Retrospective evaluation of the reproductive status of male grey wolves (Canis lupus) in Germany based on animals found dead: Influence of age, body weight and season

IF 3.3 2区农林科学 Q1 AGRICULTURE, DAIRY & ANIMAL SCIENCE

Animal Reproduction Science Pub Date : 2026-03-01 Epub Date: 2025-12-27 DOI:10.1016/j.anireprosci.2025.108094

Karin Müller , Ilka Reinhardt , Alexandra Weber , Gesa Kluth , Guido Fritsch , Claudia A. Szentiks

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Abstract

Since the return of the grey wolf (Canis lupus) to Germany in the late 1990s, the Federal Documentation and Consultation Centre on Wolves has been conducting nationwide population monitoring, with animals found dead representing an important source of information. In addition to the standardized necropsy at the Leibniz Institute for Zoo and Wildlife Research, 182 male wolves were examined for their reproductive status between 2020 and 2024. Testis mass was measured and spermatogenic activity was determined by flow cytometric ploidy analyses of dissociated testis tissue and the presence of epididymal sperm. These reproductive parameters were evaluated with regard to age class (juvenile, subadult, adult) and month of death (seasonality). Deciphering seasonality in subadult and adult males showed that haploid cells and epididymal sperm are not only present during the mating season (January to March) but also before (October to December), as meiotic activity already begins in late summer. Almost no spermatogenic activity was detected between May and August. While the body mass of (sub)adult males remained relatively constant throughout the year, testis/body mass ratio increased with spermatogenic activity. Spermatogenic activity already occurred in juvenile males, but it was delayed, and the average level of reproductive parameters increased from juvenile to subadult males, reaching their maximum in adult wolves. Sperm production varied greatly among juveniles and was related to their body and testis mass. Basic sexual maturity was only reached at a body mass of more than 25 kg and a testis mass of more than 5 g.

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基于死亡动物对德国雄性灰狼（Canis lupus）生殖状况的回顾性评价：年龄、体重和季节的影响

自从灰狼（Canis lupus）在20世纪90年代末回归德国以来，联邦狼文件和咨询中心一直在进行全国范围内的种群监测，发现死亡的动物是一个重要的信息来源。除了莱布尼茨动物园和野生动物研究所的标准化尸检外，在2020年至2024年期间，还对182只雄性狼的生殖状况进行了检查。通过对游离睾丸组织和附睾精子进行流式细胞术倍体分析，测定睾丸质量和生精活性。这些生殖参数根据年龄类别（幼鱼、亚成虫、成虫）和死亡月份（季节性）进行评估。对亚成年和成年雄鱼的季节性分析表明，单倍体细胞和附睾精子不仅在交配季节（1月至3月）存在，而且在交配季节（10月至12月）之前也存在，因为减数分裂活动在夏末就已经开始了。5月至8月间几乎没有发现生精活动。虽然（亚）成年雄性的体重全年保持相对恒定，但睾丸/体重比随着生精活动的增加而增加。幼雄的生精活动已经发生，但发生时间较晚，生殖参数的平均水平从幼雄到亚成年雄增加，在成年狼中达到最大值。幼鱼的精子产量差异很大，并与它们的身体和睾丸质量有关。只有当体重超过25 kg，睾丸质量超过5 g时，才能达到基本的性成熟。

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来源期刊

Animal Reproduction Science 农林科学-奶制品与动物科学

CiteScore

4.50

自引率

9.10%

发文量

136

审稿时长

54 days

期刊介绍： Animal Reproduction Science publishes results from studies relating to reproduction and fertility in animals. This includes both fundamental research and applied studies, including management practices that increase our understanding of the biology and manipulation of reproduction. Manuscripts should go into depth in the mechanisms involved in the research reported, rather than a give a mere description of findings. The focus is on animals that are useful to humans including food- and fibre-producing; companion/recreational; captive; and endangered species including zoo animals, but excluding laboratory animals unless the results of the study provide new information that impacts the basic understanding of the biology or manipulation of reproduction. The journal''s scope includes the study of reproductive physiology and endocrinology, reproductive cycles, natural and artificial control of reproduction, preservation and use of gametes and embryos, pregnancy and parturition, infertility and sterility, diagnostic and therapeutic techniques. The Editorial Board of Animal Reproduction Science has decided not to publish papers in which there is an exclusive examination of the in vitro development of oocytes and embryos; however, there will be consideration of papers that include in vitro studies where the source of the oocytes and/or development of the embryos beyond the blastocyst stage is part of the experimental design.