Western (Aechmophorus occidentalis) and eared (Podiceps nigricollis) grebes of central Alberta : inventory, survey techniques, and management concerns /

Hanus, Stephen.; Wilkinson, Lisa.; Wollis, Hugh.

doi:10.5962/bhl.title.114306

Cited by 11 publications

(40 citation statements)

References 5 publications

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“…A detailed description of the Stony Plain study area is provided in Hanus et al (2002a). Briefly, this area is located in central Alberta (Appendix 1), and includes the counties of Barrhead, Lac Ste.…”

Section: Study Areamentioning

confidence: 99%

“…The information presented in this report represents the findings from the second year of surveying western and eared grebes within the Stony Plain study area in Alberta (Appendix 1). Baseline research and data for this area are presented in two reports by Hanus et al (2002aHanus et al ( , 2002b. A synthesis of provincial data for western and eared grebes is provided in Hanus (2002).…”

mentioning

confidence: 99%

“…3) Inventory as many other lakes as possible within the study area to identify those with active western and eared grebe populations, and locate new colonies; and 4) Implement management recommendations presented in Hanus et al (2002a).…”

mentioning

confidence: 99%

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Western (Aechmophorus occidentalis) and eared (Podiceps nigricollis) grebes of central Alberta : 2002 field summary /

Hanus¹,

Wilkinson²,

Wollis³

2002

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EXECUTIVE SUMMARYThis project is in its second year, and is designed to monitor population trends and reproductive success of western grebes (Aechmophorus occidentalis) and eared grebes ( Podiceps nigricollis) within the Stony Plain study area, Alberta. Surveys are projected to span a five year period, and the results will be used in conservation and management efforts. This project also provides information to support lake habitat conservation and public education. Survey protocols developed by this project are applicable to other regions in Alberta. In 2002, surveying effort was focused on the primary western and eared grebe populations identified in the initial year of this project. Ground nest surveys were the primary means used to estimate adult population sizes; however, this technique was modified slightly from 2001. Instead of conducting a single total nest count at the predicted peak of the nesting season, we surveyed each colony along a sample transect several times during the nesting season. Total nest counts were conducted near end or after the nesting period, and the results from which were used to derive a total breeding adult population estimate.

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Section: Study Areamentioning

confidence: 99%

mentioning

confidence: 99%

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Western (Aechmophorus occidentalis) and eared (Podiceps nigricollis) grebes of central Alberta : 2002 field summary /

Hanus¹,

Wilkinson²,

Wollis³

2002

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“…On lakes with breeding colonies of Western Grebes, nest counts frequently are used as a proxy for adult Western Grebe abundance, with two breeding adults estimated per nest counted (Resources Inventory Committee 1999, Hanus et al 2002). To minimize disturbance, we conducted nest counts in late July and early August, shortly after chicks hatched and left the nesting site.…”

Section: Nest Countsmentioning

confidence: 99%

“…One boat driver and one to two observers surveyed the lake using a systematic boat survey (Hanus et al 2002), and stopped at predetermined points along transects in the open water to count all adult and juvenile birds that were visible from that location. We used brood count data for adult abundance in the data analysis if nest count data were not available for a particular breeding lake, or if the brood count data yielded a higher adult abundance estimate for that year (Appendix 1).…”

