Raspberry Pi nest cameras: An affordable tool for remote behavioral and conservation monitoring of bird nests

Bespoke (custom-built) Raspberry Pi cameras are increasingly popular research tools in the fields of behavioral ecology and conservation, because of their comparative flexibility in programmable settings, ability to be paired with other sensors, and because they are typically cheaper than commercially built models.Here, we describe a novel, Raspberry Pi-based camera system that is fully portable and yet weatherproof-especially to humidity and salt spray. The camera was paired with a passive infrared sensor, to create a movement-triggered camera capable of recording videos over a 24-hr period. We describe an example deployment involving "retro-fitting" these cameras into artificial nest boxes on Praia Islet, Azores archipelago, Portugal, to monitor the behaviors and interspecific interactions of two sympatric species of storm-petrel (Monteiro's storm-petrel Hydrobates monteiroi and Madeiran storm-petrel Hydrobates castro) during their respective breeding seasons.Of the 138 deployments, 70% of all deployments were deemed to be "Successful" (Successful was defined as continuous footage being recorded for more than one hour without an interruption), which equated to 87% of the individual 30-s videos. The bespoke cameras proved to be easily portable between 54 different nests and reasonably weatherproof (~14% of deployments classed as "Partial" or "Failure" deployments were specifically due to the weather/humidity), and we make further trouble-shooting suggestions to mitigate additional weather-related failures.Here, we have shown that this system is fully portable and capable of coping with salt spray and humidity, and consequently, the camera-build methods and scripts could be applied easily to many different species that also utilize cavities, burrows, and artificial nests, and can potentially be adapted for other wildlife monitoring situations to provide novel insights into species-specific daily cycles of behaviors and interspecies interactions.

Modelling the distribution of Mustela nivalis and M. putorius in the Azores archipelago based on native and introduced ranges

The aims of this study were to predict the potential distribution of two introduced Mustelidae, Mustela nivalis and M. putorius in the Azores archipelago (Portugal), and evaluate the relative contribution of environmental factors from native and introduced ranges to predict species distribution ranges in oceanic islands. We developed two sets of Species Distribution Models using MaxEnt and distribution data from the native and introduced ranges of the species to project their potential distribution in the archipelago. We found differences in the predicted distributions for the models based on introduced and on native occurrences for both species, with different most important variables being selected. Climatic variables were most important for the introduced range models, while other groups of variables (i.e., human-disturbance) were included in the native-based models. Most of the islands of the Azorean archipelago were predicted to have suitable habitat for both species, even when not yet occupied. Our results showed that predicting the invaded range based on introduced range environmental conditions predicted a narrower range. These results highlight the difficulty to transfer models from native to introduced ranges across taxonomically related species, making it difficult to predict future invasions and range expansion.

The spatial ecology of invasive feral cats Felis catus on San Cristóbal, Galápagos: first insights from GPS collars

The dangers posed by invasive species for endemic island wildlife are well recognised. Introduced domestic cats (Felis catus) represent a significant threat to several endemic species of the Galápagos archipelago—including hatchling marine iguanas (Amblyrhynchus cristatus) and potentially green turtles (Chelonia mydas)—yet little is known about their spatial ecology and habitat use on these islands. Here, we describe a pilot study using GPS collars to track the movements of three feral cats at a site of conservation interest on San Cristóbal Island. Based on 175 days of GPS data, we undertook spatial analyses to ascertain home ranges, and to investigate the overlap of ranges between the cats and potential prey species. Average home range was 1.27 km2 (1.12–1.46 km2), which—though small for feral cats—is in keeping with previous findings in Galápagos. We found the cats did use the habitat of a small marine iguana population but did not change their spatial habits before and after iguana hatchlings appeared. Changes over time in the daily movements of one cat indicated a possible response of the individual to the presence of hatchling green turtles (Chelonia mydas); though the data here are insufficient to show whether the cat was hunting these hatchlings. We recommend similar work be undertaken in areas with larger marine iguana populations, where hatchlings could represent a potentially important food source for invasive feral cats, as well as further work to determine the threat posed by cats to turtle hatchlings in Galápagos.

On the landscape of fear: shelters affect foraging by dunnarts (Marsupialia, Sminthopsis spp.) in a sandridge desert environment

