Overlap in reproductive phenology increases the likelihood of cavity nest usurpation by invasive species in a tropical city

The Condor ◽  
2020 ◽  
Vol 122 (3) ◽  
Author(s):  
Joshua M Diamond ◽  
Michael S Ross

Abstract Multiple invasive cavity-nesting bird species can be present in a nest web, the network linking birds using cavities. We investigated the nest preferences and breeding phenologies of the cavity-nesting guild in the region surrounding Miami, Florida, USA, where invasive starlings, mynas, and parrots potentially usurp cavities from native woodpeckers and secondary cavity-nesters. We asked if the timing of reproduction determines which invasive species will usurp cavities from native birds with similar nest preferences. Nest usurpations between European Starlings (Sturnus vulgaris) and the woodpecker species present in Miami is well documented, but we predicted that a recently arrived sturnid species and introduced psittacids would also usurp nests. European Starlings had the largest breeding population of any species in our nest web, breeding during the peak of nesting season, and usurped the largest number of active nest cavities. We found that a small population of Common Mynas (Acridotheres tristis) usurped nests, sharing the peak-season nesting period with starlings and native woodpeckers. Parrots bred later than we expected, avoiding nest-site overlap with similarly large native birds that use cavities with similar characteristics. Parrots did not usurp any active nest cavities from native birds. Our results demonstrate how to use analysis of cavity characteristics and reproductive timing to evaluate threats to a cavity nest web posed by multiple invasive species. Common Myna currently usurp few nests; if they increase greatly in population, they could pose a problem for native cavity-nesters.

2017 ◽  
Vol 13 (1) ◽  
pp. 20160783 ◽  
Author(s):  
Gabrielle L. Davidson ◽  
Alex Thornton ◽  
Nicola S. Clayton

Strong selection pressures are known to act on animal coloration. Although many animals vary in eye colour, virtually no research has investigated the functional significance of these colour traits. Passeriformes have a range of iris colours, making them an ideal system to investigate how and why iris colour has evolved. Using phylogenetic comparative methods, we tested the hypothesis that conspicuous iris colour in passerine birds evolved in response to (a) coordination of offspring care and (b) cavity nesting, two traits thought to be involved in intra-specific gaze sensitivity. We found that iris colour and cooperative offspring care by two or more individuals evolved independently, suggesting that bright eyes are not important for coordinating parental care through eye gaze. Furthermore, we found that evolution between iris colour and nesting behaviour did occur in a dependent manner, but contrary to predictions, transitions to coloured eyes were not more frequent in cavity nesters than non-cavity nesters. Instead, our results indicate that selection away from having bright eyes was much stronger in non-cavity nesters than cavity nesters, perhaps because conspicuous eye coloration in species not concealed within a cavity would be more visible to predators.


The Condor ◽  
2004 ◽  
Vol 106 (1) ◽  
pp. 5-19 ◽  
Author(s):  
Kathy Martin ◽  
Kathryn E. H. Aitken ◽  
Karen L. Wiebe