Section: Brood Countsmentioning

confidence: 99%

Habitat associations with counts of declining Western Grebes in Alberta, Canada

Erickson¹,

Found-Jackson²,

Boyce³

2017

ACE

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ABSTRACT. During the past several decades, numbers of Western Grebes (Aechmophorus occidentalis) have declined throughout their breeding and wintering ranges in North America. We estimated Western Grebe abundance and documented habitat factors between 2007 and 2009 from 43 lakes in Alberta, Canada where Western Grebes historically have occurred, to (1) compare Western Grebe abundance with the relative probability of persistence, and (2) identify habitat correlates of grebe abundance. The relative probability of Western Grebe persistence was correlated with abundance in the study area, although only 19% of the variation in persistence probability was explained by abundance. Western Grebe abundance was positively correlated with the shoreline extent of emergent bulrush (Scirpus lacustris), which is consistent with past studies and underlies the importance of protecting emergent vegetation in efforts to conserve Western Grebes. Grebe abundance also was positively correlated with a longer shoreline perimeter, but was inversely correlated with the amount of forested backshore, which occurred on lakes primarily at the northern margins of Western Grebe range. The amount of backshore development was positively associated with Western Grebe abundance, which might reflect a preference for similar lake characteristics by humans and grebes. These relationships are important to consider in the context of implementing and managing recovery of the Western Grebe in Alberta. La probabilité relative de persistance du Grèbe élégant était corrélée avec son abondance dans l'aire d'étude, quoique 19 % seulement de la variabilité de la probabilité de persistance était expliquée par l'abondance. L'abondance de ce grèbe était positivement corrélée avec l'étendue de joncs émergents (Scirpus lacustris) sur les rives, un résultat conforme aux études passées et qui souligne l'importance de protéger la végétation émergente pour la conservation du Grèbe élégant. L'abondance de ce grèbe était aussi corrélée positivement avec un grand périmètre de rive, mais était inversement corrélée avec la quantité de haut de plage forestier, qu'on trouve principalement sur les lacs situés à la limite nord de l'aire du Grèbe élégant. Le degré de sinuosité du haut de plage était positivement associé avec l'abondance de ce grèbe, ce qui reflète sans doute une préférence pour des caractéristiques de lacs similaires chez les humains et les grèbes. Ces relations sont importantes à considérer dans la mise en place et la gestion du rétablissement du Grèbe élégant en Alberta. Associations entre l'habitat et les dénombrements de

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Dual visible‐thermal camera approach facilitates drone surveys of colonial marshbirds

McKellar

Shephard

Chabot

2020

Remote Sens Ecol Conserv

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Waterbirds are important indicators of wetland health, and understanding their status and trends is necessary for appropriate management and conservation. However, certain species are challenging to survey due to their sensitivity to disturbance and the difficulty of accessing their breeding habitats. This is especially true for colonially breeding marshbirds, for which a multi‐species survey protocol that maximizes accuracy of counts and minimizes disturbance does not exist. Small drone aircraft have shown promise for conducting accurate and low‐disturbance surveys of colonial waterbirds. However, complex marsh vegetation structures and the cryptic nature of some marshbird nests make them difficult to detect in aerial imagery. We used synchronous high‐resolution visible imagery (0.8–2 cm/pixel) and thermal‐infrared imagery (6–16 cm/pixel) captured from a drone to count nests of five species of marshbirds at eight colonies in Saskatchewan, Canada. We compared counts from the imagery to those obtained from traditional ground‐based surveys, generally considered the most accurate survey method for these species. The two types of imagery proved highly complementary, as heat signatures helped detect and confirm nests not easily spotted in the visible imagery, while the detailed visible imagery allowed species identification. For four species (Western Grebe Aechmophorus occidentalis, Franklin's Gull Leucophaeus pipixcan, Forster's Tern Sterna forsteri, and Black‐crowned Night‐Heron Nycticorax nycticorax), drone‐based counts (range 74–1524 nests per colony) were within 5% of ground‐based counts (range 75–1582), while for smaller Black Tern Chlidonias niger colonies (range 3–7 nests), counts from the two methods were always within one nest of each other. Furthermore, an assessment of flight behavior before, during, and after drone surveys found no significant evidence of disturbance by the drone. Our drone‐borne dual visible‐thermal camera approach proved promising for surveying colonial marshbirds and could potentially be implemented in a range of situations where wildlife subjects are difficult to survey with visible or thermal imagery alone.

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Western (Aechmophorus occidentalis) and eared (Podiceps nigricollis) grebes of central Alberta : inventory, survey techniques, and management concerns /

Cited by 11 publications

References 5 publications

Western (Aechmophorus occidentalis) and eared (Podiceps nigricollis) grebes of central Alberta : 2002 field summary /

Western (Aechmophorus occidentalis) and eared (Podiceps nigricollis) grebes of central Alberta : 2002 field summary /

Habitat associations with counts of declining Western Grebes in Alberta, Canada

Dual visible‐thermal camera approach facilitates drone surveys of colonial marshbirds

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