scholarly journals Patterns of Nestling Feeding in Harris's Sparrows, Zonotrichia querula and White-crowned Sparrows, Z. leucophrys, in the Northwest Territories, Canada

2003 ◽  
Vol 117 (2) ◽  
pp. 203 ◽  
Author(s):  
Christopher J. Norment
Keyword(s):  
Northwest Territories ◽  
Feeding Rates ◽  
Sympatric Populations ◽  
Male Care ◽  
Socially Monogamous ◽  
Mating Opportunities ◽  
Low Arctic ◽  
Nestling Feeding ◽  
Total Feeding

Patterns of nestling feeding by males and females were compared in sympatric populations of Harris’s Sparrows (Zonotrichia querula) and Gambel’s White-crowned Sparrows (Z. leucophrys gambelii) in the Northwest Territories, Canada. In both species, only the female brooded young. Total feeding rate (both parents), and male and female feeding rates, increased with nestling age in both species; total feeding rates did not differ significantly between species. Nestlings of both species were fed most frequently by females during the early part of the nestling period (day 0-5), and feeding rates did not approach parity until nestlings were 6-8 d old. Patterns of nestling feeding, including initially low male provisioning, in Harris’s Sparrows and White-crowned Sparrows at my low arctic study site were similar to those in other populations of Zonotrichia. Low levels of male nestling care, relative to females, appears to be relatively uncommon among socially monogamous passerines. Reduced male care may be adaptive in temperate environments, as it would allow males to pursue other mating opportunities. However, reasons for persistence of the trait in the low arctic, where breeding is highly synchronous, remain unclear.

Annotated checklist to the vascular plant flora of Tuktut Nogait National Park and the Melville Hills region (Canadian Low Arctic)

Phytotaxa ◽  
2013 ◽  
Vol 102 (1) ◽  
pp. 1 ◽  
Author(s):  
JEFFERY M. SAARELA ◽  
LYNN J. GILLESPIE ◽  
LAURIE L. CONSAUL ◽  
ROGER D. BULL
Keyword(s):  
Northwest Territories ◽  
National Park ◽  
Vascular Plant ◽  
Floristic Survey ◽  
Myriophyllum Sibiricum ◽  
Infraspecific Taxa ◽  
Plant Collections ◽  
Low Arctic ◽  
Conservation Concern ◽  
Annotated Checklist

 Tuktut Nogait National Park is located in the Melville Hills in the northeastern corner of mainland Northwest Territories in Canada's Southern Arctic Ecozone. The first major floristic survey of the Melville Hills region was conducted in 1990 as part of a natural resource inventory to determine its suitability as a National Park. We studied the flora and made extensive plant collections in Tuktut Nogait National Park and the Melville Hills region in 2009. Here, we present a comprehensive annotated checklist to the region's vascular plant flora based on a review of all existing and our own new collections. This includes the citation of all specimens examined, colour photographs for a subset of taxa and detailed taxonomic comments. The Melville Hills flora comprises 268 taxa (265 species and three additional infraspecific taxa), a 16% increase from the first survey, 215 of which are known from Tuktut Nogait National Park. Forty-eight taxa are newly recorded for the region and 54 taxa are newly recorded for Tuktut Nogait National Park. Noteworthy records include range extensions for Botrychium lunaria, Carex concinna, Draba borealis, Myriophyllum sibiricum, Plantago eriopoda, Poa alpina, Poa ammophila, Puccinellia banksiensis, Salix arbusculoides, and Selaginella selaginoides. The flora includes 19 vascular plant species of potential conservation concern in the Northwest Territories, including six assessed as "May Be At Risk", of which one occurs in the Park and 13 assessed as "Sensitive", of which eight occur in the Park.

