Tracking small animals in complex landscapes: a comparison of localisation workflows for automated radio telemetry systems

Peer reviewe

O papel da nutrição na saúde mental e nos transtornos psiquiátricos: uma perspectiva translacional

Mental as well as neurological disorders are among the leading causes of disability worldwide. In recent years, multiple epidemiological studies have investigated the relationship between dietary patterns and mental status, emphasizing the influence of genetic and environmental factors on the development of such disorders.Las enfermedades mentales y los trastornos neurológicos se encuentran entre las principales causas de discapacidad a nivel mundial. En los últimos años, múltiples estudios epidemiológicos han investigado la relación existente entre los patrones dietéticos y el estado mental, con énfasis en la influencia de factores genéticos y ambientales en el desarrollo de dichos trastornos.Doenças mentais e distúrbios neurológicos estão entre as principais causas de incapacidade em todo o mundo. Nos últimos anos, vários estudos epidemiológicos têm investigado a relação entre padrões alimentares e estado mental, enfatizando a influência de fatores genéticos e ambientais no desenvolvimento desses transtornos.&nbsp

Morphology and Function of the Drinking Apparatus in Hummingbirds

My research aims to answer the questions: How do hummingbirds feed? And, how do the mechanics of feeding define the limits and adaptive values of feeding behaviors? I meticulously study every step of nectar capture and ingestion. My dissertation chapters are organized following a morpho-functional and feeding sequence approach: 1) Feeding Apparatus Morphology; with emphasis on the understudied morphology of the tongue grooves and bill tongue coupling. 2) Tongue Tip Dynamics; how hummingbird tongues entrap nectar. 3) Tongue Grooves Functioning: how the tongue acts as an elastic micropump while collecting nectar. 4) Bill Tip Mechanics; internal bill structures that aid in offloading nectar from the tongue. 5) Intraoral Transport: how the nectar flows inside the bill to the throat where it can finally be swallowed. My results demonstrate that capillarity equations are unsuitable to calculate energy intake rate, which is the building unit of foraging theories; therefore a development of a new theoretical framework to study hummingbird energetics and foraging ecology is needed. I describe previously unknown methods of tongue-based nectar collection, report undocumented tongue and bill structures, and offer the first test of intraoral transport hypotheses. I followed the scientific method cycle of deduction and induction. To understand the determinants of hummingbird feeding mechanics in an ecological context, I tested biophysical model predictions using data from wild birds. Elucidating the drinking mechanism of hummingbirds will facilitate downstream calculations of the rates at which birds can obtain nectar along several environmental axes (e.g. altitudinal and latitudinal ranges, migrations, corolla morphology, etc.). This will in turn inform how and where the limits of nectar uptake have shaped the distribution, ecology and evolution of hummingbirds. With their enchanting appeal and unique physical capabilities, hummingbirds captivate people of all ages. As such, they serve as ambassadors to the natural world, fostering public appreciation for scientific and conservation efforts aimed at preserving these fascinating birds, and the biodiversity upon which they depend

The hummingbird tongue is a fluid trap, not a capillary tube

Hummingbird tongues pick up a liquid, calorie-dense food that can- not be grasped, a physical challenge that has long inspired the study of nectar-transport mechanics. Existing biophysical models predict optimal hummingbird foraging on the basis of equations that assume that fluid rises through the tongue in the same way as through capillary tubes. We demonstrate that the hum- mingbird tongue does not function like a pair of tiny, static tubes drawing up floral nectar via capillary action. Instead, we show that the tongue tip is a dynamic liquid-trapping device that changes configuration and shape dramatically as it moves in and out of fluids. We also show that the tongue–fluid interactions are identi- cal in both living and dead birds, demonstrating that this mechan- ism is a function of the tongue structure itself, and therefore highly efficient because no energy expenditure by the bird is required to drive the opening and closing of the trap. Our results rule out previous conclusions from capillarity-based models of nectar feeding and highlight the necessity of developing a new biophy- sical model for nectar intake in hummingbirds. Our findings have ramifications for the study of feeding mechanics in other nectari- vorous birds, and for the understanding of the evolution of nectar- ivory in general. We propose a conceptual mechanical explanation for this unique fluid-trapping capacity, with far-reaching practical applications (e.g., biomimetics)

