Life Sciences Commons^™

Low Activities Of Digestive Enzymes In The Guts Of Herbivorous Grouse (Aves: Tetraoninae), Jennifer Sorensen Forbey

Biology Faculty Publications and Presentations

Avian herbivores face the exceptional challenge of digesting recalcitrant plant material while under the selective pressure to reduce gut mass as an adaptation for fight. One mechanism by which avian herbivores may overcome this challenge is to maintain high activities of intestinal enzymes that facilitate the digestion and absorption of nutrients. However, previous studies in herbivorous animals provide equivocal evidence as to how activities of digestive enzymes may be adapted to herbivorous diets. For example, “rate-maximizing” herbivores generally exhibit rapid digesta transit times and high activities of digestive enzymes. Conversely, “yield-maximizing” herbivores utilize long gut retention times and express lower …

Long‐Distance Natal Dispersal Is Relatively Frequent And Correlated With Environmental Factors In A Widespread Raptor, Hanna M. Mccaslin, T. Trevor Caughlin, Julie A. Heath

Biology Faculty Publications and Presentations

1. Dispersal is a critical process influencing population dynamics and responses to global change. Long‐distance dispersal (LDD) can be especially important for gene flow and adaptability, although little is known about the factors influencing LDD because studying large‐scale movements is challenging and LDD tends to be observed less frequently than shorter‐distance dispersal (SDD).
2. We sought to understand patterns of natal dispersal at a large scale, specifically aiming to understand the relative frequency of LDD compared to SDD and correlates of dispersal distances.
3. We used bird banding and encounter data for American kestrels (Falco sparverius) to investigate the effects of …

Flushing Responses Of Golden Eagles (Aquila Chrysaetos) In Response To Recreation, Robert J. Spaul, Julie A. Heath

Biology Faculty Publications and Presentations

Disturbance because of human activity, including recreation on wildlands, can affect bird behavior which in turn can reduce breeding success, an important consideration for species of management concern. We observed Golden Eagles (Aquila chysaetos) during the breeding season to determine whether the probability of flushing was affected by the type of recreationist, distance to encounter, eagle nest attendance, or date. We monitored eagles in 23 nesting territories from distant (600-1,200 m) observation points and recorded recreation activity within 1,200 m of eagles in the Owyhee Front of southwestern Idaho. In most (86%, n = 270) encounters, eagles did …