David L Anderson

The Peregrine Fund · Science Team

Arctic habitats are changing rapidly and altering trophic webs and ecosystem functioning. Understanding how species' abundances and distributions differ among Arctic habitats is important in predicting future species shifts and trophic‐web consequences. We aimed to determine the habitat–abundance relationships for three small herbivores on the Sewa...

The Gyrfalcon (Falco rusticolus) is a top avian predator, an Arctic specialist, and among the bird species most vulnerable to climate change. This vulnerability is driven by their narrow ecological niche, limited or lack of southward migration, and circumpolar distribution where the most rapid climatic changes are occurring. Climatic and habitat ch...

Quantifying resource partitioning between co-occurring species can provide insight into processes facilitating coexistence by closely related species, a fundamental question in ecology. We tested whether the habitat requirements of two closely related Neotropical forest eagles, the Crested Eagle (Morphnus guianensis) and Harpy Eagle (Harpia harpyja...

Aim A current biogeographic paradigm states that climate regulates species distributions at continental scales and that biotic interactions are undetectable at coarse‐grain extents. However, advances in spatial modelling show that incorporating food resource distributions are important for improving model predictions at large distribution scales. T...

Stable isotope mixing models (SIMMs) are widely used for characterizing wild animal diets. Such models rely upon using accurate trophic discrimination factors (TDFs) to account for the digestion, incorporation, and assimilation of food. Existing methods to calculate TDFs rely on controlled feeding trials that are time‐consuming, often impractical f...

Avian mating systems are often monogamous, although polygamy in the form of both polyandry and polygyny are regularly employed by some species and opportunistically practiced by others. Among raptors, multiple species within the genus Buteo have been documented using either polyandrous or polygynous strategies. Here, we describe the first known cas...

Climate change is expected to have a profound impact on species distributions, contracting suitable climate space. Biodiversity areas are important to mitigate these negative effects but are static by design and thus do not account for future projections of species distributions. The Harpy Eagle Harpia harpyja has a broad range across lowland Neotr...

Quantifying habitat use is important for understanding how animals meet their requirements for survival and provides information for conservation planning. Currently, assessments of range-wide habitat use that delimit species distributions are incomplete for many taxa. The Harpy Eagle (Harpia harpyja) is a raptor of conservation concern, widely dis...

A current biogeographic paradigm states that climate regulates species distributions at continental scales and that biotic interactions are undetectable at coarse-grain extents. However, recent advances in spatial modelling show that incorporating food resource distributions are important for improving model predictions at large distribution scales...

Intra- and inter-specific resource partitioning within predator communities is a fundamental component of trophic ecology, and one proposed mechanism for how populations partition resources is through individual niche variation. The Niche Variation Hypothesis (NVH) predicts that inter-individual trait variation leads to functional trade-offs in for...

Quantifying resource partitioning between co-occurring species has important ecological and evolutionary implications. Yet, few studies compare resource overlap in both geographic and environmental space. We test whether the habitat requirements of two closely related Neotropical forest eagles, the crested eagle (Morphnus guianensis) and harpy eagl...

Scoping reviews, in which the literature on a given topic is systematically collated and summarized, aid literature searches and highlight knowledge gaps on a given topic, thus hastening scientific progress and informing conservation efforts. Because much research and conservation is targeted at the species level, ornithology and bird conservation...

Understanding parasite-host ecology is increasingly important for conservation efforts in a changing world. Parasitic nest flies in the genus Philornis (Diptera: Muscidae) have been implicated in the decline of endemic island species and are also known to negatively impact breeding success of the critically endangered Ridgway’s hawk (B. ridgwayi) o...

Most raptor populations are declining and nearly a fifth are threatened with extinction; thus there is a need to increase collaboration to ensure efficient and effective research, management, and conservation. Here, we introduce the Global Raptor Impact Network (GRIN; www.globalraptors.org), a tool to enhance collaboration and conservation impact o...

Intra- and inter-specific resource partitioning within predator communities is a fundamental component of trophic ecology, and one proposed mechanism for how populations partition resources is through individual niche variation. The Niche Variation Hypothesis (NVH) predicts that interindividual trait variation leads to functional trade-offs in fora...

Habitat suitability for breeding birds is defined at scales ranging from the landscape to individual nesting sites. Nesting site characteristics that govern exposure to inclement weather may affect breeding success, although attempts to understand this effect for Arctic breeding raptors have yielded ambiguous results. Further, breeding adults incur...

ABSTRACT.—The identification of breeding habitat is essential for the implementation of conservation efforts for threatened species. Using seven natural and anthropogenic variables, and based on 27 nesting attempts over 17 yr, we created a species distribution model for Harpy Eagle (Harpia harpyja) breeding habitat across 5636 km2 in the Pacific Re...

Understanding species-environment relationships is key to defining the spatial structure of species distributions and develop effective conservation plans. However, for many species, this baseline information does not exist. With reliable presence data, spatial models that predict geographic ranges and identify environmental processes regulating di...

Bayesian stable isotope mixing models (BSIMMs) for δ¹³C and δ¹⁵N can be a useful tool to reconstruct diets, characterize trophic relationships, and assess spatiotemporal variation in food webs. However, use of this approach typically requires a priori knowledge on the level of enrichment occurring between the diet and tissue of the consumer being s...

There are currently four world bird lists referenced by different stakeholders including governments, academic journals, museums and citizen scientists. Consolidation of these lists is a conservation and research priority. In reconciling lists, care must be taken to ensure agreement in taxonomic concepts—the actual groups of individual organisms ci...

Philornis flies Meinert (Diptera: Muscidae) have been documented parasitizing over 250 bird species, some of which are endemic species threatened with extinction. Philornis parasitism is hypothesized to affect nestlings disproportionately more than adult birds because limited mobility and exposed skin of nestlings increase their vulnerability to pa...

Forest canopies contribute significantly to global forest biodiversity and ecosystem functioning, yet are declining and understudied. One reason for a knowledge gap is that accessing forest canopies can be difficult and dangerous. Thus, lack of relevant canopy access skills may compromise knowledge gain and personal safety. We assessed skill levels...

While collating contributions and comments from 36 researchers, the coordinating authors accidentally omitted Dr. Suzanne Carrière from the list of contributing co-authors. Dr. Carrière's data are described in Tables 1 and 3, Figure 2 and several places in the narrative.The new author list is thus updated in this article.

The peregrine falcon (Falco peregrinus) and the gyrfalcon (Falco rusticolus) are top avian predators of Arctic ecosystems. Although existing monitoring efforts are well established for both species, collaboration of activities among Arctic scientists actively involved in research of large falcons in the Nearctic and Palearctic has been poorly coord...

The peregrine falcon (Falco peregrinus) and the gyrfalcon (Falco rusticolus) are top avian predators of Arctic ecosystems. Although existing monitoring efforts are well established for both species, collaboration of activities among Arctic scientists actively involved in research of large falcons in the Nearctic and Palearctic has been poorly coord...

Explaining species distributions and identifying environmental constraints on species’ ecological niches is a central goal in conservation biogeography. A current paradigm in biogeography states that climate regulates species distribution at macro-scales and that biotic interactions are unimportant due to the large extent and the inherent noise in...

Climate and landscape change are expected to affect species' distributions and interactions, with potentially harmful consequences for specialist predators. Availability of optimal prey can affect reproductive success in raptors, especially in the Arctic, where dramatic differences in prey availability occur both within and between years. However,...

We know little regarding how specific aspects of habitat influence spatial variation in site occupancy by Arctic wildlife, yet this information is fundamental to effective conservation. To address this information gap, we assessed occupancy of 84 Gyrfalcon (Falco rusticolus Linnaeus, 1758) breeding territories observed annually between 2004 and 201...

Parasitic nest flies Philornis spp. are a driving force threatening the extinction of bird species endemic to Neotropical islands such as the Galápagos, where introduced Philornis downsi negatively impacts reproductive success of naïve avian hosts. Elsewhere in the Neotropics, such as in the Caribbean region where Philornis nest flies are native, e...

