caa a22 4500 463175034 CHVBK 20180406164823.0 cr unu---uuuuu 170326e20070101xx s 000 0 eng 10.1007/s10336-006-0092-2 doi (NATIONALLICENCE)springer-10.1007/s10336-006-0092-2 Effect of altitude on male parental expenditure in Mountain Bluebirds ( Sialia currucoides ): are higher-altitude males more attentive fathers? [Elektronische Daten] [L. Johnson, Jessica Brubaker, Emilene Ostlind, Susan Balenger] Male investment of time and energy in caring for offspring varies substantially both between and within bird species. Explaining this variation is of long-standing interest to ornithologists. One factor that may affect male care is breeding site altitude, through its effects on climate. The harsher, less predictable abiotic conditions at higher altitudes are hypothesized to favour increased male investment of time and energy in offspring care. We tested this hypothesis by comparing male parental behaviour in Mountain Bluebirds (Sialia currucoides) nesting at 1500 and 2500m a.s.l. in the Bighorn Mountains of Wyoming, USA. We compared rates of prey delivery to nestlings at these two altitudes at two times: 1-2days after hatching, when females spend much of their time brooding young, and 12-13days later, when brooding has ended and nestling energy demands are peaking. High-altitude males fed nestlings 18 and 28% more often than low-altitude males early and later in the nestling stage, respectively, but only the difference in late-stage feeding rates were significant. Like males, females at the high site also fed nestlings significantly more often than females at the low site later in the nestling stage (45% difference in feeding rates). Consequently, the proportion of all feeding trips made by males at the high site (40%) did not differ significantly from that at the low site (44%). Parents at the high altitude may feed nestlings more often to compensate for their greater thermoregulatory costs. Parents may also be attempting to assist nestlings in storing fat and/or attaining a large size and effective homeothermy as quickly as possible to enhance nestling ability to survive bouts of severe weather which are common at high altitudes. Dt. Ornithologen-Gesellschaft e.V., 2006 Altitude nationallicence Elevation nationallicence Mountain Bluebird nationallicence Parental care nationallicence Sialia currucoides nationallicence Johnson L. Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut Brubaker Jessica Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut Ostlind Emilene Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut Balenger Susan Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut Journal of Ornithology Springer-Verlag 148/1(2007-01-01), 9-16 0021-8375 148:1<9 2007 148 10336 https://doi.org/10.1007/s10336-006-0092-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10336-006-0092-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Johnson L. Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut NATIONALLICENCE 700 1- Brubaker Jessica Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut NATIONALLICENCE 700 1- Ostlind Emilene Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut NATIONALLICENCE 700 1- Balenger Susan Department of Biological Sciences, Towson University, 21252, Towson, MD, USA aut NATIONALLICENCE 773 0- Journal of Ornithology Springer-Verlag 148/1(2007-01-01), 9-16 0021-8375 148:1<9 2007 148 10336 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer