The distribution of Great Grey Shrike in Republic of Moldova

(Poster)

Vitalie Ajder
ajder.vitalie@gmail.com

Society for Birds and Nature Protection, Chișinău, Republic of Moldova Institute of Ecology and Geography, Laboratory of Natural and Anthropogenic Ecosystems, Chișinău, Academiei Street, 1, Moldova, Moldova
,
Silvia Ursul
Society for Birds and Nature Protection, Chișinău, Republic of Moldova Institute of Zoology, Ornithology Department, Chișinău, Academiei Street, 1, Moldova, Moldova
,
Laurențiu Petrencu
Department of Zoology, Faculty of Biology, „Alexandru Ioan Cuza” University of Iasi, B-dul, Carol I, Iasi, Romania, Romania
,
Emanuel Ștefan Baltag
Marine Biological Station „Prof. Dr. IoanBorcea”, Agigea, „Alexandru Ioan Cuza” University of Iași, Romania, Romania

DOI: 10.17011/conference/eccb2018/107840

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The Great Grey Shrike (Lanius excubitor) is the largest species from the Laniidae family, with a wide distribution in the Northern Hemisphere, across Europe, Asia and North America. Because the species occupies a large area, the data about the spring and autumn migration and wintering areas of the whole population is poor documented. The study area covers the territory of the Republic of Moldova (33 843.5 km2). Here, the Great Grey Shrike was known as a wintering visitor, being recorded during the late autumn up to early spring. The species was not considered to breed until now in the Republic of Moldova, therefore it was not listed in the Bird Atlas. Even today, the Great Grey shrike is a poorly studied species in our country and there is no up-to-date information except the actual study. The first breeding recorded was in 2012 in the north region of the country. After that, we started a monitoring program in order to check the species’ status.

The aim of the current study was to assess the distribution of the Great Grey Shrike in the Republic of Moldova and to analyze the breeding and wintering population. The study was conducted from 2014 to 2017. During two breeding seasons (2014 and 2015) we carried out point counts with a minimum distance of 400 m between them and 5 minutes of observation in each location.. The observation points were randomly selected across the study area using Hawths Tool for Arc GIS v.9.3. In 2014 we registered 20 breeding pairs out of 470 observations and for 2015 we counted 31 breeding pairs out of 631 observation points. The density of the Great Grey Shrikes in Republic of Moldova estimated, for the research period, to 0.2-0.4 breeding pairs/square km. According to our study, its breeding range is increasing (occupying 75% of the country), extending to south, contrary to previous conclusions which stated that the population is concentrated in north. The GLM analysis showed that the great grey shrike breeds in areas with higher altitudes (a mean of 174 m), low level of precipitation in November and with low average temperatures (all P< 0.05).

To estimate the wintering population, we used the line transect method. Monthly, we conducted 9 transects about 40 km long each (360 km per month), during November - February, for two seasons, 2015 – 2016 and 2016 –2017. The method consists in driving a car at slow speed (up to 40 km/h) with very short stops, if is necessary. The distribution across the country was uneven, 42 were observed in northern area, 37 in the central one and only 5 in south. The numbers of individuals in the first wintering season was 46, while in the second there were 38 individuals counted in Republic of Moldova. According to Manly’s selectivity index the Great Grey Shrike select during winter season orchards (Wi= 1,6) and grasslands (Wi= 3.0). The data collected during the winter season shows that birds tend to keep their breeding spots, being recorded near them during this harsh season.

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INTRO:
Inventories of Great Grey Shrike in Moldova to obtain information about breeding and wintering population sizes and distributions. Very appropriate for a conference poster!
MERITS:
Mostly clear text, well established bird inventory protocols, novel national information about the species distribution and commonness as a breeder and overwinterer.
CRITIQUE:
The focus is very national and there is little attempt to use the data to evaluate more general patterns or ecological theory.

The text contains several typos that can easily be fixed (e.g., using MS word's spell check).

Please clarify the following things. (1) How large was the study area for point counts, and how widely were the winter transects distributed? (2) How often, and during which periods, did you visit the points and transects? (3) Do you have an idea about how much of the expansions were real, or could they solely be because of increased sampling effort

DISCUSSION:
Can you think of using, for example, satellite images to obtain environmental data that could in turn be used to explain the shrike locations?

I am unsure about the validity of your conclusion about expansion. Please justify this better. Is it possible that you observed the expansion only because of increased sampling effort? Also, three years may not be sufficient to conclude an expansion but it could equally well be just random year-to-year variation in abundance and/or habitats used by the species.

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INTRO:
The work presented is of interest for conservation of great grey shrike in the Republic of Maldova. The abstract is of very good standard and written in an acceptable English. However, there are comments that need to be addressed. There is no information on the number and how the locations for observations were selected---was it done to cover the whole country or some parts, if so then the authors will need to specify how those locations were selected?

The aim of the current study was to assess the distribution of the great grey shrike in the Republic of Moldova and hence authors should quantify aspects of the breeding range. For instance, it could be stated how much area great grey shrikes occupy (km2, ha?) presently and the changes in area that has occurred over the years.

The fact that there was a difference in the number of wintering individuals recorded for each section of the country does not seem to me strong evidence to conclude that the great grey shrike is a partial migratory species in the country because other factors could be involved in influencing these differences. Authors could specify some factors that could confound this distribution.
MERITS:
The work here presented is of interest for species conservation and the duration of the work is acceptable.
CRITIQUE:
There should be more information on the experimental design----size of study area, locations for observations and number of locations selected.

More information on distribution---area presently occupied and changes over the years
DISCUSSION:
Very little discussion. Most of the information in the abstract is on introduction and results with little attention to discussion. Authors should improve on abstract by adding up more discussion of the results.