3 research outputs found
Lovebirds in the air:trade patterns, establishment success and niche shifts of Agapornis parrots within their non-native range
Understanding the factors influencing the establishment of non-native species is pivotal with regards to the development of effective biosecurity policies. In this paper, we aim to assess the role of climate matching, trade patterns and breeding origin as drivers of establishment success of introduced lovebirds (Agapornis species). A comprehensive database on the worldwide distribution of eight species of non-native lovebirds (including establishment success and population size from 21 countries spanning 27 years) was compiled. We combined climate-based species distribution models with environmental niche analyses to evaluate environmental suitability and potential niche shifts in the introduced range of lovebirds. Then, we tested whether combining habitat suitability with information on trade, introduction effort and breeding origin (captive-bred or wild-caught) of imported birds can improve model predictions at the country level. Although climate-based models fit well with the current distribution of non-native lovebirds at 5-arcminute resolution and significant niche similarity was found for 3 species, we also observed successful establishments in areas climatically distinct from those occupied in native ranges. At the country level, only a significant relationship between the number of established populations and both the number of introduction sites and the year of first importation was observed. A significant effect of breeding origin was not found, but most traded birds had a captive-bred origin. Our work contributes to the growing evidence of the complexity of the invasion process and the difficulty of pre-introduction invasion assessments based solely on the characteristics of the recipient environments for the Agapornis species. Surveillance protocols should be applied to both wild-caught and captive-bred lovebirds, as additional data becomes available to better tease apart the role of origin in those species.The realisation of this manuscript was supported by the European Cooperation in Science and Technology COST Action ES1304 (ParrotNet). The contents of this paper are the authors’ responsibility and neither COST nor any person acting on its behalf is responsible for the use that might be made of the information contained in it. LuĂs Reino was funded by FEDER Funds through the Operational Competitiveness Factors Program “COMPETE”, and by National Funds through the Foundation for Science and Technology (FCT) within the framework of the Project “PTDC/AAG-GLO/0463/2014-POCI-01-0145-FEDER-016583” and FCT Post-doc Grant SFRH/BPD/93079/2013. LC was funded by the H2020-MSCA-IF-2016 fellowship No. 752149.Peer reviewe
The older the richer: significant increase in breeding bird diversity along an age gradient of different coppiced woods
Forest structural complexity could be a good predictor of overall species diversity. Since tree harvesting
has a negative effect on forest structure, it is important to analyse the effects of this disturbance on sensitive
groups, as forest birds. In this study, we aimed to shed light on this aspect by analysing a set of univariate metrics
in bird communities breeding in three coppiced forest habitats (coppiced of chestnut, coppiced of Turkey
oak and high forest of beech) along a gradient in age classes. We hypothesised that, with increasing forest age,
(i) breeding bird communities will progressively increase in diversity and, (ii) due to higher habitat heterogeneity
due to coppicing, a higher species turnover in the first age classes could appear. In each forest habitat, all
the metrics significantly increased, from recently coppiced to more mature forests, due to progressively higher
availability of resources and niches along the gradient. When comparing paired forest habitats, abundance and
richness were significantly different only in the two oldest age classes, highlighting that responses to different
tree composition were more marked in the mature phase. In all forest habitats, species turnover (w diversity)
decreased progressively along the age gradient and was highest in the youngest age classes where many vegetation
layers were present. Due to different coppice management practices, growth regime and consequent habitat
heterogeneity, chestnuts showed a different pattern when compared to other forest habitats, with an increase in
species turnover (w diversity) at intermediate level. With increasing age of the forests, all the diversity metrics
increased and species turnover decreased, highlighting the role of older forests as strategic habitats for highly
structured bird communities
A morphometric sexing approach for the Ring-necked Parakeet Psittacula krameri in Italy.
Only one fact is certain when sexing the Ring-necked Parakeet visually: adult males have a rosecoloured
ring and a black bib that is fully developed by their third year. Sexually immature males
(those <3 years old) and females are considered impossible to separate without using biometric
measures, some additional to those in previous literature. While the biometrics of males and
females overlap broadly in value, males tend to be slightly larger than females in all
measurements. We tested the possibility of sexing individuals of this species using a series of
biometric measurements. A total of 97 parakeets were captured and measured in 2016–17.
Measurements of wing length, tail length, bill length, height and thickness, tarsus length, mass,
third-primary length and number of yellow underwing coverts were recorded for these individuals.
In addition, photographs of the head and wing were taken. Feather samples were taken from all
individuals for DNA extraction and 45 of these birds (26 females and 19 males) have been sexed.
The measurements from these known-sex individuals were pooled with the measurements for
adult males and a logistic regression of the known sexes was performed to verify whether the
mean value of the biometric variables was statistically different between females and males. We
found that it is possible to separate the sexes using morphological measures of wing, tail, bill
length and thickness, tarsus and the number of yellow underwing cover