Abstract The mixed forests of interior British Columbia, Canada, support a rich community of cavity nesters, accounting for about one-third of forest vertebrate species. For 20 cavity-nesting bird and six cavity-nesting mammal species, representing excavators and secondary cavity nesters, we measured nest-cavity and nest-tree characteristics over 8 years in Interior Douglas-fir (Pseudotsuga menziesii) forest ecosystems. There was overwhelming selection for quaking aspen (Populus tremuloides); 95% of 1692 cavity nests were in aspen, which comprised only 15% of trees available. The full range of live and dead trees were used, but we observed a strong preference for live trees with decay (45% of nests) or dead trees (45% of nests). A cluster analysis based on tree and cavity characteristics divided the community into five groups, including large- and medium-sized woodpeckers and a group comprised mostly of weak excavators. A fourth group included Northern Flickers (Colaptes auratus), the most abundant excavator, and the larger secondary cavity nesters. The final group contained the most aggressive and most abundant secondary cavity nesters. European Starling (Sturnus vulgaris), the most aggressive secondary cavity nester, occupied a narrower nest niche (in less-decayed trees with smaller entrances) relative to their size. Less-competitive excavators and secondary cavity nesters occupied wider nest niches in terms of tree decay class and cavity size. We constructed a nest web for community structure that showed most cavity resource use flowed up the community through aspen trees and cavities excavated by Northern Flickers. Thus, aspen was the critical nesting tree and Northern Flickers were the keystone excavators in this community. Sitios de Nidificación y Redes de Nidos en Comunidades que Nidifican en Cavidades en el Interior de British Columbia, Canadá: Características de los Nidos y Separación de Nichos Resumen. Los bosques mixtos del interior de British Columbia, Canadá, albergan una rica comunidad de animales que nidifican en cavidades, los cuales representan aproximadamente un tercio de las especies de vertebrados de bosque. En este estudio medimos características de las cavidades y de los árboles de nidificación para 20 especies de aves y seis de mamíferos que nidifican en cavidades (incluyendo especies excavadoras y las que utilizan cavidades secundariamente) a lo largo de ocho años en ecosistemas de bosque interior de Pseudotsuga menziesii. Hubo una selección abrumadora de árboles de la especie Populus tremuloides; el 95% de 1692 cavidades de nidificación se encontraron en árboles de esta especie, la cual comprendía sólo el 15% de los árboles disponibles. Todo el espectro de árboles vivos y muertos fue utilizado, pero observamos una preferencia fuerte por árboles vivos con descomposición (45% de los nidos) o árboles muertos (45% de los nidos). Un análisis de agrupamiento basado en características de los árboles y las cavidades dividió la comunidad en cinco grupos, incluyendo carpinteros de tamaño grande y mediano, y un grupo formado principalmente por excavadores débiles. Un cuarto grupo incluyó al carpintero Colaptes auratus (el excavador más abundante) y a las especies de mayor tamaño que nidifican en cavidades secundarias. El último grupo incluyó a las especies más abundantes y agresivas que nidifican en cavidades secundarias. El estornino Sturnus vulgaris, la especie más agresiva que nidifica en cavidades secundarias, ocupó un nicho más estrecho (árboles menos descompuestos con entradas más pequeñas) con relación a su tamaño. Los excavadores menos competitivos y los usuarios de cavidades secundarias ocuparon nichos de nidificación más amplios en términos de la categoría de descomposición de los árboles y el tamaño de la cavidad. Construimos una red de nidos para estudiar la estructura de la comunidad, la cual mostró que la mayor parte del uso de las cavidades como recurso fluye en la comunidad a través de los árboles de P. tremuloides y las cavidades excavadas por C. auratus. Por lo tanto, P. tremuloides fue el árbol de nidificación crítico y C. auratus fue la especie de excavador clave en esta comunidad.


2005 ◽  
Vol 119 (3) ◽  
pp. 367 ◽  
Author(s):  
Collette L. Adkins Giese ◽  
Francesca J. Cuthbert

