The heat-acclimated rock pigeon is thought to use cutaneous water evaporation (CWE) as the 'preferred' route for heat dissipation, and this mechanism is controlled by adrenergic signaling. In the present study, we tested the hypothesis that adjustments in skin blood flow are a crucial component of this adaptation. Skin blood flow was measured by laser Doppler flowmetry and by ultrasonic flowmet...

Three experiments evaluated whether the apparent reflexivity effect reported by Sweeney and Urcuioli (2010) for pigeons might, in fact, be transitivity. In Experiment 1, pigeons learned symmetrically reinforced hue-form (A-B) and form-hue (B-A) successive matching. Those also trained on form-form (B-B) matching responded more to hue comparisons that matched their preceding samples on subsequent...

1. White Carneau pigeons develop genetic atherosclerosis. The aorta shows intimal cushions at birth, cholesterol accumulation at 9 months of age and definite atherosclerotic lesions by 3 years of age. To determine whether these age-related arterial changes can be prevented by dietary restriction started early in life, 3-month-old pigeons were subjected to dietary restriction (40% of ad lib. die...

Coccidiosis caused by Eimeria spp. is a common parasitic disease in homing pigeons. The study objective was to evaluate the incidence of coccidia infections in pigeon lofts during racing season. The intensity of coccidiosis was determined by floatation analyses of faeces samples collected from three pigeon groups performed in three replications (before the racing season, in mid-season and after...

This research investigated the source of an ostensible reflexivity effect in pigeons reported by Sweeney and Urcuioli (2010). In Experiment 1, pigeons learned two symmetrically reinforced symbolic successive matching tasks (hue-form and form-hue) using red-green and triangle-horizontal line stimuli. They differed in their third concurrently trained baseline task: form-form matching with stimuli...

It has been proposed that memory for personal experiences (episodic memory, rather than semantic memory) relies on the conscious review of past experience and thus is unique to humans. In an attempt to demonstrate episodic-like memory in animals, we first trained pigeons to respond to the (nonverbal) question "Did you just peck or did you just refrain from pecking?" by training them on a symbol...

DiPietro et al (2002 Perception 31 1299-1312) reported a dramatic improvement in pigeons' recognition of partially occluded objects after the birds had been trained to recognize objects that were placed on top of another surface. Here, we investigated whether training with partially erased stimuli or with notched stimuli that had a thin gap between the object and another surface would similarly...

Recently (Troje, Huber, Loidolt, Aust, & Fieder 1999), we found that pigeons discriminated between large sets of photorealistic frontal images of human faces on the basis of sex. This ability was predominantly based on information contained in the visual texture of those images rather than in their configural properties. The pigeons could learn the distinction even when differences of shape and...

One-month-old, inexperienced homing pigeons, prior to any opportunity to learn a navigational map, were subjected to either right or left unilateral ablation of the hippocampal formation (HF). These pigeons were then held together with a group of age-matched control birds in an outdoor aviary, where they were kept for about 3 months with the opportunity to learn a navigational map. When subsequ...

Several health problems can affect pigeons but parasitic infections play a major role. The genus Haemoproteus includes a large number of intracellular protozoan parasites. A total of 103 pigeons were captured from different localities of Qena Governorate from March 2013 to April 2014, blood films were obtained, fixed, stained and examined microscopically. Lungs and liver were also examined hist...