slope forest over valley forest, and they foraged low, either at the edge of forest, in slope forest, or in maquis (shrubland). Horned Parakeets generally fed at greater heights than did New Caledonian Parakeets, preferred valley forest to slope forest, and avoided maquis. We suggest that the observed difference in habitat use between the New Caledonian Parakeet and Horned Parakeet is the result of spatial resource partitioning, which allows these closely related species to coexist.

Efficiency of a New Reverse-Bait Trigger Snap Trap for Invasive Rats and a New Standardised Abundance Index

We compared trapping and kill efficiency, and by-catch rate of a new reverse-bait trigger rat trap (Ka Mate) with conventional snap traps (Ezeset and Victor), and assessed methods for calculating abundance indices, over 2879 trap nights on Wallis & Futuna and New Caledonia. Ka Mate traps were most effective at killing larger (> 100 g) rats whereas Ezeset traps had the best capture rates of smaller (< 100 g) rodents. Victor mouse traps caught rodents up to 50 g, but were no more efficient than rat traps. Proportions of live captures were similar for Ka Mate and Ezeset traps, but the mass threshold for live rats in Ezeset traps was much lower than that of the Ka Mate traps. Ka Mate traps had much lower non-target by-catch rates than Ezeset traps in habitats free of land crabs. We developed a new rodent abundance index to standardise results of different trap systems.

Inventory of alien birds and mammals in the Wallis and Futuna Archipelago

In November 2007 and November 2008, we conducted a bird and mammal survey on Wallis and Futuna. We found two non-native bird species on Wallis: the Common Myna (Acridotheres tristis) and the Chestnut-breasted Munia (Lonchura castaneothorax), and one on Futuna: the Jungle Myna (Acridotheres fuscus). We also recorded Black Rats (Rattus rattus) on Futuna, a recent introduction to this island. The introduction of 3 bird species and Black Rats in the last decade denotes a lack of preventive measures and demonstrates that the issue of invasive species has not received sufficient priority.