Characteristics of woodpecker nest trees have been widely studied in some regions of North America. However, there is little research from the Upper Midwest. Forest managers need information on woodpecker nest tree characteristics so they can recommend leaving during harvest trees that meet the needs of cavity-dwelling wildlife. Information specific to the Upper Midwest is especially important given that declines in several species of cavity nesting birds have been predicted by an environmental analysis of timber harvest in Minnesota. Our purpose was to identify attributes of nest trees used by primary cavity-nesting birds. We compared nest trees to unused trees and examined differences in nest trees among woodpecker species. We found 166 active woodpecker nests in upper midwestern oak forests in 1997 and 1998. For each nest tree, we recorded height, diameter, status, and aspects of tree decay. We also measured four potential nest trees (non-nest trees, within size requirements of cavity-nesting birds, with at least 2 indicators of heartwood decay) closest to each active nest tree. Additionally, we recorded these measurements for 137 randomly selected potential nest trees. Using paired t-tests and chi-square analysis, we found each woodpecker species had a unique set of characteristics that separated nest trees from potential nest trees. Using an extension of the McNemar test for related samples, we found woodpeckers as a group used trees that were larger, both in diameter and height, more often elm (Ulmus americana, U. rubra) or aspen (Populus tremuloides, P. grandidentata), more likely to have old cavities present, and with more decay indicators than adjacent potential nest trees. The Yellow-bellied Sapsucker (Sphyrapicus varius) differed from the other woodpecker species by nesting in living Trembling Aspens (Populus tremuloides) with intact tops, complete bark cover, and heartwood fungus. Diameters of nest trees differed significantly among woodpecker species, but unlike findings from other studies, the height of nest hole and nest tree did not. Woodpecker nest entrances faced south or southeast significantly more often than by chance alone, even when excluding leaning trees. This study suggests that generic forest management for all woodpecker species may not be adequate because individual species have specific nest tree requirements. Management recommendations for cavity-nesting birds need to be tailored to meet the needs of a diversity of species.


The Condor ◽  
2002 ◽  
Vol 104 (4) ◽  
pp. 890-896 ◽  
Author(s):  
Joshua J. Lawler ◽  
Thomas C. Edwards

Abstract We compared cavity-nesting bird communities in aspen (Populus tremuloides) woodland fragments classified on the basis of vegetation structure (tree density) and landscape context (surrounding vegetation). We found very few cavity nesters in fragments predominantly surrounded by forests. Fragments adjacent to meadows contained more species and a greater abundance of cavity nesters. Species richness and abundance were higher in sparsely than in densely treed meadow fragments. Because secondary cavity nesters are often limited by cavity availability, we augmented natural cavities with nest boxes. Although only five boxes contained bird nests, these were all in sparse aspen fragments predominantly surrounded by meadows. However, we found 25 northern flying squirrel (Glaucomys sabrinus) nests in boxes, none of which were in sparse meadow fragments. In addition to highlighting the importance of landscape context in avian and mammalian habitat relationships, our results suggest that predator or competitor interactions may help structure this cavity-nester community. Composición de las Comunidades de Aves que Nidifican en Cavidades en los Fragmentos de Bosque Montano de Álamo: El Papel del Contexto del Paisaje y la Estructura del Bosque Resumen. Comparamos comunidades de aves que nidifican en cavidades en fragmentos de bosque de álamo (Populus tremuloides) clasificados en base a la estructura de la vegetación (densidad de árboles) y al contexto del paisaje (vegetación circundante). Encontramos muy pocas aves que nidifican en cavidades en los fragmentos rodeados predominantemente por bosque. Los fragmentos adyacentes a prados presentaron más especies y mayor abundancia de aves. La riqueza y la abundancia de especies fueron mayores en fragmentos con baja densidad de árboles que estuvieron rodeados por prados. Debido a que las aves que nidifican en cavidades secundarias están a menudo limitadas por la disponibilidad de cavidades, aumentamos las cavidades naturales con cajas de anidaje. Aunque solamente cinco cajas contuvieron nidos de aves, éstas estuvieron todas en los fragmentos con baja densidad de álamos rodeados predominantemente por prados. Sin embargo, encontramos 25 nidos de ardillas voladoras norteñas (Glaucomys sabrinus) en las cajas de anidaje, de las cuales ninguna estuvo en fragmentos con baja densidad de árboles rodeados por prado. Nuestros resultados destacan la importancia del contexto del paisaje en las relaciones entre el hábitat y las aves y mamíferos, y sugieren que las interacciones con depredadores o competidores pueden influenciar la estructura de la comunidades de aves que anidan en cavidades.