Nestling feeding rates and body size of adult House Sparrows

1984 ◽  
Vol 62 (3) ◽  
pp. 381-385 ◽  
Author(s):  
W. Bruce McGillivray
Keyword(s):  
Body Size ◽  
Feeding Rate ◽  
Passer Domesticus ◽  
The Body ◽  
Feeding Rates ◽  
House Sparrows ◽  
Relative Contribution ◽  
Nestling Feeding ◽  
The Relationship

Much of the variance in feeding rates of nestlings by adult House Sparrows (Passer domesticus) at Calgary, Alberta appears to be due to individual variation in the quality of the parents. Males contribute less to nestling feeding than do males at other localities. The body size and sexual size dimorphism of House Sparrows has been shown to increase with increasing latitude in North America. Hence, sparrows at Calgary are larger than average and there is a suggestion that the relative contribution by the sexes is related to male size and concomitant energetic limitations. The relationship between weight and body size is strong in the fall for both male and female House Sparrows but is poor during the breeding season. Adult females, but not males, increase their nestling feeding rate in inclement weather.

scholarly journals Paternal care and litter size coevolution in mammals

2016 ◽  
Vol 283 (1829) ◽  
pp. 20160140 ◽  
Author(s):  
Paula Stockley ◽  
Liane Hobson
Keyword(s):  
Litter Size ◽  
Mating Systems ◽  
Life History Traits ◽  
Paternal Care ◽  
Biparental Care ◽  
Offspring Survival ◽  
Offspring Production ◽  
Male Care ◽  
Socially Monogamous ◽  
Social Behaviours

Biparental care of offspring occurs in diverse mammalian genera and is particularly common among species with socially monogamous mating systems. Despite numerous well-documented examples, however, the evolutionary causes and consequences of paternal care in mammals are not well understood. Here, we investigate the evolution of paternal care in relation to offspring production. Using comparative analyses to test for evidence of evolutionary associations between male care and life-history traits, we explore if biparental care is likely to have evolved because of the importance of male care to offspring survival, or if evolutionary increases in offspring production are likely to result from the evolution of biparental care. Overall, we find no evidence that paternal care has evolved in response to benefits of supporting females to rear particularly costly large offspring or litters. Rather, our findings suggest that increases in offspring production are more likely to follow the evolution of paternal care, specifically where males contribute depreciable investment such as provisioning young. Through coevolution with litter size, we conclude that paternal care in mammals is likely to play an important role in stabilizing monogamous mating systems and could ultimately promote the evolution of complex social behaviours.

Thermal adaptation as a factor affecting colonizing success of introduced Sturnidae (Aves) in North America

1974 ◽  
Vol 52 (12) ◽  
pp. 1559-1576 ◽  
Author(s):  
Stephen R. Johnson ◽  
Ian McTaggart Cowan
Keyword(s):  
Resource Use ◽  
Thermal Adaptation ◽  
Active Phase ◽  
Egg Laying ◽  
Feeding Rates ◽  
Sympatric Populations ◽  
The Common ◽  
Incubation Temperatures ◽  
Nesting Season

Two species of starlings (Sturnidae) have established themselves in southwestern British Columbia: the crested myna (Sturnus cristatellus), by escape from captivity about 5897, and the common starling (Sturnus vulgaris), by natural invasion during the 1950's. The crested myna has shown little capacity to expand its range or its population. The common starling is in an active phase of increasing density and distribution. These sympatric populations have been studied over a period of 3 years. This paper reports comparative aspects of reproduction, and resource use by the two species.We have found that the nesting season for starlings was synchronized into definite peaks of nest building, egg laying, hatching and fledging, which was not the case for crested mynas.Clutch and brood sizes were higher in starlings than mynas. Starlings successfully reared more second broods than mynas (38% vs. 9%). Per 100 pairs/annum, starlings contributed significantly more offspring (547 compared to 238) to the sturnid population.Although development of plumage and endothermy were similar in myna and starling chicks, feeding rates, quality of foods, and subsequent growth rates of chicks were significantly different.Egg transplant and heater nest box experiments suggested that poor nest attentiveness and low incubation temperatures maintained by crested mynas resulted in the low hatching and consequent low fledging success.

