Fringilla Polatzeki Research Articles

Establishment success of the reinforced population of Gran Canaria Blue Chaffinch Fringilla polatzeki

The Gran Canaria Blue Chaffinch is the rarest forest passerine in the western Palaearctic with a population reduced to a single locality, Inagua, in the west of the island. After a forest fire, some birds were established in another location and a reinforcement programme was launched with the aim of consolidating this new population. Between 2010 and 2019, 194 Blue Chaffinches were released in the pine forest of La Cumbre, in the centre of the island and at a higher altitude than the previous one. Birds of two origins were used for this action: captive-bred birds were released using “soft” release methods, and wild-caught birds from the Inagua source population were released using “hard” release methods. Survival of radio-tagged birds (20–42 days of battery life) was high and similar between the two groups. Wild-caught birds occupied 12–15 times more surface area than captive-bred birds that remained close to supplementary feeding sites. All translocated birds displayed breeding behaviour in the following breeding season, although the rate of contribution to the new population was significantly lower for wild-caught birds (21% compared to 54% for captive-bred birds). This disparity can be partly attributed to nearly one-fifth of the wild-caught birds returning to Inagua. We conclude that the establishment phase of the Blue Chaffinch reinforced program in Gran Canaria has been successful. To retain wild-caught birds and deter their return to the source population, we recommend employing methods akin to the soft-release techniques utilized for captive-bred birds. Ongoing monitoring of the enhanced population, collecting data on survival and breeding success, will enable the evaluation of the long-term success of the translocation program.

The complete mitochondrial genome of the Brambling Fringilla montifringilla (Passeriformes: Fringillidae) from Maor Mountain, China

The Brambling (Fringilla montifringilla) (Linnaeus 1758) is a member of the Passeriformes family of birds and primarily feeds on grass seeds and grains. Muscle tissue was collected from birds sampled from Moar Mountain, China, and the complete mitochondrial genome was sequenced. Its mitochondrial genome consists of 13 protein-coding genes (PCGs), 2 rRNA genes (12S rRNA and 16S rRNA), 22 tRNA genes, and 1 control region (CR). The genome comprises 30.30% A, 23.32% T, 14.31% G, and 32.07% C bases. Phylogenetically, F. montifringilla is closely related to the Fringilla coelebs, Fringilla teydea teydea and Fringilla polatzeki.

Population size, abundance, habitat relationships and the result of a translocation programme in the Gran Canaria Blue ChaffinchFringilla polatzeki

SummaryThe Gran Canaria Blue ChaffinchFringilla polatzekiis a threatened, endemic, forest‐dwelling bird species of the Canary Islands, whose core population at the end of the 20th century was restricted to the pine forests of Inagua Nature Reserve (38 km2). A translocation programme released birds from a breeding centre into the nearby (<3 km) pine forests of La Cumbre in the years following 2010. From 2015 to 2019 the La Cumbre population was reinforced by translocation of wild juveniles from the source population of Inagua. We estimate the population size, the spatial variation of abundance, and recent temporal changes in density of the species in Inagua and La Cumbre by means of line transects, distance sampling, and habitat suitability modelling using random forests. The average density of the Blue Chaffinch in Inagua Nature Reserve was 10.2 birds/km2in spring 2019, with a population estimated at 362 birds (95% CI: 257–489). The most important variables affecting the distribution of the Blue Chaffinch in Inagua were the amount of precipitation during the summer (July–September), the solar radiation in June, and the northern position in the reserve, highlighting the importance of abiotic factors related to thermal and hydric stress during the breeding season. The density was considerably lower in the translocated population inhabiting 21 km2of pine forests in La Cumbre (3.3 birds/km2), with an estimate of 68 Blue Chaffinches (35–141) breeding freely in the wild. The translocation programme successfully contributed to the establishment of a second viable nucleus, accounting for 16% of the total population within a time span of 10 years. This result reinforces the role of translocations in preventing extinctions of endangered species with very low population sizes restricted to only one isolated area.

Striking resilience of an island endemic bird to a severe perturbation: the case of the Gran Canaria blue chaffinch