Survival and recruitment estimates are important for predicting population viability and the efficacy of translocations. This information requires intensive monitoring postrelease, which is often economically or logistically infeasible. Since 2009, juveniles of the critically endangered Ridgway’s Hawk (Buteo ridgwayi) have been translocated from Lo...

Nest collapse has been documented in many bird species, with little discussion of adult behavior following collapse. We present evidence of a partial collapse of a Gyrfalcon (Falco rusticolus) nest during the nestling period and the subsequent adult response. A nest camera captured the nest collapse and showed one adult Gyrfalcon holding a live nes...

We report Crested Auklet Aethia cristatella as a prey item of a Gyrfalcon Falco rusticolus nesting in inland western Alaska. This represents the first documented case as a Gyrfalcon prey item during the breeding season in North America, and the fourth documented case of inland movements of Crested Auklet. The presence of the auklet in the Gyrfalcon...

The availability of reliable information on tree climbing methods is critical for the development of canopy science and for the safety of workers accessing the forest canopy. To assess the breadth and quality of information contained in published climbing information, we performed searches in Web of Science and Google Scholar and evaluated 54 publi...

Populations of Red-throated Caracaras (Ibycter americanus) have been extirpated or are in serious decline throughout Middle America. We describe the first nest outside South America and provide only the third nest description for the species. We observed four adults and one immature Red-throated Caracara provide cooperative care to a single nestlin...

The Cerulean Warbler (Setophaga cerulea) has one of the longest migrations of any small passerine, traveling approximately 4,000 km between breeding grounds in eastern North America and nonbreeding residency in northern South America. However, unlike many migratory birds, little is known about this aspect of the ecology of this species. In 2004 – 2...

Birds of the forest canopy are an integral component of bird communities of neotropical forests but remain largely unstudied, inhibiting any broad characterization of their assemblages. We present the first description of a canopy-bird assemblage from Middle America and, on the basis of > 11000 detections in lowland rainforests in Honduras and Amaz...

The Honduran Emerald Amazilia luciae is endemic to dry forests of Honduras and currently recognised as ‘Critically Endangered.’ Here we present the first modern assessment of its distribution, ecology, and conservation, based partly on our rediscovery of the species in western Honduras and on our observations in three Honduran departments. We found...

Birds of the forest canopy are important components of tropical forest ecosystems, but difficulty of access or viewing into the canopy complicates their study. If ground methods are biased against canopy birds, as has been suggested, this bias could affect our understanding of forest ecology as well as biological monitoring and conservation practic...

In the first comprehensive survey of tern colonies in the Honduras Bay Islands, 46 cays were surveyed in 2005 and 2006 and three species of terns were observed nesting in colonies on ten individual cays. Apparent colony turnover was high between years for Least (Sternula antillarum) and Roseate (Sterna dougallii) Terns, from 71% to 100%, respective...

Summary of the content of a compilation country by country of all IBAs existing in the Americas

Se realizó el cuarto año del proyecto de identificación de hábitats de paso en el Norte de Centro América para el ave de rápida disminución Chipe Cerúleo (Setophaga cerulea) en Honduras, Guatemala y el Sur de México desde el 30 de Marzo al 22 de Abril de 2007. El proyecto empezó con un taller de técnicas de muestreo e identificación de migratorios...

Ground and aerial surveys for Orange-breasted Falcons (Falco deiroleucus) were conducted during March-June 1999 in Honduras, and March-May 2000 in El Salvador, Honduras, Nicaragua, Costa Rica, and Panama, all within the likely range of this species. Sixty-six cliffs were checked by ground surveys. No Orange-breasted Falcon was found in Central Amer...

I studied the relationship between diurnal raptor diversity, density, and richness, and landscape heterogeneity in continuous primary forests and forests farmed by native Amerindians in the Río Plátano Biosphere Reserve of northeastern Honduras from January to June 1996 and 1997. I estimated landscape heterogeneity–the variability in naturally occu...