scholarly journals Preferences, perceptions, and veto players: explaining devolution negotiation outcomes in the Canadian territorial north

Polar Record ◽  
2012 ◽  
Vol 49 (2) ◽  
pp. 167-179 ◽  
Author(s):  
Christopher Alcantara
Keyword(s):  
Federal Government ◽  
Northwest Territories ◽  
Canadian Arctic ◽  
Veto Players ◽  
Land Claims ◽  
Secondary Sources ◽  
Elite Interviews ◽  
Final Agreement ◽  
Territorial Government

ABSTRACTSince the early part of the 20th century, the federal government has engaged in a long and slow process of devolution in the Canadian Arctic. Although the range of powers devolved to the territorial governments has been substantial over the years, the federal government still maintains control over the single most important jurisdiction in the region, territorial lands and resources, which it controls in two of the three territories, the Northwest Territories and Nunavut. This fact is significant for territorial governments because gaining jurisdiction over their lands and resources is seen as necessary for dramatically improving the lives of residents and governments in the Canadian north. Relying on archival materials, secondary sources, and 33 elite interviews, this paper uses a rational choice framework to explain why the Yukon territorial government was able to complete a final devolution agreement relating to lands and resources in 2001 and why the governments of the Northwest Territories and Nunavut have not. It finds that the nature and distance of federal-territorial preferences, combined with government perceptions of aboriginal consent and federal perceptions of territorial capacity and maturity, explain the divergent outcomes experienced by the three territorial governments in the Canadian arctic.The following acronyms are employed: AIP: Agreement-in-Principle; DTA: Devolution Transfer Agreement; GEB: gross expenditure base; GN: Government of Nunavut; GNWT: Government of Northwest Territories; NCLA: Nunavut Land Claims Agreement; NTI: Nunavut Tunngavik Incorporated; NWT; Northwest Territories; ON: Ontario; TFF: Territorial Formula Financing; UFA: Umbrella Final Agreement; YDTA: Yukon Devolution Transfer Agreement; YTG: Yukon Territorial Government; YK: Yukon;

An Isolated Population of Arctic Char (Salvelinus alpinus) Inhabiting a Warm Mineral Spring Above a Waterfall at Cache Creek, Northwest Territories

1974 ◽  
Vol 31 (8) ◽  
pp. 1408-1414 ◽  
Author(s):  
P. McCart ◽  
H. Bain
Keyword(s):  
Northwest Territories ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Isolated Population ◽  
Mineral Spring ◽  
Pyloric Caeca ◽  
Low Arctic ◽  
Oxygen Concentrations

Cache Creek Spring provides an unusual overwintering habitat for a population of Arctic char (Salvelinus alpinus) isolated above a falls impassable to fish moving upstream. During winter, water temperatures (14–16 C) and dissolved solid concentrations (approximately 2600 ppm) are high and oxygen concentrations (0.2–6.8 ppm) are low. Arctic char in the springs differ meristically from those downstream of the falls. The former have significantly more gillrakers (mean 21.7 compared with 21.1) and parr marks (15.1 and 13.5) but fewer pyloric caeca (26.0 and 28.2) and vertebrae (64.7 and 67.1) than the latter. Growth appears similar to that of char inhabiting more typical spring habitats.

Nest intrusions in relation to breeding status in the spotless starling

Behaviour ◽  
2013 ◽  
Vol 150 (13) ◽  
pp. 1553-1566 ◽  
Author(s):  
José P. Veiga ◽  
Vicente Polo ◽  
Marta Arenas ◽  
Sara Sánchez
Keyword(s):  
Personal Information ◽  
Public Information ◽  
Feeding Rates ◽  
Nest Boxes ◽  
Sturnus Unicolor ◽  
Nesting Site ◽  
Nesting Sites ◽  
Spotless Starling ◽  
Nestling Feeding ◽  
Breeding Status