espanolSon pocos los datos disponibles sobre la tendencia demografica de las especies en peligro de extincion en zonas de proteccion especial y su capacidad de recuperarse de perturbaciones catastroficas. Se estudia la tendencia demografica del pinzon azul de Gran Canaria (Fringilla polatzeki), un especialista de habitat endemico de las Islas Canarias, restringido al pinar de Inagua, que sufrio un devastador incendio forestal en julio de 2007. Mediante un programa de censo estandarizado que tiene en cuenta la variacion en la capacidad de deteccion, se ha hecho un seguimiento de la tendencia demografica de la especie desde la declaracion de Inagua como reserva natural integral en 1994. La densidad reproductiva del pinzon azul se mantuvo estable en Inagua desde el inicio del programa de seguimiento en 1994 hasta un ano antes del incendio. No obstante, en la primavera de 2008, la densidad de la poblacion se redujo a la mitad en comparacion con los anos anteriores. A partir de 2008, la poblacion del pinzon azul ha venido aumentando gradualmente hasta alcanzar la densidad mas alta jamas registrada en 2016 (15,8 aves/km2), lo que equivale a un incremento anual medio del 23,7% y pone de manifiesto la resistencia impresionante de estas poblaciones ante catastrofes. Por lo tanto, la creacion de la reserva integral de Inagua no promovio el aumento de poblacion ni protegio al pinzon azul frente a una grave crisis demografica, sino que probablemente evito que la disminucion de la poblacion fuera mas profunda o que se produjeran otras reducciones. Aparte de los dos anos inmediatamente posteriores al incendio forestal de 2007, la densidad de poblacion del pinzon azul en Inagua se mantuvo relativamente estable alrededor de 9–16 aves/km2, la menor abundancia jamas registrada para un paseriforme forestal de tamano pequeno en todo el paleartico occidental. EnglishEvidence regarding population trends of endangered species in special protection areas and their recovery ability from catastrophic disturbances is scarce. We assessed the population trend of the Gran Canaria blue chaffinch (Fringilla polatzeki), a habitat specialist endemic to the pine forest of Inagua in the Canary Islands, following a devastating wildfire in July 2007. Using a standardized census program that accounts for detectability, we have monitored the population trend of the species since Inagua was declared a Strict Nature Reserve in 1994. The breeding population density of the blue chaffinch remained stable in Inagua from the beginning of the monitoring program in 1994 until the year before the wildfire. However, in spring 2008, the population density decreased by half with respect to density in the preceding years. Since 2008, the population has gradually increased, reaching its highest recorded density in 2016 (15.8 birds/km2).This represents an average annual increase of 23.7%, indicating impressive resilience to catastrophic events. The creation of Inagua as a strict nature reserve did not therefore increase the global population or protect the blue chaffinch against a demographic crisis but probably prevented a deepening of the demographic crisis or further declines. Except for the two years immediately after the severe wildfire of 2007, the population density of the blue chaffinch in Inagua has remained relatively stable at around 9–16 birds/km2, the lowest recorded abundance for a small woodland passerine in the Western Palearctic.

Habitat suitability-density relationship in an endangered woodland species: the case of the Blue Chaffinch (Fringilla polatzeki).

BackgroundUnderstanding constraints to the distribution of threatened species may help to ascertain whether there are other suitable sectors for reducing the risks associated with species that are recorded in only one protected locality, and to inform about the suitability of other areas for reintroduction or translocation programs.MethodsWe studied the Gran Canaria blue chaffinch (Fringilla polatzeki), a habitat specialist endemic of the Canary Islands restricted to the pine forest of Inagua, the only area where the species has been naturally present as a regular breeder in the last 25 years. A suitability distribution model using occurrences with demographic relevance (i.e., nest locations of successful breeding attempts analysed using boosted classification trees) was built considering orographic, climatic and habitat structure predictors. By means of a standardized survey program we monitored the yearly abundance of the species in 100 sectors since the declaration of Inagua as a Strict Nature Reserve in 1994.ResultsThe variables with the highest relative importance in blue chaffinch habitat preferences were pine height, tree cover, altitude, and rainfall during the driest trimester (July–September). The observed local abundance of the blue chaffinch in Inagua (survey data) was significantly correlated with habitat suitability derived from modelling the location of successful nesting attempts (using linear and quantile regressions). The outcomes of the habitat suitability model were used to quantify the suitability of other natural, historic, pine forests of Gran Canaria. Tamadaba is the forest with most suitable woodland patches for the species. We estimated a population size of 195–430 blue chaffinches in Inagua since 2011 (95% CI), the smallest population size of a woodland passerine in the Western Palearctic.DiscussionHabitat suitability obtained from modelling the location of successful breeding attempts is a good surrogate of the observed local abundance during the reproductive season. The outcomes of these models can be used for the identification of potential areas for the reintroduction of the species in other suitable pine forests and to inform forest management practices.