Disturbances such as fire reduce the structural complexity of terrestrial habitats, increasing the risk of predation for small prey species. The postfire effect of predation has especially deleterious effects in Australian habitats owing to the presence of invasive mammalian predators, the red fox (Vulpes vulpes) and feral cat (Felis catus), that rapidly exploit burned habitats. Here, we investigated whether the provision of artificial shelter could alleviate the risk of predation perceived by two species of small marsupial, the dunnarts Sminthopsis hirtipes and S. youngsoni, in open postfire habitat in the sandridge system of the Simpson Desert, central Australia. We installed artificial shelters constructed from wire mesh that allowed passage of the dunnarts but not of their predators at one site, and measured and compared the perceived risk of predation by the dunnarts there with those on a control site using optimal patch-use theory (giving-up densities, GUDs). GUDs were lower near artificial shelters than away from them, and near dune crests where dunnarts typically forage, suggesting that the shelters acted as corridors for dunnarts to move up to the crests from burrows in the swales. Foraging was lower near the crest in the control plot. Two-day foraging bouts were observed in dunnart activity, with recruitment to GUD stations occurring a day earlier in the augmented shelter plot. Despite these results, the effects of the shelters were localized and not evident at the landscape scale, with GUDs reduced also in proximity to sparse natural cover in the form of regenerating spinifex grass hummocks. Mapping dunnart habitat use using the landscape of fear (LOF) framework confirmed that animals perceived safety near shelter and risk away from it. We concluded that the LOF framework can usefully assess real-time behavioral responses of animals to management interventions in situations where demographic responses take longer to occur.

Inter-sexual habitat and isotopic niche segregation of the endangered Monteiro's storm-petrel during breeding

At-sea distribution and trophic ecology of small seabird species (i.e.<100 g) is far less known when compared to their larger relatives. We studied the habitat use (spatial ecology) and isotopic niches (trophic ecology) of the endangered Monteiro's storm-petrel Hydrobates monteiroi during the incubation and chick-rearing periods of 2013. There was a sexual foraging segregation of Monteiro's storm-petrels during the breeding period (tracking data) but also during the non-breeding stage (stable isotope analysis). Females took advantage of their longer wings to forage over the shallower Mid-Atlantic ridge (MAR) north of Azores, under colder and windier regimes when compared to males, who mostly exploited northern deep waters comparatively closer to the breeding colony. Between-sex differences in the spatial distribution were more obvious during the incubation period, with the overlap in their distribution increasing during the chick-rearing phase. There was also an isotopic segregation between sexes both during the previous breeding and the non-breeding stages, with females exhibiting a narrower, lower level isotopic niche when compared to males. Though the distribution patterns reported here should be useful for the at-sea conservation of this endangered species, future research should focus on (1) performing year-round tracking to map the species' distribution during the non-breeding period and (2) gathering multi-year tracking information to understand the effect of inter-annual environmental stochasticity on the foraging choices and trophic habits of the species.

Birds from the Azores: An updated list with some comments on species distribution

BACKGROUND

An updated checklist of the Birds of the Azores is presented based on information compiled from Rodrigues et al. (2010) and from the websites, Azores Bird Club. (2014), Aves dos Açores (2014) Azores Bird Sightings (2014) and Vittery (2014), since 2010.

NEW INFORMATION

The checklist has a total of 414 species, including 38 new species. Almost half of the species and subspecies that occur in the Azores have a Palearctic origin, the remaining ones being essentialy Nearctic and Holarctic species. São Miguel is the island with the highest number of bird species, followed by Terceira, Corvo and Flores islands.

Nest fidelity is driven by multi-scale information in a long-lived seabird

Although the reproductive success of most organisms depends on factors acting at several spatial scales, little is known about how organisms are able to synthesize multi-scale information to optimize reproduction. Using longitudinal data from a long-lived seabird, Monteiro's storm-petrel, we show that average breeding success is strongly related to oceanic conditions at the population level, and we postulate that (i) individuals use proximal information (their own reproduction outcome in year t) to assess the qualities of their mate and nest and to decide to retain them or not in year t + 1; (ii) the intensity of these responses depends on the quality of the oceanic environment in year t, which affects the predictability of reproduction outcome in year t + 1. Our results confirm that mate and nest fidelities are higher following successful reproduction and that the relationship between the success of a given pair and subsequent nest fidelity is stronger in years with unfavourable oceanic conditions, suggesting that individuals rely on distant information to modulate their use of proximal information and adjust their breeding strategy.

The interaction between reproductive cost and individual quality is mediated by oceanic conditions in a long-lived bird

Environmental variability, costs of reproduction, and heterogeneity in individual quality are three important sources of the temporal and interindividual variations in vital rates of wild populations. Based on an 18-year monitoring of an endangered, recently described, long-lived seabird, Monteiro's Storm-Petrel (Oceanodroma monteiroi), we designed multistate survival models to separate the effects of the reproductive cost (breeders vs. nonbreeders) and individual quality (successful vs. unsuccessful breeders) in relation to temporally variable demographic and oceanographic properties. The analysis revealed a gradient of individual quality from nonbreeders, to unsuccessful breeders, to successful breeders. The survival rates of unsuccessful breeders (0.90 +/- 0.023, mean +/- SE) tended to decrease in years of high average breeding success and were more sensitive to oceanographic variation than those of both (high-quality) successful breeders (0.97 +/- 0.015) and (low-quality) nonbreeders (0.83 +/- 0.028). Overall, our results indicate that reproductive costs act on individuals of intermediate quality and are mediated by environmental harshness.