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Hummingbirds are well known for their hovering flight, one of the most energetically expensive modes of locomotion among animals. Molt is a costly event in the annual cycle, in which birds replace their feathers, including all their primary feathers, which, in hummingbirds, comprise most of the area of the wing. Despite this, the effects of molt on hovering flight are not well known. Here, we examined high-speed videos (14 individuals of three species from the Colombian Andes recorded at 1200 FPS) comparing molting and non-molting hummingbirds' wing kinematics and wingtip trajectories. We found that molting hummingbirds rotated their wings in more acute angles during both downstroke and upstroke compared to non-molting individuals (10° vs 20°, and 15° vs 29°, respectively), while other flight parameters remained unchanged. Our findings show that hummingbirds are capable of sustaining hovering flight and thereby maintaining their weight support even under impressive wing area reductions by adjusting their stroke amplitudes.

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Dedicated nectarivory is a derived feeding habit that requires specialized cranial and soft-tissue morphologies to extract nectar from flowers. Nectarivory has evolved many times in terrestrial vertebrates, and in four bat families (Pteropodidae, Phyllostomidae, Vespertilionidae, and Mystacinidae). Within phyllostomids, specializations to nectarivory have been well documented in two subfamilies, Glossophaginae and Lonchophyllinae. However, nectarivory has also evolved independently in the genus Phyllostomus (subfamily Phyllostominae). Since Phyllostomus species have an omnivorous diet with a high consumption of nectar, they can be used to explore the basic morphological modifications linked to evolving a nectarivorous habit. Here, we focused on describing and comparing the morphological features potentially associated with nectarivory in Phyllostomus discolor. We present the first detailed tongue and palate morphological descriptions for P. discolor and perform skull morphometric analysis including 10 species. We found hair-like papillae on the tongue of P. discolor, a convergent feature with Glossophaginae and nectarivorous Pteropodids; these papillae likely confer an advantage when feeding on nectar. P. discolor does not show skull morphological features characteristic of nectarivorous bats, such as a long and narrow snout. We pose that the consumption of a variety of food, such as hard insects and fruits, and the large size of P. discolor relative to specialized nectarivores may create trade-offs against morphological specialization of the skull towards nectarivory. In contrast, a long and mobile tongue with hair-like papillae may be an evolutionary solution for nectar extraction that does not have a major impact on this species' ability to feed on other resources.

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Los mielolipomas suprarrenales son tumores benignos inusuales de crecimiento lento, compuestos por tejido adiposo maduro y células hematopoyéticas. Se presentan en adultos entre la quinta y la sexta década de la vida y usualmente miden entre 3 y 7 cm. El 70 % de los casos son asintomáticos y hacen parte de los denominados 'incidentalomas' de la glándula suprarrenal. El tratamiento puede ser conservador o quirúrgico, dependiendo de los síntomas, el tamaño de la masa y el crecimiento tumoral en estudios consecutivos de imágenes diagnósticas. La suprarrenalectomía laparoscópica es un procedimiento seguro, que tiene una recuperación rápida, no requiere instrumentos, dispositivos o fuentes de energía costosos, y estéticamente es superior a la técnica abierta. Se presenta el caso de un hombre de 63 años con antecedentes de hipertensión arterial sistémica, diabetes mellitus de tipo 2 e hiperlipidemia, quien presentó como hallazgo incidental en imágenes diagnósticas una masa suprarrenal derecha. El examen físico y los estudios paraclínicos descartaron que el tumor fuera funcional. Se practicó suprarrenalectomía derecha laparoscópica sin complicaciones y se diagnosticó un mielolipoma por histopatología.

Adrenal myelolipomas are rare slow-growing benign tumors composed of mature adipose tissue and hematopoietic cells. They most often occur in adults in the 5th-6th decade, and usually measure between 3 and 7 cm; 70% of cases are asymptomatic and are part of the so called incidentalomas of the adrenal gland. Treatment can be conservative or surgical, depending on the symptoms, the size of the mass and the growth of the tumor in consecutive imaging studies. We report a 63-year old man with history of systemic arterial hypertension, diabetes mellitus type 2 and hyperlipidemia. A right adrenal mass was reported as incidental finding in diagnostic imaging. Physical examination and paraclinical studies ruled out a functioning tumor. Right laparoscopic adrenalectomy was performed without complications and a myelolipoma was diagnosed by histopathology. Myelolipomas should be included in the differential diagnosis of the adrenal gland incidentalomas. Laparsocopic adrenalectomy is a safe procedure with rapid recovery, does not require special instruments or devices, and is cosmetically superior to the open technique.

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Pumping is a vital natural process, imitated by humans for thousands of years. We demonstrate that a hitherto undocumented mechanism of fluid transport pumps nectar onto the hummingbird tongue. Using high-speed cameras, we filmed the tongue-fluid interaction in 18 hummingbird species, from seven of the nine main hummingbird clades. During the offloading of the nectar inside the bill, hummingbirds compress their tongues upon extrusion; the compressed tongue remains flattened until it contacts the nectar. After contact with the nectar surface, the tongue reshapes filling entirely with nectar; we did not observe the formation of menisci required for the operation of capillarity during this process. We show that the tongue works as an elastic micropump; fluid at the tip is driven into the tongue's grooves by forces resulting from re-expansion of a collapsed section. This work falsifies the long-standing idea that capillarity is an important force filling hummingbird tongue grooves during nectar feeding. The expansive filling mechanism we report in this paper recruits elastic recovery properties of the groove walls to load nectar into the tongue an order of magnitude faster than capillarity could. Such fast filling allows hummingbirds to extract nectar at higher rates than predicted by capillarity-based foraging models, in agreement with their fast licking rates.

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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 (Anthocephala floriceps), 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 A. floriceps 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 A. floriceps has been discontinous for a long period of time and that populations exhibit different climatic niches have taxonomic and conservation implications.

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El síndrome del niño sacudido es una de las formas más severas de maltrato infantil que ocurre principalmente en niños menores de un año. Por la vulnerabilidad de las víctimas y por las secuelas que puede producir, incluyendo la muerte, es necesario, en el abordaje clínico, tener presente la sospecha diagnóstica ante lesiones de explicación insatisfactoria por parte de los encargados del menor. Asimismo si se trata de un abordaje médico legal deben tenerse las consideraciones necesarias para documentar las lesiones, tanto en el paciente vivo, como en los casos de homicidio, para colaborar con la administración de justicia. Para ello se debe tratar de implementar una metodología homogénea para la realización de dichas pericias, tanto en la parte clínica como patológico forense. En este artículo se describe la forma habitual de presentación clínica del síndrome del niño sacudido y se expone una guía básica para la realización de autopsias medico legales en casos de muertes por esta causa.

The shaken baby syndrome is one of the most severe presentations of child abuse that is seen in children especially under the first year of age. The great vulnerability of this group of patients and the serious consequences that they may encounter in the future, including death, are enough reason to inquire, during the clinical approach, about the possibility that the patient being attended may be a victim of physical abuse. From a medico-legal evaluation, it is pertinent to document and describe thoroughly the physical lesions in the living patient and in cases of homicide, in order to contribute scientifically in the administration of justice. For that reason it is essential to follow a uniform methodology in the management of both the clinical and the forensic assessment. This article reviews the usual clinical presentation of the shaken baby syndrome and proposes a basic guide to evaluate the autopsies in cases of deaths originated by this cause.

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