Nest intruders are common in many avian species. In the spotless starling (Sturnus unicolor), a passerine closely related to the European starling (Sturnus vulgaris), it has been recently shown that visits to alien nests were in most cases related to get familiarity and personal information about prospected nest boxes and that collecting public information seems also to be involved in the intruding behaviour. In the present study we investigate whether nest intrusions are related to breeding status in both males and females. Individuals that had bred previously in the colony were detected as frequently as those without previous breeding experience intruding nests and the proportion of intruders that were owners and those that had not a nesting site during the current year was balanced. Males that were actively breeding and those that were not breeding intruded with similar frequencies in alien nests, while most females were not actively breeding when they were observed intruding a nest box. The nests more frequented by male intruders were those showing the highest female nestling feeding rates, but the frequency of female intrusions was not similarly affected by female owner feeding rates. The results suggest that some of the intrusions by males are related to nest acquisition although in general males seem to intrude to obtain other breeding resources, presumably extra-pair matings. Female intruders with a nesting territory but not currently breeding could be sampling alternative nesting sites while female floaters that intruded nests could be searching for nesting sites or attempting to lay parasitic eggs. Birds behaving as intruders at some moment of their stay in the breeding colony raised more fledglings that birds never observed performing this behaviour.

scholarly journals Pre- and Postcopulatory Traits ofSalvatorMale Lizards in Allopatry and Sympatry

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Sergio Naretto ◽  
Cecilia S. Blengini ◽  
Gabriela Cardozo ◽  
Margarita Chiaraviglio
Keyword(s):  
Interspecific Interactions ◽  
Reproductive Traits ◽  
Spatial Gradient ◽  
Lizard Species ◽  
Sympatric Populations ◽  
Before And After ◽  
Mating Opportunities ◽  
Testis Mass ◽  
Sperm Traits ◽  
Secondary Sexual

The reproductive traits of males are under influence of sexual pressures before and after copulation. The strength of sexual selection varies across populations because they undergo varying competition for mating opportunities. Besides intraspecific pressures, individuals seem to be subjected to pressures driven by interspecific interactions in sympatry. Lizards may vary their reproductive strategies through varying sexual characters, body size, gonadal investment, and sperm traits. We evaluated the reproductive traits, involved in pre- and postcopulatory competition, in allopatric and sympatric populations ofSalvatorlizards. We observed a spatial gradient of male competition among populations, with the following order: allopatric zone ofS. rufescens; sympatric zone; and allopatric zone ofS. merianae. Accordingly, variation in secondary sexual character, the relative testis mass, and the length of sperm component was observed between allopatry and sympatry in each species, suggesting differences in the investment of reproductive traits. However, we found that these twoSalvatorspecies did not differ in secondary sexual characters in sympatry. Interestingly, the trade-off between testes and muscle varied differently from allopatry to sympatry between theseSalvatorspecies, suggesting that the influence of social context on reproductive traits investment would affect lizard species differently.

scholarly journals Stability and value of male care for offspring: is it worth only half the trouble?

2007 ◽  
Vol 3 (3) ◽  
pp. 234-236 ◽  
Author(s):  
Lutz Fromhage ◽  
John M McNamara ◽  
Alasdair I Houston
Keyword(s):  
Game Theory ◽  
Parental Investment ◽  
Population Model ◽  
Fertilization Success ◽  
Theory Model ◽  
Evolutionary Stability ◽  
Trade Off ◽  
Male Care ◽  
Mating Opportunities ◽  
The Cost

Models of parental investment often assume a trade-off for males between providing care and seeking additional mating opportunities. It is not obvious, however, how such additional matings should be accounted for in a consistent population model, because deserting males might increase their fertilization success at the cost of either caring males, other deserting males or both. Here, we present a game theory model that addresses all of these possibilities in a general way. In contrast to earlier work, we find that the source of deserting males' additional matings is irrelevant to the evolutionary stability of male care. We reject the claim that fitness gains through male care are intrinsically less valuable than those through desertion, and that the former must therefore be down-weighted by 1/2 when compared with the latter.

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