Species-level divergences in multiple functional traits between the two endemic subspecies of Blue Chaffinches Fringilla teydea in Canary Islands

One of the biggest challenges in avian taxonomy is the delimitation of allopatric species because their reproductive incompatibility cannot be directly studied in the wild. Instead, reproductive incompatibility has to be inferred from multiple, divergent character sets that indicate a low likelihood of allopatric populations amalgamating upon secondary contact. A set of quantitative criteria for species delimitation has been developed for avian taxonomy. Here, we report a broad multi-trait comparison of the two insular subspecies of the Blue Chaffinch Fringilla teydea, endemic to the pine forests of Tenerife (ssp. teydea) and Gran Canaria (ssp. polatzeki) in the Canary Islands. We found that the two taxa were reciprocally monophyletic in their whole mitogenomes and two Z chromosome introns. The genetic distance in mitogenomes indicates around 1 Mya of allopatric evolution. There were diagnostic differences in body morphometrics, song and plumage reflectance spectra, whose combined divergence score (=11) exceeds the threshold level (=7) set for species delimitation by Tobias et al. (Ibis 152:724–746, 2010). Moreover, we found a marked divergence in sperm lengths with little range overlap. Relatively long sperm with low intra- and intermale CV compared to other passerines suggest a mating system with high levels of sperm competition (extrapair paternity) in these taxa. The large and diagnostic divergences in multiple functional traits qualify for species rank, i.e., Tenerife Blue Chaffinch (Fringilla teydea) and Gran Canaria Blue Chaffinch (Fringilla polatzeki). We encourage a wider use of sperm traits in avian taxonomy because sperm divergences might signal reproductive incompatibility at the postcopulatory prezygotic stage, especially in species with sperm competition.

Integrative taxonomy reveals Europe's rarest songbird species, the Gran Canaria blue chaffinchFringilla polatzeki

The conservation of endangered taxa often critically depends on accurate taxonomic designations. The status of the Gran Canaria population of the blue chaffinchFringilla teydea polatzekihas not been reevaluated since the early 1900s when this taxon was described as a subspecies and combined with the much more common Tenerife blue chaffinchF. t. teydeain a single species. We show that multiple diagnostic differences in plumage, songs, calls and morphometrics distinguishF. t. polatzekifromF. t. teydea. Preliminary playback experiments suggest thatF. t. polatzekiis able to discriminate between songs of both taxa. Along with previously reported differences in mitochondrial DNA, these findings show that the blue chaffinches on Gran Canaria and Tenerife represent two distinctive species:F. polatzekiandF. teydea. Gran Canaria blue chaffinch is Europe's rarest passerine species and should be classified as critically endangered. Its long‐term survival in the wild currently depends on a very small (< 20 km2) area in southwest Gran Canaria. Reclassification of Gran Canaria blue chaffinch as a species increases the urgency of ongoing conservation efforts. Our study underscores the critical importance of taxonomic clarification of threatened taxa that are currently classified as ‘subspecies’.

Genetic signature of a severe forest fire on the endangered Gran Canaria blue chaffinch (Fringilla teydea polatzeki)

Habitat destruction has been identified as one of the main threats to biodiversity. Among all factors causing habitat disturbance, wildfire is recognized as one of the most important ecological forces that influences not only the physical environment, but also the structure and composition of floral and faunal communities. These processes are often translated in population bottlenecks, which occur frequently in threatened species and result in loss of genetic diversity and evolutionary potential. In this study, we analyzed the genetic consequences of a demographic bottleneck produced by a forest fire that reduced the population of the endangered blue chaffinch (Fringilla teydea polatzeki), which inhabits the island of Gran Canaria, to approximately 122 individuals. Analysis of nine microsatellite loci revealed that, while a decline in census was observed during the bottleneck, there was no observed excess of heterozygosity or evidence of a decline in allelic richness, two characteristic bottleneck signatures. On the contrary, we observed that the Gran Canaria blue chaffinch has retained significant levels of genetic diversity and shows no evidence of an increased level of inbreeding (FIS) either before or after the bottleneck. The results from this study have important implications for the conservation of this endangered subspecies and provide insights concerning management strategies to prevent its extinction.

Bird Size and Density: A Regional Approach

Previous articleNext article No AccessNotes and CommentsBird Size and Density: A Regional ApproachL. M. Carrascal and J. L. TelleriaL. M. Carrascal Search for more articles by this author and J. L. Telleria Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The American Naturalist Volume 138, Number 3Sep., 1991 Published for The American Society of Naturalists Article DOIhttps://doi.org/10.1086/285250 Views: 2Total views on this site Citations: 18Citations are reported from Crossref Copyright 1991 The University of ChicagoPDF download Crossref reports the following articles citing this article:AHMAD FITRI AZIZ, CHARLIE JUSTIN MERGIE LAMAN Species Abundance and Body Size Relationship of Bird Assemblages at Selected Sites in Western Sarawak, Trends in Undergraduate Research 3, no.22 (Dec 2020): a18–25.https://doi.org/10.33736/tur.1414.2020Luis M. Carrascal, Ángel C. 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