Anatomical differences in three wing muscles of the Grey heron (Ardea cinerea), the Common buzzard (Buteo buteo) and the Common kestrel (Falco tinnunculus): a possible functional interpretation

In this paper, a description of the coracobrachialis caudalis, the scapulotriceps and the extensor carpi radialis muscles is presented in three different species (Common kestrel, Common buzzard and Grey heron) that exhibit notably differing flight styles. The primary goal of this research is to describe the gross anatomy of species not previously examined. Secondly, we attempt to advance a functional interpretation of the structures studied, to understand if such noticeable differences in flight style could have induced a differentiation in the above mentioned wing muscles. Regarding the coracobrachialis caudalis muscle, the Grey heron exhibited an unusual conformation with two \u201creversed\u201d heads and a great amount of fibrous bundles. Moreover, the \u201canchors\u201d of the scapulotriceps muscle were well developed in the Grey heron and vestigial in the Common kestrel, while an intermediate situation was observed in the Common buzzard. In addition, the extensor carpi radialis muscle showed interesting findings concerning the number of heads and their disposition. Our data may corroborate some previously advanced functional interpretation. In particular, the structure of the coracobrachialis muscle is in line with the hypothesis of its role as muscular strut. Moreover, the humeral and scapular anchors could play a role in increasing the scapulotriceps tension during some phases of the beat cycle or it may be involved in maintaining wing posture. Regarding the different number of heads and the disposition of the extensor carpi radialis muscle, we believe that it could play a role in maintaining the wing position. Although a correct functional interpretation can be obtained only through multidisciplinary studies, we believe that an in-depth gross anatomy study should always be conducted beforehand, to serve as basis for further and more specific research

Migration flyway of the Mediterranean breeding Lesser Crested Tern Thalasseus bengalensis emigratus

© 2016 NISC (Pty) Ltd. The Lesser Crested Tern Thalasseus bengalensis emigratus breeding population in the Mediterranean is found exclusively in Libya, on the two coastal islands of Gara and Elba and one wetland on the mainland coast at Benghazi. In order to improve knowledge of the species migration to wintering quarters in West Africa, a ringing programme was conducted from 2006–2008 and 2009–2012. From a total of 1 354 nestlings ringed using metal and/or colour rings, 64 were recovered along their flyway and in their wintering range, representing 6.9% of birds ringed with both colour and metal rings. This provided the opportunity to collect information on post-natal movements (staging and wintering ranges), breeding philopatry and recruitment, in addition to a preliminary estimate of their migration journey duration. This paper indicates sighting and recovery distributions in space and time, highlighting the important areas for the species during its journey between breeding and wintering sites. The findings indicate that several areas where ringed terns stop-over during pre- and post-breeding migration journeys are not protected, causing an additional threat to their survival, as some wintering areas are also not protected. Conservation of this highly localised and threatened population needs not only to address protection at breeding sites but also at migratory stop-overs and wintering strongholds

Nest Change and Individual Fitness in a Scopoli’s Shearwater Population: A Capture-Recapture Multistate Analysis

Seabirds are compelled to nest on land, away from their feeding areas, which they can only reach by leaving eggs or chicks in the nest, often for long periods of time. For this reason, almost all of them have evolved social monogamy as a reproductive system, cooperation between partners for incubation and chick rearing, and long-lasting pair bonds. Additionally, nesting conditions are essential for successful reproduction, and the nest can be considered a resource if it provides more guarantees in this aspect. As a result, the nest may be a source of contention and intraspecific competition, especially among males. In this work, we analyze long-term data of the Scopoli’s shearwater (Calonectris diomedea) population to address the fitness consequences of nest change regarding survival and reproductive success. We used capture–recapture multistate models and the AICc model selection approach to test three hypotheses: breeding failure triggers nest change; nest change affects breeding success probability; nest change affects survival. Each year, about 5% of the breeders move to a new nest. For males, it was mainly a way to improve their breeding conditions and was observed in their early years as a breeder. Conversely, for females, it was a way to improve their reproductive performance by trying with a new mate after a failure. Males that changed nests improved their breeding success probability. Instead, in females, there was no causal relation between nest change and breeding success, the latter having been more influenced by the intrinsic quality of the female as a breeder. We did not even find a link between nest change and survival. Instead, we demonstrated that reproductive failure could affect the apparent survival of females, probably because it induces breeding dispersal