Allometry of the Duration of Flight Feather Molt in Birds

Replacement of flight feathers takes disproportionately more time for large birds than it does for small birds, because feather length increases with body size almost twice as fast as feather growth rate increases

Duration of female parental care and their survival in the little auk Alle alle - are these two traits linked?

Desertion of offspring before its independence by one of the parents is observed in a number of avian species with bi-parental care but reasons for this strategy are not fully understood. This behaviour is particularly intriguing in species where bi-parental care is crucial to raise the brood successfully. Here, we focus on the little auk, Alle alle, a small seabird with intensive bi-parental care, where the female deserts the brood at the end of the chick rearing period. The little auk example is interesting as most hypotheses to explain desertion of the brood by females (e.g. “re-mating hypothesis”, “body condition hypothesis”) have been rejected for this species. Here, we analysed a possible relationship between the duration of female parental care over the chick and her chances to survive to the next breeding season. We performed the study in two breeding colonies on Spitsbergen with different foraging conditions – more favourable in Hornsund and less favourable in Magdalenefjorden. We predicted that in Hornsund females would stay for shorter periods of time with the brood and would have higher survival rates in comparison with birds from Magdalenefjorden. We found that indeed in less favourable conditions of Magdalenefjorden, females stay longer with the brood than in the more favourable conditions of Hornsund. Moreover, female survival was negatively affected by the length of stay in the brood. Nevertheless, duration of female parental care over the chick was not related to their parental efforts, earlier in the chick rearing period, and survival of males and females was similar. Thus, although females brood desertion and winter survival are linked, the relationship is not straightforward

Understanding Attitudes Towards Native Wildlife and Biodiversity in the UK: The Role of Zoos

International audienc

Anthropogenic noise is associated with changes in acoustic but not visual signals in red-winged blackbirds

Some birds in noisy areas produce songs with higher frequency and/or amplitude and altered timing compared to individuals in quiet areas. These changes may function to increase the efficacy of acoustic signals by reducing masking by noise. We collected audio recordings of red-winged blackbirds and measured noise levels. We found that males in noisier places produced songs with fewer syllables and slower repeat rate of elements in some components (rattles). Birds may also improve the efficacy of communication in noise by increasing usage of other signaling modalities. Red-winged blackbirds also perform a visual display in different intensities while singing. We also tested whether this species performs the visual display in different intensities according to current noise levels, and predicted that if the efficacy of songs is impaired in noisy places, males would compensate by performing a more intense visual display. For this, we also collected visual recordings from the same males from which we obtained acoustic recordings. We found no association between acoustic noise and the intensity of the visual display; thus, our results do not support the idea that males are using the visual display as a backup signal to communicate under acoustic noise. We discuss some possible explanations of this negative finding and for the observed noise-related changes in song length and rattle rate in the context of communication under noise

Evaluating habitat connectivity methodologies: a case study with endangered African wild dogs in South Africa

Context In fragmented landscapes, connectivity between subpopulations is vital for species’ persistence. Various techniques are used to assess the degree of connectivity between habitat patches, yet their performance is seldom evaluated. Models are regularly based on habitat selection by individuals in resident populations, yet dispersers may not require habitat which supports permanent residence. Objectives and methods Using a database of African wild dog (Lycaon pictus) occurrence records in northeastern South Africa (n = 576), we developed and compared ecological niche models (ENM) for wild dogs packs and dispersers. Additionally, we used least cost path (LCP) and current flow models to assess connectivity. Results were further validated using occurrence records (n = 339) for cheetah (Acinonyx jubatus). Results and conclusions The ENM for wild dog packs identified large but isolated patches of suitable habitat, while the disperser ENM had greater suitability values for areas in between highly suitable patches. Without disperser-specific data, models omitted large areas which were confirmed to have provided connectivity. Although models derived from a potentially subjective cost layer have been criticised, the current flow model outperformed the other connectivity techniques and provided the most meaningful predictions for conservation planning. We identified five priority conservation areas for wild dogs, two of which had a greater feasibility for recolonisation. The scarcity of disperser-specific data promotes models using habitat data for resident individuals but here we illustrate the pitfalls thereof. Our study provides insights into the performance of these frequently employed techniques and how they may affect conservation management decisions

Spatiotemporal dynamics of urban green spaces and human–wildlife conflicts in Tokyo

Although urban green spaces are increasingly important both for humans and wildlife, an increase in urban green spaces may also increase human–wildlife conflicts in urban areas. However, few studies have examined the relationship between the size of green spaces and the level of conflicts with wildlife in multiple taxa, including invertebrates and vertebrates. To better understand current pest statistics and predict changes that will occur as the area of green spaces increases, we analysed a dataset compiling the number of pest consultations in 53 metropolitan districts in Tokyo over a 20-year period and its relationships with the area of green space. Stinging insects (e.g., wasps) made up over 50% of pest consultations, followed (in order) by rats and other nuisance animals (e.g., snakes). The number of consultations per unit population did not correlate, or was even negatively correlated, with the proportions of green spaces (mainly forest) for many indoor pests, but did positively correlate for some outdoor pests, such as wasps and snakes. Therefore, wasps and snakes can increase when urban green spaces increase. Because even minor nuisances are relevant for urban lifestyles, considerations of ways to minimise conflicts with wildlife are critical for urban green space management