Genetic Differentiation, Niche Divergence, and the Origin and Maintenance of the Disjunct Distribution in the Blossomcrown <i>Anthocephala floriceps</i> (Trochilidae)

<div><p>Studies of the origin and maintenance of disjunct distributions are of special interest in biogeography. Disjunct distributions can arise following extinction of intermediate populations of a formerly continuous range and later maintained by climatic specialization. We tested hypotheses about how the currently disjunct distribution of the Blossomcrown (<i>Anthocephala floriceps</i>), a hummingbird species endemic to Colombia, arose and how is it maintained. By combining molecular data and models of potential historical distributions we evaluated: (1) the timing of separation between the two populations of the species, (2) whether the disjunct distribution could have arisen as a result of fragmentation of a formerly widespread range due to climatic changes, and (3) if the disjunct distribution might be currently maintained by specialization of each population to different climatic conditions. We found that the two populations are reciprocally monophyletic for mitochondrial and nuclear loci, and that their divergence occurred ca. 1.4 million years before present (95% credibility interval 0.7–2.1 mybp). Distribution models based on environmental data show that climate has likely not been suitable for a fully continuous range over the past 130,000 years, but the potential distribution 6,000 ybp was considerably larger than at present. Tests of climatic divergence suggest that significant niche divergence between populations is a likely explanation for the maintenance of their disjunct ranges. However, based on climate the current range of <i>A. floriceps</i> could potentially be much larger than it currently is, suggesting other ecological or historical factors have influenced it. Our results showing that the distribution of <i>A. floriceps</i> has been discontinous for a long period of time and that populations exhibit different climatic niches have taxonomic and conservation implications.</p></div

Potential distributions for <i>A. floriceps</i> predicted using climatic data in Maxent.

<p>Models are shown for climatic conditions of (a) the present, (b) 6,000 ybp, (c) 21,000 ybp and (d) 130,000 ybp. Dots on the present distribution map indicate localities used to build the models. Darker colors denote areas of greater climatic suitability; areas in white are below the minimum suitability threshold and are therefore considered to be unsuitable.</p

Current distribution of the Blossomcrown (<i>Anthocephala floricep</i>s).

<p>The blue area corresponds to <i>A. f. floriceps</i> from the Sierra Nevada de Santa Marta and the red to <i>A. f. berlepschi</i> from the Andes. The locations of different montane regions mentioned in the text are indicated.</p

Haplotype networks showing that no alleles are shared between populations of <i>A. floriceps</i> in any of the genes analyzed.

<p>Blue corresponds to <i>A. f. floriceps</i> and red to <i>A. f. berlepschi</i>. Circle size is proportional to the number of individuals with each haplotype; hatches indicate mutational steps. (a) ND2, (b) ND4, (c) Bfib7 and (d) ODC.</p

Model of potential distribution constructed based on localities of <i>A. f. berlepschi</i> projected onto the region where <i>A. f. floriceps</i> occurs (indicated by a blue shape; (a)).

<p>Model of potential distribution constructed based on localities of <i>A. f. floriceps</i> projected onto the region where <i>A. f. berlepschi</i> occurs (indicated by a red shape; (b)). Red and blue dots indicate localities used to build the models for <i>A. f. berlepschi</i> and <i>A. f. floriceps,</i> respectively. Darker colors denote areas of greater climatic suitability in a continuous scale (i.e., no cutoff threshold was established in Maxent). Note that localities of each population have low suitability according to the model constructed with data from the other population, indicating niche divergence.</p

Divergence-time estimates (mya) between populations of <i>A. floriceps</i> and outgroups, based on two mitochondrial genes using a Bayesian relaxed molecular-clock analysis.

<p>Node bars indicate 95% credibility intervals on node ages; scale bar shows time in million years. Values on each clade indicate posterior probabilities when greater than 0.7. Symbols indicate individuals having identical sequences in <i>A. f. floriceps</i> (*) and <i>A. f. berlepschi</i> (¶).</p