2015 ◽  
Vol 26 (2) ◽  
pp. 154-163 ◽  
Author(s):  
SABRINA KUMSCHICK ◽  
TIM M. BLACKBURN ◽  
DAVID M. RICHARDSON

SummaryAlien species can cause severe impacts in their introduced ranges and management is challenging due to the large number of such species and the diverse nature and context of their impacts. Lists of the most harmful species, like the “100 of the World’s Worst” list collated by the Invasive Species Specialist Group of the International Union for Conservation of Nature (IUCN) or the “100 of the Worst” invaders in Europe collated by the Delivering Alien Invasive Species Inventories in Europe (DAISIE) project, raise awareness about these impacts among the public, and can guide management decisions. Such lists are mainly based on expert opinion, but in recent years a more objective comparison of impacts has become possible, even between highly diverse taxa. In this study, we use a semi-quantitative generic impact scoring system to assess impacts of the three birds listed among the “100 of the World’s Worst” IUCN list (IUCN100) and the four birds on the list of “100 of the Worst” European invaders by DAISIE (DAISIE100) and to compare their impacts with those of other alien birds not present on the respective lists. We found that generally, both lists include some of the species with the highest impacts in the respective regions (global or Europe), and these species therefore deserve the dubious honour of being listed among the “worst”. However, there are broad overlaps between some species with regards to the impact mechanisms and the related issues of invasions, especially those of the Common Myna Acridotheres tristis and Red-vented Bulbul Pycnonotus cafer on the IUCN100, are very similar which might not warrant listing both species. To make the selection of species on such lists more transparent we suggest moving beyond lists based on expert opinion to a more transparent and defendable system for listing alien species based on published records of their impacts and related mechanisms.


2016 ◽  
Vol 46 (5) ◽  
pp. 725-737 ◽  
Author(s):  
Ian D. Thompson ◽  
Philip Wiebe ◽  
David A. Kirk

Forests with old-growth white pines have been severely reduced compared with historical levels. We examined resident and cavity-nesting bird species abundances in winter and the breeding season, because some of these species may prefer old-forest habitats for breeding. We counted birds over 10 years in four mixedwood types: old pine, mature pine, mature nonpine, and selection-harvested stands. We expected that old pine stands would be selected by some species because of abundant snags and large trees for foraging. We assessed habitat use among years and changes following harvesting. Counts of nomadic species varied across years but counts for others did not. Species used old and mature pine mixedwoods equally and more than nonpine or harvested stands in winter and for breeding, but old stands were not preferred. Important variables included percent pine and large tree density. Selection harvesting benefitted Yellow-bellied Sapsuckers but reduced counts of Black-capped Chickadees and Brown Creepers. Black-capped Chickadees changed habitats between seasons and in some years. Black-backed Woodpeckers were most common in pine stands but abundant in harvested stands for 2 years following cutting. Regardless of stand age, large (>40 cm) pines provide important habitat for residents and cavity nesters.


2019 ◽  
Author(s):  
J Scott MacIvor

AbstractEvaluating resource use and overlap through time and space among and within species having similar habitat requirements informs community-level conservation and coexistence, efforts to monitor species at-risk and biological invasions. Many species share common nesting requirements; one example are cavity-nest bees and wasps, which provision nests in dark and dry holes in wood, plant stems, or other plant-based materials that can be bundled together into ‘trap nests’. In this study, the adult emergence order of 47 species of solitary cavity-nesting bees and wasps, and their parasites (total N>8000 brood cells) were obtained from two hundred identical trap nests set up each year (over three years) to survey these populations across Toronto, Canada and the surrounding region. All brood cells collected were reared in a growth chamber under constant warming temperature and humidity to determine species identity, and adult emergence order. This order ranged from 0 to 38 days, with all mason bees (Osmia spp.) emerging within the first two days, and the invasive resin bee species, Megachile sculpturalis Smith significantly later than all others. Late emerging species i) exhibited significantly greater intraspecific variation in mean emergence day and ii) were significantly larger in body size, compared to early emerging species. Detailing natural history information at the species- and community-level, such as the adult emergence order of coexisting cavity-nesting bees and wasps and their parasites, can inform the timing of deployment of trap nests to support and monitor target species, and refine experimental design to study these easily-surveyed and essential insect communities.


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